Immunisation and vaccine-preventable diseases quarterly report
July to September 2024 (Q3)

Diphtheria

Background information

Diphtheria is an acute bacterial infection affecting the upper respiratory tract or the skin, caused by the diphtheria toxin produced by toxigenic strains of Corynebacterium diphtheriae (C. diphtheriae), Corynebacterium ulcerans (C. ulcerans), and less commonly Corynebacterium pseudotuberculosis (C. pseudotuberculosis).

The most common symptoms of diphtheria affecting the upper respiratory tract are membranous pharyngitis with fever, lymphadenopathy and upper respiratory tract soft tissue swelling 'bull neck' potentially leading to life-threatening airway obstruction. Cutaneous diphtheria may cause pus-filled blisters on legs, hands and feet, and ulceration of the skin.

In unvaccinated or partially vaccinated individuals, systemic absorption of the toxin can lead to late complications such as cardiac and neurological conditions, and sometimes death.

Surveillance update for July to September 2024 (week 39)

Diphtheria is rare in the UK because babies and children have been vaccinated against it since the 1940s. Prior to the introduction of a vaccine, up to 70,000 cases a year were confirmed, causing around 5,000 deaths.

There was one case of toxigenic diphtheria (C.ulcerans) reported in the first quarter of 2024. There were no cases of toxigenic diphtheria in the second or third quarters of 2024.  In 2023, there were two cases of toxigenic diphtheria (both C.ulcerans). Prior to these, the last case of toxigenic diphtheria in Scotland was reported in 2020.

The UK Health Security Agency (UKHSA) reported an increase in cases of toxigenic C. diphtheriae among asylum seekers arriving by small boat to England in 2022, with similar increases reported elsewhere in Europe. Further details can be found at Diphtheria: cases among asylum seekers in England, 2022 to January 2024 - GOV.UK (www.gov.uk).

Vaccination Information

More information on vaccines against diphtheria can be found on the following pages:

• 6-in-one vaccine
• 4-in-one vaccine
• 3-in-one vaccine

Vaccine uptake statistics

Vaccine uptake statistics for children are published in Teenage booster immunisation statistics Scotland - School year 2023/2024 and childhood immunisation statistics quarterly report.

Haemophilus influenzae

Background information

Haemophilus influenzae (H. influenzae) are bacteria commonly carried in the respiratory tract, which can cause acute invasive disease. They are divided into encapsulated and unencapsulated (non-typeable) strains. Encapsulated strains can be classified into six serotypes, from a to f, of which type b (Hib) was most prevalent prior to vaccine introduction. Infection with H. influenzae can cause the following conditions:

• meningitis
• septicaemia
• acute respiratory infections

Less frequent conditions which may be caused by H. influenzae infection include:

• epiglottitis
• osteomyelitis
• septic arthritis

For more information on H. influenzae type b, visit NHS inform.

In 1992, following introduction of the Hib vaccine for young children, the number of H. influenzae type b cases fell dramatically, not only in the vaccinated group but also in older age groups. 

Due to reduced carriage of the organism within the respiratory tract of vaccinated children, transmission to the wider community was effectively suppressed.

The addition of the Hib booster vaccine in 2006 to the childhood immunisation schedule, reduced case numbers further.

In Scotland, typing is conducted on cases with positive laboratory reports for invasive H. influenzae to monitor national trends in disease subtypes.

Further enhanced surveillance is carried out for all invasive H. influenzae cases identified in children under the age of five and type b strains across all age groups.

Surveillance update for July to September 2024 (week 39)

There were 18 invasive H. influenzae cases reported in the third quarter of 2024, bringing the total for the three quarters of 2024 to 61. This is lower than the number of cases reported to the end of the third quarter of 2023 (n=76), but higher than case numbers reported for the same period of 2022, 2021, 2020 and 2019 (n=47, n=18, n=42 and n=52 respectively).

Figure 1 is a series of line graphs showing the cumulative number of Haemophilus influenzae cases reported to Public Health Scotland per week by year. Each line represents a different year from 2019 to the end of the third quarter 2024. The number of cases reported to the end of the third quarter of 2024 is lower than the number of cases reported for the same period in 2023, but higher than for the same period of 2022, 2021, 2020 and 2019.

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Figure 1: Cumulative number of laboratory confirmed Haemophilus influenzae cases, 2019 to 2024 (week 39)

Of the 61 cases reported to the end of the third quarter of 2024:

• 26 were people aged over 65 years
• 23 were people aged between 35 and 64 years
• four were people aged between 15 and 34 years
• five were children aged between one and four years
• three were infants aged under one year

Figure 2 demonstrates the epidemiological impact of the Hib vaccine, for those aged under five (routinely vaccinated group) and for all ages (including under-fives).

There was a marked decrease in cases from 1992 in all age groups, followed by a rise in case numbers in the early 2000s. Case numbers decreased again following the introduction of the Hib booster vaccine, and figures have remained relatively stable since 2011. See the vaccine preventable disease summary for the number and incidence of Haemophilus influenzae disease in Scotland over the last five years.

Figure 2 is a line graph showing the number of invasive Haemophilus influenzae type b disease cases reported in Scotland from 1988 to the end of the third quarter 2024. There are two lines on the graph, one representing the under 5 age group and the other, total number of cases (including under 5 years). Following introduction of the Hib vaccine in 1992, cases rapidly decreased to single figures. However, in 2001 a sharp increase was observed, and total number of cases peaked at 31 in 2002, prompting introduction of the Hib booster campaign in June 2003. Cases across all ages subsequently decreased and following introduction of a routine Hib booster in 2006, reached low numbers by 2009. There have been no Hib cases reported since 2020. The last Hib case in the under 5 age group was reported in 2015.

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Figure 2: Number of laboratory confirmed Haemophilus influenzae type b disease in Scotland, 1988 to 2024 (week 39)

Figure 3 presents laboratory reports by serotype, since the introduction of the Hib booster campaign in 2003.

Of the 61 isolates to the end of the third quarter of 2024:

• two were type a
• one was type e
• two were type f
• 30 were non-typable (i.e. non-encapsulated type)
• typing was not carried out/available for the remaining 26 isolates

Figure 3 is a bar chart showing the laboratory reports of Haemophilus influenzae by type from 2003 to the end of the third quarter 2024. The chart shows a steady decline in type b infection since introduction of the Hib vaccine in 2003, with a corresponding increase in non-typeable strains. Non-typeable strains are now the most commonly reported type followed by type f, with very few reports of types a, b, d, and e.

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Figure 3: Number of laboratory confirmed invasive Haemophilus influenzae cases by serogroup, 2003 to 2024 (week 39)

Vaccination information

More information on vaccines against invasive Haemophilus influenzae type b can be found on the following pages:

• 6-in-one vaccine
• Hib/MenC vaccine

Vaccine uptake statistics

Vaccine uptake statistics are published in our childhood immunisation statistics quarterly report.  

Measles

Background information

Measles is a rash illness resulting from infection with the measles virus. It can affect people of all ages but infants less than one year of age and those who are immunocompromised are at increased risk of complications and death. It is one of the most communicable diseases with one case having the potential to infect another 12 to 18 individuals through airborne transmission and respiratory droplets in susceptible populations.

Before vaccination, measles was a very common childhood disease in Scotland and deaths attributable to measles were substantial.

Following the introduction of measles vaccine in 1968 and the subsequent introduction of the MMR vaccine in 1988, the incidence of the disease has decreased dramatically.

However, as Figure 4 shows, outbreaks have occurred in recent years. These outbreaks have largely occurred in under-immunised populations.

Figure 4 is a line chart showing the number of laboratory-confirmed cases of measles reported in Scotland by year from 1988 to September 2024 (week 39). The figure shows a sharp increase in the number of measles cases in 1994, when 536 cases were reported. The number of cases decreased to 23 in 1995 and has generally remained low since, with the exception of 2008 (when 54 cases were reported) and 2013 (when 51 cases were reported). There were no cases reported in 2015, 26 cases reported in 2016, 5 cases reported in 2017, and 2 cases reported in 2018. Eighteen cases were reported in 2019, no cases were reported in 2020 or 2021. One case was reported in 2022, and one in 2023. Nineteen cases were reported up to the end of quarter three (week 39) in 2024. The graph is also annotated with important measles vaccination time points, with the MMR vaccine introduced in 1988, the measles/rubella campaign initiated in 1994, and the second dose of MMR added to the vaccine schedule in 1996.

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Figure 4: Number of laboratory-confirmed cases of measles in Scotland by year, 1988 to September 2024 (week 39)

Surveillance update for July to September 2024 (week 39)

There were five laboratory-confirmed measles cases reported in the third quarter of 2024, bringing the total number of laboratory-confirmed cases to 19 for the first three quarters of 2024. Of these 19 cases, ten are thought to have been imported and related to travel outwith the UK, and one further (secondary) case was related to one of these imported cases. Of the remaining eight cases, three cases had history of recent travel in England and may have acquired measles there; the other five cases had no history of recent travel out with Scotland. The lack of onward transmission associated with most of these cases highlights the success of the MMR vaccination programme, the importance of maintaining high vaccine uptake in Scotland, and reflects the robust public health management of these cases.   

As shown in Figure 5, the number of cases each year has been variable. See vaccine preventable disease summary for the number and incidence of measles in Scotland over the last five years. There was one case of laboratory-confirmed measles reported in 2023 and one in 2022, prior to which there had been no cases since 2019.

Weekly updates on measles case numbers in Scotland are available on the PHS website.  

In highly vaccinated populations such as Scotland, it is rare but possible for individuals who have received two doses of MMR vaccine to develop symptoms following exposure to a measles case. However, symptoms are usually attenuated, and individuals are unlikely to be as infectious.

Figure 5 is a bar chart showing the number of laboratory-confirmed cases of measles reported in Scotland by month and year between 2015 to September 2024 (week 39). The graph shows that the number of measles cases fluctuates each year. In 2016, measles cases were reported throughout the year, with a peak in October. In 2017 and 2018, cases were reported during the spring and summer months. In 2019, cases were reported in February, in May through to August and October. No cases were reported in 2020 or in 2021. One case was reported in 2022, and one in 2023. In 2024, six cases were reported in the first quarter, eight cases in the second quarter and five cases in the third quarter.

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Figure 5: Number of laboratory-confirmed cases of measles in Scotland by month and year, 2015 to September 2024 (week 39)

The age distribution of measles cases has varied over recent years, but most cases are observed in children and young adults.

Of the cases reported in the first three quarters of 2024:

• one case was in the under 1 year age group
• one case was in the one-to-four-year age group
• five cases were in the five-to-nine-year age group
• one case was in the 10-to-14-year age group
• seven cases were in the 20-to-29-year age group
• four cases were aged 30 years or older

Measles in Europe and the UK

Measles outbreaks occurred across Europe throughout 2018 and continued into 2019 but there was a notable reduction in cases from March 2020. Following a rise in laboratory-confirmed cases since late 2022, many countries in the WHO European Region have reported measles cases in recent months. In February 2024, WHO Europe issued a press release highlighting the urgency of a swift and concerted response to measles outbreaks in the WHO European Region. In the same month, ECDC released a threat assessment brief on the rise in measles cases in EU/EEA, and considerations for public health response. Both highlight the critical importance of achieving and sustaining high MMR vaccine coverage.

In the most recent 12 months to August 2024 there were a total of 14,241 cases of measles reported to the European Centre for Disease Prevention and Control. The EU/EEA countries with highest reported rates of cases for this period were Romania, Austria, Belgium, and Cyprus with rates of 752.9, 58.4, 51.6 and 28.2 cases per million population, respectively.

On 30 January 2024, UKHSA published data indicating a resurgence of measles in England in 2023. They reported 362 laboratory-confirmed cases in 2023, with the initial rise in cases in Spring 2023 mainly driven by activity in London then a rapid escalation in cases in the West Midlands from October 2023. UKHSA have reported 2,579 cases of measles in 2024 (to the end of September). Updates on the epidemiology of the current UKHSA national measles incident are published.

Ongoing measles activity in Europe and globally poses a threat to international travellers and Scotland will continue to face an elevated risk of imported cases from other countries and other regions of the UK.

Vaccination information

More information on vaccines against measles can be found on the following page:

• MMR vaccine

Vaccine uptake statistics

Vaccine uptake statistics are published in our childhood immunisation statistics quarterly report.

Meningococcal Disease

Background information

Meningococcal disease is an invasive infection of Neisseria meningitidis (N. meningitidis) bacteria in:

• blood
• cerebrospinal fluid (CSF)
• other normally sterile site

Meningococcal disease cases overwhelmingly show symptoms of meningitis (inflammation of the meninges) or septicaemia (blood poisoning). It can also present as a combination of both or as a rarer clinical presentation, such as joint infection. Meningitis can be caused by a variety of viruses or bacteria, of which N. meningitidis is one. Meningococcal disease is a significant cause of morbidity and mortality in children and young adults.

Although approximately 10% of the population are estimated to carry N. meningitidis in the nasopharynx, the vast majority do not have symptoms or develop invasive disease. Invasive cases acquire infection through inhalation of, or direct contact with, respiratory droplets, from either an infected person or asymptomatic carrier.

N. meningitidis is classified according to its outer membrane characteristics via a process known as serogrouping. There are several different serogroups, the most common of which in the UK is B, followed by W. Cases of serogroup Y, Z and C disease have also been reported.

In 1999, the Meningococcal Invasive Disease Augmented Surveillance (MIDAS) system was introduced.

The surveillance scheme is managed jointly by Public Health Scotland and the Scottish Haemophilus Legionella Meningococcus and Pneumococcus Reference Laboratory (SHLMPRL).

Surveillance data from MIDAS informs the epidemiology of meningococcal disease in Scotland, as analyses can be conducted according to:

• age
• serogroup
• molecular typing
• clinical presentation
• outcome

Against a background of declining cases of meningococcal disease in the UK, surveillance indicated that there had been an increase in cases of severe invasive disease caused by serogroup W (MenW) since 2009. Clinical follow up of cases revealed that intensive care admission was high, particularly among older children and young adults, and for the first time in a decade MenW was associated with fatal outcomes in children and adolescents. MenACWY vaccine was recommended by the Joint Committee on Vaccination and Immunisation (JCVI) and offered to 14 to 18-year-olds as a measure to address the increasing number of meningococcal serogroup W cases in this age group. A phased catch-up programme ran in Scotland between August 2015 and March 2016.

The vaccine was also offered to students under the age of 25 attending university for the first time from Autumn 2015. MenACWY vaccine continues to be offered routinely to those in secondary school year 3 (S3).

Surveillance update for July to September 2024 (week 39)

There were seven cases of meningococcal disease reported in the third quarter of 2024 (week 39), bringing the total for the first three quarters of the year to 46. This is higher than the number of cases reported in the same period of the previous five years (range n=8 to n=43), as shown in Figure 6.

Figure 6 is a series of line graphs showing the cumulative number of meningococcal cases reported to MIDAS per week, by year. Each line represents a different year from 2019 to the end of the third quarter of 2024. The number of cases reported in the first three quarters of 2024 is higher than the number of cases reported in the same period of the previous five years.

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Figure 6: Cumulative number of meningococcal disease cases reported to MIDAS, 2019 to 2024 (week 39)

Figure 7 shows the number of meningococcal disease cases, according to age group and by quarter from 2001 to the end of the third quarter of 2024 (week 39).

To the end of the third quarter of 2024, there were:

• six cases aged under five years, of whom three were aged under one year
• 17 cases in the five to 24 years age group
• 23 cases in those aged 25 years or over

Figure 7 is a series of line graphs showing the number of meningococcal cases reported to MIDAS per quarter, by year. The data covers 2001 to the end of the third quarter of 2024. Each line on the graph represents number of cases for a specific age group, and there is a line for the total number of cases. Historically, cases were more frequent in the under-five age group. However, since 2016 those aged above 25 years have overtaken the under-fives as the group with highest number of cases overall.

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Figure 7: Meningococcal disease cases reported to MIDAS by age group and quarter, 2001 to 2024 (week 39)

Of the 46 cases of meningococcal disease reported in the first half of 2024:

• 33 were serogroup B
• five were serogroup W
• three were serogroup Y
• one case was non-groupable (un-encapsulated)
• four cases were based on clinical diagnosis, as shown in Figure 8

Figure 8 is a bar chart showing the number of meningococcal cases reported to MIDAS by serogroup, from 2005 to the end of the third quarter of 2024. Since 2012, serogroup B infections comprise the majority of laboratory confirmed cases. In 2016, laboratory reports of serogroup C infection increased, alongside serogroup W infections.

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Figure 8: Meningococcal disease cases reported to MIDAS by serogroup, 2005 to 2024 (week 39)

Serogroup W cases continue to be reported separately following introduction of the MenACWY immunisation programme. Figure 9 demonstrates a positive impact of the MenACWY vaccine for the eligible population.  Five serogroup W cases were reported to the end of the third quarter of 2024, two in the first quarter, one in the second quarter and two in the third quarter.

Figure 9 is a series of line graphs showing the number of serogroup W cases reported from 2009 to the end of the third quarter of 2024, by age group. From 2014 to 2016 there was an increase in serogroup W amongst all age groups with exception of those aged 5 to 14 years. Since 2017, serogroup W case numbers have declined.

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Figure 9: Meningococcal serogroup W by age group reported to PHS 2009 to 2024 (week 39)

The number of deaths between 2004 and the end of the third quarter of 2024, reported by serogroup, is shown in Figure 10. There were three deaths from meningococcal disease to the end of the third quarter of 2024.

See the vaccine-preventable disease summary for the number and incidence of invasive meningococcal disease in Scotland over the last 5 years.

Figure 10 is a bar chart showing the number of deaths from meningococcal disease reported to MIDAS by serogroup, from 2005 to the end of the third quarter of 2024.

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Figure 10: Meningococcal deaths by serotype reported to PHS 2005 to 2024 (week 39)

Vaccination information

More information on vaccines against meningococcal disease can be found on the following pages:

• MenB vaccine
• Hib/MenC vaccine
• MenACWY vaccine

Vaccine uptake statistics

Vaccine uptake statistics are published in our childhood immunisation statistics quarterly report.

Vaccine uptake statistics for the teenage MenACWY vaccine can be found at: Teenage booster immunisation statistics Scotland Publications - Public Health Scotland.

Mumps

Background information

Mumps is a disease resulting from infection by the mumps virus.

It was a common childhood disease prior to the introduction of the MMR vaccine in 1988, with more than 85% of adults having evidence of previous infection.

The rate of disease has decreased substantially following the introduction of the vaccine. However, there was a widespread increased incidence of mumps throughout the UK, from 2004 with the number of laboratory-confirmed cases peaking in 2005. These numbers substantially declined by 2008 although cases remained higher than those reported before 2004 until early 2020.

Cases of mumps are commonly identified by laboratory testing based on positive PCR or IgM serology and reported to PHS, with only laboratory-confirmed cases presented in this report. However, many cases of mumps may be diagnosed clinically, with no laboratory confirmation testing, or go undiagnosed since individuals may not present to healthcare. Therefore, the reliance on laboratory reports may represent an underestimate of the true rate of disease in the community.

For more information on mumps, visit NHS Inform.

Surveillance update for July to September 2024 (week 39)

There was one case of laboratory-confirmed mumps reported in the third quarter of 2024, bringing the total for the first three quarters of 2024 to ten cases.

Since April 2020, there has been a substantial reduction in number of cases of mumps reported. As shown in Figure 11, outbreaks since 2008 have occurred in:

• 2009
• 2012
• 2014 to 2015
• 2019 to early 2020

At these points in time, most of the individuals affected were adolescents and young adults in higher education who had not received two doses of MMR vaccine.

Figure 11 is a line chart showing the number of laboratory-confirmed cases of mumps by year from 2000 to the end of September 2024 (week 39). The figure shows the outbreak which started in 2004 and peaked in 2005 with 1,892 and 2,586 cases, respectively. While the number of cases has decreased since 2005, smaller outbreaks have occurred in 2009, 2012, 2014 to 2015 and 2019 to early 2020. The graph shows cases increasing again after 2016 with a total of 784 laboratory-confirmed cases of mumps reported in 2019, 864 from January to December 2020 and only one laboratory confirmed case in 2021. There were ten cases of laboratory-confirmed cases reported to September 2024 (week 39).

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Figure 11: Number of laboratory-confirmed cases of mumps in Scotland by year, 2000 to September 2024 (week 39)

See vaccine preventable disease summary for the number and incidence of mumps in Scotland over the last five years.

An increase in cases of mumps was observed in late 2019 and early 2020, primarily in adolescents and young adults. This may have represented poorer initial immune response to the mumps component of the MMR vaccine, waning immunity, or a combination of both within fully and partially vaccinated individuals. The sharp decrease in reported cases from April 2020 was likely a result of measures and restrictions implemented in response to the COVID-19 pandemic, which will also have interrupted the transmission of mumps. These measures also reduced attendance to the primary care setting, resulting in reduced opportunity to diagnose cases.

Figure 12 is a bar chart showing the number of laboratory-confirmed cases of mumps by month and year from 2015 to September 2024 (week 39). The graph shows recurring peaks in the number of mumps cases reported by month, with the highest peaks occurring in June 2015 (142 cases), November 2017 (122 cases), April 2019 (119 cases) and December 2019 (109). The chart shows a sharp rise in cases at the beginning of 2020; showing 316 cases in January, 343 in February and 194 in March. However, following this the number of cases fell to zero from June to November 2020, with a single case in December 2020. Only one case was reported in 2021, seven cases in 2022 and 16 cases in 2023. There have been ten cases reported to September 2024 (week 39).

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Figure 12: Number of laboratory-confirmed cases of mumps in Scotland by month and year, 2015 to September 2024 (week 39)

Age distribution of cases

Figure 13 shows that most mumps cases in recent years have been in those aged 17 to 34 years. However, in the first three quarters of 2024, eight of the ten cases have been in the 35 years and over age group.

Although the vaccination status of cases is not routinely collected, this is consistent with the age groups that are likely to be under-immunised with a mumps-containing vaccine, or for whom there is waning immunity.

Figure 13 is a bar chart showing the number of laboratory-confirmed cases of mumps by age group and year from 2015 to September 2024 (week 39). In 2024, most cases have been in the 35 years and over age group. In most previous years, whilst the overall number of cases varies by year, the majority of mumps cases have occurred in individuals aged 17 to 34 years.

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Figure 13: Number of laboratory-confirmed cases of mumps in Scotland by age group and year, 2015 to September 2024 (week 39)

The incidence of mumps by age group in 2020, shown in Figure 14, reflects a higher incidence among individuals aged 17 to 20 years compared to other age groups (130.0 cases per 100,000 population). This was followed by those aged 21 to 24 years (92.2 cases per 100,000 population).

Figure 14 is a bar chart and shows the incidence per 100,000 population of laboratory-confirmed cases of mumps by age group between 01 January and 30 December 2020. The incidence of mumps was highest among individuals aged 17 to 20 years, at 130.0 cases per 100,000 population. This was followed by those aged 21 to 24 years, at 92.2 cases per 100,000 population. Data from 2021 to 2024 are not presented due to the low number/absence of cases.

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Figure 14: Incidence of laboratory-confirmed cases of mumps by age group, 2020*

*There is insufficient data from 2021 to 2024 to represent the ages of cases, therefore 2020 data has been presented to reflect the age distribution of cases, which is similar to that seen in previous years.

Vaccination information

More information on vaccines against mumps can be found on the following page:

• MMR vaccine

Vaccine uptake statistics

Vaccine uptake statistics are published in our childhood immunisation statistics quarterly report.

Pertussis

Background information

Pertussis (or whooping cough) is an acute bacterial disease of the respiratory tract, resulting from infection with Bordetella pertussis.

It can affect people of all ages. Unimmunised infants are more likely to develop complications from pertussis infection which can require hospital treatment and, in severe cases, can be fatal. It is often less severe in adolescents and adults, however they may suffer a prolonged cough.

In response to the increase in cases and to protect young infants in the first few weeks of life until starting the routine childhood immunisation programme at eight weeks, a programme was introduced in October 2012 to offer pertussis vaccination to all pregnant women.

Pregnant women are typically vaccinated between gestational weeks 16 and 32 in order to protect newborn babies from disease before they are old enough to receive their first vaccine at 8 weeks. Antibodies that protect against disease, produced by the vaccinated mother, can be transferred across the placenta to protect the baby. Women may still be immunised after week 32 of pregnancy but this may not offer as high a level of passive immunological protection to the baby. Vaccination late in pregnancy may, however, directly protect the mother against disease and thereby reduce the risk of exposure to her infant. As pertussis continues to circulate in Scotland, immunisation of pregnant women and young children is vital.

The immunity that young infants receive from their mother, although very important in the first few weeks of life, offers only short-term protection. Therefore, it is important that infants are vaccinated as part of the routine childhood schedule on time to provide longer-term protection.

For more information on pertussis, visit NHS inform.

Surveillance update for July to September 2024 (week 39)

Pertussis case numbers in Scotland have been increasing since late 2023 as shown in Figure 15. Case numbers peaked in June 2024, and have declined since.

In 2023, there were 73 laboratory confirmed cases, the majority of which (n=56) were reported in the final quarter of the year. There were 1,084 laboratory confirmed cases in the first quarter of 2024, 3,765 cases in the second quarter and a further 1,883 cases between July and September 2024, bringing the total for the first three quarters of 2024 (week 39) to 6,732. There has been one reported death in quarter two of 2024 in an infant under one year of age who developed pertussis.

Prior to 2024, the last significant outbreak in Scotland occurred in 2012 and 2013, with 1,896 and 1,188 laboratory confirmed cases per year, respectively. There was also increased pertussis activity in 2016, with 1,075 cases laboratory confirmed cases that year.

In 2020, there were 198 laboratory reports of B. pertussis, the majority of which occurred in the first quarter of the year. This reduction in numbers from the pre-pandemic period was likely attributable to social distancing measures implemented to mitigate the transmission of COVID-19. In 2022 and 2021, there were three and four cases of laboratory-confirmed pertussis reported, respectively.

Weekly updates on pertussis case numbers in Scotland are available on the PHS website.  PHS published monthly reports on pertussis case numbers from July to November 2024.

Figure 15 is a bar chart showing the number of laboratory reports of Bordetella pertussis by month from 2012 through to September 2024 (week 39). The figure shows the outbreak that occurred in 2012 into 2013 with 1,896 and 1,188 reports, respectively, as well as an increase in activity that occurred in 2016 (1,075 reports). From the first quarter of 2020, cases can be seen to drop to nearly zero with only four cases reported in 2021 and three cases reported in 2022. Pertussis activity has been increasing since late 2023. 73 cases were reported in 2023, most of which were in the last quarter of the year. In 2024, there were 1,084 laboratory confirmed cases in the first quarter, 3,764 cases in the second quarter and a further 1,883 cases in the third quarter.

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Figure 15: Number of laboratory reports of Bordetella pertussis in Scotland by month, 2012 to September 2024 (week 39)

Age breakdown of cases

Figure 16 presents the number of laboratory reports of pertussis by age group from January to September 2024 (week 39). The graph shows that the 10 to 14 years age group accounted for the highest number of cases in the first three quarters of 2024. The highest incidence of infection in the first three quarters of 2024 was observed in the under one year age group, as in previous years (2017 to 2023), with 407.0 cases per 100,000 population, as shown in Figure 17. The second highest incidence rate in the first three quarters of 2024 was observed in the 10 to 14 years age group with 391.1 cases per 100,000 population.

Figure 18 presents the percentage of cases of pertussis by age group and year from 2012 to September 2024 (week 39). Case numbers in 2021 and 2022 were low, and age distribution for those years should be interpreted in that context. Data for the first three quarters of 2024 shows that the relative proportions of cases in children aged five to nine years and 10 to 14 years are higher than that in recent pre-pandemic years.

Figure 16 is a bar chart showing the number of laboratory reports for Bordetella pertussis by age group in the first three quarters of 2024. The graph shows that the ten to 14 years age group accounted for the highest number of cases.

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Figure 16: Number of laboratory reports of Bordetella pertussis in Scotland by age group, January to September 2024 (week 39)

Figure 17 is a bar chart showing the incidence of Bordetella pertussis per 100,000 population by age groups from under 1 years to over 70 years between 2017 and September 2024 (week 39). Data for the first three quarters of 2024 shows the highest incidence in the under 1 year age group, with the second highest incidence rate in the ten to 14 years age group.

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Figure 17: Incidence of Bordetella pertussis per 100,000 population in Scotland by age group, 2017 to September 2024 (week 39)*

* Updated mid-year estimates for 2022 and new NRS mid-year population estimates for 2023 and have been used to calculate incidence for 2022 and 2023 respectively. Incidence rates for 2024 use the mid-year population estimates for 2023.​

Figure 18 is a stacked bar chart that shows the percentage of laboratory reports of pertussis by age group and year from 2012 through to September 2024 (week 39). The chart shows that in the first three quarters of 2024, children aged ten to 14 years accounted for the largest proportion of cases.

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Figure 18: Percentage of Bordetella pertussis laboratory reports in Scotland by age group and year, 2012 to September 2024 (week 39)

Cases by NHS Health Board

NHS Greater Glasgow and Clyde, NHS Lothian and NHS Grampian had the greatest number of laboratory-confirmed pertussis cases in the first three quarters of 2024, as shown in Figure 19. Data presented in Figure 20 shows that NHS Greater Glasgow and Clyde, NHS Borders and NHS Grampian were the Health Boards with the highest incidence in the first three quarters of 2024, with 164.5, 160.3 and 157.8 cases per 100,000 population, respectively. Incidence rates were also high in NHS Highland, NHS Forth Valley and NHS Lothian with 152.4, 148.0 and 132.3 cases per 100,000 population.

Figure 19 is a bar chart that shows the number of laboratory reports of Bordetella pertussis in Scotland by NHS Health Board for the first three quarters of 2024. The chart shows that NHS Greater Glasgow and Clyde, NHS Lothian and NHS Grampian had the highest number of cases.

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Figure 19: Number of laboratory reports of Bordetella pertussis in Scotland by NHS Health Board, January to September 2024 (week 39)

Figure 20 is a bar chart showing the incidence of laboratory confirmed pertussis in Scotland by NHS Health Board for the first three quarters of 2024. The chart shows that NHS Greater Glasgow and Clyde, NHS Borders and NHS Grampian had the highest incidence rates in that period.

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Figure 20: Incidence of laboratory confirmed Bordetella pertussis in Scotland by NHS Health Board, January to September 2024 (week 39)

Vaccination information

More information on vaccines against pertussis can be found on the following pages:

• Pertussis (maternal)
• 6-in-one vaccine
• 4-in-one vaccine

Vaccine uptake statistics

Childhood vaccine uptake statistics are published in our childhood immunisation statistics quarterly report.

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Invasive pneumococcal disease

Background information

Pneumococcal infections are defined as invasive or non-invasive according to which area of the body is affected. Invasive pneumococcal disease (IPD) is caused by infection of normally sterile sites, for example, blood and cerebrospinal fluid (CSF).

IPD is a major cause of morbidity and mortality, especially amongst:

• the very young
• the elderly
• those with impaired immunity

Non-invasive forms of the infection commonly cause:

• middle ear infection (otitis media)
• worsening of bronchitis
• pneumonia

As with most infectious respiratory diseases, the numbers of cases of pneumococcal infection peak during winter. Up to 50% of people can carry pneumococci in their nose and throat without developing serious infection.

Streptococcus pneumoniae (S. pneumoniae) is the bacterium responsible for causing pneumococcal infection and is characterised by its outer coat, known as capsular polysaccharide. Different capsular types can be distinguished via a process known as serotyping. Over 90 different types of pneumococci have been identified, about a quarter of which are known to cause serious illness.

For further information on pneumococcal disease, visit NHS inform.

IPD surveillance is based on local and reference laboratory reports confirming isolation of Streptococcus pneumoniae from sterile body sites, mainly blood and cerebrospinal fluid (CSF).

In 1999, the Scottish Pneumococcal Invasive Disease Enhanced Reporting (SPIDER) scheme was introduced. The enhanced surveillance scheme is jointly managed by Public Health Scotland and the Scottish Haemophilus, Legionella, Meningococcus and Pneumococcus Reference Laboratory (SHLMPRL).

Data from SPIDER informs understanding of the epidemiology of IPD in Scotland.

Surveillance update July to September 2024 (week 39)

There were 84 cases of IPD reported in the third quarter of 2024, bringing the total for the first three quarters of the year to 372.

This is higher than the number of cases reported for the same period in the previous four years (range n=181 to n=321), but lower than the number of cases reported for the same period in 2019 (n=429), as shown in Figure 21, which was the last full pre-pandemic year for which data are presented.

Figure 21 is a series of line graphs showing the cumulative number of invasive pneumococcal disease cases reported to SPIDER per week by year. Each line represents a different year from 2019 to the end of the third quarter 2024. Across all years there is a steady increase in the cumulative number of cases per week. The graphs show that case numbers for the three quarters of 2024 are higher than those reported for 2020, 2021, 2022 and 2023, but lower than 2019.

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Figure 21: Cumulative number of invasive pneumococcal disease cases reported to SPIDER, 2019 to 2024 (week 39)

Figure 22 presents data on cases by age group and indicates that the burden of IPD is in adults over 35 years. To the end of the second quarter of 2024:

• 175 cases were aged 65 years or older (47.0%)
• 145 cases were aged 35 to 64 years (39.0%)
• 16 cases were aged 15 to 34 years (4.3%)
• 11 cases were aged five to 14 years (3.0%)
• 25 cases were aged under five years (6.7%)

Figure 22 is a series of line graphs showing the number of invasive pneumococcal disease cases reported to SPIDER per quarter by year from 2004 to the end of the third quarter 2024. Each line represents number of cases for each age group. The graphs show that the majority of cases were observed in those aged 35 years and over.

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Figure 22: Cases of IPD reported to SPIDER by quarter and by age group, 2004 to 2024 (week 39)

IPD in children under five years old

Of the 372 IPD cases reported in the first three quarters of 2024, 25 were children under five years of age.

This is lower than the number of cases in children aged under five years in the same period in 2023 (n=37), 2022 (n=37) and 2019 (n=26), but higher than in 2021 (n=23) and 2020 (n=13).

Serotypes detected among children aged under five years in the first three quarters of 2024 are shown in Table 1.

*Typing results not available  

Pneumonia was the most common clinical presentation in children aged under five years old.

Seven of the 25 children aged under five years who had IPD in the first three quarters of 2024 were known to have an underlying condition.

Circulating serotypes of Streptococcus pneumoniae

All IPD isolates and specimens should be sent to the reference laboratory for further typing and antimicrobial sensitivity testing. Typing results were available for 274 of the 372 cases reported in the first three quarters of 2024. This accounts for 73.7% of cases reported.  

The four most common serotypes reported were:

• Serotype 8 (38 cases)
• Serotype 22F (28 cases)
• Serotype 3 (27 cases)
• Serotype 9N (23 cases)

​A total of 64 cases, or 23.4% of those with available typing results, were caused by serotypes covered by the PCV13 vaccine.​

For the most recent information on antimicrobial resistance in Streptococcus pneumoniae, see Scottish One Health Antimicrobial Use and Antimicrobial Resistance in 2023.

Vaccination information

More information on vaccines against pneumococcal disease can be found on the following pages:

• PPV23 pneumococcal vaccine
• PCV13 pneumococcal vaccine

Vaccine uptake statistics

Vaccine uptake statistics for PCV13 are published in our childhood immunisation statistics quarterly report. Vaccine uptake statistics for PPV23 are published in the PHS Vaccination Surveillance Dashboard.

Poliomyelitis

Background information

Poliomyelitis (polio) is an acute viral illness caused by one of the three serotypes of poliovirus. Most infections cause no symptoms, but in a small number of people can result in a potentially life-threatening infection that can cause temporary or permanent paralysis.

People may become infected with the poliovirus through contact with infected faecal matter or respiratory secretions.

For more information on polio see NHS inform.

Surveillance

Following the introduction of the vaccine, the number of cases fell rapidly:

• the last UK case of poliomyelitis caused by wild polio virus was in 1984.
• the last imported case of polio in the UK was 1993.

Poliovirus is targeted by the World Health Organization (WHO) for eradication and due to the efforts of countries worldwide, two of the three wild poliovirus types (type 2 and type 3) have been eradicated. In August 2024, the WHO Emergency Committee on the international spread of poliovirus stated that evidence indicated global transmission of wild poliovirus type 1 was geographically limited to Pakistan and Afghanistan, noting that there had been geographical spread within the two countries in 2023 and 2024. The committee also noted the ongoing transmission of circulating vaccine derived polio virus (cVDPV) in the African Region and that many of the cVDPV infected countries remain conflict affected, disrupting routine immunisation as well as polio vaccination campaigns. Those travelling to countries where there may be a risk of exposure should seek specific advice in advance.

In early 2022, vaccine-derived poliovirus type 2 (VDPV2) was detected in sewage samples from London sewage works (for details, please visit: Poliovirus detected in sewage from North and East London - GOV.UK (www.gov.uk). These detections suggest some spread between closely linked individuals in areas of London. No associated cases of paralysis or human infections of poliovirus have been reported in the UK. This particular strain of poliovirus has been identified in wastewater elsewhere with cases of poliomyelitis in Israel and the USA. A full list of countries currently reporting cVDPD is available from the Polio Global Eradication Initiative.

Acute flaccid paralysis (AFP) surveillance

Public Health Scotland has recently established surveillance of AFP, which is a rare but serious set of symptoms that affects the nervous system, and can be caused by poliovirus or other non-polio viruses such as enteroviruses. View further information on AFP and AFP surveillance forms.

Vaccination Information

More information on vaccines against polio can be found on the following pages:

• 6-in-one vaccine
• 4-in-one vaccine
• 3-in-one vaccine

Vaccine uptake statistics

Vaccine uptake statistics for children are published in Teenage booster immunisation statistics Scotland - School year 2023/2024 and childhood immunisation statistics quarterly report.

Rotavirus

Background information

Rotavirus is highly infectious and a leading cause of gastroenteritis in children worldwide. In Scotland, most children will have had at least one rotavirus infection by five years old.

Rotavirus infections in children and adults can last approximately three to eight days and symptoms include:

• severe diarrhoea
• vomiting
• stomach cramps
• mild fever

The combination of symptoms can lead to dehydration, requiring admission to hospital, especially in young infants.

Before the introduction of a national infant rotavirus vaccination programme in 2013, an estimated 55,000 gastroenteritis cases caused by rotavirus occurred in Scotland each year in children less than five years old. Approximately 1,200 of these children were hospitalised (2.2% of cases). Rotavirus reports peaked between February and April. This caused considerable additional pressure on the NHS, particularly in primary care and paediatric healthcare facilities.

In July 2013, Rotarix®, a live attenuated vaccine was introduced into the routine infant vaccination schedule in the UK, with doses given at 8 and 12 weeks.

For further advice on the transmission and prevention of rotavirus, visit NHS inform.

Surveillance update July to September 2024 (week 39)

Figure 23 shows the number of rotavirus laboratory reports in Scotland from 2011 to the end of the third quarter of 2024 (week 39).

Following the introduction of the immunisation programme, there was a marked reduction in the number of laboratory reports, which clearly demonstrates the impact of the vaccine.

A reduction of laboratory-confirmed rotavirus samples has also been seen in unvaccinated children suggestive of indirect population protection due to the vaccine. See the vaccine-preventable disease summary for the number and incidence of rotavirus laboratory reports in Scotland over the last 5 years.

Figure 23 is a line graph which presents the number of rotavirus laboratory reports in Scotland by month and year from 2011 to September 2024 (week 39). There has been a marked reduction in the number of laboratory reports following introduction of the rotavirus vaccine.

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Figure 23: Laboratory reports of rotavirus in Scotland from 2011 to September 2024 (week 39)

Vaccination information

More information on the rotavirus vaccine can be found on the following page:

• rotavirus vaccine

Vaccine uptake statistics

Vaccine uptake statistics are published in our childhood immunisation statistics quarterly report.  

Rubella

Background information

Rubella is a rash illness caused by the rubella virus. It's generally a mild illness, but if acquired by women in the first 16 weeks of pregnancy can have devastating effects on the unborn child, leading to Congenital Rubella Syndrome (CRS). The virus can affect all foetal organs and lead to serious birth defects such as learning difficulties, cataracts, deafness, cardiac abnormalities, restriction of intrauterine growth and inflammatory lesions of the brain, liver, lungs and bone marrow

Before the introduction of rubella vaccination, more than 80% of adults had evidence of previous exposure to rubella.

A vaccination programme targeting girls and non-immune women of childbearing age was introduced in the UK in 1970 and reduced the number of congenital rubella syndrome (CRS)-related births and terminations.

In 1988, the Measles, Mumps and Rubella (MMR) vaccine was introduced for both boys and girls and further decreased cases of rubella to near elimination levels (Figure 22).

In 2016, the decision was made to end the national policy of screening for rubella susceptibility (external site, PDF) in pregnancy. This followed a review of evidence by the UK National Screening Committee and considering the high levels of uptake of the MMR vaccine.

For more information on rubella see NHS inform.

Surveillance update July to September 2024 (week 39)

No laboratory-confirmed cases of rubella were reported in the first three quarters of 2024. The last reported case of laboratory-confirmed rubella in Scotland was reported in 2017.

Figure 24 is a line chart showing the number of laboratory-confirmed cases of rubella reported in Scotland by year from 1988 through to September 2024 (week 39). The figure shows that the number of cases of rubella fluctuated each year between 1988 and 1995. The number of cases peaked in 1996 at 766 but decreased dramatically in 1997 before increasing slightly to 47 cases in 1999. Since 1999, the number of cases has been low and stable. No laboratory-confirmed cases of rubella have been reported in Scotland since 2017, when one case was reported. The graph is also annotated with relevant time points in rubella vaccination, with the MMR vaccine introduced in 1988, the measles/rubella campaign initiated in 1994, and the second dose of MMR added to the vaccine

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Figure 24: Number of laboratory-confirmed cases of rubella in Scotland by year, 1988 to September 2024 (week 39)

Congenital rubella surveillance

Information about congenital rubella surveillance can be viewed on the Royal College of Paediatrics and Child Health (RCPCH) website.

Vaccination Information

More information on vaccines against rubella can be found on the following page:

• MMR vaccine

Vaccine uptake statistics

Vaccine uptake statistics are published in our childhood immunisation statistics quarterly report.   

Shingles

Background information

Shingles, also known as herpes zoster, is caused by reactivation of latent varicella zoster virus. Varicella zoster is the same virus that causes chickenpox.

Shingles is characterised by a painful skin rash. The main complication from shingles is post-herpetic neuralgia (PHN), a long-lasting neuropathic pain after the rash has disappeared.

PHN can persist for months or years and the risk and severity increases with age. Its effect can be very debilitating.

The Scottish Morbidity Record 01 (SMR01) is a national dataset held by the NHS Information Services Division and provides data on inpatient and day case admissions. It is used to investigate the burden of disease on hospital inpatient and day-case discharges from acute specialties from hospitals in Scotland.

Shingles surveillance data

Shingles is not a notifiable disease, so the number of hospital admissions for shingles and related complications are used to estimate the burden of shingles.

Figure 25 shows the rate of admissions per 100,000 population for shingles and related complications by age group between 2010 and 2022.

This graph shows that the rate of admissions is higher among the older age groups, which is why older age groups are offered shingles vaccine.

Figure 25 is a line graph which shows the rate of admissions per 100,000 population for shingles and related complications by age group between 2010 and 2022. This graph shows that the rate of admissions increases with increasing age.

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Figure 25 Rate of admissions per 100,000 population for shingles and related complications by age group and year, 2010 to 2022

Vaccination information

More information on shingles vaccination can be found on the following page:

• shingles immunisation

Vaccine uptake statistics

Shingles vaccine uptake statistics are published in the PHS Vaccination Surveillance Dashboard.