Immunisation and vaccine-preventable diseases quarterly report
April to June 2023 (Q2)

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

Diphtheria has been 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 have been no cases of toxigenic diphtheria reported to date in 2023. The last case of toxigenic diphtheria in Scotland was 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 since 2022, with similar increases reported elsewhere in Europe. Further details can be found here: Diphtheria: cases among asylum seekers in England, 2022 and 2023 - 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 our COVID wider impacts dashboard, Teenage booster immunisation statistics Scotland - School year 2020/2021 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 in order that national trends in disease subtypes can be monitored.

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 April to June 2023

There were 26 invasive H. influenzae cases reported in the second quarter of 2023, bringing the total number of cases in the first half of 2023 to 59. This is higher than the number of cases reported in the first half of the previous four years (range 10 to 40).

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 second quarter of 2023. All years show a steady increase in cumulative number of cases per week. The number of cases in the first half of 2023 is higher than the number of cases reported in the same period of the previous four years.

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Figure 1: Cumulative number of Haemophilus influenzae cases reported to PHS, 2019 to 2023 (week 26)

Of the 59 cases reported in the first half of 2023:

• 30 were people aged over 40 years
• five were people aged between 21 and 40 years
• eight were people aged between five and 20 years
• 16 were children aged under five years old, eight of whom 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 to Public Health Scotland from 1988 to the end of the first half of 2023. 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. Only one case has been observed in the under 5 age group between 2011 and the end of the first half of 2023.

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Figure 2: Laboratory reports of invasive Haemophilus influenzae type b disease in Scotland, 1988 to 2023 (week 26)

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

Of the 59 isolates in the first half of 2023:

• 32 were non-typable (i.e., non-encapsulated type)
• two were identified as type e
• one was identified as type a
• one was identified as type f
• typing was not carried out/available for the remaining 23 isolates

Figure 3 is a bar chart showing the laboratory reports of Haemophilus influenzae by type from 2003 to the end of the second quarter of 2023. 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: Laboratory reports of Haemophilus influenzae by serogroup, 2003 to 2023 (week 26)

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 COVID wider impacts dashboard and 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 the end of June 2023. 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. 18 cases were reported in 2019 and no cases were reported in 2020 or 2021. One case has been reported thus far in 2022, in February. 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 end of June 2023

Surveillance update for April to June 2023

There were no cases of laboratory-confirmed measles in the first or second quarter of the year and only one case reported in 2022 which was the first case reported since 2019.

As shown in Figure 5, the number of cases each year has been variable. See the vaccine-preventable disease summary for the number and incidence of measles in Scotland over the last 5 years.

The single case in 2022 (February) was imported from outwith the UK. No further transmission occurred in Scotland, highlighting the success of the MMR vaccination programme and the importance of maintaining high vaccine uptake in Scotland.

Of the 18 laboratory-confirmed cases of measles reported in 2019:

• one case was acquired elsewhere within the UK, outwith Scotland, from which two further Scottish cases were identified,
• seven cases were imported from outwith the UK, and resulted in two import-related cases in Scotland,
• six laboratory-confirmed cases of measles in Scotland were of unknown origin, four of which typing was available for. The type identified (D8) indicated that these cases were strains identified elsewhere in the UK and Europe, which demonstrates transmission within the UK and across the continent prior to the COVID-19 pandemic.

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 the end of June 2023. 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, in February.

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Figure 5: Number of laboratory-confirmed cases of measles in Scotland by month and year, 2015 to June 2023

The age distribution of measles cases has varied over recent years, but most cases are observed in children and young adults. Of cases reported in 2019, the median age of the 18 laboratory-confirmed measles cases was 24 years. This is similar to the median age of cases in 2016, which was 22 years, and 2017 which was 27 years. Of the two laboratory-confirmed cases reported in 2018, one case was in the under one year age group and the other case reported was in the 30 to 39 year age group.

Measles in Europe

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, several countries in the WHO European Region have reported measles cases in recent months, and WHO Europe has issued the following press statement: Immediate and targeted catch-up vaccination needed to avert measles resurgence.

In the most recent 12 months up to June 2023 there were a total of 378 cases of measles reported to the European Centre for Disease Prevention and Control. The EU/EEA countries with highest reported rate of cases between this time period were Austria, Romania, Belgium and Estonia with rates of 14.59, 3.47, 3.36 and 2.25 cases per million of population, respectively.

Data published by UKHSA reports a total of 128 cases of laboratory confirmed measles in England between 1 January to the end of June 2023, the majority of which were reported in London. However, all regions in England have had at least one case reported this year.

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 COVID wider impacts dashboard and 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 a number of 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 April to June 2023

There were nine cases of meningococcal disease reported in the second quarter of 2023, bringing the total for the first half of the year to 24. This is the same as the number of cases reported for the same period in 2020, higher than the number of cases in 2021 (n=5) and 2022 (n=15), and lower than the number of cases in 2019 (n=32) 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 second quarter of 2023. The number of cases reported for the first half of 2023 is higher than the number of cases reported for the same period in 2021 and 2022, the same as that reported in 2020, but lower than that reported for the same period in 2019.

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Figure 6: Cumulative number of meningococcal disease cases reported to MIDAS, 2019 to 2023 (week 26)

Figure 7 shows the number of meningococcal disease cases, according to age group and by quarter from 2001 to the end of the second quarter of 2023.

In the first half of 2023, there were:

• four cases aged under five years, two of whom were aged under one year
• 16 cases in the five to 24 years age group
• four 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 second quarter of 2023. 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 2023 (week 26)

Of the 24 cases of meningococcal disease reported in the first half of 2023:

• 19 were serogroup B
• one was serogroup W
• 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 2003 to the end of the second quarter of 2023. 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, 2003 to 2023 (week 26)

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. One serogroup W case has been reported in 2023 so far (first quarter).

Figure 9 is a series of line graphs showing the number of serogroup W cases reported from 2009 to the end of the second quarter of 2023, 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 decreased.

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Figure 9: Meningococcal serogroup W by age group reported to PHS 2009 to 2023 (week 26)

The number of deaths between 2003 and the end of the first half of 2023, reported by serogroup, is shown in Figure 10. There were two deaths from meningococcal disease reported in the first half of 2023.

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 2003 to the end of the second quarter of 2023. The overall trend is varied, with the highest number of deaths in 2004 (15 deaths).

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Figure 10: Meningococcal deaths by serotype reported to PHS 2003 to 2023 (week 26)

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 have remained higher than those reported before 2004.

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 April to June 2023

There were ten cases of laboratory-confirmed mumps reported to the end of June 2023, nine of which were reported between January and March. In 2022 there were seven laboratory-confirmed cases of mumps reported in total.

Since April 2020, there has been a substantial reduction in number of cases of mumps reported with only one laboratory-confirmed case of mumps reported in 2021. As shown in Figure 11, outbreaks occurred in:

• 2009
• 2012
• 2014 to 2015

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 June 2023. 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, and 2014 to 2015. 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 have been ten laboratory-confirmed cases reported thus far in 2023.

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Figure 11: Number of laboratory-confirmed cases of mumps in Scotland by year, 2000 to June 2023

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

In 2020, the majority of reported cases occurred in the first three months, as shown in Figure 13. The decrease in reported cases since April 2020 was likely a result of social distancing 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.

NHS boards experienced clusters of mumps into the first quarter of 2020, occurring mainly in adolescents and young adults. The observed increase in cases in 2019 and early 2020, prior to the implementation of COVID-19 social restriction measures, 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.

Figure 12 is a bar chart showing the number of laboratory-confirmed cases of mumps by month and year from 2015 to the end of June 2023. 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 start 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 to the end of 2021. seven cases in 2022 and ten cases reported thus far in 2023.

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Figure 12: Number of laboratory-confirmed cases of mumps in Scotland by month and year, 2015 to June 2023

Age distribution of cases

Figure 13 shows that the majority of mumps cases in recent years have been in those aged 17 to 34 years.

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 14 is a bar chart showing the number of laboratory-confirmed cases of mumps by age group and year from 2015 to June 2023. While the overall number of cases varies by year, the majority of mumps cases in all years 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 June 2023

The incidence of mumps by age group in 2020, shown in Figure 15, reflects a higher incidence among individuals aged 17 to 20 years compared to other ages (137 cases per 100,000 population).

This was followed by those aged 21 to 24 years (88 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 1st January and 30th December 2020. the incidence of mumps was highest among individuals aged 17 to 20 years, at 137 cases per 100,000 population. This was followed by those aged 21 to 24 years, at 88 cases per 100,000 population. Data from 2021, 2022 and 2023 are not presented due to the low number/absence of cases.

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

*There is insufficient data from 2021, 2022 and 2023 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 COVID wider impacts dashboard and 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 April to June 2023

There were no cases of laboratory-confirmed pertussis in the first quarter of 2023 and three cases reported in the second quarter between April and June 2023. In 2022 and 2021, there were three and four cases of laboratory-confirmed pertussis reported, respectively.

In 2020, there were 198 laboratory reports of B. pertussis, the majority of which occurred in the first quarter of the year. This reduction is likely to be attributable to social distancing measures implemented to mitigate the transmission of COVID-19.

Figure 15 shows the number of positive laboratory reports of B. pertussis in Scotland from 2012 to the end of June 2023.

In 2012 and 2013, an outbreak occurred in Scotland, with 1,896 and 1,188 laboratory reports of pertussis, respectively.

Since then, the number of reports annually has been lower than those years:

• 533 in 2017
• 443 in 2018
• 746 in 2019

Figure 15 is a bar chart showing the number of laboratory reports of Bordetella pertussis by month from 2012 through to the end of June 2023. 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). The number of laboratory reports has declined since 2016 but remains elevated when compared with pre-outbreak levels. From the first quarter of 2020, cases can be seen to drop to nearly zero with only four cases reported in 2021, three cases were reported in 2022 and three thus far in 2023.

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Figure 15: Number of laboratory reports of Bordetella pertussis in Scotland by month, 2012 to June 2023

Age breakdown of cases

Figure 16 presents the percentage of cases of pertussis by age group and year from 2012 to June 2023.

The data for 2020 indicate that adults aged 50 to 59 years accounted for a comparatively higher percentage of laboratory reports than individuals in other age groups.

Of the four reported cases in 2021:

• one case was aged between 15 and 19 years
• one case was between 50 to 59 years
• two cases were older than 70 years

The three cases reported in 2022 were under 50 years.

Of the 951 cases reported in the last 5 years, 41 were under one year of age.

Figure 17 presents the number of laboratory reports for pertussis by age group from January to December of 2020.The graph shows that the 50 to 59 age group accounted for the highest number of cases. However, incidence is consistently highest among children under one year of age as shown in Figure 18. Incidence of cases between 2016 and 2021 show a similar pattern across all age groups, all of which have displayed decreases over this time, with the exception of a peak year in 2019.

Figure 16 is a stacked bar chart that shows the percentage of laboratory reports of pertussis by age group and year from 2012 through the June 2023. The data for 2020 indicate that adults aged 50 to 59 years accounted for a comparatively higher percentage of laboratory reports than did individuals in other age groups. It is worth noting that there were only four cases reported in 2021, three in 2022 and three thus far in 2023.

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Figure 16: Percentage of Bordetella pertussis laboratory reports in Scotland by age group and year, 2012 to June 2023

Figure 17 is a bar chart showing the number of laboratory reports for Bordetella pertussis by age group during 2020. The graph shows that the 50-59 age group accounted for the highest number of cases.

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Figure 17: Number of laboratory reports of Bordetella pertussis in Scotland by age group, 2020*

*The low number of cases in 2021 (n=4), 2022 (n=3), and to date 2023 (n=3) means that only data until 2020 is presented.

Figure 18 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 2016 and end of June 2023. It shows notably higher incidence in the under 1 year age group compared with all other age groups. Incidence has decreased across all age groups from 2016 to end of June 2023, within an exception of a raised incidence in 2019.

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Figure 18: Incidence of Bordetella pertussis per 100,000 population in Scotland by age group, 2016 to June 2023

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 COVID wider impacts dashboard and childhood immunisation statistics quarterly report.

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 April to June 2023

There were 112 cases of IPD reported in the second quarter of 2023, bringing the total for the first half of the year to 242.

This is higher than the number of cases reported for the same period in 2022 (n=178), 2021 (n=113) and 2020 (n=188), but lower than the number of cases reported in 2019 (n=340) as shown in Figure 19.

The lower number of cases of IPD observed since early 2020 is likely due to the impact of social distancing measures and other restrictions implemented in response to the COVID-19 pandemic.

Figure 19 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 second quarter of 2023. Across all years there is a steady increase in the cumulative number of cases per week. The graphs show that case numbers for the first half of 2023 are higher than those reported for the same period in 2020, 2021 and 2022, but lower than 2019.

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Figure 19: Cumulative number of invasive pneumococcal disease cases reported to SPIDER, 2019 to 2023 (week 26)

Figure 20 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 first half of 2023:

• 123 cases were aged 65 years or older (50.8%)
• 77 cases were aged 35 to 64 years (31.8%)
• 11 cases were aged 15 to 34 years (4.5%)
• Three cases were aged five to 14 years (1.2%)
• 28 cases were aged under five years (11.6%), of whom six were infants aged under one year

Figure 20 is a series of line graphs showing the number of invasive pneumococcal disease cases reported to SPIDER per quarter by year from 2003 to the end of the second quarter of 2023. 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 20: Cases of IPD reported to SPIDER by quarter and by age group, 2003 to 2023 (week 26)

IPD in children under five years old

Of the 242 IPD cases reported in the first half of 2023, 28 were children under five years of age, 26 of whom were old enough to have been eligible for at least a first dose of PCV13 vaccination.

This is higher than the number of cases reported in children aged under five years in the same period in for the previous four years (range 12 to 26).

Serotypes detected in children aged under five years, to the end of the second quarter, are shown in Table 1.

*Typing results not available  

Pneumonia and septicaemia were the most common clinical presentations in children aged under five years old.

Seven of the 28 children aged under five years who had IPD in the first half of 2023 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 201 of the 242 cases reported in the first half of 2023. This accounts for 83.0% of the cases reported.

The three most common serotypes reported were:

• Serotype 3 (33 cases)
• Serotype 8 (32 cases)
• Serotype 22F (18 cases)

​A total of 55 cases, or 27.4% 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 2020.

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 children are published in our COVID wider impacts dashboard and childhood immunisation statistics quarterly report.

Vaccine uptake statistics for adults are published by our Clinical and Protecting Health Directorate.

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, polio is now eliminated from four of the six WHO regions. Pakistan and Afghanistan are considered the countries with the highest risk, where the virus is endemic. Polio outbreaks do occur in other countries when the disease is spread amongst people who may not be fully vaccinated. More information on those who may be at risk of exposure through travel can be found at our fitfortravel pages.

Vaccine-derived poliovirus type 2 (VDPV2) has been 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 circulating VDPV is available from the Polio Global Eradication Initiative (external site, PDF).

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 our COVID wider impacts dashboard 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 April to June 2023

Figure 21 shows the number of rotavirus laboratory reports in Scotland from 2011 to the end of June 2023. Please note that data differs slightly from previously published data due to a revalidation exercise.

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 21 is a line graph which presents the number of rotavirus laboratory reports in Scotland by month and year from 2011 to the end of June 2023. There has been a marked reduction in the number of laboratory reports following introduction of the rotavirus vaccine.

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Figure 21: Laboratory reports of rotavirus in Scotland from 2011 to end of June 2023

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 COVID wider impacts dashboard and 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 April to June 2023

No laboratory-confirmed cases of rubella were reported in the second quarter of 2023, with the last reported case of laboratory-confirmed rubella in Scotland reported in 2017.

Figure 22 is a line chart showing the number of laboratory-confirmed cases of rubella reported in Scotland by year from 1988 through to the end of June 2023. 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 schedule in 1996.

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Figure 22: Number of laboratory-confirmed cases of rubella in Scotland by year, 1988 to end of June 2023

Congenital rubella surveillance

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 COVID wider impacts dashboard and 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 and GP consultations for shingles and related complications are used to estimate the burden of shingles.

Figure 23 shows the rate of admissions per 100,000 population for shingles and related complications by age group between 2010 and 2021. In 2021, there were 276.9 hospital admissions per 100,000 population for shingles and related complications.

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 23 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 2021. This graph shows that the rate of admissions increases with increasing age.

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Figure 23: Rate of admissions per 100,000 population for shingles and related complications by age group and year, 2010 to 2021*

*Rates are calculated using an updated methodology, which differs from that previously used to estimate burden of disease. This is therefore not comparable to graphs in previous reports.

Vaccination information

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

• shingles immunisation

Two vaccines are available to protect against shingles and PHN. All patients in the eligible age group for shingles vaccination should be clinically assessed to inform vaccine selection. Download the screening tool to identify when the Zostavax® vaccine is contraindicated.

Vaccine uptake statistics

Tables 2 and 3 present the shingles Zostavax® vaccine coverage by NHS Board among the routine cohort (aged 70 years) and catch-up cohort (those aged between 71 and 79 years) for the most recent season 1 September 2021 to 31 August 2022. Table 4 presents the Scottish annual coverage in the routine cohort, catch up cohort and all eligible age groups from seasons 2015/2016 to 2021/2022. The Vaccine Management Tool is now used for recording shingles vaccination events and work is currently underway within PHS to develop public-facing dashboards for reporting up-to-date vaccine uptake/coverage statistics.

The national coverage in 2021 to 2022 for the routine cohort was 45.12%, an increase from the previous season 2020 to 2021 of 24.48%. The national coverage in 2021 to 2022 in the catch-up cohort was 63.08%, increased from 55.49% in the previous season.

Tetanus

Background information

Tetanus is a disease resulting from infection with the bacteria Clostridium tetani.  These bacteria are common in the environment and are present in soil and the manure of animals. They may cause infection by producing a neurotoxin when they enter the body through a wound, burn, puncture or scratch.

The most common symptoms of infection are lockjaw, muscle spasms, fever, sweating and tachycardia (high heart rate). If not treated, symptoms can get worse over the following hours and days. Tetanus cannot spread from person to person although people who inject drugs (PWID) are at increased risk of infection, through sharing contaminated objects such as needles, and clusters of infection have been previously reported in PWID.

Immunisation against tetanus is the most effective method of prevention and has been part of the childhood immunisation schedule since 1961.

For more information on tetanus see NHS Inform.

Surveillance

No cases of tetanus have been reported in Scotland since 2014. Data on the annual reported cases of tetanus in England from the UKHSA can be found on Tetanus in England: annual reports - GOV.UK (www.gov.uk).

Vaccination information

Find out more information about vaccines against tetanus:

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

Vaccine uptake statistics

Vaccine uptake statistics for children are published in our COVID wider impacts dashboard and childhood immunisation statistics quarterly report.