Research and analysis

Confirmed cases of pertussis in England by month

Updated 8 November 2024

Applies to England

Confirmed cases of pertussis in England by month, to end September 2024

In England, provisionally there were 13,952 laboratory confirmed cases of pertussis reported to the UK Health Security Agency (UKHSA) between January and September 2024 with 555 cases in January 2024 increasing by month to 3,049 in May and then decreasing by month to 703 in September ^{[footnote 1]} (Figure 1, Table 1). This compares with 856 laboratory confirmed cases of pertussis reported throughout 2023. There have been 10 reported deaths in infants who developed pertussis between January and September 2024 ^{[footnote 2]}. Whilst monthly case numbers in 2024 have fallen since May, pertussis activity remains high and continues to be closely monitored.

Pertussis is a cyclical disease that peaks every 3 to 5 years, with the last cyclical increase occurring in 2016 and the last major outbreak occurring in 2012 (Figure 2, 3). Intervention measures implemented to help control the spread of COVID-19 between March 2020 and July 2021 also had an impact on other infectious diseases, including pertussis. Consequently, pertussis activity was exceptionally low across England from April 2020 and persisted at low levels until Summer 2023 when case numbers began to increase (Figure 1). Overall numbers in 2023 remained lower than pre-pandemic years (Figure 2, Table 1). The recent increase in pertussis cases has been observed across all age groups and in every region in England. Case numbers rose across the first 5 months of 2024 to May, as expected based on usual seasonal patterns, and fell but remained elevated compared to pre-pandemic years between June and September. Confirmed cases in the second quarter of 2024 were notably high, exceeding those in any quarter of the 2012 outbreak year and in the third quarter of 2024 have fallen to levels similar to those observed in Q3 and Q4 of 2012 (Figure 3).

Of the 13,952 cases confirmed between January and September 2024, 57.6% (8,033 cases) were in those aged 15 years or older with 18.7% in children aged between 10 and 14 years (2,614 cases) and 11.5% (1,601) in children aged 5 to 9 years (Table 2).

The number of confirmed cases in infants under 3 months, who are at highest risk of severe disease and too young to be fully vaccinated, peaked at 407 cases in the earlier 2012 outbreak then fell after the introduction of maternal vaccination. In recent years, cases in infants under 3 months increased from 2 cases in 2022 to 48 cases in 2023 but remained lower than pre-pandemic cyclical peak years; there were 83 cases in infants under 3 months in 2019 (Table 2). Incidence continued to be highest in infants under 3 months in 2023 (Figure 2). There were 422 infants aged under 3 months with confirmed pertussis between January and September 2024 whilst there were 335 cases in the same period in 2012

In the 12 years prior to the introduction of maternal pertussis vaccination in October 2012, 63 deaths occurred in babies aged under one year with confirmed pertussis. Since the introduction of pertussis vaccination in pregnancy, from 2013 to the end of September 2024, there have been 31 deaths in babies with confirmed pertussis who were all too young to be fully protected by infant vaccination. Sadly, this includes 10 deaths in infants who had contracted pertussis between January and September 2024. Of the 31 infants that died, 25 had mothers who were not vaccinated in pregnancy.

Maternal vaccination is very effective against pertussis disease and hospitalisation (Optimization of Timing of Maternal Pertussis Immunization, Clinical Infectious Diseases 2023). Calculated maternal vaccine effectiveness against infant death was updated to include recent deaths to the end of August 2024 and remains very high at around 91% (unpublished UKHSA data).

Vaccine uptake levels in pregnant women, babies and young children have fallen in recent years across England. Maternal vaccine uptake fell from 74.7% in December 2017 to 58.9% in March 2024. The mean coverage for 2024 quarter 2 (April to June) was 59.6%, which was 1.5 percentage points higher than the mean coverage for the same quarter in the 2023 to 2024 financial year and the first quarterly increase in coverage since quarter 4 of the 2019 to 2020 financial year. The annual coverage for 2023 to 2024 was 58.6%, 2.1 percentage points lower than the 2022 to 2023 financial year and 6.1 percentage points lower than the 2021 to 2020 financial year.

Vaccination in pregnancy is key to passively protecting babies before they can be directly protected by the infant vaccine programme. Pertussis vaccination is recommended in every pregnancy and women should normally receive their whooping cough vaccine around the time of their mid-pregnancy scan (usually 20 weeks) but can receive it from 16 weeks. To help provide optimal protection, the vaccine should be given before 32 weeks; but women who miss out can still have the vaccine later. It is also important that babies are vaccinated on time when they become eligible for infant doses at 8, 12 and 16 weeks of age and that those who miss vaccination are caught up at the earliest opportunity.

Guidance on public health management during periods of increased pertussis activity has recently been further updated and includes details on the appropriate public health actions and laboratory investigation of suspected cases of pertussis. This public health advice is informed by the age of the suspected case and time since onset of their symptoms. Appropriate confirmatory testing allows the situation to be closely monitored, ensures public health action is undertaken where needed and supports appropriate clinical management.

Figure 1. Laboratory confirmed cases of pertussis by month in England: 2018 to September 2024 (note 1)

Figure 2. Annual incidence by age group of laboratory confirmed cases of pertussis in England: 2011 to 2023 (note 1)

Laboratory confirmed cases of pertussis by quarter in England: 2011 to July-September (Q3) 2024 (note 1)

Table 1. Laboratory confirmed cases of pertussis by reporting month in England: 2023, 2024 (note 1)

Month of reporting	Total number of cases reported, 2023	Cumulative total of cases for 2023	Total number of cases reported, 2024	Cumulative total of cases for 2024
January	9	9	555	555
February	9	18	918	1,473
March	11	29	1,428	2,901
April	20	49	2,110	5,011
May	33	82	3,049	8,060
June	53	135	2,429	10,489
July	72	207	1,700	12,189
August	93	300	1,060	13,249
September	102	402	703	13,952
October	101	503
November	110	613
December	243	856

Table 2. Laboratory confirmed cases of pertussis by age group in England: 2018 to 2023 and to September 2024 (note 1 and 2)

Age group	2018	2019	2020	2021	2022	2023	2024, cumulative to end September
Under 3 months	49	83	30	1	2	48	422
3 to 5 months	26	32	15	1	3	23	217
6 to 11 months	17	21	5	0	0	25	226
1 to 4 years	87	147	49	3	10	52	839
5 to 9 years	139	222	52	2	3	78	1,601
10 to 14 years	288	467	150	3	3	177	2,614
15 years and over	2,342	2,706	693	39	47	453	8,033
Total	2,948	3,680	994	49	68	856	13,952

Note 1: Data for 2023 and 2024 is provisional.

Note 2: 2019 total excludes 2 cases where the age was not known.

1. Note that the number of laboratory confirmed cases presented are provisional and can increase as further test results are finalised but also decrease if cases are confirmed as vaccinated within a year of a positive serology or oral fluid test: both recent vaccination and/or recent infection will give a positive result using these test methods. ↩

2. Deaths are reported to the UKHSA pertussis enhanced surveillance programme from Health Protection Teams, Office of National Statistics or Patient Demographic Service. These are also provisional as there can be delays in reporting of deaths in babies with whooping cough. ↩