Common animal-associated infections (England and Wales): fourth quarter 2022
Updated 14 February 2023
Applies to England and Wales
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This quarterly report is produced by the Emerging Infections and Zoonoses team in the Clinical and Emerging Infections Directorate, UK Health Security Agency (UKHSA).
The report summarises laboratory-confirmed cases (and probable cases for leptospirosis) of selected zoonoses reported in England and Wales between October and December 2022 (fourth quarter) and includes additional information on the quarterly trends for hepatitis E, leptospirosis, Lyme disease and toxoplasmosis.
It is important to note that not all cases will present to healthcare services, and cases may be treated empirically based on clinical suspicion without a confirmatory test. Therefore, the numbers in this report are an underestimate of the true burden of zoonotic disease in England and Wales, biasing towards severe infections as individuals with severe or symptomatic disease may be more likely to be tested. Furthermore, not all zoonoses presented in this report are notifiable in England and Wales. As such, it is likely not all confirmed laboratory test results are reported to UKHSA. For a list of notifiable diseases and causative organisms in England and Wales please see the Notifiable diseases and causative organisms: how to report.
The impacts of the public health measures implemented in England and Wales due to the coronavirus (COVID-19) pandemic during 2020 and 2021 should be considered when making comparisons with this time period.
Data reported as provisional is subject to change due to late notifications and de-duplication.
The data presented in this report supersedes data in previous reports due to late notifications and de-duplication.
Overview
Table 1. Animal-associated infections in England and Wales: quarterly confirmed laboratory reports by specimen date, Q1 2020 to Q4 2022
| Disease (organism) | Q1 2020 | Q2 2020 | Q3 2020 | Q4 2020 | Total 2020 | Q1 2021 | Q2 2021 | Q3 2021 | Q4 2021 | Total 2021 | Q1 2022* | Q2 2022* | Q3 2022* | Q4 2022* | Total 2022* |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Anthrax (Bacillus anthracis) | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Brucellosis (Brucella spp.) | 1 | 1 | 6 | 1 | 9 | 1 | 3 | 3 | 1 | 8 | 1 | 3 | 4 | 2 | 10 |
| Hepatitis E | 317 | 234 | 321 | 244 | 1,116 | 363 | 368 | 286 | 315 | 1,332 | 330 | 410 | 354 | 442 | 1,536 |
| Leptospirosis (Leptospira spp.) | 15 | 7 | 22 | 7 | 51 | 8 | 5 | 16 | 26 | 55 | 4 | 11 | 26 | 14 | 55 |
| Lyme disease (Borrelia burgdorferi) | |||||||||||||||
| All cases | 173 | 188 | 625 | 276 | 1,262 | 119 | 225 | 573 | 239 | 1,156 | 160 | 232 | 548 | 239 | 1,179 |
| Acute infections | 53 | 132 | 468 | 155 | 808 | 59 | 146 | 477 | 180 | 862 | 102 | 186 | 421 | 164 | 873 |
| Pasteurellosis (Pasteurella spp.) | 175 | 153 | 214 | 190 | 732 | 195 | 258 | 243 | 188 | 884 | 210 | 242 | 269 | 230 | 951 |
| Psittacosis (C. psittaci/C. abortus) | 1 | 0 | 0 | 1 | 2 | 2 | 1 | 2 | 0 | 5 | 0 | 0 | 0 | 0 | 0 |
| Q-fever (Coxiella burnetii) | |||||||||||||||
| All cases | 7 | 5 | 3 | 2 | 17 | 3 | 2 | 5 | 2 | 12 | 6 | 5 | 9 | 9 | 29 |
| Acute infections | 6 | 3 | 3 | 1 | 13 | 2 | 2 | 5 | 2 | 11 | 4 | 2 | 6 | 6 | 18 |
| Toxoplasmosis (Toxoplasma gondii)† | 53 | 26 | 44 | 63 | 186 | 48 | 52 | 40 | 52 | 192 | 55 | 39 | 57 | 47 | 198 |
*Provisional data
† Based on date specimen received
Hepatitis E
The national hepatitis E virus (HEV) surveillance reports reference laboratory data (Public Health Laboratory Birmingham and Blood Borne Virus Unit Colindale) together with additional cases reported by local laboratories through the Second Generation Surveillance System (SGSS). The combined data sets provide a more accurate reflection of the number of acute HEV infected cases reported in England and Wales. Following an internal UKHSA review, historical issues in processing of surveillance data in England and Wales were identified and, as a result, case numbers from 2018 have been updated. No clinical or public health implications are currently anticipated as a result of this review.
There were 442 laboratory reported cases of HEV infection in the fourth quarter of 2022, bringing the total to 1,536 cases reported in 2022. This is an increase compared to 315 cases reported in the fourth quarter of 2021 and 1,332 cases reported in 2021 overall. Figure 1 shows the number of HEV infections by quarter between 2018 and 2022. The data shows a decline in cases in 2020 (n=1,116) followed by an increase since 2021.
Figure 1. Laboratory confirmed cases of hepatitis E by quarter, Q1 2018 to Q4 2022
Of the cases reported in the fourth quarter of 2022, 259 (59%) were male (aged 16 to 96 years, median 58 years) and 180 (41%) were female (aged 14 to 95 years, median 60 years; Table 2). There were 3 cases where information on sex was not available. The persisting observation of the predominance of older men (aged 45 years and over) remains unexplained.
Table 2. Laboratory confirmed cases of hepatitis E by age group and sex, Q4 2022
| Age group | Male | Female | Unknown | Total |
|---|---|---|---|---|
| 0 to 14 | 0 | 1 | 0 | 1 |
| 15 to 24 | 11 | 10 | 0 | 21 |
| 25 to 44 | 44 | 47 | 2 | 93 |
| 45 to 64 | 106 | 53 | 1 | 160 |
| Over 64 | 98 | 69 | 0 | 167 |
| Total | 259 | 180 | 3 | 442 |
Leptospirosis
Data for leptospirosis was obtained from the Rare and Imported Pathogens Laboratory (RIPL, UKHSA Porton Down). As of 1 August 2020, a laboratory confirmed case of leptospirosis is defined by a positive 16S ribosomal RNA (rRNA) polymerase chain reaction (PCR) result only. An immunoglobulin M (IgM) enzyme-linked immunoabsorbent assay (EIA) continues to be performed on all samples of suspected leptospirosis cases. A case with a positive leptospirosis IgM result will usually be treated clinically on the basis of this result, even in the absence of a positive PCR result. A case with a positive IgM but without a confirmatory PCR result is therefore reported as a probable case for surveillance purposes. National surveillance of probable cases of leptospirosis was introduced in 2021.
There were 14 confirmed cases and 37 probable cases of leptospirosis reported in the fourth quarter of 2022, compared to 26 confirmed and 32 probable cases reported in the same quarter of 2021. Overall, there were 55 confirmed and 115 probable leptospirosis cases reported in 2022, compared to 55 confirmed and 87 probable cases in 2021. Figure 2 shows the number of confirmed cases reported by quarter over the past 5 years (2018 to 2022).
Figure 2. Laboratory confirmed and probable cases of leptospirosis by quarter, Q1 2018 to Q4 2022
In the fourth quarter of 2022, 12 confirmed cases (86%) were male (aged 16 to 70 years) and only 2 cases (14%) were female (aged 59 – age was unknown for one case). Cases were reported in the South East (5), the South West (3), Wales (2), London (1), the North West (1), the West Midlands (1) and the East Midlands (1).
Of the confirmed cases, 6 (43%) reported recent travel abroad. Of these, 2 cases had visited south-east Asia, 2 cases had visited central America, one case had visited South America and one case had visited the Caribbean. Country of recent travel does not necessarily reflect where the infection was acquired.
Of the 14 confirmed cases, 5 reported potential exposures:
- 3 cases had an exposure linked to a water source – of these, 2 cases reported freshwater swimming or rafting, and one case reported exposure to canal water
- 2 cases had an exposure linked to animals, both of which reported contact with rats
Lyme disease
Data for Lyme disease was obtained from the Rare and Imported Pathogens Laboratory (RIPL, UKHSA Porton Down). The total number of confirmed Lyme disease cases reported in the fourth quarter of 2022 (n=239) was the same compared to the same time period in 2021 (n=239). The total number of acute cases reported was lower in the fourth quarter of 2022 (n=144) compared to the same time period in 2021 (n=173). It should be noted that diagnosis for acute Lyme disease presenting with erythema migrans is clinical and testing is not recommended. The number of laboratory confirmed cases presented in this report are therefore an underestimate of the true burden of acute Lyme disease. Overall, the total number of cases reported in 2022 (n=1,179) was similar to 2021 (n=1,156), with a similar trend observed for acute cases (2021: 862, 2022: 873).
Figure 3 shows how the number of cases continue to peak during the summer months (third quarter), which corresponds to the peak times of exposures to ticks in the UK in the spring and summer months.
Figure 3. Laboratory confirmed cases of Lyme disease by quarter, Q1 2018 to Q4 2022
Of the total cases reported in the fourth quarter, 164 (69%) were acute (including 20 with neurological Lyme disease), and 75 (31%) were longstanding. Of the acute cases, 80 were male (aged 6 to 78 years, median 42.5 years) and 84 were female (aged 2 to 82 years, median 45 years). Table 3 shows the age group and sex distribution.
Table 3. Laboratory confirmed acute cases of Lyme disease by age group and sex, Q4 2022
| Age group | Male | Female | Total |
|---|---|---|---|
| 0 to 14 | 5 | 5 | 10 |
| 15 to 24 | 9 | 5 | 14 |
| 25 to 34 | 13 | 17 | 30 |
| 35 to 44 | 16 | 14 | 30 |
| 45 to 54 | 10 | 12 | 22 |
| 55 to 64 | 14 | 19 | 33 |
| 65 to 74 | 11 | 10 | 21 |
| Over 74 | 2 | 2 | 4 |
| Total | 80 | 84 | 164 |
The regions that reported the most acute cases in the fourth quarter of 2022 were the South East (n=41), the South West (n=35) and London (n=33) (Table 4). Only 7 of the acute cases reported foreign travel. Overall, the South East reported the highest number of acute Lyme disease cases in 2022 (n=250) as well as in the previous year (2021: 227). This data is based on the location of the referring hospital or laboratory and does not necessarily reflect the geographic area where the tick bite occurred. Four of the acute cases in the fourth quarter of 2022 reported foreign travel. Of these, one travelled to Eastern Europe, one to West Africa, and 2 cases travelled to both Western Europe and the Middle East.
Table 4. Laboratory confirmed acute cases of Lyme disease by region, Q1 2021 to Q4 2022
| UKHSA Centre | Q1 2021 | Q2 2021 | Q3 2021 | Q4 2021 | Total 2021 | Q1 2022 | Q2 2022 | Q3 2022 | Q4 2022 | Total 2022 |
|---|---|---|---|---|---|---|---|---|---|---|
| East Midlands | 2 | 2 | 5 | 1 | 10 | 4 | 1 | 1 | 3 | 9 |
| East of England | 7 | 11 | 24 | 14 | 56 | 4 | 12 | 23 | 15 | 54 |
| London | 21 | 27 | 83 | 45 | 176 | 24 | 31 | 68 | 33 | 156 |
| North East | 3 | 6 | 15 | 5 | 29 | 2 | 2 | 16 | 7 | 27 |
| North West | 4 | 24 | 52 | 19 | 99 | 13 | 19 | 28 | 12 | 72 |
| South East | 11 | 30 | 150 | 36 | 227 | 22 | 56 | 131 | 41 | 250 |
| South West | 6 | 31 | 115 | 36 | 188 | 19 | 53 | 105 | 35 | 212 |
| West Midlands | 3 | 3 | 7 | 6 | 19 | 6 | 0 | 22 | 2 | 30 |
| Yorkshire and Humber | 1 | 8 | 20 | 11 | 40 | 5 | 8 | 21 | 11 | 45 |
| Wales | 1 | 4 | 6 | 7 | 18 | 3 | 4 | 6 | 5 | 18 |
| Total | 59 | 146 | 477 | 180 | 862 | 102 | 186 | 421 | 164 | 873 |
Toxoplasmosis
Data for toxoplasmosis was obtained from the Toxoplasma Reference Unit (TRU, Public Health Wales Swansea).
There were a total of 47 confirmed toxoplasmosis cases reported in the fourth quarter of 2022, compared to 52 in the same quarter of 2021. Overall, there were 198 confirmed cases in 2022, similar to the number of cases in 2021 (n=192).
Figure 4. Laboratory confirmed cases of toxoplasmosis by quarter, Q1 2018 to Q4 2022
Of the total confirmed cases, 18 were male (aged 14 to 82 years, median 42 years) and 28 were female (aged 0 to 79 years, median 33 years). There was one case with an unknown sex and one case with unknown age. Table 5 shows the age group and sex distribution.
Table 5. Laboratory confirmed cases of toxoplasmosis by age group and sex, Q4 2022
| Age group | Male | Female | Unknown | Total |
|---|---|---|---|---|
| 0 to 14 | 1 | 2 | 0 | 3 |
| 15 to 24 | 3 | 3 | 0 | 6 |
| 25 to 44 | 6 | 16 | 1 | 23 |
| 45 to 64 | 4 | 4 | 0 | 8 |
| Over 64 | 4 | 2 | 0 | 6 |
| Unknown | 0 | 1 | 0 | 1 |
| Total | 18 | 28 | 1 | 47 |
Psittacosis
Data for psittacosis was obtained from the Respiratory and Vaccine Preventable Bacteria Reference Unit (RVPBRU) in Colindale and from cases reported by local laboratories through the SGSS. Psittacosis data has not been reported since 2017 due to concerns surrounding the interpretation of serology test results. It is recognised that it is difficult to diagnose infection retrospectively through serological assays and, as such, following an external review, the surveillance case definitions for psittacosis were reviewed. As of 1 January 2023, a confirmed case of psittacosis is defined by a positive 16S rRNA PCR result or culture isolation only.
It should be noted that the existing PCR assay is unable to differentiate between Chlamydia psittaci (C. psittaci) and Chlamydia abortus (C. abortus). However, as there are currently no other reliable methods of psittacosis identification, the numbers presented in these reports will reflect laboratory confirmed cases with a positive PCR result for C. psittaci/C. abortus.
There were no reports of psittacosis in 2022, compared to 5 reports in 2021. Figure 5 shows the number of laboratory confirmed cases of psittacosis between 2013 and 2022.
Figure 5. Laboratory confirmed cases of psittacosis by quarter, Q1 2013 to Q4 2022
Other zoonotic organisms (provisional data)
There were 17 reports of Capnocytophaga spp. infection in the fourth quarter of 2022, bringing the total to 101 cases reported in 2022. This is a small increase compared to 96 cases reported in 2021. Of the cases reported this quarter, 12 were further speciated to C. canimorsus. Of those speciated, 6 were male and 6 were female, and cases were reported in the East of England (2), the North East (1), the North West (2), the South East (3) and the South West (3). One case was also reported in Wales. Capnocytophaga spp. are frequently carried in the mouths of companion animals (cats and dogs) or humans, and may be associated with an animal or human bite or opportunistic infections in those with impaired immune systems.
There were 3 reports of Mycobacterium marinum infection in the fourth quarter of 2022, bringing the total to 20 reported cases in 2022. This is an increase compared to 8 cases reported in 2021. Of the cases reported this quarter, one was male and one was female. Both cases were reported in England.
There were 2 reports of Erysipelothrix rhusiopathiae infection in the fourth quarter of 2022, bringing the total to 9 reported cases in 2022. This is a decrease compared to 17 cases reported in 2021. Of the cases reported this quarter, both were female and were reported in England.
There were 3 reports of toxigenic Corynebacterium ulcerans infection in the fourth quarter of 2022, bringing the total to 11 cases reported in 2022. This is an increase compared to 7 cases reported in 2021. Of the cases reported this quarter, 2 were linked as part of a cluster, 2 were male and one was female, and all cases were aged above 60 years. All cases were reported in England and reported contact with companion animals. In England, contact with companion animals remains the most frequently reported exposure for individuals with confirmed toxigenic C. ulcerans infections. However, the animals may not show evidence of infection, and it is not always possible to confirm the carriage of C. ulcerans in animals.
There were 7 reports of Taeniasis in the fourth quarter of 2022, bringing the total to 26 cases reported in 2022. This is an increase compared to 19 cases reported in 2021. Of the cases reported this quarter, 3 were further speciated to T. saginata and one to T. solium.
There were no reports of Toxocariasis in the fourth quarter of 2022. There were a total of 2 reports in 2022.