Research and analysis

Common animal-associated infections (England and Wales): third quarter 2022

Updated 14 February 2023

Applies to England and Wales

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 confirmed (and probable for leptospirosis) cases of selected zoonoses reported in England and Wales between July and September 2022 (third quarter) and includes additional information on the quarterly trends for hepatitis E, leptospirosis, Lyme disease and toxoplasmosis. The impacts of the public health measures implemented in England and Wales due to the coronavirus (COVID-19) pandemic during the third quarter of 2021 should be considered when making comparisons with this time period. It is likely that reported numbers are an underestimate, biasing towards severe infections as individuals with severe or symptomatic disease are more likely to be tested.

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 Q3 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	Total 2022
Anthrax (Bacillus anthracis)	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	8
Hepatitis E	317	233	321	244	1,115	364	367	286	315	1,332	330	409	321	1,060
Leptospirosis (Leptospira spp.)	15	7	22	7	51	8	5	16	26	55	4	11	25	40
Lyme disease (Borrelia burgdorferi)
All cases	173	188	625	276	1,262	119	225	573	239	1,156	142	232	548	922
Acute infections	53	132	468	155	808	59	146	477	180	862	92	186	421	699
Pasteurellosis (Pasteurella spp.)	175	153	214	190	732	196	258	243	188	885	211	242	269	722
Q-fever (Coxiella burnetii)
All cases	7	5	3	2	17	3	2	5	2	12	6	4	9	19
Acute infections	6	3	3	1	13	2	2	5	2	11	4	2	6	12
Toxoplasmosis (Toxoplasma gondii)†	53	26	44	63	186	48	52	40	52	192	55	39	57	151

*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 datasets 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 and identification of cases in England and Wales were identified and, as a result case numbers from 2018 have been updated. No public health implications are currently anticipated as a result of this review.

There were 321 laboratory reported cases of HEV infection in the third quarter of 2022 compared to 286 cases in the same quarter of 2021. Of those, 188 (59%) were male (aged 16 to 86 years, median=59.5) and 132 (41%) were female (aged 11 to 88, median=59; Table 2). There was one case where information on sex was not available. The persisting observation of the predominance of older men remains unexplained.

Table 2. Laboratory confirmed cases of hepatitis E by age group and sex, Q3 2022

Age group	Male	Female	Unknown	Total
<15	0	1	0	1
15-24	10	10	0	20
25-44	33	23	0	56
45-64	64	44	0	108
>64	81	54	1	136
Total	188	132	1	321

Figure 1 shows the number of HEV infections by quarter between 2018 and 2022. The data shows a decline in cases in 2020 (n=1,115) followed by an increase in 2021 (n=1,332).

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 rRNA PCR result only. An 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.

There were 25 confirmed cases of leptospirosis reported in the third quarter of 2022, compared to 16 cases reported in the same quarter of 2021. There were 36 probable cases reported in the third quarter of 2022, compared to 15 in the same quarter of 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 Q3 2022

In the third quarter of 2022, 20 confirmed cases (20 out of 25, 80%) were male (aged 17 to 75 years) and 5 cases (5 out of 25, 20%) were female (aged 48 to 51). Cases were reported in the South East (8), London (5), the East of England (4), the South West (3), Yorkshire and Humber (2), the North West (1), the West Midlands (1) and the East Midlands (1). No cases were reported in Wales.

Of the confirmed cases, 16 (64%) reported recent travel abroad. Of these, 6 cases had visited southeast Asia, 6 cases had visited central America, one case had visited South America, 2 cases had visited southern Europe and one case had visited western Europe.

Of the 25 confirmed cases, 9 reported potential exposures (some cases reported more than one exposure):

• 8 cases had an exposure linked to a water source; of these, 7 cases reported freshwater swimming, rafting or fishing, and one case reported an occupational exposure to sewage water
• 2 cases had an exposure linked to animals; of these, both cases 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 third quarter of 2022 (n=548) was slightly lower compared to the same time period in 2021 (n=573). The total number of acute cases was lower in the third quarter of 2022 (n=421) compared to the same time period in 2021 (n=477).

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 Q3 2022

Of the total cases, 421 (77%) were acute (including 29 with neurological Lyme disease), and 127 (23%) were longstanding. Of the acute cases, 218 were male (aged 1 to 87, median 49) and 202 were female (aged 2 to 84, median 53). Age was unknown for one case, as was sex for one case. Table 3 shows the age group and sex distribution.

Table 3. Laboratory confirmed acute cases of Lyme disease by age group and sex, Q3 2022

Age group	Male	Female	Unknown	Total
0 to 14	22	14	0	36
15 to 24	10	9	0	19
25 to 34	32	18	0	50
35 to 44	38	34	0	72
45 to 54	38	46	0	84
55 to 64	44	31	1	76
65 to 74	22	35	0	57
Over 75	11	15	0	26
Unknown	1	0	0	1
Total	218	202	1	421

The regions that reported the most acute cases in the third quarter of 2022 were the South East (n=131), the South West (n=105), and London (n=68) (Table 4). Only 7 of the acute cases reported foreign travel. Of these, 3 travelled to eastern Europe, one to southern Europe, one to western Europe and one to northern Europe. One case did not report a travel destination. 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.

Table 4. Laboratory confirmed acute cases of Lyme disease by region, Q1 2021 to Q3 2022

UKHSA Centre	Q1 2021	Q2 2021	Q3 2021	Q4 2021	Total 2021	Q1 2022	Q2 2022	Q3 2022	Total 2022
East Midlands	2	2	5	1	10	4	1	1	6
East of England	7	11	24	14	56	4	12	23	39
London	21	27	83	45	176	22	31	68	121
North East	3	6	15	5	29	2	2	16	20
North West	4	24	52	19	99	12	19	28	59
South East	11	30	150	36	227	18	56	131	205
South West	6	31	115	36	188	16	53	105	174
West Midlands	3	3	7	6	19	6	0	22	28
Yorkshire and Humber	1	8	20	11	40	5	8	21	34
Wales	1	4	6	7	18	3	4	6	13
Total	59	146	477	180	862	92	186	421	699

Toxoplasmosis

Data for toxoplasmosis was obtained from the Toxoplasma Reference Unit (TRU, Public Health Wales Swansea).

There were a total of 57 confirmed toxoplasmosis cases reported in the third quarter of 2022. Of the total confirmed cases, 25 were male (aged 0 to 64, median 34) and 32 were female (aged 15 to 69, median 33). Table 5 shows the age group and sex distribution.

Table 5. Laboratory confirmed cases of toxoplasmosis by age group and sex, Q3 2022

Age group	Male	Female	Total
Under 15	1	0	1
15 to 24	4	4	8
25 to 44	14	24	38
45 to 64	6	3	9
Over 64	0	1	1
Total	25	32	57

Other zoonotic organisms (provisional data)

There were 47 reports of Capnocytophaga spp. infection in the third quarter of 2022. Of these, 34 were further speciated to C. canimorsus. Of those speciated, 22 were male and 12 were female. Cases were reported in all regions of England: the East Midlands (2), the East of England (2), London (1), the North East (4), the North West (4), the South East (5), the South West (3), the West Midlands (4), and Yorkshire and Humber (8). 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 5 reports of Mycobacterium marinum infection in the third quarter of 2022. Of these, 4 cases were reported in England and one in Wales. All cases were male.

There were 4 reports of Erysipelothrix rhusiopathiae infection in the third quarter of 2022. Of these, 3 were male and one was female; all were aged 45 years or older; 3 cases were reported in England and one case in Wales.

There were 4 reports of toxigenic Corynebacterium ulcerans infection in the third quarter of 2022, all of which were linked as part of a cluster. Of these, 2 were female and 2 were male, and cases were aged between 22 and 62 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 9 reports of Taeniasis in the third quarter of 2022, 2 of which were further speciated to T. saginata.

There were no reports of Toxocariasis in the third quarter of 2022.