The number of Cryptosporidium outbreaks involving an agency of the UK Department for Environment, Food and Rural Affairs (Defra) increased in 2023.

The Animal and Plant Health Agency (APHA) assisted with investigations into seven Cryptosporidium parvum outbreaks linked to an animal origin. Five were in England and two were in Wales. One outbreak of cryptosporidiosis was epidemiologically linked to a milk vending machine.

Of the other human outbreaks, three were epidemiologically linked to open farms, two to commercial farms, and one to a farm shop which had animals on site.

For the on-farm vending machine incident and one of the open farm investigations, APHA performed animal sampling, involving the collection of fresh feces samples. Testing detected Cryptosporidium parvum DNA which matched human cases in both outbreaks.

In 2022, APHA was involved in three outbreak investigations of cryptosporidiosis. All of them were from April to June and associated with open or petting farms.

Two E. coli outbreaks
APHA was also part of investigations into two Shiga toxin-producing E. coli (STEC) outbreaks in 2023 which were epidemiologically linked to separate animal-contact visitor attractions.

For both outbreaks APHA visited the site at the request of the Incident Management Team (IMT) and collected floor, field, or pen environmental and feces samples from a range of animal species.

The first was a STEC O157 incident which started in Q4 2022. There was a suspect E. coli O157 cultured by APHA in a pig sample. This sample underwent further investigation including WGS analysis which confirmed the pig isolate was an identical strain to human cases.

E. coli O157 and E. coli O26 were implicated in the second outbreak. There was a link established for the cases with an animal-contact visitor attraction premises. However, the outbreak strains were not found in animal samples. Environmental sampling at the premises detected E. coli O26 in a children’s play area.

Due to intermittent shedding and asymptomatic carriage, negative sampling results can only be interpreted as E. coli O157 and E. coli O26 not being detected on the day of sampling. They do not confirm absence on the premises, said APHA.

The most common deficiencies at animal contact visitor attractions include: suboptimal handwashing facilities; poor supervision of animal contact; contamination of walkways with soiled animal bedding or feces; and unclear signage of animal contact versus non-contact areas.

In all of 2022, APHA was part of five E. coli investigations. The agency helped the UK Health Security Agency (UKHSA) investigate E. coli O103, O157, O26, and two O145 outbreaks.