Laboratory reports of pathogens including Campylobacter, Salmonella and Shiga toxin producing E. coli (STEC) O157 have all increased compared to last year in England and Wales.

Data is based on common gastrointestinal infections in England and Wales reported to Public Health England (PHE) until the end of October.

Campylobacter spp. rose from 47,675 infections from January 2017 to the end of October 2017 to 51,497 in the same period this year.

Salmonella spp. was up from 7,319 cases last year to 7,631 infections and STEC O157 increased from 530 to 578 in the same period. The most common Salmonella serotypes include Salmonella enteritidis and Salmonella typhimurium.

Cryptosporidium spp., Guardia spp., Shigella spp. and norovirus infections also went up with rotavirus the only one to decrease based on the gastrointestinal infections reported.

Lab report figures are from PHE’s Second Generation Surveillance System (SGSS) and STEC O157 results are from PHE’s National Enhanced Surveillance System for STEC.

PHE urged caution when comparing data from one year to the next.

“Numbers of infections vary from year to year, this may be due to changes in laboratory methods, outbreak activity, pathogen seasonality or as the result of food safety or public health interventions. It’s important that the figures are not viewed in isolation – trends should only be measured over years using appropriate methods that account for the inter- and intra-year variability mentioned above,” a spokeswoman told Food Safety News.

The Notifications of Infectious Diseases (NOIDs) weekly report shows this year, through Dec. 2, food poisoning cases in England and Wales were at 10,352 which is lower than the 10,911 figure last year and 12,359 in the same period in 2016.

“Food poisoning is included in the list of notifiable diseases and is based on clinical suspicion of the cause, rather than laboratory confirmed testing. Changes over time may be due to better access to laboratory testing, changes in clinical perception of the problem or of the system of notification, secular trends or as the result of food safety or public health communications,” said the PHE spokeswoman.

PHE uses laboratory confirmed cases for routine surveillance and monitoring trends.

“Notifications of cases and outbreaks of suspected food poisoning is usually on the basis of clinical suspicion and is known to be variable. The first and second infectious intestinal disease in the community (IID) studies examined this aspect in detail and developed ways of interpreting the reporting ratios between the number of community cases and those reported to national surveillance,” said the spokeswoman.

“There is no generic criteria for when we would proactively communicate about an outbreak. However, the key factors we consider are: the public health interventions available, whether there is action people can take and whether our action will protect the public.”

Whole Genome Sequencing (WGS) in real time monitors Salmonella, Shigella, STEC, Campylobacter and Listeria monocytogenes.

PHE surveillance data is used to interpret trends by reviewing microbiological data each week to identify changes that may require further investigation as outbreaks, include relevant data in the UK Zoonoses Report and report surveillance statistics to the European Food Safety Authority (EFSA) and European Centre for Disease Prevention and Control (ECDC) for the annual report on zoonoses, zoonotic agents and foodborne outbreaks.

Bi-annual reports are also provided to the Epidemiology of Foodborne Infections Group (EFIG). EFIG is a UK group with membership from PHE, the Food Standards Agency (FSA) and Animal and Plant Health Agency (APHA). The FSA provides a summary of data reported at EFIG to the Advisory Committee on the Microbiological Safety of Food (ACMSF).

In an update to a Salmonella Typhimurium outbreak linked to lamb and mutton, PHE said, as of Nov. 19, there have been 190 cases of the outbreak strain reported since June. This is up from the 165 cases reported in October. An increase in cases with this strain type was identified in July 2017 and more than 300 infections and one death has been reported since.

The agency also provided an update on an outbreak of Salmonella Enteritidis linked to a brand of liquid egg white from France with raw material from Spain, Germany and the Netherlands. Nine cases were identified as being part of the outbreak, up from the seven infections reported in October. The last case was recorded at the beginning of Sept. 2018.

(To sign up for a free subscription to Food Safety News, click here.)