Yesterday, the US Centers for Disease Control and Prevention (CDC) closed its investigation into the multistate Listeria outbreak tied to Boar's Head deli meat after 61 cases and 10 deaths were reported. 

The latest report on the 19-state outbreak noted two more cases.

Even when there are no ongoing Listeria outbreaks, people who are pregnant, aged 65 or older, or have a weakened immune system should avoid deli meat.

"This outbreak is over," the CDC said. “Even when there are no ongoing Listeria outbreaks, people who are pregnant, aged 65 or older, or have a weakened immune system should avoid deli meat or reheat it to an internal temperature of 165°F or until steaming hot to kill any germs.”

60 of 61 patients hospitalized 

Of the 61 patients in this outbreak, 60 were hospitalized. One pregnant woman was sickened during the outbreak, and her pregnancy continued after she recovered, the CDC said. The average age of case-patients was 68 years, with 49% female and 51% male. Seventy-eight percent were White, 16% were Black, and 3% were Asian.

In investigative interviews, most case-patients reported eating deli meat before becoming ill. 

"Of the 48 people able to be interviewed, 45 (94%) reported eating deli meats," the CDC said. "Forty-three of the 45 (96%) reported eating meats sliced at a deli. Of the 44 people who answered if they ate liverwurst, 27 (61%) reported [eating] deli-sliced liverwurst before getting sick and 20 specifically reported Boar's Head brand."

In July, Boar’s Head voluntarily recalled all deli products made at their Jarratt, Virginia, facility, including packaged deli products and ready-to-eat liverwurst products. All products are now past shelf-life. 

Three countries have new polio cases this week, according to the latest weekly update from the Global Polio Eradication Initiative (GPEI). 

Pakistan has one more wild poliovirus type 1 case, and Chad and Nigeria have more vaccine-derived cases. 

In Pakistan, the case-patient experienced paralysis in late September in Balochistan. The country now has reported 49 polio cases this year.

Five circulating vaccine-derived polio type 2 (cVDPV2) cases were reported this week in Chad,  from N’Djamena and Tandjile, with onsets of paralysis in August and September. The cases bring Chad’s 2024 total to 20. 

Nigeria reported a single case of cVDPV2 in September and now has 81 cases for the year.

Detections in Poland, Spain were related

Of note, the GPEI also said an environmental sample in Poland shows cVDPV2, but there is no evidence of local circulation. The sample was obtained in October in Warsaw.

Initial analysis suggests it is linked to the cVDPV2 emergence originating in Zamfara, northern Nigeria, which has this year been detected internationally, including recently also in Barcelona, Spain.

"Initial analysis suggests it is linked to the cVDPV2 emergence originating in Zamfara, northern Nigeria, which has this year been detected internationally, including recently also in Barcelona, Spain," the GPEI said. "Poland has high vaccination coverage, estimated at above 90% with three doses of IPV, both national and in the affected subnational area."

Analysis of surveillance data from 17 European countries found an increase in Escherichia coli isolates carrying carbapenem-resistance genes, researchers reported yesterday in Eurosurveillance.

The analysis focused on E coli sequence type (ST)131, a high-risk lineage that has emerged as a frequent source of severe, multidrug-resistant E coli infections worldwide, primarily urinary tract infections (UTIs). E coli ST131 has been associated with the worldwide spread of the extended-spectrum beta-lactamase gene bla_CTX-M-15, which confers resistance to multiple classes of antibiotics. Carbapenems are a primary option for treating infections caused by E coli ST131. 

Among the 594 clinical isolates submitted by national reference laboratories in 17 European Union/European Economic Area countries, molecular analysis detected 18 different carbapenemase genes, primarily bla_OXA-244 (230) and bla_OXA-48 (224), which together accounted for 76% of isolates. The isolates carrying bla_OXA-48 were detected in 14 countries, and those carrying bla_OXA-244 in 12.

While isolates carrying bla_OXA-48 appeared earlier than those carrying bla_OXA-244 (2012 vs 2017), their frequency of detection increased only moderately over time. In contrast, detection of isolates carrying bla_OXA-244 increased sharply from 2021 to 2023. Isolates carrying bla_OXA-244 formed multi-country clusters, while clusters of bla_OXA-48-carrying isolates were predominantly detected within one country (eg, France or Ireland).

Concerns about wider spread

The study authors said the age, sex, sample type, and travel history distribution of E coli isolates carrying bla_OXA-244 suggest a potential association with community-acquired urinary tract infections.

"The increasing detection of carbapenemase genes in E. coli ST131 documented in this study is of concern because E. coli can cause a variety of infections in healthcare and community settings, frequently urinary tract infections, but also including bloodstream infection," they wrote. "Further spread of E. coli carrying carbapenemase genes would mean that carbapenems could no longer be consistently effective for empiric treatment of severe E. coli infections."

British Columbia government officials yesterday announced the identification of another chronic wasting disease (CWD) case in the province, for a total of three detections since February 2024.

Measures are in place within this zone to continue to collect data to help mitigate the risk of disease spread.

The white-tailed deer in the Kootenay region, in the southeastern region of the province, was harvested in October within 2 kilometers (1.2 miles) of a CWD-positive white-tailed doe killed in a vehicle collision in Cranbrook in February 2024. The other case of the fatal neurodegenerative disease was detected in a hunter-harvested male mule deer in the same area that same month.

"All cases to date have been found within a chronic wasting disease management zone that includes 14 wildlife management units in the Kootenay region," the press release said. "Measures are in place within this zone to continue to collect data to help mitigate the risk of disease spread."

Cooking cannot neutralize prions

Caused by misfolded infectious proteins called prions, CWD affects cervids such as deer, elk, moose, and reindeer. Prions are extremely resilient and can persist in the environment for years. CWD can spread from animal to animal and through environmental contamination. 

The disease isn't known to infect humans, but officials recommend not eating meat from a sick animal (cooking temperatures cannot kill prions) and using precautions when handling the carcasses.