New data show double the risk of Guillain-Barre syndrome after RSV in seniors

News brief

antibodies attacking a nerve — *Dr_Microbe / iStock*

A large study of US adults 65 and older enrolled in Medicare finds that the risk of Guillain-Barre syndrome (GBS)—a rare autoimmune disorder in which the body's immune system attacks its own nerves—doubles in adults 65 and older infected with respiratory syncytial virus (RSV).

The study, published today in Clinical Infectious Diseases, involved 452,471 patients with RSV infection requiring medical care from 2011 through 2024. The study authors documented fewer than 11 GBS cases during the risk period, which was up to 42 days after RSV disease onset. (Medicare data policies prohibit case counts under that number from being displayed in data searches, but they can be used for data calculations.)

The team noted 34 GBS cases in the control period, which was 22 to 180 days before (19 cases) or 43 to 180 days (15 cases) after RSV disease onset. Among patients with GBS, 55.4% were women, and 60.7% were age 75 or older.

"We leveraged this large nationwide database to conduct the first study to investigate GBS risk following medically attended RSV disease," the authors noted.

As high as fourfold risk in those 75 and older

The adjusted incident rate ratio (IRR) for GBS post-RSV disease was 2.11, reflecting a slightly more than double risk. The risk was consistent across sensitivity analyses and after excluding coinfections. The IRR was 3.98 in those 75 years and older, but the confidence interval for that age-group was much wider, indicating less reliable findings.

"These findings," the authors conclude, "are consistent with the known ability of other respiratory viruses, such as influenza and SARS-CoV-2, to rarely provoke GBS events.

These findings are consistent with the known ability of other respiratory viruses, such as influenza and SARS-CoV-2, to rarely provoke GBS events.

"GBS following respiratory infection is thought to result from an autoimmune response triggered by molecular mimicry, where the immune system mistakenly attacks peripheral nerves."

They add, "The observed 2–2.5 fold increase in incident GBS risk following medically attended RSV disease was lower than that observed with some other infections." They said a potential reason for this finding is that, for various reasons, the specific onset dates of RSV infections were uncertain.

Allergan joins Michigan's CWD-positive county list with detection in young doe

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Mary Van Beusekom, MS

White-tailed doe — Katja Schulz / Flickr cc

An emaciated 1.5-year-old doe that Allergan County, Michigan, private landowners reported in late summer has tested positive for chronic wasting disease (CWD), pushing the state's CWD-positive county tally to 17.

Yesterday, the Michigan Department of Natural Resources (DNR) said the Wisconsin Veterinary Diagnostic Laboratory confirmed the test result. The sample has also been sent to the US Department of Agriculture's National Veterinary Services Laboratory in Ames, Iowa, for confirmation of the fatal neurologic disease.

Public's reporting of sick deer key

The deer, which was in poor physical condition with no body fat, was euthanized in late September, the DNR said.

"The care that's demonstrated when people take the time to share their observations is a critical contribution to our disease-testing efforts," Brent Rudolph, PhD, DNR deer, elk and moose management specialist, said in the news release. "Public reporting of deer that appear unhealthy is very important for identifying CWD that may exist at low levels in previously undetected areas."

The care that's demonstrated when people take the time to share their observations is a critical contribution to our disease-testing efforts.

Brent Rudolph, PhD

The detection occurred in Leighton Township, in northwestern Allegan County, adjacent to CWD-positive Kent County. Allegan County was under focused CWD surveillance in 2021, when roughly 500 deer were tested, with negative results.

CWD has also been found in Clinton, Dickinson, Eaton, Genesee, Gratiot, Hillsdale, Ingham, Ionia, Isabella, Jackson, Kent, Mecosta, Midland, Montcalm, Ogemaw, and Washtenaw counties.

Since the disease was first detected in Michigan in 2015, "more than 144,000 wild deer have been tested through DNR surveillance efforts that started in 2002, with 265 CWD-positive deer identified," the release said, reflecting a 0.2% detection rate. "In addition, since direct hunter submissions of deer to the MSU [Michigan State University] lab began in 2020, more than 3,400 submitted samples have yielded 61 additional confirmed positives."

CWD, which affects cervids such as deer, elk, and moose, is caused by infectious misfolded proteins called prions. It spreads from cervid to cervid and through environmental contamination. The disease is not known to infect people, but authorities advise against eating meat from infected cervids and urge caution when field-dressing or processing their carcasses.

Quick takes: Polio in German wastewater, cholera in Africa, antimicrobial resistance in England

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Chris Dall, MA

The Global Polio Eradication Initiative (GPEI) said in its weekly update that a wild poliovirus type 1 (WPV1)-positive sample was isolated from wastewater in Hamburg, Germany, this week. The sample has been linked to a WPV1 strain last identified in Kandahar, Afghanistan, in August. No associated cases of paralysis have been detected in Germany, and the European Centre for Disease Prevention and Control said the risk to Europeans is low given the high rates of vaccination in the region. GPEI said it's working with German health officials to support ongoing investigations. GPEI also reported new cases of circulating vaccine-derived poliovirus type 2 (cVDPV2) in Chad and Nigeria. The two cases reported in Chad bring the country's cVDPV2 total for 2025 to 20 cases. Nigeria added five new cases, bringing its total for the year to 50.
Officials with the Africa Centres for Disease Control and Prevention (Africa CDC) said yesterday at their weekly briefing that the current cholera outbreak is the continent's worst in 25 years. Through early November, 303,953 cases of the highly contagious bacterial infection have been reported in Africa, with 7,013 deaths—a 30% increase in cases compared with last year and nearly three times the number reported in 2022. The Democratic Republic of the Congo, Sudan, and South Sudan have been the hardest-hit countries, accounting for 70% of cases, but Angola and Burundi have also reported major increases in recent weeks.
The number of bloodstream infections caused by drug-resistant bacteria rose by 9.3% in England from 2023 to 2024, the UK Health Security Agency (UKHSA) reported this week in its annual surveillance report on antimicrobial use and resistance. The increase was primarily driven by rising incidence of Escherichia coli bloodstream infections, which accounted for 70.5% of all drug-resistant bloodstream infections. The UKHSA report also noted that the rate of drug-resistant bloodstream infections was 47.2% higher in areas with the highest levels of social deprivation compared with the lowest levels. Total antibiotic consumption in 2024 was 2% lower than the 2019 pre-pandemic level.