Chikungunya outbreak spreads on Reunion island

News brief

Chikungunya mosquito — Frank Hadley Collins / CDC

More than 35,000 cases of the mosquito-borne disease chikungunya have been reported on the French Indian Ocean island of Reunion, according to media reports.

Radio France Internationale (RFI) reports that French president Emmanuel Macron visited the island yesterday to discuss the outbreak with local officials. Calling the outbreak a "huge public health problem," Macron urged people on the island to take protective measures, and said that French military personnel were being mobilized to help with vaccination efforts.

Reunion recently received 40,000 doses of the Ixchiq vaccine, which has been approved by US and European regulators for adults aged 18 and older.

Sharp rise in cases

The outbreak on Reunion began in August 2024, but the number of cases has increased sharply in recent weeks, according to a recent report from the European Centre for Disease Prevention and Control. Regional health authorities believe as many as 100,00 could be infected. Seven people have died, including an infant who was less than 1 month old, RFI reports.

Spread by Aedes aegypti and Aedes albopictus mosquitoes, chikungunya causes fever, severe joint pain, rash, and fatigue. While most cases are self-limited, the disease can affect neurologic and cardiovascular systems, leading to poor outcomes, including death. A 2005-2006 outbreak on Reunion killed 250 people.

In addition to vaccination, island residents are being encouraged to use mosquito nets and remove objects around homes that contain water and serve as potential mosquito propagation sites.

Georgia reports second CWD-infected deer in same area as the first

News brief

Mary Van Beusekom, MS

White-tailed buck in woods — Daniel Arndt / Flickr cc

A second deer in Georgia with chronic wasting disease (CWD) has been found in Berrien County, roughly 400 yards from where the state's first case of the fatal neurologic disease was discovered in January, the Georgia Department of Natural Resources (DNR) Wildlife Resources Division announced yesterday.

The newly identified deer, a 4.5-year-old white-tailed buck, was harvested by a landowner helping with ongoing sampling as part of the DNR's CWD response plan. The finding of the state's first case in neighboring Lanier County led to the establishment of a CWD-management zone in both counties.

Our staff continues to work in collaboration with landowners and hunters in the CWD Management Area to sample for the disease.

Walter Rabon, MPA

Additional deer near the CWD detections will be harvested in an effort to contain the disease.

"Our staff continues to work in collaboration with landowners and hunters in the CWD Management Area to sample for the disease," Georgia DNR Commissioner Walter Rabon, MPA, said in a news release. "These collaborative efforts will help us manage CWD and ensure Georgia maintains healthy deer herds."

Not known to infect people

CWD is caused by infectious misfolded proteins called prions, which spread among cervids such as deer, elk, and moose through direct contact and environmental contamination.

The disease isn't known to infect people, but experts fear it could cause illness similar to the prion disease bovine spongiform encephalopathy ("mad cow" disease). The US Centers for Disease Control and Prevention warns against eating meat from infected animals.

Mouse study suggests prolonged post-mortem SARS-CoV-2 infectivity

News brief

Mary Van Beusekom, MS

Lab mouse in gloved hand — *anyaivanova / iStock*

A study on the post-mortem infectivity of influenza A virus (IAV), respiratory syncytial virus (RSV), and SARS-CoV-2, the virus that causes COVID-19, in euthanized transgenic mice tissues suggests persistent contagiousness ranging from a few hours for flu to a week or more for COVID.

For the study, published this week in the Journal of Infection, Chinese researchers collected tissue samples from virus-infected mouse cadavers at three temperatures (4℃ [39.2ºF], room temperature [20º to 22℃; 68º to 71.6ºF], and 37℃ [98.6ºF]) for a predetermined period to estimate the post-mortem stability and transmission potential of the viruses.

Infectivity was examined in K18-hACE2 and C57BL/6J transgenic mice, which are genetically modified so their cells facilitate SARS-CoV entry, similar to human cells.

These findings underscore the need for enhanced post-mortem biosafety protocols to mitigate occupational exposure risks in forensic and clinical settings.

The team analyzed viral kinetics and distribution. The researchers also compared cadaveric tissues with in vitro tissues to estimate the survival of IAV and RSV under the same conditions.

"A precise understanding of post-mortem viral persistence is critical for mitigating infection risks among healthcare professionals, forensic pathologists, and mortuary personnel handling deceased individuals, particularly in cases involving highly transmissible pathogens such as SARS-CoV-2," they noted.

Potential implications for handling cadavers

SARS-CoV-2 demonstrated post-mortem infectivity for up to 5 days at room temperature and at 37℃ and more than 7 days at 4℃, with the highest risk of transmission in the first 72 hours at room temperature and first 24 hours at 37℃. In contrast, RSV remained viable for 1 to 2 days, and IAV persisted for just a few hours. Viral decay rates depended on temperature and varied by tissue type and pre-mortem viral load, showing distinct post-mortem survival kinetics.

"This study presents the first comprehensive analysis of viral persistence in cadavers," the study authors wrote. "These findings underscore the need for enhanced post-mortem biosafety protocols to mitigate occupational exposure risks in forensic and clinical settings."

"By elucidating viral decay dynamics across environmental conditions, this research establishes a critical foundation for infection control strategies, informing biosafety policies for emerging respiratory pathogens," they concluded.