Additional Bird Flu Infection Is Reported in Missouri

In Missouri, a resident who lived with a person hospitalized for bird flu has also contracted the virus. Health care workers caring for the patient showed no signs of infection. This development alleviates concerns that the H5N1 virus has gained the ability to easily spread among people. However, bird flu cases continue to rise in the US, with California confirming 15 cases and Washington State reporting two infected poultry workers. Currently, there are 31 confirmed cases in the country, yet experts believe this figure may be an undercount. Further investigations may lead to more cases being identified.

Despite new cases, the risk to the general public remains low. In Missouri, household members had no exposure to infected animals or consumption of raw milk products. Some experts are questioning how these individuals contracted the virus, debating whether it was through wildlife or a distributed food product. Federal officials have indicated a shared source of infection rather than person-to-person transmission, but experts warn this does not entirely rule out human transmission.

A Missouri patient initially tested positive for H5N1 during routine surveillance. Around this patient, health care workers developed symptoms but tested negative for flu, and tests on antibodies also suggested no infection. The household contact did not meet the criteria for a 'case' but possessed antibodies, suggesting likely exposure. Both Missouri cases showed low virus levels, with gastrointestinal symptoms instead of typical respiratory symptoms of the flu.

Recent virus analyses from California reveal mutations but none appear to aid human transmission. Factory workers' mild symptoms led to no hospitalizations, despite direct cow exposure. This raises concerns due to California's significant dairy industry, with infections reported on numerous farms. As flu season nears, experts warn the virus might evolve, gaining human transmission capabilities by swapping genes with seasonal flu strains.

Ongoing vigilant surveillance is essential to monitor and understand infections among farmworkers who might not show symptoms. Tracking antibody presence might shed light on undocumented exposures and the infection's progression.