CDC
This image of electronic microscopy shows two viruses of influenza A (H5N1), a type of virus from the flu influenza
The mystery around the sudden fall in cases of aviary flu in humans in the US is raising fears that government cuts have decreased the number of despisting tests and are affecting the monitoring of the disease. But there are other possible explanations.
The intriguing interruption in reported cases of Avian influenza in humans He led health authorities to renew appeals to surveillance, while experts discuss various theories about this sudden decrease.
Health authorities continue to recommend cautionat a time when issues about the potential factors that may have contributed to the It is abrupt from reported cases United States.
Among the possible reasons, the impact of government cuts in the detection of cases, the increased fear among workers immigrant agricultural (a demographic group disproportionately affected by the virus) to perform tests due to concerns about the application of immigration laws, and the possibility of a Natural decline in infections.
“Simply We don’t know why there are no more cases,”Says the epidemiologist Jennifer NuzzoDirector of the Brown University Pandemic Center, quoted by The Independent. “I think we should assume that there are infections to occur in agricultural workers who They are simply not being detected“.
A H5N1 Avian flu It has been broadly propagated among wild birds, capoeira birds and other animals worldwide for several years, and since the beginning of last year has become and cows in the US.
In the last 14 months, they have been reported Infections in 70 people In the United States – most workers in dairy and poultry explorations. The infection caused the death of a person, But most people infected had slight diseases.
California, which recorded 3/4 of the country’s infections in dairy cattle, was recently a critical point of infection, but the tests and cases between people decreased.
According to state records, until the end of 2024, at least 50 people were tested monthly, but Only three people were tested in March, One in April, and so far no person has been tested this month. The state has so far confirmed H5N1 infections in 38 people – none after January 14.
Why the cases have diminished
An employee of the quoted by The Independent notes that there is a Seasonality in Avian Flu: Cases reach the spike in the fall and early winter, possibly due to Wild bird migration patterns which are the main propagators of the virus.
This could mean that the US is experiencing a natural decline – Perhaps temporary – in cases of influenza in birds.
New infections continue to be detected in birds and cattle, but not as often as a few months ago. In addition, the sewage and wastewater virus monitoring system has recently shown limited viral activity.
“Since the Number of detections in animals decreasedaccording to data from the US Department of Agriculture, it is not surprising that the human cases also decreased“Said the CDC in a statement quoted by The Independent.
AND unlikely that a serious human infectionthat requires hospitalization, go unnoticed, says Michael Osterholmspecialist in infectious diseases at the University of Minnesota.
Gregory Grayspecialist in infectious diseases at the University of Texas, considers it likely At least some lighter infections are not being detected. The investigator fears that the effort to identify these infections is decreasing.
The CDC considers low the risk of H5N1 infection for the general publicalthough it is higher for people who work with cattle and poultry, or in contact with wild birds.
Earlier this month, an assessment of the governmental disease prevention agency concluded that there is a “moderate risk” can cause a future pandemic.
The CDC stresses however that other emerging stretches of avian flu were in the past labeled in a similar waywithout having originated a pandemic.
