The Michigan Department of Health and Human Services (MDHHS) reported on 23 May 2024 the second case of human infection with the highly pathogenic avian influenza virus (H5N1) in the United States. It was identified in a worker at a dairy farm in this city in the eastern US, who had been regularly exposed to livestock infected with the pathogen, according to Efe.
The man reported his symptoms and underwent a nasal test that returned a negative result for the disease at MDHHS laboratories; however, an ocular sample sent to the Centers for Disease Control and Prevention (CDC) ultimately confirmed the infection. He has since recovered, as confirmed by MDHHS.
It was on 1 April when Texas reported the first human infection case with the highly pathogenic avian influenza virus (H5N1) following confirmation by the CDC. This is a landmark event as it is the first time this virus has been found in a cow, and the second human case reported in the country, where the disease had only previously been detected in 2022 in a poultry worker in Colorado.
In late March, it was reported that dairy cows in Texas and Kansas were infected with avian influenza, and days later, officials from the US Department of Agriculture (USDA) reported infections in a dairy herd in Michigan that had recently received animals from Texas. Infections among livestock in New Mexico and Illinois have also been investigated.
Throughout this year there have been other isolated cases of human transmission, the most recent in mid-May in Australia, involving a minor who arrived in March on a flight from India showing symptoms of the disease. The child experienced a “severe infection” but has since recovered, and no further transmission has been detected.
So far, there are no signs that this virus has evolved in a way that would allow it to spread rapidly among humans, according to federal officials. Nevertheless, the World Health Organization (WHO) warned in early May that the infections occurring in the US are concerning and require “much stronger surveillance of animals at a global level.”
This was stated by the director of the organisation’s Epidemic and Pandemic Prevention and Preparedness (EPP) department, Maria Van Kerkhove, who also highlighted that “although current attention is focused mainly on the US, we are witnessing a global epizootic (i.e., a disease affecting one or more animal species due to a general and transient cause, equivalent to an epidemic in humans), with a concerning situation in which avian influenza infections are being seen in new species such as marine and terrestrial mammals, in addition to wild or domestic birds.” This disease is responsible for the deaths of millions of birds worldwide, but the US cases represent the first time it has occurred in livestock.
However, health authorities do not consider these developments to change the human health risk from H5N1 avian influenza for the general public, which continues to be assessed as low, primarily because there have been no changes that would make these viruses resistant to the antiviral influenza medications approved and recommended by the FDA.
Experts also note that this virus is closely related to two existing candidate vaccine viruses already available to manufacturers, which could be used to produce compatible vaccines if necessary.
For further information:
-. Avian Influenza on NeXusAvicultura.com