On Wednesday, the World Health Organization (WHO) declared that there had been a bird flu death in Mexico by a 59-year-old State of Mexico resident making it the first ever incident of human infection with the H5N2 variant. The deceased passed on April 24th after developing fever, diarrhea, shortness of breath and nausea. A statement from Mexican health ministry indicated that despite not having any history of contact with birds or other animals, this person had various medical problems including type 2 diabetes and chronic kidney disease.
According to WHO, the patient was admitted at one hospital in Mexico City after being bedridden for three weeks prior to onset of acute symptoms; she died on the same day. The case is significant as it marks both the first lab-confirmed human infection caused by an influenza A(H5N2) virus worldwide and also the first identification of an avian H5 virus in Mexico.
“The source of exposure to the virus in this instance is currently unknown,” said WHO. However this does not mean that no cases occurred among domestic poultry in Mexico since “A(H5N2) viruses have been reported in poultry in Mexico,” according to WHO. The laboratory tests were conducted by Mexican health authorities who informed UN health body about confirmation of situation on May 23rd.
Michoacan state witnessed H5N2 cases in backyard poultry farm whereas State of Mexicoreported other cases. However, there has been little success linking these events with infections affecting people. The general population’s risk is estimated as “low” according to the WHO.
Furthermore, all identified contacts samples tested negative for contagion risk alerting Mexican health ministry to calm down fears because there is no danger for ordinary people. Authorities are consequently watching closely over farms neighboring victim’s homeand installed around-the-clock wildlife monitoring system to detect possible similar incidents nearby.
In relation to such a situation Andrew Pekosz, an influenza expert at Johns Hopkins University, said “How this individual got infected is a big question mark that at least this initial report doesn’t really address thoroughly.
The WHO and Mexican authorities are still trying to find out where the infection came from. Some mammals such as bears, raccoons, seals and cattle have been exposed to Bird flu which is usually caused by contact with these birds’ faeces. Scientists anticipate virus changes that may indicate adaptation for human transmission.
In another instance of bird flu in US, dairy cow herds experienced the disease outbreaks but there were few reported cases involving human beings. However, none of these cases involved human-to-human transmission.
It is worth mentioning that no transmission was observed; however, Australia announced its first case of A(H5N1) infection in May along with more poultry H7 bird flu farms in Victoria state.
According to Pekosz since 1997 H5 viruses have been tending to infect mammals more often than other avian influenza viruses. “So it continues tol ring that warning bell that we should be very vigilant about monitoring for these infections because every spillover is an opportunity for that virus to try to accumulate those mutations that make it better infect humans,” Pekosz added.
