Reacción a "Reactions: bird flu cases detected in Spain in 2022 were not real infections"

I find this interesting, but not surprising. It had already been commented on many occasions that these two positive cases in the workers at the farm in Guadalajara were possibly false positives. In fact, this information appears in official documents from the Ministry of Health, which have been available on the web since 4 February. I have commented in several interviews that it was possible that it was a contamination of the nasal mucosa rather than an active infection. 

It seems to me very appropriate to change the protocol to avoid as much as possible these false positives due to environmental contamination: that samples are taken in a medical centre and not the farm premises and that a few days have passed since the last contact with the contaminated area. All this, of course, if we are talking about totally asymptomatic people, as happened in this case. If there were respiratory symptoms or general malaise, it would be advisable to do the analytical tests as soon as possible. 

It is very likely that environmental contamination is also the cause of the positive case in the United States (another infected poultry worker) and the United Kingdom (a man keeping poultry at home). The former reported mild fatigue and the latter no symptoms at all. This suspicion has been openly expressed by the CDC in the US case: "While it is possible the detection of H5 bird flu in this specimen is a result of surface contamination of the nasal membrane, that can't be determined at this point and the positive test result meets the criteria for an H5 case". 

I have not found information on the serological tests in these US and UK cases, but if the absence of specific antibodies to H5 were proven (as has happened with the two cases in Spain), it would confirm that these were false positives. 

As the article indicates, it is important to avoid this type of false positive because in the current situation of panzootic [pandemic affecting animals] in which we find ourselves and with increasingly frequent jumps to mammals, these cases in humans are very alarming and can have dire consequences for the poultry industry - for fear of the general public to consume poultry products, for example. Public health authorities must establish very well the protocols for taking samples from humans exposed to highly contaminated environments in order to minimise the risk of false positives, but at the same time intensify this surveillance, since in the current epidemiological situation it would be very serious if a human case of H5N1 were to slip under the radar.