Tuesday, 23 April 2013

WHO panel wraps up visit.

"The primary focus of the investigation is to determine whether this is in fact spreading at a lower level among humans. But there is no evidence for that so far except in these very rare instances," said the WHO panel.

So presumably there are no signs or symptoms of disease spreading within these clusters. It is remains unclear from this visit whether the spread of the virus can be ruled out among these cases. Realistically (and pedantically), its very likely that the virus entered the airways and eyes of close contacts during sneezing, coughing etc. It just didn't cause obvious signs or self-reported symptoms of disease as a result of that challenge. 

Presumably the virus lacks something when replicating in humans that it has when coming from the suspected animal source, which allows it to cause disease in humans. Or that other theory - it can infect humans and cause mild and subclinical disease. 

The quickest way to resolve this question, a very important one for short-term and future containment of the virus, is to use PCR-based lab testing of contacts; look for virus in eye and upper airway swabs and, for a little bit, forget about being led by symptomatic illness alone.