After months of mounting concern, Chinese health officials are breathing a sigh of relief: no new human cases of H7N9 have been reported in the country in more than a week. The milestone marks the first time since March, when the H7N9 outbreak first began, that human cases haven't continued to increase.
In the week beginning May 13, one previously infected patient succumbed to the virus, according to a statement issued on Monday by China's National Health and Family Planning Commission. That death brings the H7N9 fatality toll to 36, with 130 confirmed cases in total.
A promising signal
All of those cases appear to be linked back to human contact with infected birds, and officials say they've yet to detect strong evidence of human-to-human transmission. That's a promising signal, as health experts around the world have cautioned for months that, were H7N9 to mutate and become more easily transmissible, the virus would likely attain pandemic status. H7N9 also appears to be particularly deadly to humans, with World Health Organization (WHO) officials in April describing it as "one of the most lethal influenza viruses" that scientists have ever seen.
Warmer weather lulling the virus into temporary submission
The virus' current ebb is likely due to a combination of factors. For one, the seasonal nature of influenzas might be contributing to a decrease in infection rates, with warmer weather lulling the virus into temporary submission. The widespread closure of live-poultry markets, a suspected source of the virus, may also have helped.
While several provinces have already scaled back their emergency response protocols, global health officials are also warning that H7N9 likely isn't gone for good. "Influenza viruses constantly reinvent themselves," Margaret Chan, the head of the WHO, said on Monday. "No one can predict the future course of this outbreak."