Observations on H5N1 Bird Flu in 2015
No new human cases of human influenza A(H5N1) infections have been officially reported anywhere in the world since June 2015.[Note] This is a six-month period without reports of any new human cases. Since 2003 when the World Health Organization (WHO) first began reporting human cases of H5N1, the longest interval with no reported H5N1 cases was a span of three months. Three of these 3-month periods of quiescence have occurred, one each in 2004, 2008, and 2012. Is the lack of human H5N1 cases in the last six month a sign that H5N1 is no longer a pandemic threat? Can we breathe a sigh of relief? Paradoxically, the answer is no. The lack of cases in the past six months should not lull us into a sense of complacency. Between January and June in 2015 there were a total of 143 human cases of H5N1 reported. This is the largest number of reported cases of H5N1 in any one year since the WHO started tracking human infections in 2003. The chart below shows the number of H5N1 cases reported by y...