A fourth human case of avian influenza (HPAI) A (H5N1), associated with the ongoing multi-state outbreak amongst dairy cows in the US, has been detected – this time in a Colorado dairy farm worker.

According to the Johns Hopkins Center for Health Security, health experts are beginning to press for more widespread testing of humans, animals, wastewater, as a lack of response so far on the part of the US government and dairy farmers themselves points to the virus becoming “endemic in poultry, cows and other animals, with an ever-present risk of the virus evolving to transmit more easily to and between humans”.

The US Department of Agriculture has in the last 30 days reported detections of H5N1 avian influenza (2.3.4.4b clade) in 49 dairy cattle herds in 6 states, bringing the total number of affected herds to 146 in 12 states since the outbreak was first reported in March.

The US Department of Health and Human Services (HHS) last week awarded US$176 million to Moderna to develop an mRNA-based pandemic influenza vaccine. The government is also working with other pharmaceutical companies, including CSL Seqirus and Sanofi, to develop and stockpile other bird flu vaccines.

It is a little over four weeks since the last human case was reported.

---