Thursday, July 25, 2013

H5N1 Poultry Vaccination in Egypt Will Not Stop the Spread of the Virus

Influenza A(H5N1) can still be considered a novel infectious disease even though it has been infecting people since 1999.  As of July, 2013,  more than 600 people around the world have been infected with H5N1.[1] Of these, more than half have died. If you are infected, it is a deadly disease.
A review of H5N1 case descriptions reported by the World Health Organization (WHO) almost always identifies the source of the infection as sick or dying poultry. In countries where H5N1 is endemic, vaccination of poultry is a strategy used to control the spread of H5N1.
In an article by El Masry and colleagues in Tropical Animal Health and Production published earlier this month, the authors  discusses the effectiveness of vaccinating poultry in Egypt against H5N1. [2]

The key observation by these researchers: 

Despite the enormous effort put into rural house-hold poultry AI vaccination by the Egyptian government, village CAFI [a measure of flock immunity] is unlikely to be maintained at the levels required to significantly reduce the virus load and restrict transmission. Reducing HPAI H5N1 viral load and transmission requires maintenance of high levels of flock immunity. This will require massive additional financial means, and it is questionable if it can be logistically feasible.
The authors conclude that current H5N1 poultry vaccination strategies in Egypt will be unsuccessful in controlling the virus load and transmission within local poultry flocks.  We can expected more human cases of H5N1 in Egypt from sick and dying poultry.

[2] Modelling influenza A H5N1 vaccination strategy scenarios in the household poultry sector in Egypt.

Tuesday, July 23, 2013

Researchers find MERS-CoV related Coronavirus in Bats in Africa (map)

In an upcoming article in Emerging Infectious Diseases, researchers are reporting that a coronavirus sample from a bat in South Africa is currently the closest match to the  MERS-CoV that has infected more than 90 people around the world since 2012. [1] The sample, PML/2011, was collected from a female Neoromicia zuluensis bat in 2011.  The genus Neoromicia is included in the Vespertilionidae bat family.  Because this sample was collected before the human outbreak, the authors suggest that MERS-CoV may have originated in bat populations in eastern or southern Africa and spread to the Arabian Peninsula. This new development means that surveillance for human MERS-CoV cases need to be expanded beyond the Arabian Peninsula into Africa as well.  Additional coronavirus research on Vespertilionidae bats in Kenya and surrounding countries is urgently needed.

 [1] Ithete NL, Stoffberg S, Corman VM, Cottontail VM, Richards LR, Schoeman MC, et al. Close relative of human Middle East respiratory syndrome coronavirus in bat, South Africa [letter]. Emerg Infect Dis [Internet]. 2013 Oct.

Saturday, July 20, 2013

A New A(H7N9) Case in China (map)

Today, Xinhua reported a new influenza A(H7N9) case in China, a 61-year old woman who become symptomatic on July 10 in Hebei province. [1] This is a significant case for several reasons. There is a 50 day gap between the onset date for the last reported case, the young boy in Beijing, and this woman. Hebei now becomes the 11th province in China to report A(H7N9) cases. H7N9 has not gone away and is still spreading geographically.