Senegal: Media Reports Of Large Equine Influenza Epizootic

#14,010

Ten days ago the Ministry of Livestock and Animal Productions in Dakar, Senegal notified the OIE of the first occurrence in that country of Equine Influenza (serotype pending), which at that time had resulted in the deaths of 5 donkeys and/or horses. 

While equine influenza (H3N8 for the past 50+ years), isn't considered to be a zoonotic disease, it has jumped species (to dogs in 2004), and has been shown experimentally capable of infecting pigs (see J.Virol.: Experimental Infectivity Of H3N8 In Swine).

Making large epizootics, such as appears to be occurring in West Africa, worthy of out attention. First this (translated) report from APS (Agence de Presse Sénégalaise), then I'll return with more.

Equine flu: 3,473 cases confirmed at Fatick (official)

April 16, 2019 

Fatick, Apr. 16 (APS) - A total of 3,473 cases of equine influenza have been officially counted in the region of Fatick (center), said Monday, the head of the departmental department of livestock of Foundiougne, Alphonse Sène.

"Among these equine equine infected equine, there are 1782 donkeys and 1691 horses and we have recorded to date 15 dead horses and 247 dead donkeys," told reporters Mr. Sène, who is acting chief regional livestock service.

Equine influenza diagnosed in equines about three weeks ago is an acute and contagious respiratory disease. According to sampling, he said, the disease was detected in 37 households or areas of the Fatick region.

The veterinary officer invited the populations or owners of the dead equids to cremate the carcasses and bury the bones to prevent any spread of the virus.

       (Continue . . . )


According to the above article, Senegal does not require or support equine influenza vaccination as part of their annual livestock vaccination campaign.  A quick check of the Ministry of Livestock and Animal Production's infrequently updated website unfortunately finds no mention of the outbreak.

Earlier this year, we followed a limited equine influenza outbreak in the UK (see UK BHA: All Horse Racing Halted After Equine Flu Reported In Vaccinated Horses) which somewhat surprisingly, turned out to be due to the “Florida Clade 1” strain, which is endemic to North and South America. 

The Clade 2 strain is endemic to Europe.

Since January, Nigeria has reported ongoing, widely scattered outbreaks of equine influenza to the OIE (see update #9), which are still listed as `Not typed' in the latest report. While both countries are in located West Africa, they are separated by more than 1000 miles, making epidemiological links difficult to assume.

In 2016, in Epizootics, Host Ranges, and Conventional Wisdom we looked at the history of equine epizootics - including the panzootic of 1872 - and at a study (see A Review of Evidence that Equine Influenza Viruses Are Zoonotic) that argued that human EIV infections may occasionally occur. 

Regardless - all influenza viruses evolve - and their threat profile and current vaccine effectiveness can change over time (see Equine H3N8: Looking At A long-shot In The Pandemic Sweepstakes).

For now the biggest concern over equine influenza outbreaks in West Africa is the toll it can take on horses and donkeys and the impact it can have on the local economy.

Given the lack of influenza vaccination of equines in Senegal, and presumably in some of their neighboring countries as well, this epizootic could have `legs'. 

Hopefully we'll get some more precise information on the serotype behind the outbreaks in both Senegal, and Nigeria, and whether they are epidemiologically linked.