According to the World Health Organization (WHO), the parasites are spread by sandflies of the genus Phlebotomus in the Old World, and of the genus Lutzomyia in the New World. At least 93 sandfly species are proven or probable vectors worldwide, with 21 species causing disease in humans. About 700,000 to 1,600,000 new cases of Leishmaniasis are reported every year.
Leishmaniasis is classified as a neglected tropical disease by the WHO, primarily affecting those in tropical and subtropical regions without adequate housing and sanitation. The disease is a zoonotic disease, meaning it is transmitted from animals (particularly, dogs) to humans.
The disease, in its various forms, can cause damage to the skin, mucous membrane, internal organs, and potentially disfigurement, and even death in extreme cases.
A new threat to North America?
The Canadian Press is reporting that recently, veterinarians in the U.S. and Canada have been finding Leishmania in imported dogs in 18 U.S. states, and in four Canadian provinces, Ontario, Nova Scotia, British Columbia, and in Quebec with 10 cases in the past year.
The majority of the cases seem to be coming from dogs imported into the two countries, with many of them being “rescue” dogs. All the dogs were accompanied by health certificates showing they appeared to be in good health. CTV News Canada reports that “we were presented with a case ourselves: a dog imported with suspected “fight wounds” later diagnosed to be Leishmania.”
In Canada, the rules on bringing animals into the country are a bit lax, with the only requirement for canines being a recent rabies vaccination certificate and a veterinary note saying the animal appears in good health.
And while it is true that so far, the particular species of sandfly that’s a vector for Leishmania is not present in the U.S. or Canada, the parasite has managed to maintain itself in kenneled animals. There have been reports of kenneled foxhounds in 18 U.S. states and two provinces having the parasite, suggesting the disease can be transmitted from dog to dog: through bites, breeding, or blood transfusions.
Interestingly, the Infectious Disease Advisor reported in December 2019 that “most human cases of leishmaniasis in the United States occur in Texas, where sand flies and animals known to harbor leishmaniasis are found, while additional cases are attributed to immigration and international travel.
As for mandatory reporting of Leishmaniasis, the only U.S. state that is required to report cases is Texas. It seems that Canada has the same problem with a lack of reporting requirements, something numerous scientists and veterinarians are requesting – not only for the health of the animals but humans, too.
