Canada may have a new uninvited visitor in 2019. For the first time in eight decades, a new tick species has arrived in the United States — one that in its Asian home range carries diseases to humans and livestock.
Numerous Asian long-horned ticks were identified on an Icelandic sheep in New Jersey in 2017. This invasive tick has spread to Maryland, Arkansas, North Carolina, Virginia, West Virginia and both New York and Pennsylvania – two states that border the Great Lakes.
The Asian long-horned tick should not be confused with the Asian long-horned beetle which is an invasive tree pest that attacks broadleaf trees. This beetle was introduced into the United Stares via wooden shipping pallets in the 1990s and was first identified in Canada in 2003. It is expected that like long-horned beetle the long-horned tick will also make its way to Canada, the only question is when.
The impact this invasive tick will have on public health and livestock in North America is not known at this time. But the tick is a known to transmit diseases to both humans and livestock in its native range in China, Korea and Japan.
To date, there have not been any human bites reported from this tick in the United States. It is a known vector of many human diseases in Asia including SFTS (Severe fever with thrombocytopenia syndrome) a viral disease and Japanese spotted fever which is a rickettsia disease. There are concerns that this invasive tick might be capable of transmitting diseases that native North American ticks currently transmit including Lyme disease.
Currently, scientists believe this tick poses the greatest risk to cows and sheep. This invader is a competent vector of the bovine theileriosis in Asia and in Australia and New Zealand where this tick species has become established. Theileriosis can affect cattle of all ages, however pregnant, lactating, and stressed cows tend to be at the highest risk. The main signs that affected cattle have shown are fever, anaemia, jaundice and a reduced milk production. These invasive ticks are known to swarm livestock which can cause anemia in sheep and cattle which contributes in lowered milk production or reduced wool quality. As of now, there has not been any verified cases of the Asian long horned tick transmitting diseases to livestock in the United States.
To monitor the extent of the Asian long-horned ticks spread farmers and pet owners should submit any unusual ticks found on pets or livestock to their veterinarian or local public health department.