During the summer of 2000, I had a moderately strange job: trapping birds and drawing small blood samples. The Ohio Department of Health was looking for West Nile Virus, as it was newly identified in the country and thought to be spreading westward. Migratory birds follow a significant pathway along the Great Lakes, and can possibly transport West Nile long distances over short periods of time.
The virus is spread from bird do bird by mosquitoes, and hence, humans if the mosquito bites an infected bird, then an unlucky person. A small team of us set up 100-foot-long mist nets, which resemble an almost invisible huge volleyball net, next to everyones’ favorite spot in county fairgrounds: the horse manure pile. Our permit allowed only for the capture of non-native birds, such as English sparrows, who apparently have a taste for grains in horse excrement. After setting up the net and waiting patiently, we would pop up and a flock of sparrows would fly into our net. The net is so fine that they would look as if they were frozen in mid-air! From there we gently removed them and drew a small blood sample to be submitted to the state lab. Our feathered friends were released with a tale to tell their mates.
During that summer no birds in Ohio tested positive, but that did not last long. West Nile Virus spread rapidly across a number of states, infecting humans and notably, horses. Infections in dogs are known, but rare, with dogs appearing to have few, if any clinical effects from West Nile. Humans are a different story, though.
Seeing that there are few privately-owned horses in the city and the disease isn’t of concern in dogs, let’s talk people. Yes, a veterinarian is talking about human healthcare. This is part of the One Health concept: where animals and humans have interconnected healthcare concerns, This disease relies upon birds as the host species, with mosquitoes as the vector of delivery.
The city recently posted a bulletin to healthcare providers indicating four positive birds were found in July. So far, no humans have tested positive, but it is important to note that the virus is circulating within the avian population. The last positive case was in two birds in 2021. Several cases in humans have occurred over the past five years, but none this year.
Around 80% of people infected with West Nile virus will be asymptomatic – not showing any signs of illness. Clinical signs of the disease may mimic other illness: fever, headache, muscle pain, vomiting, and rash. Rarely it can cause severe neurologic disease. People over the age of 50 and those with compromised immune systems are at a higher risk of developing severe illness. At present there is no vaccine against West Nile for people (although there is for horses), and prevention of mosquito bites is the best proactive measure one can take against the virus.
Preventing mosquito bites also helps your dog: mosquitoes are the vector to transmit canine heartworm disease! If you have a garden, patio, or house, be sure there is no standing water in pots, gutters tires, furniture, etc. Mosquitoes need water to reproduce, therefore eliminating breeding areas will greatly reduce their presence. Wear long sleeves when outside and use an approved bug repellant, too. Check all window screens and install screen doors on patio doors or main entrance doors if they are left open for ventilation. The virus cannot be spread from touching a wild or dead bird or objects; it must be transmitted by a mosquito bite.
With changing weather patterns, possibly milder winters, and increased large rainstorms, mosquitoes may be on the rise. While not common at this time, West Nile and other mosquito-borne illnesses may become more prevalent in the near future. Prevention is worth the effort.
Dr. Teich is the founder of the District Veterinary Hospitals in Navy Yard, Eastern Market and Brookland. Visit www.districtvet.com for more information.
