Strategies:

• Protection against Dirofilaria infection can be achieved by avoiding mosquito bites in known endemic areas.  Mosquito repellants, netting, and long pants will be effective in this strategy.

• Since the distribution of human dirofilariasis infection in the world roughly parallels the distribution of infection in the animal hosts, the most effective means of prevention is to reduce the incidence and prevalence of infection in the animal hosts.  This strategy will be most effective in the species, D. immitis, which is the infectious agent of heartworm in dogs, and to a lesser extent cats.  There are three drugs that can be given orally to domestic dogs and cats for the prevention of heartworm, including Ivermectin (Heartguard), Milbemycin oxime (Interceptor), and Diethylcarbamzaine (DEC).  Diligent and widespread use of these medications will be an effective means of reducing the rate of dirofilariasis in the parasite's natural hosts, and as a result, in humans as well.

Adults of Dirofilaria immitis recovered from a dog's heart.  Image from
Ohio State University: http://www.biosci.ohio-state.edu/~parasite/dirofilaria.html.