What Diseases Are Spread by Animals & Insects?

What’s the Difference between Zoonotic Diseases and Vector-borne Diseases?

Vector-borne diseases include infections transmitted through the bite of infected blood-feeding insects such as mosquitoes, ticks and fleas, and other biting pests. Common vector-borne diseases include Lyme Disease and Rocky Mountain Spotted Fever, which are transmitted by ticks, and West Nile Virus, which is transmitted by mosquitoes.

A zoonosis is an infectious disease that has jumped from an animal to a human. Zoonotic pathogens may be bacterial, viral, or parasitic and can spread to humans through direct contact or through food, water, or the environment. 

What are heartworms?

Heartworm disease is a serious and potentially fatal disease that affects dogs, cats, ferrets, various mammals, and in rare instances, humans. It is caused by heartworms that live in the heart, lungs, and other blood vessels, and can cause severe lung disease, heart failure, and organ damage. In their hosts, heartworms produce microfilariae that circulate in the blood and are ingested by mosquitoes during a blood meal. After ingestion by mosquitoes, the microfilariae develop into larvae that migrate to the proboscis, which is the long, tubular part of a mosquito’s mouth that punctures the skin during a bite, where they are ready to infect another host the next time a mosquito bites an animal or human. Mosquitoes that are capable of transmitting heartworms include Aedes, Anopheles, and Mansonia species.

Can humans get heartworms from animals?

Humans can get heartworms, but it is not transmitted through the bodily fluids of pets or other animals.

How can humans get heartworms?

Heartworms are only transmitted to humans through the bite of an infected mosquito. In humans, the microfilaria that enter the body via a mosquito bite often do not survive the passage through tissue under the skin. But if they do survive, they remain sexually immature and are not able to transmit the infection to other hosts. This is unlike the infection in other mammalian hosts, like dogs. In these hosts, the infection can be transmitted to other animals because microfilariae are produced and then ingested by mosquitoes in blood meals.

How do vets test for heartworms?

Veterinarians can administer a heartworm disease test. The earlier heartworms are detected, the better the chances the pet will recover. The test requires just a small blood sample from your pet, and it works by detecting the presence of heartworm proteins.

Where are heartworms most commonly found?

Heartworms have been found in all 50 states, although certain areas have a higher risk than others. Some very high-risk areas include large regions, such as near the Atlantic and Gulf coasts, and along river tributaries. Factors affecting the level of risk of heartworm infection include the climate, the species of mosquitoes in the area, and the presence of mosquito breeding areas along with animal “reservoirs” such as infected dogs, foxes, or coyotes.

Hantavirus (HPS) Facts

Hantaviruses are a group of viruses that may be carried by some rodents. Some hantaviruses can cause a rare but deadly disease called hantavirus pulmonary syndrome (HPS). Anyone who encounters rodents that carry hantaviruses is at risk. Rodent infestation in and around the home remains the primary risk for Hantavirus exposure. In North America, the types of rodents that can transmit hantavirus are the deer mouse, the white-footed mouse, the rice rat, and the cotton rat. However, not every one of these rodents carries Hantavirus. Other rodents, such as house mice, roof rats, and Norway rats, have never been known to give people HPS. However, it is best to avoid all wild mice and rats and to safely clean up any rodent urine, droppings, or nests in your home.

What is Lyme Disease?

Ticks that can carry the borrelia bacteria that causes Lyme Disease live throughout most of the United States. However, Lyme disease is most common in the upper Midwest and the northeastern and mid-Atlantic states. You're at risk of Lyme disease if you spend time where ticks live, such as in grassy, brushy, or wooded areas. Taking safety measures like using tick repellent and staying out of areas infested with ticks can lower the risk of tick bites and Lyme disease. Symptoms of Lyme disease include a bulls-eye rash, fever, headache, fatigue, joint stiffness, muscle aches, and swollen lymph nodes.

What is scrub typhus?

Scrub typhus is a disease caused by a bacteria called Orientia tsutsugamushi. It is spread to people through bites of infected chiggers. The most common symptoms of scrub typhus include fever, chills, headache, enlarged lymph nodes, body aches, and a dark, scab-like region at the site of the chigger bite.

Chagas Disease Facts

Chagas disease, or American trypanosomiasis, is caused by the parasite Trypanosoma cruzi. Chagas disease is most common in rural areas of Mexico, Central America, and South America, but rare cases have been noted in the southern United States.

How is Chagas Disease transmitted?

The main way people can become infected is through the bite of Triatomine bugs. Because they tend to bite people’s faces, triatomine bugs are also known as “kissing bugs.” These pests get infected with T. cruzi after biting an infected animal or person. Once infected, the bugs pass the parasites in their feces. During the day, the bugs hide in crevices in the walls, roofs, and other protective places inside buildings. At night, when the inhabitants are sleeping, the bugs emerge to feed. After they bite and ingest blood, they defecate on the person. The person can become infected if T. cruzi parasites in the pest’s feces enter the body through mucous membranes or breaks in the skin.

To learn more about diseases that are spread by insects and how to protect you and your family, call your local Orkin branch today.