Diseases caused by parasites that were once rare in the United States are becoming more common, according to recent reports. Factors such as increased international travel and changes in climate have contributed to this trend, making conditions more favorable for insects that carry these diseases.
One of the most well-known parasitic diseases is malaria, which is transmitted through mosquito bites. Most U.S. cases occur among travelers returning from regions where malaria is prevalent, including Asia, South America, and sub-Saharan Africa. Symptoms include high fever, chills, and flu-like signs such as headaches and body aches. Malaria can be fatal if not treated promptly but is curable with proper medication.
Chagas disease is another infection on the rise. It is spread by triatomine insects known as “kissing bugs,” which have expanded their range northward due to warmer temperatures. The disease has two phases: an acute phase with mild symptoms like fever or swelling near the bite site, followed by a chronic phase that may last years without symptoms. However, 20-30% of those infected develop severe complications affecting the heart or digestive system. Early detection during the acute phase allows for effective treatment.
Leishmaniasis results from infection with leishmania parasites carried by sand flies found in parts of Asia, North Africa, Southern Europe, Latin America, and increasingly in the U.S. There are three forms: cutaneous (skin sores), visceral (affecting internal organs), and mucosal (impacting mucous membranes). Visceral leishmaniasis can be life-threatening if not treated quickly.
Cysticercosis arises when people ingest eggs of the tapeworm Taenia solium through contaminated food or water or undercooked pork containing larvae. The larvae form cysts in tissues such as muscles or even the brain and spinal cord—potentially causing seizures or other neurological issues. Treatment options depend on severity and location of cysts.
A rare but deadly parasite known as “brain-eating amoeba” lives in warm freshwater lakes and rivers. Infection occurs when contaminated water enters through the nose; swallowing does not cause infection. Symptoms appear within days and rapidly worsen—most cases are fatal within two weeks.
Medical professionals advise anyone experiencing symptoms after travel to at-risk areas to seek care promptly and inform their doctor about recent travel history so that appropriate diagnostic steps can be taken.
