Protecting Americans from Chagas Disease, an Emerging Health Threat

From its labs in Atlanta and around the world, Centers for Disease Control and Prevention scientists have been dissecting insects and the parasites they leave in humans for more than 65 years. The kissing bug, also known as a triatomine, can be infected by Trypanosoma cruzi, the parasite that causes Chagas disease. It is not widespread in the United States, but 300,000 people are infected by Trypanosoma cruzi and have Chagas disease.

Chagas can cause cardiac disease including stroke and arrhythmias, and gastrointestinal disease over time. It can take several years to decades for the infection to take its toll on the human heart and stomach.

Most people with Chagas disease have no apparent symptoms, so people infected don’t know they have it. When people are diagnosed, with the exception of those who are already very sick, it’s easily treatable with drugs the CDC gives to health care providers.

Often people find out they have it when donating blood as blood banks use the FDA’s guidelines to test and notify donors. In addition to blood transfusions, the parasite is also transmitted through organ and tissue transplants. CDC has collaborated with transplant experts to publish recommendations for testing organ donors and monitoring organ recipients to prevent Chagas disease so that transplant centers can help protect their patients from the parasite.

CDC estimates that as many as 315 babies are born with Chagas disease every year in the United States. CDC recommends that health care providers test women who could be at-risk and are planning to conceive or already pregnant, as Chagas disease can be transmitted to fetuses and can cause low birth weight, anemia, respiratory distress, and even death.

If a woman is found to carry Chagas disease, CDC recommends that her other children are tested and treated immediately. If the mother was not tested before or during pregnancy, CDC recommends that health care providers test the baby at birth and treat the newborn immediately if Chagas disease is confirmed.

The World Health Organization estimates that more than eight million people are infected in the Americas. Those who have visited or lived in Mexico, Central America, or South America are at particular risk, especially those who have been in rural areas. Although most people with Chagas disease acquired the infection in their country of origin, CDC has found triatomine bugs infected with the parasite in the Southern United States and confirmed that at least 23 people have been infected with Chagas disease here in the United States.

Currently there is no federal requirement for health care providers, blood banks, and organ/tissue banks to report Chagas diagnoses to their state health department, which then report to CDC. Three states have laws — Arizona, Massachusetts, and Tennessee — requiring reporting by their providers and donor banks to their health departments. Prevention and monitoring is complicated by the fact that the disease is relatively unknown among U.S. health care providers.

CDC has been working to educate health care providers about how to diagnosis and treat Chagas disease. For instance, CDC offers providers a free continuing education online course and online diagnostic information. CDC also offers providers diagnostic assistance, treatment drugs, and medical consultation regarding Chagas disease and other parasitic diseases 24 hours a day.

Voluntary reporting shows that people donating blood have tested positive all over the country (see map or figure).  Helping people with Chagas disease get their infections diagnosed and treated properly will help reduce the serious heart disease that can develop, thereby improving health, saving lives, and reducing health care costs for the nation. Although Chagas disease is still rarely transmitted in the United States, there is much work to be done to protect people’s health through research, policy and partnerships. For more information about the parasite and Chagas, visit www.cdc.gov/parasites/chagas.

Dr. Susan Montgomery, an epidemiologist at the Centers for Disease Control and Prevention, coordinates CDC activities related to Chagas disease and other neglected parasitic diseases in the United States. Dr. Montgomery received her DVM degree from Cornell University and MPH degree from Harvard School of Public Health.