Recognized as one of the world’s neglected diseases, Chagas is a major public health concern in Latin America and is a growing concern in the United States and regions of Europe as the number of infected immigrants increase. It is estimated that 16 to 18 million people are infected with the disease with nearly 100 million people at risk in 21 countries. This includes approximately 25% of the population of Latin America. An estimated 50,000 deaths occur annually. In Latin America, an estimated 65 million people inhabit endemic areas where there is risk of infection. Approximately 15 to 20 million inhabitants of rural and urban areas are thought to be infected with T. cruzi.
Chagas is transmitted by Trypanosoma cruzi, a protozoan parasite of the hematophagous triatomine insect. Infection occurs when the insect bites its mammalian host and releases infective trypomastigotes in its excreta while feeding. Alternatively, infection can occur through blood transfusions, organ transplantation, ingestion of contaminated food and congenitally. Prevalence of congenital infection is 10% in children born to chagastic mothers.
The disease manifests itself in stages. The initial acute phase may cause illness and death, especially in young children. However, more commonly, 90% of infected individuals enter the chronic stage of infection that may last several months to years. Among them about 30% are characterized by cardiomyopathy and/or megasyndromes involving the esophagus or colon. The leading manifestation of chagas is chronic myocarditis resulting in high morbidity and mortality.
Treatment administered during the acute stage of infection is usually effective. Once Chagas has progressed to the chronic stage, there is no effective treatment. Therefore, early detection and treatment, especially in young children, can have a significant impact on both patient outcome and health care costs.
The incidence of Chagas is highest in rural areas where some serological tests (ELISA, PCR, IHA and IFA) are impractical to perform due to requirements for specialized instrumentation, cold storage and interpretation by a trained clinician.
Recombinant antigens provide a convenient tool to improve current methods of serological diagnosis of chagas disease. Several assays such as immunofluorescence, hemagglutination, complementation fixation, radioimmunoassay and ELISA are available for diagnosis. However, these assays may be impractical to perform in rural areas due to requirements for laboratory instrumentation to perform or interpret the tests. Most also require cold storage.
Chembio Diagnostic Systems, Inc.’s Chagas STAT-PAK® rapid assay is easy-to-perform, requires no cold chain storage, uses a minimal sample size and provides visual detection of antibodies to T. cruzi.
Further Resources:
American Society of Tropical Medicine and Hygiene (www.astmh.org)
Centers for Disease Control and Prevention (www.cdc.gov)
National Institute of Allergy and Infectious Diseases (www.niaid.nih.gov)
Pan American Health Organization (www.paho.org)
Seattle Biomedical Research Institute (sbri.org)
World Health Organization (www.who.it)
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