Chagas disease is an emerging disease in Australia. GPs are best placed to offer opportunistic Chagas disease screening to those at risk from endemic regions as they are likely to be the first point of contact.
In Australia there were 116,430 persons born in endemic regions in 2011, a 46% increase since 1997, not including adoptees, visitors or second-generation immigrants. Epidemiological models suggest that 2000–3000 persons could be infected but 95% of cases remain undiagnosed.
Chagas disease is the most prevalent communicable tropical disease in Latin America. The most important vectors are the Triatoma infestans in Argentina, Bolivia, Brazil, Chile, Paraguay, Uruguay and Peru; the R. prolixus in Colombia, Venezuela and Central America; the T.
Within Australian native wildlife, trypanosomes have been reported from the woylie (Bettongia penicillata), quoll (Dasyurus geoffroii), eastern grey kangaroo (Macropus giganteus), common wombat (Vombatus ursinus), platypus (Ornithorhynchus anatinus), short necked turtle (Emydura signata), quokka (Setonix brachyurus), ...
Scientists have found that about 50% of kissing bugs are infected with the Chagas parasite. Kissing bugs are a 'vector' because they can carry a parasite that can make people and animal sick. The parasite is Trypanosoma cruzi, and it causes Chagas disease.
Anyone who suspects that they may have Chagas disease should ask their doctor to order this test. Patients who test positive for the infection should have a cardiac check-up. This is done using radiography, an electrocardiogram and occasionally an echocardiogram.
African trypanosomiasis, or sleeping sickness, is caused by Trypanosoma brucei parasites in sub-Saharan Africa and is transmitted by the tsetse fly? (Glossina). American trypanosomiasis, or Chagas disease, is caused by Trypanosoma cruzi parasites in Latin America and is transmitted by the triatomine or 'kissing' bug.
Chagas disease and sleeping sickness are both infectious diseases caused by the parasite Trypanosoma. In particular, Chagas disease is caused by the parasite Trypanosoma cruzi, while sleeping disease is caused by Trypanosoma gambiense. These parasites live in animals and can be transmitted from person to person.
The triatomine bug thrives in poor housing conditions (for example, mud walls, thatched roofs), and where the bug is present, people living in rural areas are at greatest risk for getting infected.
Risk factors
Living in poor rural areas of Central America, South America and Mexico. Living in a residence that contains triatomine bugs. Receiving a blood transfusion or organ transplant from a person who carries the infection.
Treatment. To kill the parasite, Chagas disease can be treated with benznidazole or nifurtimox. Both medicines are fully effective in curing the disease if given soon after infection at the onset of the acute phase, including the cases of congenital transmission.
One subfamily of assassin bugs feed on vertebrate blood, and some spread the debilitating and sometimes fatal chagas disease. But these 'kissing bugs' do not occur in Australia, and the species found here are minor pests at best.
Chagas disease has an acute and a chronic phase. If untreated, infection is lifelong. Acute Chagas disease occurs immediately after infection, and can last up to a few weeks or months.
However, an estimated 20–30% of infected people will develop health problems years to decades later that are often fatal. The most common symptoms in this late symptomatic stage are cardiac and include conduction abnormalities (arrhythmias), heart failure and sudden death.
The parasites enter the body when the person instinctively smears the faeces or urine into the bite, the eyes or the mouth. It can be between 10 and 30 years before people develop symptoms so most are unaware they have Chagas, often called a “silent and silenced disease”.
Kissing bugs can cause patches of bites, often around the mouth. The bites are usually painless, but they may swell and look like hives. Itching from the bites may last a week.
Chagas disease (T. cruzi infection) is also referred to as American trypanosomiasis.
Where are triatomine bugs typically found? Triatomine bugs (also called “kissing bugs”, cone-nosed bugs, and blood suckers) can live indoors, in cracks and holes of substandard housing, or in a variety of outdoor settings including the following: Beneath porches. Between rocky structures.
University of Pennsylvania Health System: “Penn Study Shows Bed Bugs Can Transmit Parasite that Causes Chagas Disease.”
Summary: Bed bugs, like the triatomines, can transmit Trypanosoma cruzi, the parasite that causes Chagas disease, one of the most prevalent and deadly diseases in the Americas, research has confirmed. The bed bug may be just as dangerous as its sinister cousin, the triatomine, or "kissing" bug.
If untreated, infection is lifelong and can be life threatening. The impact of Chagas disease is not limited to only rural areas of Latin America in which vectorborne transmission (diseases transmitted by insects) occurs.
After the incubation period of 1 to 2 weeks, infected patients enter the acute phase of Chagas disease. Transfusion- and transplant-associated cases may have a longer incubation period, sometimes up to 120 days.
* Benznidazole is FDA-approved for the treatment of Chagas disease (American trypanosomiasis) caused by Trypanosoma cruzi in pediatric patients 2–12 years of age.