Chagas’ Disease

Also known as South American trypanosomiasis, Chagas’ disease is most common in Brazil but affects about 18 million people between Mexico and Argentina; 21,000 people die from it every year. Not a tropical disease per se, it has a discontinuous distribution—Panama and Costa Rica, for instance, are Chagas-free.

Since it is spread by the bite of the vinchuca (conenose or assassin bug), which lives in adobe structures and feeds at night, avoid such structures; if it’s impossible to do so, sleep away from the walls. DEET-based inspect repellents offer some protection. Chickens, dogs, and opossums may help spread the disease, but according to recent studies the insect vector is near eradication in Chile.

Chagas’ initial form is a swollen bite that may be accompanied by fever, which soon subsides. In the long run, though, it may cause heart damage leading to sudden death, intestinal constipation, and difficulty in swallowing; there is no cure. Charles Darwin may have been a chronic Chagas sufferer.

Dengue

Like malaria, mosquito-borne dengue is a disease of the lowland tropics, but it’s less common and only rarely fatal. Debilitating in the short term, its symptoms include fever, headache, joint pain, and skin rashes, but most people recover quickly though there is no treatment. Uncommon but often fatal, the more severe dengue hemorrhagic fever sometimes occurs in children, particularly those infected previously.

Mainland Chile has not recorded any dengue, but the arrival of the white-spotted mosquito vector Aëdes aegypti on Easter Island (Rapa Nui)—an apparent arrival from tropical French Polynesia—caused an outbreak there. This mosquito bites during the daytime, making the usual malarial recommendation for long sleeves and long trousers harder to live up to—if you must wear shorts and short sleeves, make sure you’re covered with insect repellent.

© Wayne Bernhardson from Moon Chile, 2nd edition