Photos for download: Chagas disease
Triatomine bug (Rhodnius prolixus) taking a blood meal. Mexico
Triatomine bugs usually bite exposed areas of the body, such as the face. After an intake of blood meal, the bugs defecate, usually close to the bite. Parasites (Trypanosoma cruzi) enter the body when the person instinctively smears the parasite-contaminated faeces of the bug into the itching, bitten area, or, when the faeces inadvertently come into contact with the eyes, mouth, or into any skin break.
From left to right, male and female adult triatomine bugs, four stages of triatomine nymphs and triatomine eggs. Mexico
Male and female, adult and nymphs are all blood-sucking (haematophagous) bugs. All such infected bugs transmit the parasite found in their faeces.
A house colonized with triatomine bugs. Mexico
Photo shows an adult bug and a nymph with clear defecation marks on the wall. Fresh defecation can contain live parasites and can be infective. Normally these bugs live in the cracks of poorly-constructed homes in rural or suburban areas. They hide during daylight and are active in taking their blood meal at night.
Space spraying of house interiors with residual insecticides (after removing and cleaning all furniture and belongings) is a crucial method of control. Mexico
Vectorial control also means home improvement, such as plastering of walls, installing concrete floors and corrugated iron roofing and maintaining house hygiene. Personal preventive measures such as using bednets and observing hygiene practices when preparing, handling and consuming food are important.
A man plasters cracks in the walls of a house. Mexico
Thatched walls or roofs of homes in rural or suburban areas provide ideal habitats for the triatomine bugs.
Bolivian health workers meeting residents in a village in Palmarito, Bolivia to explain as part of information, education and communication activities related to Chagas disease control.
During the day triatomine bugs hide in dark places, such as under mattresses, in clothes-bags, in-between folded clothes, behind calendars, etc. These places should be regularly cleaned to remove adult bugs, nymphs and eggs. Bolivia
Doctor examining a patient's heart. Bolivia
Up to 30% of chronically infected people develop cardiac alterations and up to 10% develop digestive, neurological or mixed alterations which may require specific treatment. Most infections show no symptoms of infection.