Chagas Disease

More commonly, it is referred to as paleoparasitology (Ferreira et al., 2000). The discovery of the presumed parasite in the human remains is then extrapolated to the present relationship between the host and the parasite
Chagas disease or American trypanosomiasis is caused by Trypanosoma cruzi. The reservoir exists in wild amongst various animal species constituting the sylvatic cycle (Afuderheide et al., 2004). The vector for its transmission is reduviid bug (family Reduviidae, subfamily Triatominae). These insects hide in the crevices, nests or human dwellings in case of domestic cycle and emerge at night to feed upon the blood of their prey (Afuderheide et al., 2004). The infection is caused by rubbing of the bitten area where the parasite deposits the faecal matter (Afuderheide et al., 2004). This leads to entry of the parasite into the blood stream from the breached skin or conjunctiva. Parasitemia may lead to acute manifestations of myocarditis or meningoencephalitis that have a mortality rate of 10% (Afuderheide et al., 2004). The disease may progress to a chronic stage characterised by flare up of febrile episodes and progressive damage to myocardium or gut leading to dilated cardiomyopathy or segmental paralysis of parts of gastrointestinal system respectively (Afuderheide et al., 2004).
Researchers to study the archaeological remains for the evide…
These findings were supplemented by discovery of dwellings made of mud bricks, which is a common habitat of these bugs.
Molecular studies included immunochemical methods and electron microscopy. Histological sections have also demonstrated the parasite even in desiccated mice tissue (Bastos et al. 1996).
However, the most vital tool that has enabled the authors to draw important inferences regarding the evolution and epidemiology of Chagas disease is the extraction and amplification of DNA segments of T. cruzi from mummified tissues.
Origin of samples: Atacama Desert with its dry hot winds and arid climate has been a source of mummified tissues for many researchers (Ferreira et al., 2000. Afuderheide et al., 2004. Guhl et al., 2000). This type of climate favours the preservation of body tissues in a dehydrated form and nearly arrests its decomposition. Moreover, this geographical region coincides with the distribution of the disease, along coastal region of South America in Peru and Chile. South American natives buried their dead in shallow sandy soils that led to preservation of tissues in a desiccated mummified form
Laboratory techniques: This desiccated tissue is rehydrated and pulverised and DNA is extracted. The extracted DNA is then amplified using the Polymerase chain reaction. The amplified DNA participates in the hybridization process with standardised primers and probes under controlled conditions. Hybridisation of the DNA extracted from the mummified tissue samples with the probe nucleotides constitutes a positive test result. Hybridisation can be identified by gel electrophoresis and analysis of bands by radioisotope techniques.
Authentication and sources of error
Concern has been raised