Franklin Vargas

Epidemiology of American trypanosomiasis in northern Peru

In recent years, the World Health Organization has had notable success in controlling and interrupting the vectorial transmission of Trypanosoma cruzi, via the so-called Southern Cone Initiative, in Argentina, Brazil, Bolivia, Chile, Paraguay and Uruguay (Moncayo and Ortiz Yanine, 2006). In Peru, as a result of this success and the recommendations and support of the World Health Organization, Pan American Health Organization and Canadian Agency for International Development (CIDA), much epidemiological and entomological research, with direct relevance to the control of both domestic and non-domestic species of triatomine bug, is currently in progress. Control strategies are being successfully developed or adapted to match the entomological conditions, and the impact of Chagas disease on public health is being re-assessed (Guhl et al., 1999). Most of the focus has been on the south of the country, however, where there are many domestic Triatoma infestans. Although the disease was once considered to have a serious impact only in the south of Peru, and not in the north, where there are no Tri. infestans, there is now growing evidence that the disease is a national and not just a southern problem. Peri-domestic or sylvatic Tri. carrioni, Panstrongylus chinai, P. herreri and Rhodnius ecuadoriensis in northern Peru are sometimes naturally infected with Try. cruzi and often invade dwellings in many localities (Cáceres et al., 2002; Cuba Cuba et al., 2002). In addition, acute cases of Chagas disease have been detected in the north–eastern region, and blood donors who are seropositive for Try. cruzi infection have been found in all regions (Anon., 2004). There is therefore now a clear need for Peru to expand the programme of research and control to the north and into Amazonia, with the strategies altered, if necessary, to match the epidemiology of American trypanosomiasis in each region (PAHO, 2004). In any endemic area, the development of effective strategies for the control of the vectors of Try. cruzi depends on the availability of reliable data on the geographical distribution, infection, ecological characteristics and behavioural tendencies of the triatomine species present in that area. The aim of the present study was to determine the triatomine species that are most common in domestic or peri-domestic settings in north and north–eastern Peru, and the prevalences of infection with Try. cruzi (and Try. rangeli) in domestic samples of each triatomine species, so that the most important vectors in these areas can be identified and targeted in control efforts.

Identificación de especies de Leishmania en pacientes y flebotominos en áreas de transmisión en una región del Perú

Objectives. To identify the species of Leishmania present in the skin lesions of patients and Lutzomyias living in endemic areas of La Libertad, Peru. Materials and methods. Molecular methods based on PCR and RFLP were used, which allowed to have efficient data with small amounts of samples (small specimens), due to their high sensitivity and ease of application in the field work. Results. The results of PCR of clinical samples of patients and insect vectors showed the presence of Leishmania (V.) peruviana as a major causative agent of andean leishmaniasis transmitted by Lutzomyia peruensis. The presence of Leishmania (V.) guyanensis in Lutzomyia ayacuchensis, was found as well. Conclusions. The presence of L. (V.) peruviana and L. (V.) guyanensis in the Andean areas under study was found. These findings remark the need of a wider research about the geographical distribution of L. (V.) guyanensis and clinical features related to the infection in endemic areas of cutaneous leishmaniasis.