The mechanisms involved in the pathology of chronic chagasic cardiomyopathy are still debated, and the controversy has interfered with the development of new treatments and vaccines. Because of the potential of DNA vaccines for immunotherapy of chronic and infectious diseases, we tested if DNA vaccines could control an ongoingTrypanosoma cruziinfection. BALB/c mice were infected with a lethal dose (5 × 10⁴parasites) as a model of acute infection, and then they were treated with two injections of 100 μg of plasmid DNA 1 week apart, beginning on day 5 postinfection. Control mice had high levels of parasitemia and mortality and severe cardiac inflammation, while mice treated with plasmid DNA encoding trypomastigote surface antigen 1 or Tc24 had reduced parasitemia and mild cardiac inflammation and >70% survived the infection. The efficacy of the immunotherapy also was significant when it was delayed until days 10 and 15 after infection. Parasitological analysis of cardiac tissue of surviving mice indicated that most mice still contained detectable parasite kinetoplast DNA but fewer mice contained live parasites, suggesting that there was efficient but not complete parasite elimination. DNA vaccine immunotherapy was also evaluated in CD1 mice infected with a low dose (5 × 10²parasites) as a model of chronic infection. Immunotherapy was initiated on day 70 postinfection and resulted in improved survival and reduced cardiac tissue inflammation. These results suggest that DNA vaccines have strong potential for the immunotherapy ofT. cruziinfection and may provide new alternatives for the control of Chagas' disease.

Cutaneous leishmaniasis (CL) is endemic to the Yucatan Peninsula of Mexico. The main causative agent is the parasite Leishmania mexicana (Biagi) (Kinetoplastida: Trypanosomatidae) and, based on the classic work of Dr Biagi's research team, it has been generally accepted and frequently reported that the only vector of L. mexicana in the region is the sandfly Lutzomyia olmeca olmeca (Vargas & Diáz‐Nájera) (Diptera: Psychodidae). Evidence gathered from recent entomological studies conducted mainly in Calakmul, Campeche, however, suggests that other species may also be vectors of L. mexicana . We conducted a field study in two villages in Calakmul, Campeche in the Yucatan Peninsula, where recent cases of CL have been reported, to document the species composition and relative abundances of the sandfly fauna and to identify which species are likely to be the main vectors by assessing the biting rates and parasite infection rates of the suspected vector species. Sandfly catches were conducted from November 2005 to February 2006 in Unión 20 de Junio and Dos Lagunas Sur. Sandflies were captured using Shannon (18.00–22.00 hours), Disney and CDC light traps (18.00–06.00 hours). Biting and infection rates were calculated for the four most abundant species: Lutzomyia cruciata (Coquillett), Lu. o. olmeca , Lutzomyia panamensis (Shannon) and Lutzomyia shannoni (Dyar). In Dos Lagunas Sur, Lu. panamensis and Lu. o. olmeca exhibited the highest biting rates throughout the sampling period. In Unión 20 de Junio, Lu. cruciata and Lu. o. olmeca had the highest biting rates over the same period. Regarding infection rates, we report herein the establishment of a polymerase chain reaction protocol and validation of IR1 and LM17 oligonucleotides to analyse the infection rates of sandflies. Out of 769 females analysed, the overall infection rates were 1.4% in Dos Lagunas Sur and 5.3% in Unión 20 de Junio. In Dos Lagunas Sur we found L. mexicana infections in two sandfly species, Lu. shannoni and Lutzomyia ylephiletor (Fairchild & Hertig), whereas in Unión 20 de Junio we found infections in Lu. shannoni , Lu. cruciata , Lu. o. olmeca and Lu. panamensis . The possible role of these four sandfly species in relation to L. mexicana transmission in Calakmul is discussed.

Chagas disease, caused by the protozoan parasite Trypanosoma cruzi, is a major public health problem in most of Latin America. A key priority is the

Hurricanes can have devastating effects on health and may directly modulate vector-borne diseases. Chagas disease is a zoonosis caused by the protozoan parasite Trypanosoma cruzi and transmitted by triatomine bugs, and the effect of hurricanes on these bugs is largely unknown. We thus performed a detailed study of the changes in Triatoma dimidiata geographic distribution and infection rates after Hurricane Isidore devastated the Yucatán Peninsula in September 2002. Bugs were collected in 34 villages from the entire peninsula, during a year, starting 3 months after the hurricane. Pre- and posthurricane bug collections were compared to assess changes. The most notable effect was a large increase in domestic abundance of T. dimidiata during the 6 months after the hurricane. This increase was maximum along the path of the hurricane. These results suggest that vector control programs should be implemented along the path of hurricanes to prevent an increase in Chagas disease transmission risk in the ensuing months.