No abstract

In order to better comprehend the putative association between genotype Trypanosoma cruzi II and primates, an evaluation of the infection in free ranging primates and specimens born in captivity from different geographical areas, the Amazon and the Atlantic forest, was carried out. Seroprevalences of the T. cruzi infection among the primates was similar in both biomes (45.5% and 46%). The parasites were isolated from 8 and 4 different species of primates, respectively from the Amazon and Atlantic forest. Multi-locus enzyme electrophoresis (MLEE) typed the isolates from Amazon as zymodeme 1. Mini-exon gene analysis characterized all these isolates as T. cruzi I, the main genotype circulating in the region. In the Atlantic forest, primates infected with TCI and TCII, as well as a mixed infection (TCI and TCII), were detected. These findings prove that primates may maintain stable infections by both genotypes. Moreover, data show that T. cruzi can occur in a wide range of primate genera, independent of their social behaviour, niches or habitats. Considering the high seroprevalence and stability of T. cruzi infection among the primates, these animals play an important role in the maintenance of the parasite in nature.

In a study of sandfly species in the Samuel Ecological Station, in Porto Velho, Rondônia State, the following species were identified: Lutzomyia brasiliensis, L. evangelistai, L. gomezi, L. anduzei, L. flaviscutellata, L. richardwardi, L. shawi, L. umbratilis, L. yuilli yuilli, L. dendrophyla, L. puctigeniculata, L. shannoni, L. amazonensis, L. ayrozai, L. carrerai carrerai, L. claustrei, L. davisi and L. lainsoni. L. richardwardi, L. umbratilis and L. c. carrerai were the predominant species captured of man forming 60.30% of the total catch. L. richarwardi was the most frequent at ground level (29.9%), while L. umbratilis predominated in the canopy (48.5%)

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RESUMODurante o período de 2002 a 2003 foram realizadas coletas de flebotomíneos em duas áreas do estado do Amazonas (Base de treinamento militar -BI1 e Tarumã Mirim). Nessas coletas foram capturadas um total de 1.440 fêmeas de Lutzomyia (Nyssomyia) umbratilis. Lu.umbratilis é a principal responsável pela transmissão da Leishmaniose Tegumentar Americana (LTA) ao norte do Rio Amazonas. Do total coletado apenas 15 espécimens (ou 1,04%) apresentaram infecção natural por tripanosomatídeos, sendo 12 na BI1 e 3 em Tarumã-Mirim. Isso representou uma taxa de infecção de 1,66% (12 dos 720 capturados em BI1) e 0,42% (3 dos 720 em Tarumã-Mirim). Estes resultados confirmam as informações prévias por outros autores de reduzidos valores de infecção natural por tripanosomatídeos em flebotomíneos, mesmo em áreas altamente endêmicas para leishmaniose. 04%) presented natural infection with trypanosomatids, being 12 at Bl1 and 3 at Tarumã-Mirim. The infection rate was 1,66% (12 of the 720 collected at BI1) and 0,42% (3 of the 720 at Tarumã-Mirim). These results confirm the previous informations described by other authors that insects have low rates of natural infection by trypanosomatids even in high endemic areas for leishmaniasis.

The human filarial nematode Mansonella ozzardi occurs widely in the Neotropical region from southern Mexico to northwestern Argentina. It causes mansonellosis and is transmitted by blackflies of the genus Simulium and biting midges of the family Ceratopogonidae. The embryonic unsheathed microfilariae with sharp, unnucleated tails are detectable in the blood (and occasionally in the skin) 1 day after being released by the fertilized adult female worms. After being ingested by a vector, the microfilariae reach the insect's thoracic musculature through the hemocoel and develop, after two moults, into infective L3 larvae that migrate to the head and mouth parts of the vector. Cross-sectional surveys in endemic areas show an increase in both M. ozzardi prevalence and microfilarial load with patients' age until they reach their 60s. Most cases of mansonellosis appear to be asymptomatic, but mild symptoms and a recently recognized ocular pathology have been associated with this infection.

Mansonellosis is caused by three filarial parasite species from the genus Mansonella that commonly produce chronic human microfilaraemias: M. ozzardi, M. perstans and M. streptocerca. The disease is widespread in Africa, the Caribbean and South and Central America, and although it is typically asymptomatic it has been associated with mild pathologies including leg-chills, joint-pains, headaches, fevers, and corneal lesions. No robust mansonellosis disease burden estimates have yet been made and the impact the disease has on blood bank stocks and the monitoring of other filarial diseases is not thought to be of sufficient public health importance to justify dedicated disease management interventions. Mansonellosis´s Ceratopogonidae and Simuliidae vectors are not targeted by other control programmes and because of their small size and out-door biting habits are unlikely to be affected by interventions targeting other disease vectors like mosquitoes. The ivermectin and mebendazole-based mass drug administration (iMDA and mMDA) treatment regimens deployed by the WHO´s Elimination of Neglected Tropical Diseases (ESPEN) programme and its forerunners have, however, likely impacted significantly on the mansonellosis disease burden, principally by reducing the transmission of M. streptocerca in Africa. The increasingly popular plan of using iMDA to control malaria could also affect M. ozzardi parasite prevalence and transmission in Latin America in the future. However, a potentially far greater mansonellosis disease burden impact is likely to come from shortcourse curative anti-Wolbachia therapeutics, which are presently being developed for onchocerciasis and lymphatic filariasis treatment. Even if the WHO´s ESPEN programme does not choose to deploy these drugs in MDA interventions, they have the potential to dramatically increase the financial and logistical feasibility of effective mansonellosis management. There is, thus, now a fresh and urgent need to better characterise the disease burden and ecoepidemiology of mansonellosis so that effective management programmes can be designed, advocated for and implemented.

Gestational malaria is a multi-factorial syndrome leading to poor outcomes for both the mother and foetus. Although an unusual increasing in the number of hospitalizations caused by Plasmodium vivax has been reported in Brazil, mortality is rarely observed. This is a report of a gestational malaria case that occurred in the city of Manaus (Amazonas State, Brazil) and resulted in foetal loss. The patient presented placental mixed-infection by Plasmodium vivax and Plasmodium falciparum after diagnosis by nested-PCR, however microscopic analysis failed to detect P. falciparum in the peripheral blood. Furthermore, as the patient did not receive proper treatment for P. falciparum and hospitalization occurred soon after drug treatment, it seems that P. falciparum pathology was modulated by the concurrent presence of P. vivax. Collectively, this case confirms the tropism towards the placenta by both of these species of parasites, reinforces the notion that co-existence of distinct malaria parasites interferes on diseases' outcomes, and opens discussions regarding diagnostic methods, malaria treatment during pregnancy and prenatal care for women living in unstable transmission areas of malaria, such as the Brazilian Amazon.