Can fleas from dogs infected with canine visceral leishmaniasis transfer the infection to other mammals?

In order to investigate the possible role of dog fleas in the transmission of trypanosomatids, ectoparasites were removed from 59 dogs testing positive for canine zoonotic visceral leishmaniasis according to the indirect fluorescent antibody test (IFAT). Of the fleas collected, 4/207 (1.9%) showed the presence of promastigotes in smears stained by Giemsa, whilst 43/144 (29.9%) exhibited positive polymerase chain reaction (PCR) amplification assays for Leishmania DNA. Fleas (409) from 9 Leishmania chagasi-infected dogs, each hosting more than 20 fleas per animal, were macerated and administered by peritoneal injection or orally to 36 hamsters. After 6 months, the 30 surviving hamsters were sacrificed and liver and spleen fragments were removed for PCA assay and to produce imprint smears, whilst blood samples were subjected to IFAT assay. Sixteen hamsters tested positive for Leishmania infection, 14 on the basis of PCR amplification and four by IFAT assay (two animals testing positive in both assays). Of the infected hamsters, 11/16 (68.7%) had been infected peritoneally and 5/16 (31.2%) orally. The imprint smears for all animals were, however, negative. Since both PCR and IFAT could present cross-reactivity for Leishmania and Leptomonas, the possibility of oral transmission of L. chagasi by fleas cannot be proven unambiguously even though the hamsters developed infection.

Participation of Rhipicephalus sanguineus (Acari: Ixodidae) in the epidemiology of canine visceral leishmaniasis.

The vectorial competence of the tick Rhipicephalus sanguineus is discussed in relation to the epidemiology of canine visceral leishmaniasis, taking into account its strict association with dogs and the low indices of natural infection presented by its known vector, the phlebotomine sand fly Lutzomyia longipalpis. In order to evaluate natural infection by Leishmania chagasi and the infectivity of these parasites in the tick, 39 specimens (6 females, 11 males and 22 nymphs) of R. sanguineus were removed from 21 dogs showing diverse symptoms of zoonotic visceral leishmaniasis (ZVL). Six ticks (15.4%) gave positive results for the genus Leishmania using the PCR technique. To determine the infectivity of the parasites, 36 hamsters were inoculated orally and peritoneally with macerates of ticks removed from nine dogs symptomatic for visceral leishmaniasis. After 6 months the hamsters were sacrificed and necropsied. Serum was removed for IFAT, as well as spleen and liver fragments to make imprint smears and for PCR. Eight (88.9%) of these dogs presented ticks that were infective for 14 hamsters (41.2%), 12 (85.7%) of them infected peritoneally and two (14.3%) orally. PCR revealed 27 smears (40.9%) to be positive, 20 (62.5%) of them infected peritoneally and seven (20.6%) orally. IFAT showed 14 positive animals (41.2%). Based on these findings, we suggest that the vectorial capacity of R. sanguineus for L. chagasi should be evaluated further, opening new perspectives in the epidemiology of ZVL.

Água e saúde: (des)integração entre vigilâncias e as lições da práxis / Water and health: (dis)integration of surveillance and the lessons of practice

A integração entre as ações intra e intersetoriais na área de saúde constitui desafio para gestores municipais, uma vez que prevalece no cotidiano do serviço a prática fragmentada da geração de dados e da análise dissociada das informações, resultando em obstáculos para um planejamento integrado. Um possível caminho para essa almejada integração funcional permeia o estabelecimento de canais de comunicação permanentes, possibilitando a programação conjunta das intervenções envolvendo diferentes departamentos e setores. Uma avaliação do processo de articulação entre as vigilâncias epidemiológica e ambiental em saúde relacionada à água para consumo humano (Vigiagua), desenvolvida no município de Contagem-MG, identificou, por meio de análise do conteúdo de entrevistas realizadas com a coordenação da Vigilância em Saúde Ambiental, os condicionantes que interferem em sua institucionalização. A busca por maior domínio e valorização do trabalho pelos profissionais do Vigiagua, e a expectativa de agregar diferentes interlocutores e áreas de conhecimento na resolução de problemas comuns foram identificados como principais motivadores e facilitadores do processo. Em outro polo, foram detectados como pontos de estrangulamento: recursos humanos e financeiros; materiais insuficientes; falta de autonomia técnico-gerencial para o estabelecimento de canais de comunicação coesos; e incipiente prática de planejamento no serviço. Seminários e reuniões caracterizaram-se como espaços de interação dialógica no serviço e possibilitaram uma aproximação de gestores do nível central com "executores" das instâncias locais. Entretanto, pleiteia-se que o estímulo para essa interlocução seja contínuo, o que demanda capacitação e desejo de gestores e profissionais para esse exercício.

The integration of intra and inter-sectoral actions in health care is a challenge for municipal managers, once fragmented data generation and analysis of dissociated information prevail in the daily practice of the service, resulting in barriers to integrated planning. A possible path to that desired functional integration permeates the establishment of permanent communication channels, enabling the joint programming of interventions involving different departments and sectors. An evaluation of the process of articulation between the epidemiological surveillance and environmental health related to drinking water (Vigiagua), developed in the municipality of Contagem-MG, identified through content analysis of interviews with the coordination of the Environmental Health Surveillance, the factors that interfere with their institutionalization. The search for greater appreciation of the work area and by professionals of the Vigiagua, and the expectation of bringing together different agents and areas of expertise in solving common problems were identified as key drivers and facilitators of the process. Still, the obstacles identified were: human and financial resources; inadequate materials; lack of technical and managerial autonomy to establish cohesive communication channels; and incipient planning practice in the service. Seminars and meetings were characterized as spaces of interaction and dialogue in the service and allowed an approximation of central-level managers to "executors" of local authorities. However, the stimulus to this dialogue should be continuous, which requires training and desire of managers and professionals for this exercise.

Wild birds as hosts of Amblyomma cajaennense (Fabricius, 1787) (Acari: Ixodidae)

We evaluated the prevalence, mean intensity and relative density of ticks in 467 wild birds of 67 species (12 families) from forest and cerrado habitats at two protected areas of Minas Gerais, between March and September 1997. Ticks collected (n=177) were identified as larvae and nymphs of Amblyomma cajennense and four other species of Amblyomma. Wi report for the first time 28 bird species as hosts of the immature stages of A. cajennense, demonstrating the lack of host specificity of the larve and nymphs. A. cajennense had 15 (por cento) prevalence on birds, with a mean infestation intensity of 0.37 ticks per host sampled, and 2.5 ticks per infested bird. Prevalence varied in relation to host species, diet and between birds from forests at two seccessional stages. There were no differences in relation to host forest dependence, participation in mixed flocks of birds, and nest type constructed. A. cajennense es a species of medical and veterinary importance, occurring on domestic animals but is known littles of its occurrence on wildlife.