The distance of attraction of a human bait to <i>Lutzomyia verrucarum</i> (Diptera: Psychodidae) in crops

AbstractLutzomyia verrucarum (Townsend) is an abundant anthropophilic phlebotomine sandfly in the Peruvian Andes between 1500 m and 3000 m asl, where it has been incriminated as a vector of both Leishmania peruviana (cutaneous leishmaniasis) and Bartonella bacilliformis (bartonellosis). Previous studies of this vector demonstrated that sandfly activity, measured by sticky traps, was related to crop type. In this paper, we report the results of a field experiment in Peru (Department of Ancash) which show that a single human host in a crop does not attract Lu. verrucarum from distances of 5 m or more, and that there is a positive correlation between the number of Lu. verrucarum collected by sticky traps and the number attracted to a human host in the same field. The results imply that variation in sandfly activity between crop types could lead to differential risk of both leishmaniasis and bartonellosis for humans working at night in different crops.</jats:p

Clonal variation within a mucosal isolate derived from a patient with Leishmania (Viannia) braziliensis infection Variação clonal de um isolado derivado de um paciente com infecção mucosa pela Leishmania (Viannia) braziliensis

Three isolates over 5 years from a patient with persistent relapsing mucosal leishmaniasis due to Leishmania (Viannia) braziliensis and 7 clones from one of these isolates were studied by zymodemes and scrodemes analysis. Results showed evidences of clonal phenotypic variation. Eight isoenzymes markers demonstrated clear differences on Cellulose Acetate (CA) and thin starch gel electrophoresis. Also a panel of specific monoclonal antibodies showed such differences. Our observations provide additional evidence that Leishmania (Viannia) braziliensis is composed by subpopulations of parasites with peculiar biochemical and antigenic characteristics.<br>No transcurso de um período de 5 anos foram estudados 3 isolados de um paciente com leishmaniose mucosa recidivante causada pela Leishmania (Viannia) braziliensis e 7 clones de um desses isolados. Este estudo foi feito pela análise dos serodemas e zimodemas. Os resultados indicaram a ocorrência de variações fenotípicas clonais. Oito marcadores isoenzimáticos demonstraram diferenças nos padrões eletroforéticos em Acetato de Celulose (AC), bem como em camada fina de amido. Da mesma forma foram consultadas diferenças em um painel de anticorpos monoclonais específicos e subespecíficos. Nossas observações indicam ainda que a Leishmania (Viannia) braziliensis está composta por subpopulações de parasitas com características bioquímicas e antigênicas peculiares

Low efficacy of azithromycin to treat cutaneous leishmaniasis in Manaus, AM, Brazil Azitromicina para tratamento de leishmaniose cutânea em Manaus, AM, Brasil

An open trial to evaluate the azithromycin efficacy in cutaneous leishmaniasis patients was carried out in Manaus (AM), where Leishmania (Viannia) guyanensis is the main etiologic agent. Forty-one patients with skin lesions of less than 12 weeks duration, without specific treatment for the last three months and a positive imprint to Leishmania sp. were included. From these, 31 (75.6%) were male with median age of 30.2. All of them received a daily-single oral dose of 500 mg of azithromycin for ten days. At 25th day, 16 (39%) presented therapeutic failure and received intramuscular pentavalent antimonial, four were considered lost, 21, that had improved or were inaltered received another ten-day series of azithromycin and were monthly followed, but nine (21.9%) of them presented a poor clinical response and switched to intramuscular pentavalent antimonial on day 55. Of the 12 remaining cases evaluated on day 55, despite of clinical improvement, three asked for antimony therapy and 9 (21.9%) continued the follow-up but, only three were cured on 55th, 85th and 115th days, and six did not come back for final evaluation. The intention-treatment overall response rate was 22% and whole cure was seen in three (7.3%) of cases. Thus, azithromycin showed a low efficacy to treat cutaneous leishmaniasis in Manaus.<br>Para avaliar a eficácia da azitromicina na leishmaniose cutânea, foi realizado ensaio clínico em Manaus, Amazonas, onde o agente etiológico predominante é a Leishmania (Viannia) guyanensis. Incluídos 41 pacientes com lesões de menos de 12 semanas, sem história de tratamento específico nos últimos três meses e com esfregaço positivo para Leishmania sp. Destes, 31 (75,6%) eram masculinos, idade média 30,2 anos. Todos receberam azitromicina 500 mg em dose única oral, diária, por 10 dias. No dia 25º, 16 (39%) pioraram e receberam antimonial pentavalente via intramuscular por 20 dias e, 21 (61%) que apresentaram melhora da lesão ou esta permanecia inalterada no 25º dia, receberam outro ciclo de 10 dias de azitromicina e foram acompanhados mensalmente. Destes, nove (21,9%) apresentaram piora das lesões na avaliação do dia 55 e iniciaram tratamento com antimonial neste dia. Dos 12 que permaneceram no estudo, porque tinham melhorado clinicamente, três optaram por tratamento com antimonial pentavalente no 55º dia e três apresentaram reepitelização completa das lesões nos dias 55º, 65º e 115º. Seis pacientes não retornaram para avaliação final. Análise por tentativa de tratamento foi 22% e cura confirmada em três (7,3%) casos. Estes resultados mostraram que azitromicina tem baixa eficácia para tratar leishmaniose em área onde a Leishmania (Viannia) guyanensis é o agente etiológico predominante

Comparison of small mammal prevalence of Leishmania (Leishmania) mexicana in five foci of cutaneous leishmaniasis in the State of Campeche, Mexico Comparación de las prevalencias de Leishmania (Leishmania) mexicana en mamíferos pequeños en cinco focos de leishmaniosis cutánea en el estado de Campeche, México

In the Yucatan Peninsula of Mexico, 95% of the human cases of Cutaneous Leishmaniasis are caused by Leishmania (Leishmania) mexicana with an incidence rate of 5.08 per 100,000 inhabitants. Transmission is limited to the winter months (November to March). One study on wild rodents has incriminated Ototylomys phyllotis and Peromyscus yucatanicus as primary reservoirs of L. (L.) mexicana in the focus of La Libertad, Campeche. In the present study, the prevalence of both infection and disease caused by L. (L.) mexicana in small terrestrial mammals were documented during five transmission seasons (1994-2004) in five foci of Leishmaniasis in the state of Campeche. Foci separated by only 100 km, with similar relative abundances of small mammals, were found to differ significantly in their prevalence of both symptoms and infection. Transmission rates and reservoir species seemed to change in space as well as in time which limited the implementation of effective control measures of the disease even in a small endemic area such as the south of the Yucatan Peninsula.<br>En la Península de Yucatán, México, la Leishmaniosis Cutánea es causada por Leishmania (L.) mexicana en 95% de los casos humanos, con una incidencia de 5.08% por cada 100,000 habitantes. El ciclo de transmisión se limita a la estación de invierno (noviembre- marzo). Un estudio de mamíferos silvestres incrimina a Ototylomys phyllotis y Peromyscus yucatanicus como reservorios primarios de L. (L.) mexicana en el foco de infección de La Libertad, Campeche. En el presente estudio, se documenta la prevalencia de infección/enfermedad causada por L. (L.) mexicana en pequeños mamíferos, durante cinco estaciones de transmisión (1994-2004) en cinco focos de CL del estado de Campeche. Los focos separados por solamente 100 km. de distancia, aún cuando tienen abundancias relativas de pequeños roedores similares, fueron significativamente diferentes en relación a la prevalencia de síntomas así como de infección. Las tasas de transmisión y las especies de reservorios parecen estar cambiando tanto en el tiempo como en el espacio, lo cual impide el establecimiento de adecuadas medidas de control de la enfermedad aún en un área endémica tan pequeña como lo es el sur de la Península de Yucatán