Paulo Augusto Sessa

An experimental vaccine against American dermal leishmaniasis: experience in the State of Espírito Santo, Brazil

A vaccine prepared from killed and sonicated promastigotes of five Brazilian strains of Leishmania was used during an epidemic of American dermal leishmaniasis that occurred in Viana county, State of Espírito Santo, Brazil. Initially, all of the participants in the vaccination programme had negative reactions to Montenegro antigen. Forty days after the last dose of vaccine had been given, 87.6% of the 216 vaccinated individuals had become Montenegro-positive whereas the 266 unvaccinated persons remained Montenegro-negative. The study area had an unstable population and details are given about the human population changes that occurred during the two-year study period. Taking into account population movements, 1.5% of those vaccinated and 6.4% of the unvaccinated group developed dermal leishmanial lesions by the end of the first year. At the end of the second year, 1.7% of those vaccinated and 8.9% of the unvaccinated group had become infected. The difference in infection rates of the two groups is statistically significant at both the end of the first and second years of observation. Diagnosis of the disease(s) was based on the clinical appearance of lesions combined with parasitological and/or immunological evidence and subsequent responses to treatment. The experience gained in Viana also provided information about the storage and administration of the experimental vaccine which have been used in mounting a randomized clinical trial.

Participação do cão no ciclo de transmissão da Leishmaniose tegumentar no município de Viana, Estado do Espírito Santo, Brasil

In an endemic area of cutaneous leishmaniasis in the viana municipality, Espirito Santo state, an investigation was performed on natural hosts of leishmania among domestic animals, trying to correlate the presence of infected animals with the occurrence of the disease in humans. Within a three weeks period 186 dogs were examined and 32 (17,2%) were found infected.Eleven new cases of cutaneous leishmaniasis were recorded during one year, among people living in the endemic area. A close relationship was between the presence of infected dogs and the occurrence of human leishmaniasis. In the area studied, the disease seems to behave as a zoonosis maintained by domestic dogs.

Distribution of sand flies (Diptera: Psychodidae) at different altitudes in an endemic region of American cutaneous leishmaniasis in the State of Espírito Santo, Brazil

The involvement of different sand fly species in the transmission of American cutaneous leishmaniasis (ACL) at different altitudes was evaluated in the municipality of Afonso Cláudio in the State of Espírito Santo, Brazil, from November 1995 to February 1997. CDC light traps and Shannon traps baited with human volunteers were hung simultaneously at three altitudes of a river valley: (a) 650-750 m in an area of active ACL transmission; (b) 750-850 m in a transitional area; and (c) 850-950 m in an area where no ACL transmission occurred. A total of 13,363 specimens belonging to 28 species was collected. The five most abundant man-biting species were Lutzomyia intermedia, which constituted 24.3% of the total, Lu. migonei (22.3%), Lu. whitmani (15.4%), Lu. fischeri (14.9%) and Lu. monticola (5.8%). Analysis of the distribution of these species at the three altitudes provided evidence that Lu. fischeri and Lu. monticola were not involved in ACL transmission, whereas Lu. migonei and Lu. whitmani might act as secondary vectors of Leishmania (Viannia) braziliensis and Lu. intermedia was probably the principal vector of the parasite. These results reinforce those published in the existing literature, which indicate that Lu. intermedia is the main vector of Le. (V.) braziliensis in Southeast Brazil, while Lu. migonei and Lu. whitmani are of secondary importance.

Foco de leishmaniose tegumentar americana nos municípios de Viana e Cariacica, Estado do Espirito Santo, Brasil

Descreve-se um foco de leishmaniose tegumentar americana abrangendo quatro localidades dos municipios de Viana e Cariacica situados proximo ao litoral do Estado do Espirito Santo, Brasil. Foram diagnosticados 71 casos no periodo de maio de 1978 a dezembro de 1982. A confirmacao laboratorial foi obtida pela intradermorreacao de Montenegro em 66 pacientes e pelo encontro do parasita em 15. A faixa etaria mais acometida foi a de 0-10 anos. Amostras do parasita isoladas de 3 pacientes e de 27 caes foram classificadas como Leishmania braziliensis braziliensis. De apenas dois Proechimys iheringi, entre 257 mamiferos silvestres estudados, isolou-se Leishmania, que foi identificada como Leishmania mexicana aristedesi. As especies de flebotomineos mais numerosas (Lutzomyia intermedia, L. fischeri e L. migonei) apresentaram um elevado grau de adaptacao aos ambientes intra e peri-domibiliar. Levantou-se a hipotese da transmissao estar ocorrendo no intra e peri-domicilio.Descreve-se um foco de leishmaniose tegumentar americana abrangendo quatro localidades dos municipios de Viana e Cariacica situados proximo ao litoral do Estado do Espirito Santo, Brasil. Foram diagnosticados 71 casos no periodo de maio de 1978 a dezembro de 1982. A confirmacao laboratorial foi obtida pela intradermorreacao de Montenegro em 66 pacientes e pelo encontro do parasita em 15. A faixa etaria mais acometida foi a de 0-10 anos. Amostras do parasita isoladas de 3 pacientes e de 27 caes foram classificadas como Leishmania braziliensis braziliensis. De apenas dois Proechimys iheringi, entre 257 mamiferos silvestres estudados, isolou-se Leishmania, que foi identificada como Leishmania mexicana aristedesi. As especies de flebotomineos mais numerosas (Lutzomyia intermedia, L. fischeri e L. migonei) apresentaram um elevado grau de adaptacao aos ambientes intra e peri-domibiliar. Levantou-se a hipotese da transmissao estar ocorrendo no intra e peri-domicilio.

Effects of the installation of the Rosal hydroelectric power station, Itabapoana River, States of Espírito Santo and Rio de Janeiro, on anophelinae, planorbidae and phlebotominae

The construction of dams usually changes the composition of the fauna within their areas of influence. In the area where the Rosal hydroelectric power station has been installed, in the States of Espírito Santo and Rio de Janeiro, changes to the abundance of anophelinae, planorbidae and phlebotominae were evaluated before (1998-2000) and after (2000-2005) the damming. Nine sample collection points were defined, each represented by a home and its outbuildings, shelters for domestic animals and water collection points within a radius of 150m. One hundred and three adult anophelinae were collected before the damming and 313 afterwards; 200 immature anophelinae before and 708 afterwards; 868 planorbidae before and 486 afterwards; and 2,979 phlebotominae before and 912 afterwards. The vector record, consisting of anophelinae, planorbidae and phlebotominae, shows the potential of this area for transmission of malaria, schistosomiasis and American cutaneous leishmaniasis. However, the environmental changes did not increase the risk of the occurrence of these diseases.

Tentativa de controle da leishmaniose tegumentar americana por meio do tratamento dos cães doentes

An attempt was made to control cutaneous leishmaniasis in the municipality of Santa Leopoldina, Espírito Santo State, Brazil, by treating infected dogs. Another area in the municipality of Afonso Cláudio, which is ecologically similar, served as the control area, and dogs were left untreated there. In an initial survey, 34/141 inhabitants of the first area had positive leishmanin tests and 8/26 dogs had cutaneous leishmaniasis, while in the second area 37/127 individuals had positive leishmanin tests and 7/44 dogs were infected. After treatment of the sick dogs in the first area the populations of both areas were periodically examined for new infections. More new human infections were observed in the control area, but the difference was not statistically significant.

Distribuição geográfica da leishmaniose tegumentar americana no Estado do Espírito Santo - Brasil

Analysis of the case records of 729 patients with cutaneous leishmaniasis collected from January 1972 to December 1982 permitted the authors to study the geographical distribution of this infection in the State of Espirito Santo, Brazil. Cases were found in 36 of the 53 counties of this State, the counties of Viana and Cariacica being the ones with greatest incidence of the disease. The cases observed in these two counties totalled 441 (60,47%) with 258 patients living in a few contiguous small villages in the endemic region. The transmission probably occurred inside and outside the house. From this highly endemic area in the valley ofthe Formate ri ver disease has already spreaded up to Domingos Martins county through the village of Biriricas. In the other regions cutaneous leishmaniasis was characterised as a longstanding disease in the State.

Dynamics of feeding and defecation in Triatoma vitticeps (Stal, 1859) (Hemiptera, Reduviidae, Triatominae) and its potential in the transmission of Trypanosoma cruzi

Adults of Triatoma vitticeps infected by flagellates similar to Trypanosoma cruzi are frequently captured by the inhabitants of rural areas in the Brazilian state of Espirito Santo. The dynamics of feeding and defecation were observed in three groups of adult triatomines, consisting of sylvatic T. vitticeps and laboratory-reared specimens of this species and T. infestans. Triatomines were observed from the moment they were presented with an immobilized chicken as a bloodmeal source until 240 min after feeding had ended. Mean times between the end of feeding and defecation for T. infestans, wild T. vitticeps and laboratory-reared specimens of the latter species were 1.2, 21.1, and 64 min respectively. All T. infestans defecated within 10 min of feeding, while only 29.9 of wild and 52.8% laboratory-reared specimens of T. vitticeps did so within this period. These results may explain the low efficiency of T. vitticeps in T. cruzi transmission to man. The shorter time between feeding and defecation in laboratory-reared T. vitticeps may indicate a change in behaviour of this species as a result of adaptation to an artificial environment.

Lutzomyia gasparviannai Martins, Godoy & Silva, 1962, probable vector of Leishmania mexicana ssp. in Viana municipality, Espírito Santo State, Brazil

Dos flebotomos atraidos pelo Proechimys iheringi numa area onde esse roedor foi achado naturalmente infectado por Leishmania mexicana ssp., 98,1% foram Lutzomyia gasparviannai, o que sugere que essa especie nao antropofilica seja o transmissor entre os roedores mas nao habitualmente ao homem.

Primeira descrição de singamose brônquica ocorrida no Estado do Espírito Santo

We report the case of a 48-year-old man who presented progressive dry cough associated with chest pain over a four-month period. After ruling out the most probable etiologies, bronchofibroscopy was performed and showed a pair of Syngamus laringeus inside the left upper lobe bronchus. The patient became asymptomatic after the nematodes had been removed.