[Comparative study between larval surveys and ovitraps to monitor populations of Aedes aegypti]. / Comparação entre pesquisa larvária e armadilha de oviposição, para detecção de Aedes aegypti.

This study compares two techniques for detecting the presence of Aedes aegypti: larval surveys and the oviposition trap. In two areas of the municipality of Salvador, Bahia, Brazil were investigated 5,026 households. Larval surveys and oviposition traps were used simultaneously in these households. Different positivity levels (larvae and/or eggs) were detected between and within the two areas. However, only the use of the oviposition trap detected a significant statistical difference between the areas (z = 9,520, p < 0.001). Comparison of the Breteau, Household and Oviposition Indices reveals greater power of detection of positivity in the oviposition trap. There were prevalence ratios of positivity for oviposition trap of 3.4 and 2.1 (for areas 1 and 2 respectively) when compared with larval surveys. The oviposition trap proved to be an economical and operationally viable method, and the most effective in the surveillance of this species.

[Aedes albopictus in rural zone of Brazil and its implication in the wild yellow fever transmission]. / Aedes albopictus em área rural do Brasil e implicações na transmissão de febre amarela silvestre.

Larvae and adult forms of Aedes albopictus were found during ecological study of anopheline mosquitos in the rural zone of the state of Mato Grosso do Sul in Brazil. This occurrence was registered, for the first time in Brazil, in an enzoootic area if sylvatic yellow fever virus. This implies a potential risk of the transfer of this virus to an urban area infested with Aedes aegypti.

[Strategy and perspectives for the control of cutaneous leishmaniasis in the state of São Paulo]. / Estratégia e perspectivas de controle da leishmaniose tegumentar no estado de São Paulo.

The multiplicity of factors involved in the transmission of American cutaneous leishmaniasis (ACL) make it difficult to formulate an efficient strategy for the control of the disease. On the basis of the number of notified cases per location, the State of São Paulo determines the application of DDT in houses in those areas where two or more human cases have occurred. This procedure, however, impairs part of the program because 40% of the counties report only one human case each. These and other factors are analyzed in the light of the increase in the incidence of the disease in the State, its advance in the extra-forest environment and the delay in the decision-making process about the efficacy of the program. It is recommended that the control strategy be reviewed.

Estratégia e perspectivas de controle da leishmaniose tegumentar no estado de São Paulo / Strategy and perspectives for the control of cutaneous leishmaniasis in the state of São Paulo

The multiplicity of factors involved in the transmission of American cutaneous leishmaniasis (ACL) make it difficult to formulate an efficient strategy for the control of the disease. On the basis of the number of notified cases per location, the State of São Paulo determines the application of DDT in houses in those areas where two or more human cases have occurred. This procedure, however, impairs part of the program because 40% of the counties report only one human case each. These and other factors are analyzed in the light of the increase in the incidence of the disease in the State, its advance in the extra-forest environment and the delay in the decision-making process about the efficacy of the program. It is recommended that the control strategy be reviewed.

A multiplicidade de fatores que envolve a transmissão da leishmaniose tegumentar americana resulta em dificuldades para se formular estratégia eficiente de controle da doença. O Estado de São Paulo, considerando o número de casos notificados por localidade, estabelece aplicação de DDT em área com ocorrência de dois ou mais casos. Com isto, parte do programa fica afetado, pois em 40% dos municípios tem-se registrado apenas um caso humano. Esses e outros fatores são analisados diante de um crescimento de distribuição da incidência no Estado e da evolução da doença em ambiente extraflorestal. Procedimentos administrativos com retardamento na tomada de decisão afetam a eficácia do programa. Daí, a necessidade de uma revisão na estratégia.

[Natural features of oviposition of Culex (Melanoconion) Group Pilosus (Diptera: Culicidae)]. / Observação sobre característica natural de oviposição de Culex (Melanoconion) Grupo Pilosus (Diptera: Culicidae).

Eggs of Culex (Melanoconion) Grupo Pilosus were found in three oviposition traps set in the toilet of a Bus Station in Joinville city, State of Santa Catarina, Brazil, during a surveillance study of Aedes aegypti. The intrinsic characteristic of group oviposition not directly on the water was confirmed.

[Anthropophilic behavior of Aedes albopictus (Skuse) (Diptera: Culicidae) in the Vale do Paraíba Region, southeastern Brazil]. / Comportamento antropofílico de Aedes albopictus (Skuse) (Diptera: Culicidae) na região do Vale do Paraíba, Sudeste do Brasil.

INTRODUCTION: The epidemiological role of Aedes albopictus has been investigated in the State of S. Paulo by the study of its biological and ecological characteristics. The biting activity of Ae.albopictus taking stationary and moving collectors as parameters, is determined. MATERIAL AND METHOD: The study area was a small farm located in the periurban zone of Tremembé city, Vale do Paraíba, State of S. Paulo, Brazil. Aedes albopictus was caught by using two human-bait modalities. One lasted 24 hours as the collectors remained sitting in only one place and in the other the collectors visited 48 different points for five minutes each over a total period of four hours in the morning and the afternoon. Both catches were made once a month for the period of a year (1989/90). RESULTS: The 24 catches undertaken yielded 637 females of Ae.albopictus, of which 54 (8.4%) and 583 (91.6%) corresponded, respectively to fixed and moving human-bait conditions. An analysis of the data was made to discover the influence of host movement as attracting stimulus for Ae.albopictus. The biting activity took place during the day with peaks at 6:00 a.m., 1:00-2:00 p.m. and the highest between 4:00 and 5:00 p.m. The majority of the adults were collected during the summer and autumn and the moving catches were positive for Ae.albopictus throughout the year. Rainfall and rising temperature were correlated to the abundance of this species. CONCLUSION: This study has shown the complex influence of the endogenous and exogenous factors relating to the blood feeding habit of Ae.albopictus. However, it seems clear that its biting behavior depends on two distinct flights. On one, the blood feeding is obtained by the flight direct to the host, over a small supposedly short distance, and another less significant apetente flight when collectors were in a stationary position. The biting activity took place during the day and may occur all year round.

Duration of larval and pupal development stages of Aedes albopictus in natural and artificial containers.

Aedes albopictus were reared in different containers: a tree hole, a bamboo stump and an auto tire. The total times from egg hatching to adult emergence were of 19.6, 27.3 and 37.5 days, respectively, according to the container. The first, second and third-instar larvae presented growth periods with highly similar durations. The fourth-instar larvae was longer than the others stages. The pupation time was longer than the fourth-instar larvae growth period. The temperature of the breeding sites studied, which was of 18 degrees C to 22 degrees C on average, was also taken into consideration. The mortality of the immature stages was analysed and compared as between the experimental groups; it was lower in the natural containers than in the discarded tire. The average wing length of adult females emerging from tree hole was significantly larger (p < 0.05) than that of those emerging from the tire.

Studies on mosquitoes (Diptera: Culicidae) and anthropic environment. 1--Parity of blood seeking Anopheles (Kerteszia) in south-eastern Brazil.

Populations of Anopheles (Kerteszia) were sampled fortnightly over a one-year period (August 1991 to July 1992) at Ribeira Valley, S. Paulo State, Brazil. Indoor and outdoor collections were made on human bait at evening crepuscular period. The Polovodova technique for age grading was applied to 3,501 females of Anopheles cruzii and to 416 females of An. bellator. That sample represented 34.4% of the total number of mosquitoes collected. The most abundant species found was An. cruzii. However, An. bellator showed an endophagy that was almost three times greater than that of An. cruzii. The overall parous rate was 25.4% and uniparity was practically dominant one. A proportion of 26.9% of An. cruzii and 12.0% of An. bellator were found to be uniparous. Only three outdoor females of the former species (0.1%) showed biparity. Parity of An. cruzii was higher in females caught indoors than in those caught outdoors. Nevertheless, 497 nulliparous females examined (417 cruzii and 80 bellator) had ovaries that had advanced to Christophers and Mer stages III to V. These results imply that these females had already practised hematophagy. Relating these results to those from the parous females, a high statistical significance was found, leading to the conclusion that gonothophic discordance is a common pattern among these anophelines. Further, these results obtained with human bait catches strongly suggest that nearly 38.0% of these host-seeking females had already taken at least one previous blood-meal. So it is possible that enough time could thus be available for the plasmodian development in the vectors.

[Microhabitats of Aedes albopictus (Skuse) in the region of the Paraiba Valley, São Paulo State, Brazil]. / Microhabitats de Aedes albopictus (Skuse) na região do Vale do Paraíba, Estado de São Paulo, Brasil.

The objective of this study was the determination of extent of the spatial distribution of Aedes albopictus in the Paraíba River Valley, State S. Paulo, Brazil. Thus, collections of larvae and pupae mosquitoes were carried out at six sites distributed along a transection with a 10-km extension. The target was the tree-holes but artificial containers were also used in this investigation. Aedes terrens and Ae. albopictus were the only species of genus Aedes present in the tree-holes mentioned. The segregation of seven species of the tree-hole community was undertaken in the light of macrohabitat and microhabitat features. Thus, the distribution of Ae. albopictus was found to cover the rural, rural-urban and urban zones, but the rural-urban held the preference. Ae. albopictus never present in the residual and primary forest. The favorable factor to infestation with Ae. albopictus in the Paraíba Valley seems to have been the large number of natural niches made vacant by human influence. The rain has been important in the production of larvae and pupae, but the rainfall period does not coincide with the maximum production on them. The tree-holes whose volume exceeded 600 ml were the most productive breeding places. The abundance of these two stages occurs in the summer and autumn. However, the highest peak was observed in the months of March and April. These seasonal variations were found to be common in both the bamboo trap and the artificial container. The temperature data suggest a limit of from 17 to 23 degrees C for the best development of larvae. In the light of this, the strain of Ae. albopictus studied seems to have originated in tropical Asia. Just as happened with Ae. aegypti it may become an important epidemiological vector for the dengue fever and provide links for yellow fever transmission in Brazil.

[Ecological aspects of American cutaneous leishmaniasis. 9. Prevalence/incidence of the human infection in the municipality of Pedro de Toledo and Miracatu, São Paulo, Brazil]. / Aspectos ecológicos da leishmaniose tegumentar americana 9. Prevalência/incidência da infecção humana nos municípios de Pedro de Toledo e Miracatu, São Paulo, Brasil.

The epidemiologic study was conducted during the 1973-1984 period. The clinical prospective exam and Montenegro skin, immunofluorescent and passive hemagglutination tests have been carried out in three small localities between Pedro de Toledo e Miracatu municipalities, São Paulo, Brazil. The retrospective study of human-cases involved 108 and 65 cases registered in Pedro de Toledo e Miracatu, respectively. In the three communities studied, 273 people were examined clinically and serologically. Twenty two individuals had had signals of cutaneous leishmaniasis; 10.2 and 12.8% were seropositive to IF and HA. Leishmanin skin testing of a sample of 154 people residents in Pedra do Largo showed prevalence of Leishmania infection in 25.5%. This result involved individual of all ages and sex. However, 5.8% of them were from 0 to 9 years old. The data confirmed that active parasite transmission didn't occur every year, either. The human infection seems not to depend on man contact with a forest. The incidence relatively low suggests low endemic area for cutaneous leishmaniasis and an explosive behavior of the cases. The temporal distribution of disease was irregular and the epidemiological pattern seen was different from the other endemic area of South America.

[Domiciliation of Culex mosquitoes (Melanoconion), in man-made deeply modified environment]. / Observações sobre domiciliação de mosquitos Culex (Melanoconion), em ambiente com acentuadas modificações antrópicas.

Some data on Culex (Melanoconion) mosquito behavior in human environments are presented. Adults were collected simultaneously through peridomiciliary and extradomiciliary catches, with the use of human bait inclusive. Dominant species were identified as Cx. delpontei, Cx. ocossa, Cx. ribeirensis, Cx. sacchettae and Cx. taeniopus. In the domiciliary environment Cx. ribeirensis and Cx. sacchettae, the principal species found, were collected with considerable frequency by the use of human bait placed in the peridomiciliar environment. Cx. delpontei and Cx. ocossa showed a lower frequency in that environment. Greater numbers of adults were obtained in the first three months of the year, particularly in March. Nocturnal activities showed two apparently distinct patterns. One of them was presented by Cx. ribeirensis, Cx. sacchettae and Cx. taeniopus as a curve increasing quickly during the first hours os the night and maintaining the same level until dawn. The other was shown by Cx. delpontei and Cx. ocossa, as a curve which increased gradually until midnight, and then decreased gradual by until dawn. Breeding places of Cx. delpontei were found in medium and large rivers with a covering of aquating floating vegetation, mainly Pistia. Considerations relating to those ecological aspects of epidemiological interest are made.

[Shelters of mosquitoes Culex (Culex) in rural zones (Diptera: Culicidae)]. / Abrigos de mosquitos Culex (Culex) em zona rural (Diptera: Culicidae).

The human activities carried out in rural zones have been affecting the behavior of mosquitoes of the Culex (Culex) subgenera, which was the reason for undertaking this investigation with a view to registering data on the natural resting places in pastures and on the edge of or within primitive and residual forest areas. Three localities with different mesological conditions, as to type of human activity, all them situated in the Ribeira Valley region of S. Paulo State, Brazil, were chosen. The species most abundantly found were Cx. mollis (28.0%), Cx. declarator (25.0%), Cx. lygrus (13.0%) and Cx. coronator (9.6%). The collection of mosquitoes Cx. bidens + Cx. dolosus + Cx. chidesteri, known to be more urban, was much smaller than that of any other species of the group. With reference to outdoor environments, woodland contributed with 2,281 individuals (71.4%) suggesting their preference for this resting place, except for Cx. quinquefasciatus. Results are evaluated for the determination of the potential domicilation of each species and consequence of the same for the human population.

[Findings of Phlebotominae (Diptera: Psychodidae) in the southern coast of the State of São Paulo, Brazil]. / Nota sobre encontro de Phlebotominae (Diptera:Psychodidae) no litoral sul do Estado de São Paulo, Brasil.

Five species of phlebotomine sandflies were caught on the Southern part of the coast of S. Paulo, Brazil. CDC-light and Shannon traps were used, as well as human-bait, during two investigations into Culicidae mosquitoes. Lutzomyia intermedia and L. flaviscutellata were found among those sandflies. The localities investigated were swampy environments and scant human cases of cutaneous leishmaniasis have been notified there. Both situations suggest the autochthonous nature of the human cases registered there.

[Frequency in human environment and dispersion of Culicidae mosquitoes in an area adjacent to a primitive Atlantic plain forest]. / Freqüência ao ambiente humano e dispersão de mosquitos Culicidae em área adjacente à mata Atlântica primitiva da planicie.

Results of peridomiciliary and forest environment mosquito catches are presented. By using the method single host, mosquitoes were identified according to blood-meal and thus their dispersal was observed. Evidence was obtained for movements of Aedes scapularis, due apparently were appetential flights, as well as its permanence in peridomiciliar resting places. Occurrence in domestic animal shelters was recorded for this species. Peridomiciliar human bait catches showed regular occurrence of Ae. scapularis, Anopheles bellator, An. cruzii and Culex sacchettae, but anophelines abandoned the human environment for the surrounding forest. Feeding index showed clearly a preference on the part of Ae. scapularis for bovine hosts. The peridomiciliar frequency of Cx. sacchettae suggests a domiciliary tendency. The influence of large domestic animals in the human environment surrounded by primitive Atlantic plain forests, on the domiciliation of the sylvatic mosquitoes, is emphasized.

[Ecological aspects of American tegumentary leishmaniasis: 8. Evaluation of the enzootic activity of Leishmania (Viannia) braziliensis, in forest and peridomiciliary environments of the Ribeira Valley region, São Paulo State, Brazil]. / Aspectos ecológicos da leishmaniose tegumentar Americana. 8. Avaliação da atividade enzoótica de Leishmania (Viannia) braziliensis, em ambiente florestal e peridomiciliar, região do Vale do Ribeira, Estado de São Paulo, Brasil.

The evidence of mucocutaneous leishmaniasis transmission in the non-forest environment in the Ribeira Valley region, São Paulo, Brazil, has made this epidemiologic four years' study possible, viewing the enzootic activity of L. (V.) braziliensis. Furthermore, the natural infection in small mammals and the domestic dog population has been completed in collecting of phlebotomine sandflies in the forest and peridomiciliar environments. Positive test-results have only been found in resident dogs (Canis familiaris) with a rate of 5.6 and 2.4% for serological and parasitological test respectively. Among silvatic and synanthropic rodents collected, Oryzomys (Olygoryzomys) and Rattus rattus are pre-eminent having both been collected in equal proportions, in peridomiciliar environment. The sandfly Lutzomyia intermedia has contributed only with 166 feminine specimens due to insecticide (DDT) application on and in the human and domestic habitations. From the general epidemiologic standpoint the fragile L. (V.) braziliensis cycle in the unforested areas as well as the canine and small mammals roles as a domiciliar infection source are discussed, and their potencial in the dispersion of this parasite in the researched area is analysed too.

[Adult Culicidae mosquitoes in the irrigated culture of rice in the Vale do Ribeira, State of São Paulo, Brazil]. / Observações sobre mosquitos Culicidae adultos em cultivo irrigado de arroz no Vale do Ribeira, Estado de São Paulo, Brasil.

A collection of adult Culicidae was carried out during the period from May 1984 to September 1985, in a rice field in the polder of the Experimental Station of Pariquera-Açú, in the Ribeira Valley (S. Paulo State, Brazil). CDC miniature traps, supplemented with dry ice, were used. A total of 2,686 mosquitoes were collected. The most frequent were the Coquillettidia and Mansonia genera (nearly 55% of the specimens caught). Aedes scapularis, as an isolated species, contributed with near by 11% of the total catch. Culex (Melanoconion) represented almost 24% of the mosquitoes caught. The sequence of events involved in the flooding of rice seems be associated with the production of Coquillettidia and Mansonia. Ae. scapularis seems to profit from the artificial ecotope represented by the irrigated rice field as a means by which to increase its adaptation to the artificial human environment. No evidence was obtained on the association between Culex (Melanoconion) catches and the cultivation of the rice field. It seems that cultivation exercises no influence on the local Anopheles and Psorophora species.

[Ecologic aspects of tegumentary American leishmaniasis. 7. Phlebotomus vectorial capacity in the primitive forest environment of the Serra do Mar system, Vale do Ribeira region, State of São Paulo, Brazil]. / Aspectos ecológicos da leishmaniose tegumentar americana. 7-Capacidade vetorial flebotomínea em ambiente florestal primário do sistema da Serra do Mar, Região do Vale do Ribeira, Estado de São Paulo, Brasil.

A total of 5,038 specimens, belonging to nineteen species, were obtained during the three consecutive years of phlebotomine catches in forest and peridomiciliary environments of the Itapoan farm. Proportionally, the CDC light trap contributed with 92.2% in the forest and 0.7% in the peridomicile sites while the human bait corresponded to 7.0% in the forest. Generally speaking the outcome of the technique utilized was rather low or presented reduced geometrical averages. The most common species in the area was P. ayrozai, almost always predominant; however, the results with human bait prevent one's ascribing a high degree of anthropophilic properties to it. The implication of the reduced presence of L. intermedia, L. migonei and L. fischeri, even with human bait, is that the conditions for the transmission of the disease to man in the forest environment are inexistent. Consequently, this could indicate that the vectorial function would be performed by a population which has survived the period of devastation. For this reason a new epidemiological pattern, connected with a focus, of L.b. braziliensis seems to exist in Brazil.

[Food preferences and domiciliation of Culicidae mosquitoes in the Ribeira Valley, São Paulo, Brazil, with special reference to Aedes scapularis and Culex (Melanoconion)]. / Preferências alimentares e domiciliação de mosquitos Culicidae no Vale do Ribeira, São Paulo, Brasil, com especial referência a Aedes scapularis e a Culex (Melanoconion).

New results on blood-meal identification and the environmental distribution of mosquitoes collected in four different Ribeira Valley (S. Paulo State, Brazil) environments, during the period February to November 1986, are presented. Sources of 651 blood-meals were identified. The preference of Ae. scapularis for large mammals, chiefly cattle, horse and even man, was confirmed. Data suggests that a similar behavioral pattern is presented by Cx. ribeirensis. Both mosquitoes seem to be strongly attracted by peridomiciliar blood sources represented by domestic animals sheltered in that environment. Nevertheless, the female of Ae. scapularis females may use the extradomiciliary environment, represented by residual forests, as resting place in the same way as it uses the peridomiciliary one. The data confirm the clear tendency of both Ae. scapularis and Cx. ribeirensis to adapt to the man-made environment and thus the evolution towards domiciliation in the behavior of these mosquitoes. Other culicids, such as An. bellator, An. cruzii and Cq. chrysonotum, were collected practically only by the use of human bait. For An. cruzii the number of females collected by this method represented 31.6% of the female total collected during this project. Some data about other species are given, and the need for further researches about Culex (Melanoconion) species is emphasized.

[Ecologic aspects of American tegumentary leishmaniasis. 6. Anthropophillic Phlebotomus fauna of residual forests located in the Northeastern region of the State of São Paulo, Brazil]. / Aspectos ecológicos da leishmaniose tegumentar americana. 6. Fauna flebotomínea antropófila de matas residuais situadas na região centro-nordeste do Estado de São Paulo, Brasil.

This report shows the phlebotomine vectorial role in the endemic cutaneous leishmaniasis situated in the middle and north-eastern region of the São Paulo, Brazil. Analysis of information encloses a sandfly man-biting fauna of four different patches of residual forest. So, using the human-bait and Shannon trap for a period of one year we have caught 16,869 sandflies. The predominance of Lutzomyia intermedia (85.6%) was clear. Moreover, the low density of Lutzomyia whitmani and Lutzomyia pessoai and their epidemiological implications at present and in the past are discussed. Information about the daily activity of some species is given and we emphasize for the first time, the diurnal activity of Lutzomyia firmatoi in the São Paulo State.