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Aedes aegypti is an important vector in Brazil being the main vector of the dengue-fever. This paper employs survival curves to describe the time in days from larvae to adult forms of Aedes aegypti raised, individually and collectively, and compares it during winter and spring when positioned inside and outside a laboratory. The study was conducted in São Vicente, a coastal city in Southeastern Brazil. The lowest water temperature in winter and in spring was 20 °C and the highest was 26 °C in spring. Higher and more stable temperatures were measured in the intra compared to the peri in both seasons. Consequently, larvae positioned in the intra resulted in the lowest median time to develop in the individual and collective experiment (nine and ten days, respectively). At least 25% of the larvae positioned in the intra in the individual experiment in the spring took only seven days to reach adulthood. Sex ratios and the median time development by sex did not show significant differences. These results indicate that efforts to control Aedes aegypti must be continuous and directed mainly to prevent the intra-domiciliary sites that can be infested in a week in order to reduce the human-vector contact.

Introduction: In a region of high dengue incidence, on the coast of the State of São Paulo, 9 areas were selected to evaluate the behavior of immature Aedes aegypti., Methods: The 9 areas were grouped into 4 strata according to soil use and occupation. Larvae and pupas were collected in a sample of approximately 500 buildings in each area., Results: Although tires and canvas presented the highest positive rates for Aedes aegypti, drains and other containers fixed to the buildings were highly predominant among positive containers; 32 to 76% of the positive containers in the 4 study strata. Public areas of apartment buildings and large non-residential premises presented the highest positive rates for Aedes Aegypti, while apartments presented the lowest. Infestation levels were greater in residential areas with predominance of apartment buildings, where 76% of the breeding sites detected were containers fixed to the buildings., Conclusions: This knowledge is an important tool in the control strategy, since it reinforces the need for special attention regarding certain types of buildings and the adjustment of technical norms for pluvial water drains and improvement of building maintenance. Moreover, systematic observations are required to follow-up the occupancy dynamic of different buildings and containers by Aedes aegypti and the incorporation of this knowledge in the control of vectors in the region.

In this work, we studied the neuromuscular blockade caused by Micrurus altirostris venom (0.1-10 microg/mL) in indirect stimulated chick biventer cervicis and mouse phrenic nerve-diaphragm preparations and the ability of commercial antivenom (Instituto Butantan) and antiserum raised in rabbits to neutralize neurotoxicity and lethality in chicks and mice (LD(50) 0.042 and 0.255 mg/kg), injected i.m. and i.p., respectively, with venom (5 LD(50)):antivenom or antiserum mixtures (n = 6) of 1:1-1:2.5-1:5-1:10-1:20. The venom caused a complete and irreversible neuromuscular blockade in both preparations, inhibited the acetylcholine and carbachol contractures, without interfering on KCl response. The neuromuscular blockade was not Ca(2+) or temperature-dependent and did not affect the response to direct stimulation. Only a venom:antivenom or antiserum ratio of 1:20 neutralized the neuromuscular blockade in vitro and protected chicks and mice against 5 LD(50) of venom. Our results indicated that Micrurus altirostris venom interferes with postsynaptic neurotransmission and that commercial antivenom and rabbit antiserum have low efficacy in neutralizing the neurotoxicity and lethality of this venom.

The objective of this study was to analyze the surveillance of Chagas' disease in São Paulo State through notifications registered from 1990 to 1999. The information originated when notification of triatomines was announced by inhabitants and the established control program was followed. 20,563 triatomine notifications were received, showing a decrease over the years, with more accentuated decreases in the area of greatest frequency of Panstrongylus megistus. Each notification corresponded to an average of 1.3 examples of captured triatomines (median = 1), predominantly in the intradomicile area, while during attendance, the mean number of collected insects was 3.6 (median = 2), mostly present in the peridomicile area. The notification distribution permitted the demarcation of three different areas in the state: area 1, comprising the areas of São José do Rio Preto, Araçatuba and part of Presidente Prudente; area 2, São Vicente and Sorocaba; area 3, municipalities located to the northeast of the Campinas region. Analysis showed that entomological surveillance through triatomine notification, despite the fall in the same, has not detected intradomiciliary colonies associated with Trypanosoma cruzi which could give rise to vectorial transmission of Chagas' disease.

Objective: To analyze serological data collected in two different periods, from the late 1960's to 1983, when these data was first added to the available information about vector triatomines found in the state of São Paulo, and from 1984 to 1999, a period when serology was used to describe endemic Chagas' disease in the state., Methods: Serological surveillance data from schoolchildren (during the late 1960s and between 1973 and 1983), and the general population (between 1980 and 1982) of the municipalities of Cananéia, Iguape and Peruíbe were analyzed together with data collected on the vectors., Results: Seropositivity among schoolchildren remained low and constant in the period from 1973 to 1982, and was no more detected in 1983. Cananéia showed titer distribution patterns typical of a non-endemic area, while Iguape and Peruíbe indicated low endemicity. Most of the cases came from other states; autochthonous cases were suggestive of oral transmission. There were reports of infestation by vector triatomines in 1,261 domiciliary units (main species: Panstrongylus megistus and Triatoma tibiamaculata). A total of 5,338 blood samples were collected and 40 were seropositive (0.75%). Triatomines captured within domiciles were mostly adults, and about half of them having fed upon human blood. Serological results of residents living in households where triatomines infected with Trypanosoma cruzi had been found did not differ from those living in houses infested only with non-infected insects., Conclusions: In addition to educational activities aimed at the local population, there is a need to develop a collaboration between scientific institutions to isolate and characterize trypanosoma strains from vectors, reservoirs (sylvatic or other) and humans. Thus, evolutional, ecological, pathological and other pertinent characteristics of different strains of such parasites could be better understood.

Considered as an American tegumentary leishmaniasis (ATL) endemic area, Ribeira Valley, in the south region of São Paulo State, presented 929 notified cases in the last 15 years. Aiming to identify the phlebotomine fauna, captures were performed fortnightly in the rural area of Pedro de Toledo County during one year, from may 1994 onwards. Set at dusk Shannon traps were used in the peridomicile and CDC light traps both intra and peridomiciliarly and at the edge and in the forest. Eight species summing to 11,096 specimens were caught, L. intermedia being the dominant one (96.4%). More frequent all over the year during the first half of the night preferably in the domicile surroundings this species clearly indicated its preference for the anthropic environment. The data presented in this paper ratify L. intermedia as an important ATL vector species in the Ribeira Valley.

Achatina fulica, the intermediate snail host of angiostrongyliasis and also an agricultural pest, is being bred in Brazil for human consumption as "escargot". The snail has escaped from its artificial breeding sites and its dispersal in Itariri country, State of S. Paulo, is reported here for the first time. A. fulica is a transmitter of the rat lungworm Angiostrongylus cantonensis, nematode which causes meningoencephalic angiostrongyliasis; the risks of human contamination are commented on.

Since the beginning of the seventies the natural transmission of Chagas' infection has been considered to be under control in the State of São Paulo and not even a case of American Trypanosomiasis, transmitted by triatomine bugs, has been detected by the epidemiological surveillance system. This situation justifies the report of a case of acute Chagas' disease that occurred in a forest area considered free of domiciliary triatomines along the Southern seacoast of São Paulo State. In May, 1995 the presence of trypomastigote forms of Trypanosoma cruzi had been diagnosed in a retired 57 year-old male patient, born and living in Santos (São Paulo State), complaining of fever, fatigue and malaise. The patient reported that 40 days before he had participated with 17 friends in a 7-day excursion in a forest area of the municipalities of Itanhaém and Peruíbe. During this period the group had been lodged in three houses located within the forest. Eight days after the end of the excursion the patient began to have fever, malaise and fatigue. During the next 31 days he had received medical care both as an inpatient and an outpatient, without any significant improvement. After the detection of T. cruzi trypomastigotes in his blood stream the patient began to be treated with benzonidazole in a hospital but died 8 days after the beginning of treatment. The epidemiological investigation carried out showed no signs of the presence of triatomine bugs in the three houses where the group had been lodged, or any indication of Chagas' infection in other excursionists.

Epidemic outbreaks of dermatitis caused by Hylesia sp which occurred in the coastal region of the State of S. Paulo during the period of December 1989 to December 1991 are confirmed. The incident assumed its greatest intensity in Bertioga, in Santos County, where 612 cases were registered. The outbreak also affected 12 other counties in that region and it was estimated that hundred of affected persons sought the Local Health Service Care. The majority presented with erythematous and prutiginous lesions and papula which lasted 7 to 14 days on average. Treatment consisted of systemic administration of antihistamines, and the use of topic corticosteroids and cold compresses. During the above-mentioned period, three epidemic episodes, coinciding with the rainy season (November to January), occurred. They were first observed in the northern part of the coastal area and then spread to the south. Information as to how avoid contact with the moth was the main prophylactic measure. In highly infested buildings the effectiveness of residual insecticide procedure was used in the attempt to reduce the level of moth infestation. Satisfactory results were obtained with deltametrin applied in a dosage of 50 mg/m2 of wall.