Dengue and the risk of urban yellow fever reintroduction in São Paulo State, Brazil

OBJECTIVE: To propose a mathematical method for the estimation of the Basic Reproduction Number, R0, of urban yellow fever in a dengue-infested area. METHODS: The method is based on the assumption that, as the same vector (Aedes aegypti) causes both infections, all the quantities related to the mosquito, estimated from the initial phase of dengue epidemic, could be applied to yellow fever dynamics. It is demonstrated that R0 for yellow fever is, on average, 43% lower than that for dengue. This difference is due to the longer dengue viremia and its shorter extrinsic incubation period. RESULTS: In this study the analysis was expanded to the epidemiological situation of dengue in São Paulo in the year 2001. The total number of dengue cases increased from 3,582 in 2000 to 51,348 in 2001. It was then calculated R0 for yellow fever for every city which have shown R0 of dengue greater than 1. It was also estimated the total number of unprotected people living in highly risky areas for urban yellow fever. CONCLUSIONS: Currently there is a great number of non-vaccinated people living in Aedes aegypti infested area in the state of São Paulo.

"Multiplex PCR" identification of the atypical and monophasic Salmonella enterica subsp. enterica serotype 1,4,[5],12:i:- in São Paulo State, Brazil: frequency and antibiotic resistance patterns

Salmonella spp. are the etiologic agents of salmonellosis, a worldwide spread zoonoses causing foodborne outbreaks and clinical diseases. By serological identification, Salmonella enterica subsp. enterica serotype 1,4,[5],12:i:- accounted for 8.8% of human and 1.6% of nonhuman Salmonella strains isolated in São Paulo State, during 1991-2000. A total of 28.6% of them amplified a fragment corresponding to H:1,2 (flagellar phase two) through PCR analysis and were further assigned as S. Typhimurium. Antimicrobial resistance was detected in 36.3% of the 369 PCR-negative strains tested, including the multiresistance to ampicillin, chloramphenicol, sulfonamides, tetracycline, and streptomycin.

Enteroparasitic occurrence in fecal samples analyzed at the University of Western São Paulo-UNOESTE clinical laboratory, Presidente Prudente, São Paulo State, Brazil

This study aims to analyze the enteroparasitic occurrence in children from 0 to 12 years old consulted at the University of western São Paulo Clinical Laboratory, Presidente Prudente, SP, Brazil, in relation to the socioeconomic profile of the attended children. Stool samples were examined and a questionnaire was applied with the objective of knowing the patient's age, sex, medical attendance, characteristic of the habitation, provisioning of water, dejection and domestic waste fates, use of footwear and clinical signs. The software EPI INFO 6 (Version 6.04b) was used for the elaboration of the data bank structure and analysis after previous data codification. Among 1,000 children analyzed, as many as 21.3% presented some kind of parasite. The most frequent protozoan was Giardia lamblia (7.3%) followed by Entamoeba coli (3.9%). The most frequent helminth was Enterobius vermicularis (1.9%) followed by Hymenolepis nana (0.5%). The most frequent protozoan association was Giardia lamblia / Entamoeba coli (0.9%).

Septicemia caused by Paracoccidioides brasiliensis (Lutz, 1908) as the cause of death of an aids patient from Santos, São Paulo State, Brazil – a nonendemic area

The first case of Paracoccidioides brasiliensis in Santos (Brazil) leading to septicemia and death of an HIV-positive patient is reported here. The patient was a 34-year-old female that presented essential fever and was only diagnosed after death by positive blood culture. The authors underscore the atypical nature of the case, since the patient was a female at fertile age who was born and had always lived in Santos, which is a nonendemic area for this infection.

Molecular characterization of two rocio flavivirus strains isolated during the encephalitis epidemic in são paulo state, brazil and the development of a one-step rt-pcr assay for diagnosis

Rocio virus (ROCV) was responsible for an explosive encephalitis epidemic in the 1970s affecting about 1,000 residents of 20 coastland counties in São Paulo State, Brazil. ROCV was first isolated in 1975 from the cerebellum of a fatal human case of encephalitis. Clinical manifestations of the illness are similar to those described for St. Louis encephalitis. ROCV shows intense antigenic cross-reactivity with Japanese encephalitis complex (JEC) viruses, particularly with Ilheus (ILHV), St. Louis encephalitis, Murray Valley and West Nile viruses. In this study, we report a specific RT-PCR assay for ROCV diagnosis and the molecular characterization of the SPAn37630 and SPH37623 strains. Partial nucleotide sequences of NS5 and E genes determined from both strains were used in phylogenetic analysis. The results indicated that these strains are closely related to JEC viruses, but forming a distinct subclade together with ILHV, in accordance with results recently reported by Medeiros et al. (2007).

Epidemiological and ecological aspects related to malaria in the area of influence of the lake at Porto Primavera dam, in western São Paulo State, Brazil

A study was carried out in the area of influence of the Porto Primavera Hydroelectric Power Station, in western São Paulo State, to investigate ecological and epidemiological aspects of malaria in the area and monitor the profile of the anopheline populations following the environmental changes brought about by the construction of the lake. Mosquitoes captured were analyzed by standardized indicator species analysis (ISA) before and during different flooding phases (253 m and 257 m elevations). The local human population was studied by means of parasitological (thin/thick blood smears), molecular (PCR) and serological tests. Serological tests consisted of Enzyme Linked Immunosorbent Assay (ELISA) with synthetic peptides of the circumsporozoite protein (CSP) from classic Plasmodium vivax, P. vivax variants (VK247 and "vivax-like"), P. malariae and P. falciparum and Indirect Immunofluorescence Assay (IFA) with asexual forms of P. vivax, P. malariae and P. falciparum. The results of the entomological survey indicated that, although the Anopheles darlingi population increased after the flooding, the population density remained very low. No malaria, parasite infection or DNA was detected in the inhabitants of the study area. However, there was a low frequency of antibodies against asexual forms and a significant prevalence of antibodies against P. vivax, P. vivax variants, P. falciparum and P. malariae; the presence of these antibodies may result from recent or less recent contact with human or simian Plasmodium (a parallel study in the same area revealed the existence of a sylvatic cycle). Nevertheless, these results suggest that, as in other places where malaria is present and potential vectors circulate, the local epidemiological conditions observed could potentially support the transmission of malaria in Porto Primavera Lake if infected individuals are introduced in sufficient numbers. Further studies are required to elucidate the phenomena described in this paper.

Comparison of Bothropoides jararaca bites with and without envenoming treated at the Vital Brazil Hospital of the Butantan Institute, State of São Paulo, Brazil

INTRODUCTION: This study analyses the cases of all bites (including dry bites) caused by Bothropoides jararaca attended at the Vital Brazil Hospital of the Butantan Institute, State of São Paulo, Brazil. METHODS: A retrospective study was conducted of patients bitten by Bothropoides jararaca (n=792) from January 1990 to December 2004. The characteristics of the snake specimen, data related to the accident and clinical manifestations on admission were obtained from patient medical records. RESULTS: The majority of the cases in this study were caused by female and juvenile snakes. No stomach contents were found in 93.4% of the snake specimens after dissection. No statistical difference was observed between the occurrence of dry bites and the maturity or sex of the snake. The median SVL of snakes in mild and moderate cases was 40.5cm and in severe cases, SVL increased to 99cm. Necrosis was more common in the digits of the feet and hands (4.8%) compared to the other body regions (1.8%). A significant difference was verified between severity and a time interval greater than six hours from the bite to hospital admission. A significant association was verified between gingival bleeding and abnormal blood coagulability. In accidents caused by adult snakes, necrosis was more frequent (7.2%) compared to accidents caused by juvenile snakes (1%). CONCLUSIONS: In this work, the association between certain epidemiological data and the evolution of biological parameters in the clinical course of Bothrops sensu latu accidents were highlighted, contributing to the improvement of snake bite assistance.

First report of rabies infection in bats, Molossus molossus, Molossops neglectus and Myotis riparius in the city of São Paulo, State of São Paulo, southeastern Brazil

INTRODUCTION: This paper presents the first report of rabies in three bat species, Molossus molossus, Molossops neglectus and Myotis riparius in the city of São Paulo, Brazil. METHODS: Bats were diagnosed as positive for rabies using the fluorescent antibody test and mouse inoculation test. The isolates were characterized antigenically using a panel of eight monoclonal antibodies. The samples were also genetically analyzed by partial sequencing of the portion of nucleoprotein gene between positions 1157 and 1445nt. RESULTS: Analysis of the results verified that the sample isolated from the species M. molossus presented antigenic variant 6, while the other two samples showed a different profile from that established in the panel, one not previously reported in the literature. The results of genetic analysis revealed that the M. molossus sample segregated with Lasiurus sp. isolates, M. neglectus segregated with a subgroup of Eptesicus furinalis isolates and the Myotis riparius sample segregated with Myotis sp. isolates. CONCLUSIONS: The cases reported in this paper emphasize the need for clarification of the circumstances in which cases of rabies in wildlife occur, principally in urban areas.

Giardia survey in live-trapped small domestic and wild mammals in four regions in the southwest region of the State of São Paulo, Brazil

For the first time, a survey on Giardia in the live-trapped small domestic and wild mammals was perfomed in four regions of state of the São Paulo, Brazil, with special attention to the parasitism of Rattus rattus rattus by Giardia. This species was found infected in all studied sites: Botucatu (15.4%), Conchas (28.5%), Itaporanga (38.7%) and São Roque (100 %). Two new hosts and their frequency of infection were described for Giardia in Nectomys squamipes, an aquatic rodent and in Bolomys lasiurus, a forest rodent (100 % and 14.3 %, respectively). Both G. muris and G. duodenalis groups were found in scrapings of intestinal mucosa of those rodents. Mixed infection was observed in some animals. It is important to emphasize the infection by G. duodenalis in the black rat as this species lives as a comensal with man and in N. squamipes as it may contaminate small streams used for domestic consumption. Therefore, further investigation will be necessary to elucidate the potential of these rodents to act as reservoirs of Giardia for man.

Dispersal and survival of Nyssomyia intermedia and Nyssomyia neivai (Diptera: Psychodidae: Phlebotominae) in a cutaneous leishmaniasis endemic area of the speleological province of the Ribeira Valley, state of São Paulo, Brazil

The dispersal and survival of the phlebotomines Nyssomyia intermedia and Nyssomyia neivai (both implicated as vectors of the cutaneous leishmaniasis agent) in an endemic area was investigated using a capture-mark-release technique in five experiments from August-December 2003 in municipality of Iporanga, state of São Paulo, Brazil. A total of 1,749 males and 1,262 females of Ny. intermedia and 915 males and 411 females of Ny. neivai were marked and released during the five experiments. Recapture attempts were made using automatic light traps, aspiration in natural resting places and domestic animal shelters and Shannon traps. A total of 153 specimens (3.48%) were recaptured: 2.59% (78/3,011) for Ny. intermedia and 5.35% (71/1,326) for Ny. neivai. Both species were recaptured up to 144 h post-release, with the larger part of them recaptured within 48 h. The median dispersion distances for Ny. intermedia and Ny. neivai, respectively, were 109 m and 100 m. The greatest dispersal range of Ny. intermedia was 180 m, while for Ny. neivai one female was recaptured in a pasture at 250 m and another in a pigsty at 520 m, showing a tendency to disperse to more open areas. The daily survival rates calculated based on regressions of the numbers of marked insects recaptured on the six successive days after release were 0.746 for males and 0.575 for females of Ny. intermedia and 0.649 for both sexes of Ny. neivai. The size of the populations in the five months ranged from 8,332-725,085 for Ny. intermedia males, 2,193-104,490 for Ny. intermedia females, 1,687-350,122 for Ny. neivai males and 254-49,705 for Ny. neivai females.

The immature stages of two Caladomyia Säwedall, 1981 species, from São Paulo State, Brazil (Chironomidae, Chironominae, Tanytarsini)

The pupae and larvae of Caladomyia ortoni Säwedall, 1981 and Caladomyia riotarumensis Reiff, 2000, from São Paulo State, are described and illustrated. Caladomyia ortoni Säwedall, 1981 = Nimbocera paulensis Trivinho-Strixino & Strixino, 1991, syn. nov.

Diversity of social wasps (Hymenoptera, Vespidae, Polistinae) in three fragments of semideciduous seasonal forest in the northwest of São Paulo State, Brazil

Human exploitation of the forest in the northwest of São Paulo State has generated enormous fragmentation of that forest. Such disturbance has reduced the populations of insects in general. This work was a survey of social wasps (Hymenoptera, Vespidae; Polistinae) in three areas in different stages of regeneration: Paulo de Faria - SP (435 ha), Pindorama - SP (128 ha) and Neves Paulista - SP (1 ha). These three areas were chosen for comparative purposes. To capture the wasps, it was used: active collecting with attractant liquid (solution of water, salt and sugar) with the aid of a dorsal spray bag. During the period from July to December 2006, 414 social wasps were collected in Paulo de Faria, constituting seven species belonging to four genera; 111 social wasps were collected in Pindorama, constituting six species belonging to four genera, and 129 social wasps were collected in Neves Paulista constituting 12 species belonging to seven genera. In order to compare these three areas ecological indexes were calculated. Neves Paulista had the greatest diversity, and Paulo de Faria presented greater abundance. These factors were probably caused by neighboring areas and ecological corridors, which were limited in Paulo de Faria and Pindorama.