Epidemic of jungle yellow fever in Brazil, 2000: implications of climatic alterations in disease spread.

Seventy-seven human cases of sylvatic yellow fever were reported in Brazil during the period January-June 2000. The first cases were reported 1 week after New Year's day and originated at Chapada dos Veadeiros, a tourist canyon site in Goiás state, near Brasília, the Brazilian capital. The laboratory procedures used for diagnoses included serology with an IgM capture assay and plaque reduction neutralization test, virus isolation in suckling mice and C6/36 cells, and immunohistochemistry. All cases were diagnosed by at least two different laboratory procedures, with the exception of the first three fatal cases, which were diagnosed on the basis of clinical and epidemiological information. The cases were reported in eight Brazilian states as follows: Goiás with 64.9% (50 cases); Amazonas (1); Bahia (10); Distrito Federal (1); Mato Grosso (4); Minas Gerais (2); Pará (1); São Paulo (2); and Tocantins (6). Patient ages were within the following ranges: 13-74 years old (mean 34.3), 64 (84.4%) were male, especially agricultural workers (n = 30), but tourists (n = 11), carpenters (n = 4), fishermen (n = 4), students (n = 3), truck drivers (n = 3), and other people (n = 22) were also sickened. The case fatality rate was 50.6% (39/77). In Bahia state, a serologic survey that was carried out has suggested a symptomatic/asymptomatic coefficient of 1:4. Field studies developed in Distrito Federal, Goiás, and São Paulo states showed that Haemagogus janthinomys was the mosquito species associated with the transmission. A single strain was also obtained from Aedes scapularis in Bahia. Epizootic occurrence (monkey mortality) was observed in 49 municipalities mainly in Goiás state, where 40 municipalities made reports, 21 of which also diagnosed human cases. Data obtained by the National Institute of Meteorology in Brazil showed an increase in temperature and rain in December 1999 and the first 3 months of 2000 in Goiás and surrounding states, which perhaps has contributed to the intense and widespread transmission of the yellow fever virus. The relatively small number of cases probably reflects the extensive use of yellow fever 17D-vaccine during the last 3 years, in which about 45 million doses were used. During the last months of 1999, 16 and 11 yellow fever cases were reported in Tocantins and Goiás states, respectively. It is noteworthy that the last reported autochthonous cases of sylvatic yellow fever in São Paulo and Bahia, both states outside the endemic/enzootic area, had occurred in 1953 and 1948, respectively.

Yellow fever in Pará State, Amazon region of Brazil, 1998-1999: entomologic and epidemiologic findings.

Yellow fever (YF) is frequently associated with high severity and death rates in the Amazon region of Brazil. During the rainy seasons of 1998 and 1999, 23 (eight deaths) and 34 (eight deaths) human cases of YF were reported, respectively, in different geographic areas of Pará State; most cases were on Marajó Island. Patients were 1 to 46 years of age. Epidemiologic and ecological studies were conducted in Afuá and Breves on Marajó Island; captured insects yielded isolates of 4 and 11 YF strains, respectively, from Haemagogus janthinomys pooled mosquitoes. The cases on Marajó Island in 1999 resulted from lack of vaccination near the focus of the disease and intense migration, which brought many nonimmune people to areas where infected vectors were present. We hypothesize that YF virus remains in an area after an outbreak by vertical transmission among Haemagogus mosquitoes.

Serious adverse events associated with yellow fever 17DD vaccine in Brazil: a report of two cases.

BACKGROUND: The yellow fever vaccine is regarded as one of the safest attenuated virus vaccines, with few side-effects or adverse events. We report the occurrence of two fatal cases of haemorrhagic fever associated with yellow fever 17DD substrain vaccine in Brazil. METHODS: We obtained epidemiological, serological, virological, pathological, immunocytochemical, and molecular biological data on the two cases to determine the cause of the illnesses. FINDINGS: The first case, in a 5-year-old white girl, was characterised by sudden onset of fever accompanied by headache, malaise, and vomiting 3 days after receiving yellow fever and measles-mumps-rubella vaccines. Afterwards she decompensated with icterus and haemorrhagic signs and died after a 5-day illness. The second patient-a 22-year-old black woman-developed a sore throat and fever accompanied by headache, myalgia, nausea, and vomiting 4 days after yellow fever vaccination. She then developed icterus, renal failure, and haemorrhagic diathesis, and died after 6 days of illness. Yellow fever virus was recovered in suckling mice and C6/36 cells from blood in both cases, as well as from fragments of liver, spleen, skin, and heart from the first case and from these and other viscera fragments in case 2. RNA of yellow fever virus was identical to that previously described for 17D genomic sequences. IgM ELISA tests for yellow fever virus were negative in case 1 and positive in case 2; similar tests for dengue, hantaviruses, arenaviruses, Leptospira, and hepatitis viruses A-D were negative. Tissue injuries from both patients were typical of wild-type yellow fever. INTERPRETATION: These serious and hitherto unknown complications of yellow fever vaccination are extremely rare, but the safety of yellow fever 17DD vaccine needs to be reviewed. Host factors, probably idiosyncratic reactions, might have had a substantial contributed to the unexpected outcome.

Sandflies (Diptera: Psychodidae) of the Amazônia of Maranhão. V. Seasonal occurrence in ancient colonization area and endemic for cutaneous leishmaniasis.

In this paper, the seasonal abundance of 25 sandfly species (1 of the Brumptomyia genus and 24 of the Lutzomyia genus) found at P1V5, municipal district of Buriticupu, Maranhão State, is discussed. The capture was carried out from 18:00 P.M. to 6:00 A.M., once a month, from January to December 1996. CDC light traps were set up in the forest, in the peri and intradomicile environments. Five species were only found in the rainy season (January to June), being represented by one or two individuals; eight species occurred only in the dry season (July to December) and eleven species appeared in both seasons. The most frequent species in the dry period were: L. whitmani (26.3%), L. serrana (23%), L. choti (22.8%), L. evandroi (7.5%), L. longipalpis (5.8%), L. termitophila (3.3%), L. shannoni (3%) and L. migonei (2.5%). In the rainy season, L. whitmani was the prevailing species (74%), followed by L. termitophila (4%), L. umbratilis (3.4%), L. serrana (2.8%), L. evandroi (2,8%) and L. claustrei (2.4%). L. whitmani was thought to be an annual species, occurring in the entire year of study. The others species, with exception to L. serrana and L. evandroi, showed a seasonal, punctual or peripheric pattern.

[Health and disease among Panará (Kreen-Akarôre) Indians in Central Brazil after twenty-five years of contact with our world, with an emphasis on tuberculosis]. / Saúde e doença em índios Panará (Kreen-Akarôre) após vinte e cinco anos de contato com o nosso mundo, com ênfase na ocorrência de tuberculose (Brasil Central).

The Panará, who had previously lived in isolation from Brazilian national society in the Amazon forest, were first contacted in 1973. Two years later they were moved to another area in Central Brazil. During this same period they were reduced to 82 members, the survivors of a population of 400 to 500 in the mid-1960s. In 1995 they returned to a small area in their old territory still not occupied by outsiders. There, three years later, a health survey showed a presumed diagnosis of tuberculosis in 15 individuals out of a population of 181. Further tests in the town of Colider, based on clinical data and chest X-rays, confirmed the diagnosis in 10 Panará (6 children under 10 years of age and 4 adults from 40 to 50 years old). BCG scars were present in the entire population. The nutritional status of Panará children was better than that of other indigenous groups in the Amazon region. The following measures were introduced for Tb control: a) treatment follow-up in the village, under direct supervision by both a nurse and the local indigenous health worker; b) compliance with defined criteria for ending treatment; c) periodic control of contacts and non-contacts; c) and establishment of a reference system with the health services in Colider.

Sandflies (Diptera: Psychodidae) of the Amazônia of Maranhão. V. Seasonal occurrence in ancient colonization area and endemic for cutaneous leishmaniasis

In this paper, the seasonal abundance of 25 sandfly species (1 of the Brumptomyia genus and 24 of the Lutzomyia genus) found at P1V5, municipal district of Buriticupu, Maranhão State, is discussed. The capture was carried out from 18:00 P.M. to 6:00 A.M., once a month, from January to December 1996. CDC light traps were set up in the forest, in the peri and intradomicile environments. Five species were only found in the rainy season (January to June), being represented by one or two individuals; eight species occurred only in the dry season (July to December) and eleven species appeared in both seasons. The most frequent species in the dry period were: L. whitmani (26.3 percent), L. serrana (23 percent), L. choti (22.8 percent), L. evandroi (7.5 percent), L. longipalpis (5.8 percent), L. termitophila (3.3 percent), L. shannoni (3 percent) and L. migonei (2.5 percent). In the rainy season, L. whitmani was the prevailing species (74 percent), followed by L. termitophila (4 percent), L. umbratilis (3.4 percent), L. serrana (2.8 percent), L. evandroi (2,8 percent) and L. claustrei (2.4 percent). L. whitmani was thought to be an annual species, occurring in the entire year of study. The others species, with exception to L. serrana and L. evandroi, showed a seasonal, punctual or peripheric pattern

[Phlebotominae (Diptera: Psychodidae) of Lagoas, a city of Buriticupu, Amazonia of Maranhão. I. The richness and relative abundance of the species in an area of recent colonization]. / Phlebotominae (Diptera: Psychodidae) de Lagoas, município de Buriticupu, Amazônia Maranhense. I--Riqueza e abundância relativa das espécies em área de colonização recente.

In this study the diversity of the species and relative abundance of the sand flies in the Amazonian community of Lagoas, in Buriticupu, Maranhão State, was determined. The study consisted of adult sandflies captured with CD light-traps, Shannon-trap and manual aspiration tube, between 18 PM and 6 AM, once a month, from December/95 to January/97, in a forest fragment and in the domestic environment (peri and intra). In all, 9,393 specimens were captured (4,302 males and 5,140 females) distributed among 38 species (1 Brumptomyia and 37 Lutzomyia). The diversity and abundance of species was higher in the forest, followed by the peri and intra. The predominance in the wild ambient is a consequence of the potentialities found in the remaining fragments of the forest which have survived the lumber yard exploitation and agricultural activities. In the forest environment Lutzomyia whitmani (64.9%), L. migonei (27%) and L. serrana (3.6%) were the most frequent species. In the peri and intra domicile L. evandroi predominated (55.4% and 97.9%). The species, L. whitmani (33.4%) and L. migonei (6.4%), were important in the peri domicile. The peridomestic habit of 7.7% of the sand flies showed the greatest epidemiologic importance, due to the existence of patients with leishmaniasis ulcers, who believe they were infected near their habitations.

[Sandflies (Diptera, psychodidae) in a secondary forest area in the Paco do Lumiar city, Maranhao, Brazil: a leishmaniasis transmission area]. / Flebotomíneos (Diptera, Psychodidade) de capoeira do Município do Paço do Lumiar, Estado do Maranhão, Brasil. Area de transmissão de leishmaniose.

This paper analyzes the wealth of species, relative abundance, seasonal fluctuation, and nocturnal activity of sandflies. The field survey was conducted in a "capoeira" (secondary forest) area in the county of Paço do Lumiar, Maranhão, where cutaneous and transmission of visceral leishmaniasis frequently occurs. Sandflies were captured by CDC-type light traps from 6:00 PM to 6:00 AM, once a month, from March 1997 to February 1998. A total of 489 specimens were collected (251 males and 238 females), distributed among 10 species: Lutzomyia antunesi (45.19%), Lutzomyia whitmani (29.4%), Lutzomyia longipalpis (7.56%), Lutzomyia sordelli (6.34%), Lutzomyia flaviscutellata (4.5%), Brumptomyia avellari (4.09%), Lutzomyia evandroi (1.85%), Lutzomyia umbratilis (0.61%), Lutzomyia corossoniensis (0.41%), and Lutzomyia trispinosa (0.41%). The sandflies were present year round, with higher abundance during the rainy season. They were present in all intervals studied, with the highest frequency between 12:00 PM and 1:00 AM (31%).

[Phlebotomus (Diptera, Phlebotominae) from Saint Luis Island, Maranhão Gulf region, Brazil]. / Flebótomos (Diptera, Phlebotominae) da Ilha de São Luis, zona do Golfão Maranhense, Brasil.

This study lists 32 species of sand flies, 1 of them belonging to the genus Brumptomyia and 31 to the genus Lutzomyia, distributed among the following subgenera: Psychodopygus (6), Nyssomyia (5), Pressatia (3), Evandromyia (2), Psathyromyia (2), Sciopemyia (2), Lutzomyia (1), Micropygomyia (1), Viannamyia (1), and the groups Oswaldoi (5) and Migonei (3). The sand flies were captured in the wild (forest) and in peridomicile (pigpen, hen house and stable) and intradomicile (bedroom) areas from 06:00 PM to 06:00 AM, once a month, for 4 years on the Island of São Luis, Maranhão. All species sampled were present in the forest. Among them, 16 were found in the peridomicile, while 11 were found inside the houses. A total of 22,581 specimens were captured, 65.1% of them in the peridomicile, 17.5% in the forest and 17.4% in the intradomicile. The most common species was Lutzomyia longipalpis (66.4% of the captured specimens), followed by Lutzomyia whitmani (24%) and Lutzomyia evandroi (5.9%). The remaining 29 species represented 3.7% of the total sample.

An epidemic of sylvatic yellow fever in the southeast region of Maranhao State, Brazil, 1993-1994: epidemiologic and entomologic findings.

Yellow fever virus transmission was very active in Maranhao State in Brazil in 1993 and 1994. An investigation was carried out to evaluate the magnitude of the epidemic. In 1993, a total of 932 people was examined for yellow fever from Maranhao: 70 were positive serologically, histopathologically, and/or by virus isolation, and another four cases were diagnosed clinically and epidemiologically. In Mirador (17,565 inhabitants), the incidence was 3.5 per 1,000 people (case fatality rate [number of deaths/number of cases diagnosed] = 16.4%), while in a rural yellow fever risk area (14,659 inhabitants), the incidence was 4.2 and the case-fatality rate was 16.1% (10 of 62). A total of 45.2% (28 of 62) asymptomatic infections were registered. In 1994, 49 serum samples were obtained and 16 cases were confirmed (two by virus isolation, two by seroconversion, and 12 by serology). No fatal cases were reported. In 1993, 936 potential yellow fever vectors were captured in Mirador and a single strain was isolated from a pool of Haemagogus janthinomys (infection rate = 0.16%). In 1994, 16 strains were isolated from 1,318 Hg. janthinomys (infection rate = 1.34%) and one Sabethes chloropterus (infection rate = 1.67%). Our results suggest that this was the most extensive outbreak of yellow fever in the last 20 years in Brazil. It is also clear that the lack of vaccination was the principal reason for the epidemic, which occurred between April and June, during the rainy season, a period in which the mosquito population in the forest increases.

Circulation of eastern equine encephalitis, western equine encephalitis, Ilhéus, Maguari and Tacaiuma viruses in equines of the Brazilian Pantanal, South America.

Neutralizing antibodies to EEE (6.7%), WEE (1.2%), ILH (26.6%), MAG (28.2%) and TCM (15.7%) viruses were found in sera of 432 equines of the Brazilian Pantanal, area where undiagnosed horse deaths are frequently observed. A 4-fold rise in CF titer to EEE virus was detected in acute and convalescent sera of an encephalitis horse sacrificed in 1992. Antibodies to EEE, ILH, MAG and TCM viruses were detected in horses less than 2 years old indicating recent circulation of these viruses in the Pantanal. The evidence of recent equine encephalitis associated with rising CF titer to EEE warrants a more intensive study with attempts to isolate virus from horses with clinical manifestations of encephalitis.

Demonstration of yellow fever and dengue antigens in formalin-fixed paraffin-embedded human liver by immunohistochemical analysis.

Two immunohistochemical techniques to determine the presence of yellow fever and dengue antigens in fixed tissue samples were developed for the purpose of making retrospective diagnoses of these viral diseases in humans. A horseradish peroxidase label was used for one technique and an alkaline phosphatase label for the other. In the former technique, acid hematin was removed from the tissues, iron-containing pigments were counterstained with Prussian blue, and the product of the diaminobenzidine reaction was enhanced with a dilute solution of osmium tetroxide that differentiated antigen from lipofuscin. In the latter technique, alkaline phosphatase was used as the enzyme labeling system with a red chromogen that contrasted nicely with the pigments in the tissues, as mentioned above. Thus, pigment removal or differentiation from antigen was not required. Replicate sections were cut and mouse polyclonal antibodies for yellow fever and all dengue types were applied to individual sections. On samples positive for dengue antigen, monoclonal antibodies were applied to additional replicate sections to demonstrate antigen of dengue types 1 and 4. In order to test the assay, samples of formalin-fixed liver tissue from Brazilian and Peruvian individuals who had died from a variety of causes as long as eight years earlier were received in a blinded fashion for immunohistochemical analysis. The techniques appeared to be highly reliable for yellow fever diagnosis; however, not enough cases were observed to adequately evaluate the procedures for dengue diagnosis. Both procedures appeared to have similar sensitivity.

[Isolation of a human strain of Schistosoma mansoni, Sambon,1907]. / Sobre o isolamento de uma cepa humana de Schistosoma mansoni, Sambon, 1907.

In this paper the authors briefly describe a human Schistosoma mansoni strain from Pará State, Brazil. The CIRENE'S strain was capable of infecting 71.4% of the snail vector Biomphalaria glabrata (Telegrafo's strain) provided by the "Evando Chagas" Institute, Belém. The cycle was completed by the infection of six mice. The thoracic and abdominal organs were examined microscopically which demonstrated the passage of the worm into the liver and lungs. The authors discuss the importance of these results in the epidemiology of schistosomiasis in Pará.