Hepatitis B virus and hepatitis delta virus genotypes in outbreaks of fulminant hepatitis (Labrea black fever) in the western Brazilian Amazon region.

The genotypes of hepatitis B (HBV) and delta (HDV) viruses circulating among fulminant hepatitis cases from the western Amazon Basin of Brazil were characterized in this study. HBV and HDV isolates were obtained from liver samples from 14 patients who developed fulminant hepatitis and died during 1978-1989. HBV DNA and HDV RNA were detected in all samples. Phylogenetic analyses of HDV sequences showed that they all clustered with previously characterized sequences of HDV genotype 3 (HDV-3). HBV genotypes F, A and D were found in 50.0, 28.6 and 21.4 % of cases, respectively. These results confirm the predominance of HDV-3 in South America and its association with the severe form of hepatitis, and the finding of the co-infection of HDV-3 with different genotypes of HBV suggests that the association between HDV-3 and HBV-F is not necessarily causally related to a more severe clinical course of infection.

Pacui virus, phlebotomine flies, and small mammals in Brazil: an epidemiological study.

Pacui virus, originally obtained from forest rodents, was isolated 100 times from 61,437 specimens (658 pools) of the phlebotomine fly Lutzomyia flaviscutellata, collected from rodent-baited traps in the forests of Belem, Para, Brazil in the period October 1968 through September 1970. Isolations were made from engorged and unengorged females and from males (3 strains), and occurred in all 24 months. Pacui virus also was isolated from the blood of two wild rodents (Oryzomys), but not from 424 L. infraspinosa, 12,000 mosquitoes, or sentinel mice. Pacui virus neutralizing antibodies were detected in serum of six bait animals after exposure to biting flies in the forest, in 30% of wild rodents surveyed (including two from Amapa Territory), and in 10% of marsupials, but were absent in human survey sera and in bats. Low-passage Pacui virus produced viremia in and was lethal to infant mice by the subcutaneous route. L. flaviscutellata was most abundant in the dry season, in which period Pacui virus isolations increased. This fly is strongly attracted to rodents close to the ground. L. flaviscutellata also yielded single strains of Guama, Icoaraci, and BeAr 177325 viruses.

Transfusion-transmitted virus (TTV) in Brazil. Preliminary report.

TTV is a recently discovered DNA virus, isolated from a patient with post-transfusion hepatitis of unknown etiology by Japanese researchers. In the present study, we evaluated the presence of TTV among chronic liver diseases patients in São Paulo and Pará states, representing two geographically distinct Brazilian regions. TTV DNA was found in 21/105 (20%) and 9/20 (45%) cases from São Paulo and Pará States, respectively. DNA sequence data confirmed the presence of TTV genotypes 1a and 2a, as well as other genotypes not yet described. In conclusion, TTV is present in chronic liver diseases cases from Southeast and North Brazil. However, further studies involving healthy populations are necessary before establishing any causal relationship among TTV and human hepatitis.

Hepatitis B virus surface antigen (HBsAg) and antibody (anti-HBs) forming immune complexes in fulminant hepatitis.

This paper reports an unusual pattern of serological HBV markers and the presence of HBsAg/anti-HBs immune complexes in serum samples from two patients with fulminant hepatitis from the Brazilian Western Amazon Basin. The diagnosis was made by both serologic tests and demonstration of antigen/antibody complexes by transmission electron microscopy. Concurrent Delta virus superinfection is also discussed.

[Epidemiology of hepatitis B, C and D viruses among indigenous Parakanã tribe in the Eastern Brazilian Amazon Region]. / Epidemiologia dos vírus das hepatites B, C e D na tribo indígena parakanã, Amazônia Oriental Brasileira.

This study sought to establish the prevalence of infection with the hepatitis B, C, and D viruses (HBV, HCV, and HDV) and to describe their transmission among the Parakanã, an indigenous tribe in Pará State, Brazil. This tribe's first contacts with broader Brazilian society occurred in the 1970s and 1980s. As of October 1992, the tribe consisted of 350 individuals, of whom 222 lived in the village of Paranatinga and 128 in the village of Maroxewara. Serum samples from 96.9% of this population were tested for markers of infection with the above-named viruses by means of enzyme immunoassays. Another 106 serum samples collected from Parakanã in the 1970s were also tested. The results obtained with the modern samples showed an overall prevalence of HBV infection of 84.7% among the residents of Paranatinga, 14.4% of whom were carriers. In Maroxewara, the overall prevalence of infection was only 17.7% and no carriers were detected in the study population. HBV carriers were negative for markers of HDV infection. The prevalence of HCV infection, confirmed by immunoblot, was 1.4% and 1.6% in Paranatinga and Maroxewara, respectively. Among the notable findings of this study were that horizontal transmission of HBV takes place at an early age in Paranatinga; that HBV infection prevalences differ greatly between two nearby villages belonging to the same tribe; that HCV infection was detected in both villages; and, from the historic sera, that the prevalence of HBV infection was low and HCV infection was absent during the first years in which the Parakanã people had outside contact.

[Hepatitis C virus (HCV) in children and adolescent hemophiliacs] / Hepatite pelo vírus C (HCV) em crianças e adolescentes hemofílicos.

OBJECTIVE: To evaluate the prevalence of infection by HCV among hemophiliacs in the State of Pará (Brazil), and its possible relation to hepatic enzymes serum level, type of hemophilia involved, age, level of severity, kinds and combinations of treatment, as well as date in which treatment with hemoderivates was started.METHODS: Cross-sectional epidemiological investigation, analyzing 62 hemophilic patients of the Centro de Hemoterapia do Pará (HEMOPA), all born after 01/01/80, by means of the review of the medical records, physical examination and laboratory tests: Anti-HCV (ELISA 3.0), polymerase chain reaction - PCR - (HCV-RNA), and dosage of transaminases serum levels. Statistical analysis was carried out using Chi-square and Fisher's Exact Test, the results being considered significant if p

Arbovirus antibodies in children of rural Guanabara, Brazil.

School children living in Guanabara State, Brazil, have been tested for evidence of infection with 16 arboviruses. 3 percent were positive, and in every instance the positive reaction was attributable to St. Louis encephalitis (SLE) virus. Evidence of familial aggregation was observed.

Hepatitis delta virus infection and Labrea hepatitis. Prevalence and role in fulminant hepatitis in the Amazon Basin.

To define more exactly the epidemiology of delta virus infection and confirm its role in causing fulminant Labrea hepatitis in the Amazon Basin, we studied the prevalence of delta virus infection among persons with acute and chronic hepatitis B virus infection in the Boca do Acre district of the southern Amazon Basin. Delta virus infection was found in 24% of asymptomatic hepatitis B virus carriers, 29% of acute nonfulminant hepatitis B cases, 74% of fulminant hepatitis B cases, and 100% of chronic hepatitis B cases. Chronic delta virus infection occurred primarily in older children and adults, while acute and fulminant delta virus infection occurred in young children as well. In fulminant hepatitis cases, delta virus superinfection of hepatitis B virus carriers was the most common serological pattern; histopathologic examination showed features identical to those described in fulminant hepatitis cases of similar etiology in Colombia and Venezuela. Delta virus infection is highly endemic in the southern Amazon Basin and is the principal cause of Labrea hepatitis.

An outbreak of Oropouche virus diease in the vicinity of santarem, para, barzil.

An epidemic of human febrile illness caused by Oropouche virus was studied in the village of Mojui dos Campos, Pará State, in February 1975. The major clinical symptoms, fever, chills, headache, myalgia, arthralgia and dizziness persisted for 2 to 7 days. Leukopenia was commonly observed. Some patients were severely ill but no deaths were attributed to the disease. Recurrence of symptoms was reported in several people. 55 cases of recent infection were diagnosed in Mojuí dos Campos between February and April. In the same period 26 cases were recorded from the Palhal area, near to Mojuí. Two additional cases were observed, one in the small settlement of Terra Preta and the other in the town of Santarém, which are 12 and 20 km from Mojuí, respectively. Of the 83 infections, 65 were proven by virus isolation from the blood of patients and 18 by the demonstration of an increasing antibody level to the agent. Both sexes of the population were infected in equal proportions. Most patients were below 20 years of age. In the village of Mojuí dos Campos with a population of about 2,900, 45 (40,1%) out of 112 students aged 4 to 18, had HI antibodies to the virus when examined late in February. The epidemic, however, only declined after the middle of March. Two isolations of Oropouche virus were obtained from some 15,000 Culicoides inoculated into mice. About 4,000 Culicoides and all the 9,420 mosquitoes captured during the outbreak remain to be inoculated. Over 95% of the Culicoides were C. paraensis. Only 1 rodent of the genus Proechimys had HI antibodies to Oropouche virus out of the 602 wild and domestic mammals captured in the area. All 5 reptiles examined were negative. 34 (4.9%) out of the 681 wild birds and 12 (5.8%) out of the 206 domestic birds examined were positive for the presence of HI antibodies to the agent.