Leptospirosis in Nepal.

The study has demonstrated the evidence of leptospirosis infection in the country. It has also highlighted the challenges and the need of further researches on this disease, which seems to be under reported in the country.

Hepatitis E virus infection in chimpanzees: a retrospective analysis.

Different patterns of disease were observed among 11 chimpanzees who were inoculated intravenously with hepatitis E virus (HEV) positive fecal specimens from four different outbreaks (Nepal 1981, Uzbekistan 1981, Pakistan 1985, and Mexico 1986). Five chimpanzees had marginal or no liver enzyme elevations within 70 days of inoculation. Two of the chimpanzees had limited viremia, but did not produce detectable antibody. The four remaining chimpanzees had liver enzyme elevations, viral shedding, viremia, seroconversion to anti-HEV, and detectable HEV antigen in liver biopsy specimens. These results may reflect the range of infection patterns that develop in humans after natural exposure to the HEV.

Viral hepatitis in the Bhutanese population: preliminary results of a seroepidemiological investigation.

A seroepidemiological study of the prevalence of markers related to the most common forms of viral hepatitis was carried out in Bhutan on 1,666 healthy people of both sexes, from the general population. A group of 440 pregnant women were screened separately. Our results suggest that in Bhutan, hepatitis A and hepatitis B are widespread, while there is a low prevalence of hepatitis C and E. Anti-HAV (anti-hepatitis A virus) was found in all 171 tested subjects over 12 years of age, and anti-HBc (anti-hepatitis B core antigen) in 63.1% of 1,666 tested people. On the other hand, anti-HEV proved positive in 2.0% of 257 tested subjects, and anti-HCV in only 1.3% of 611 tested subjects. Hepatitis B surface antigen (HBsAg) was found in 5.9% of the sample from the general population (5.2% in children, 5.6% in young people and 6.3% in adults) and in 5.4% of the pregnant women. Furthermore, 29.1% of HBsAg-positive pregnant women were HBeAg- and HBV DNA-positive, too. Comparing the pregnant women's prevalence data to those found in children, we suggest that the main route of HBV transmission in the Bhutanese population is vertical, from mother to child; this finding is important for the implementation of a correct anti-HBV vaccination strategy in Bhutan.

Variations in genome fragments coding for RNA polymerase in human and simian hepatitis A viruses.

The genome of hepatitis A virus (HAV) isolated from spontaneously infected African vervet monkey (Cercopithecus aethiops) has been cloned and partially sequenced. Comparison of genome fragments (1248 and 162 bp) from the 3D (RNA polymerase) region with the corresponding parts of human HAV genomes revealed a high degree of heterogeneity: there were altogether 257 nucleotide changes leading to 44 substitutions in predicted amino acid sequence, i.e. 89% amino acid identity. This divergence is considered to be significantly greater than genomic variations usually found among human HAV strains, where amino acid identity in the 3D region is over 98%.

Aetiological agent of enterically transmitted non-A, non-B hepatitis.

Virus-like particles (VLPs) with a mean diameter of 32 nm were recovered from the stools of three acute phase cases of enterically transmitted non-A, non-B hepatitis (ET-NANBH) occurring in the Soviet Union, North Africa and North America. VLPs from two of these cases were studied in detail and were shown to react specifically with antibody in acute phase sera obtained from other cases of ET-NANBH in Asia, the Soviet Union, North Africa and North America. Partially purified VLPs were found to sediment at 183S in sucrose gradients and to cross-react with antibody in acute phase sera from geographically isolated cases of ET-NANBH. The latter virus preparations were also used to document the seroconversion of experimentally ET-NANBH-infected cynomolgus macaques to 32 nm VLPs. Our findings indicate that one virus or class of viruses is responsible for the majority of ET-NANBH.

Non-A, non-B fulminant viral hepatitis in France in returnees from Asia and Africa.

Among 61 patients admitted for non-A, non-B fulminant viral hepatitis to Hôpital Beaujon, 10 had returned from Asia or Africa, and 51 had not been outside France, within the month preceding jaundice. This suggests that hepatitis might have been contracted in Asia or Africa in the former, and in France in the latter. The interval between the onset of jaundice and the onset of hepatic encephalopathy was 10 days in the former and 26 days in the latter (P less than 0.03). The serum of the patient returning from Asia contained, and the sera of the nine patients returning from Africa did not contain, antibodies to a virus isolated from the stools of patients suffering from an epidemic fecal-oral non-A, non-B viral hepatitis in Central Asia. It is concluded that infection with Asian-African non-A, non-B viruses can be the cause of fulminant hepatitis in persons returning from these countries, that the course of this type of non-A, non-B fulminant viral hepatitis is shorter than that of non-A, non-B fulminant hepatitis contracted in France, and that different viruses might be responsible for non-A, non-B hepatitis in Asia and Africa.

Antibody response in hepatitis A and some other enteroviral infections: quantitative comparison.

Antibody levels produced in humans in the course of hepatitis A were compared with those in Coxsackie B2 infection and vaccination with live poliovaccine (type 1) using the method of immune-electron microscopy. It has been shown that the levels of antibody in hepatitis A were 25 to 800-times higher than in Coxsackie B2 infection and than after vaccination with the live poliovaccine.

Evidence for a virus in non-A, non-B hepatitis transmitted via the fecal-oral route.

Typical acute hepatitis was reproduced in a human volunteer immune to hepatitis A virus (HAV) after oral administration of pooled stool extracts from presumed cases of epidemic non-A, non-B hepatitis. Markers of hepatitis B infection, anti-HAV IgM, and increase in total anti-HAV level were not detectable in the volunteer's sera during the course of infection. Spherical 27- to 30-nm virus-like particles were visualized by immune electron microscopy (IEM) in stool samples collected during preclinical and early postclinical phases. These particles banded in CsCl at a buoyant density of 1.35 g/cm3. They reacted in the IEM test with sera from individuals who had experienced two non-B hepatitis episodes but did not react with sera from routine anti-HAV IgM-positive hepatitis patients. Intravenous inoculation of cynomolgus monkeys with the virus-containing stool extract resulted in histopathologically and enzymatically confirmed hepatitis, excretion of virus-like particles, and antibody response to them.