Adriana Fumie Tateno

Bats Worldwide Carry Hepatitis E Virus-Related Viruses That Form a Putative Novel Genus within the Family Hepeviridae

ABSTRACT Hepatitis E virus (HEV) is one of the most common causes of acute hepatitis in tropical and temperate climates. Tropical genotypes 1 and 2 are associated with food-borne and waterborne transmission. Zoonotic reservoirs (mainly pigs, wild boar, and deer) are considered for genotypes 3 and 4, which exist in temperate climates. In view of the association of several zoonotic viruses with bats, we analyzed 3,869 bat specimens from 85 different species and from five continents for hepevirus RNA. HEVs were detected in African, Central American, and European bats, forming a novel phylogenetic clade in the family Hepeviridae. Bat hepeviruses were highly diversified and comparable to human HEV in sequence variation. No evidence for the transmission of bat hepeviruses to humans was found in over 90,000 human blood donations and individual patient sera. Full-genome analysis of one representative virus confirmed formal classification within the family Hepeviridae. Sequence- and distance-based taxonomic evaluations suggested that bat hepeviruses constitute a distinct genus within the family Hepeviridae and that at least three other genera comprising human, rodent, and avian hepeviruses can be designated. This may imply that hepeviruses invaded mammalian hosts nonrecently and underwent speciation according to their host restrictions. Human HEV-related viruses in farmed and peridomestic animals might represent secondary acquisitions of human viruses, rather than animal precursors causally involved in the evolution of human HEV.

Amplification of emerging viruses in a bat colony.

Concentration and prevalence of coronaviruses and astroviruses increase when bats form maternity roosts and bear young.

Rhinovirus C and respiratory exacerbations in children with cystic fibrosis.

To investigate a possible role for human rhinovirus C in respiratory exacerbations of children with cystic fibrosis, we conducted microbiologic testing on respiratory specimens from 103 such patients in São Paulo, Brazil, during 2006–2007. A significant association was found between the presence of human rhinovirus C and respiratory exacerbations.

Hepatitis C virus in blood donors, Brazil.

To the Editor: The Fundacao de Hematologia e Hemoterapia do Amazonas is a public health service in Manaus, Brazil, that is responsible for serologic screening of all blood donations in the region. In the state of Amazon, 9.0% of donated blood is discarded on the basis of serologic findings; discarding because of hepatitis C virus (HCV) antibodies declined from 1.25% in 1995 to 0.32% in 2007. The aim of this study was to characterize the serologic and molecular profile of HCV-antibody–positive blood donors from the Fundacao de Hematologia e Hemoterapia do Amazonas. For the study, 154 donors were selected from a routine database of voluntary blood donors who had donated from September 2005 through April 2007 (82,851 donations). Fresh plasma samples were sent to the laboratory in Manaus through the usual transportation systems for regular donations; i.e., samples from 27 cities are transported by air for ≈2 hours, and samples from 21 localities are transported by boat or road, all under refrigerated conditions. An in-house standardized nested-PCR was used to detect HCV RNA (1). Genotype assignment was based on type-specific motifs on the sequenced amplicons delimited by primers HC11/HC18 from the 5′ untranslated region (2). Viral load was determined by commercial assay (HCV Monitor, Roche Molecular Systems, Inc., Branchburg, NJ, USA). An association was observed between HCV RNA and donor age; the same trend was seen in the first-time blood donor group. Associations between HCV-RNA detection and gender (p = 0.875) and place of donation (p = 0.989) were not significant. Using 18–25 years of age as the reference group, we found that odds ratios (ORs) for having HCV viremia were higher for those 45–55 years of age (OR 8.19, p<0.001) and 35–45 years of age (OR 3.49, p = 0.003). We observed increasing rates of RNA detection according to the signal-to-cutoff (S/CO) ratio. However, some donors had a weak S/CO ratio (between 1 and 2) with positive nested-PCR tests (Figure). Although adopting an S/CO ratio as a criterion for referring for further testing by recombinant immunoblot assay (RIBA) has been advocated by some groups (3), our data show that this criterion may be misleading and would deny a confirmatory diagnosis by giving false-negative results for many persons. Figure Distribution of hepatitis C virus (HCV) enzyme immunoassay signal-to-cutoff (S/CO) values by recombinant immunoblot assay (RIBA) interpretations among HCV-RNA–positive [PCR (+)] and HCV-RNA–negative [PCR (−)] donated blood samples. ... A total of 113 samples were analyzed by RIBA; among 48 RIBA-reactive samples, 9 (18.8%) were negative for HCV RNA in plasma. However, because PCR results may sometimes be negative for persons who are actually infected, a single negative PCR result should not be relied on as evidence that virus has cleared from plasma. Such patients must be observed for years before they may be declared cured (4). Among 97 RIBA-positive or -indeterminate samples, viral load was detectable in only 33 samples: 27 (81.8%) RIBA-positive samples and 6 (18.2%) RIBA-indeterminate samples. Only HCV genotypes 1 (87.1%) and 3 (12.9%) were found. Geographic distribution shows genotypes 1 and 3 in Manaus and only genotype 1 in other Amazon cities. This genotype geographic distribution is similar to that found for many Brazilian cities and Eastern countries and may reflect the route of HCV introduction into the Amazon; the virus was probably brought to the Amazon region by European immigrants and blood-derived medicines imported to Brazil. This hypothesis is corroborated by the finding of genotype 3 exclusively in Manaus, suggesting that this city is the point of arrival of HCV and that new strains were disseminated from Manaus to inner localities. Historical reconstruction of HCV in Amazon could be attempted by using these isolates as well as others from hepatitis patients in the region, including genotype 2 (5). We found a higher-than-expected rate of 50% for indeterminate immunoblot results among samples that were HCV-RNA positive by nested PCR. The presence of HCV RNA in plasma samples from 70%–75% of blood donors with indeterminate immunoblot results has also been reported by other groups in Brazil (6,7); however, in contrast, other investigators have reported RNA prevalence in such samples to be ≈2.5% (1,8). Indeterminate RIBA test results can indicate seroconversion or seroreversion or, occasionally, a chronic infection when RNA HCV is detected in plasma (9,10). To provide better understanding of the meaning of these indeterminate results, ongoing follow-up studies are examining the immune status of these persons. Our data offer insights for counseling of donors who have repeatedly HCV-reactive results. We suggest that Amazon region blood banks screen by enzyme immunoassay and use molecular testing as the first supplemental test and that immunoblot be applied to the remaining HCV-RNA nonreactive samples to distinguish between true and false anti-HCV carriers. This new algorithm would save considerable resources currently spent on immunoblot-indeterminate persons in addition to HCV-RNA reactive persons who do not require further testing for confirmation. Moreover, according to current policy, those with false-positive results may be reinstated as donors if they have negative retesting results after 6 months.

Genotypic distribution of HHV-8 in AIDS individuals without and with Kaposi sarcoma: Is genotype B associated with better prognosis of AIDS-KS?

AbstractAIDS-associated Kaposis sarcoma (AIDS-KS) caused by human herpes virus 8 (HHV-8) is the most severe and resistant form of KS tumor. Our aim was to verify whether there is an association between HHV-8 variability and development of AIDS-KS in Brazil by comparing the HHV-8 variability between individuals without and with KS. Saliva samples and blood, when available, were analyzed by polymerase chain reaction (PCR) techniques for detection of the fragments of ORF K1 of HHV-8, which were then genotyped and analyzed regarding the genetic variability. Our study described 106 positive cases for HHV-8 in the saliva from 751 AIDS patients without previous KS. In addition, we performed a phylogenetic analysis of HHV-8 in 34 of the 106 AIDS patients without KS and in 33 of the 37 patients with active KS. The distribution of HHV-8 genotypes A, B, C, and F in AIDS individuals was indistinguishable by comparing non-KS and KS groups, as well as regarding ethnicity. Considering the KS group, genotype B was associated with better prognosis of KS tumor. Interestingly, we found a particular profile of diversity within clade C and 2 recombinant patterns of HHV-8 in the saliva of AIDS individuals without KS. We emphasize the need to achieve standard genotyping protocol for ORF K1 amplification, thus allowing for substantial detection of HHV-8 variants. Our findings can shed light on the role of HHV-8 variability in the pathogenesis of AIDS-KS.

Brief communicationHIV-1 drug resistance genotypic profiles in children with undetectable plasma viremia during antiretroviral therapy

Treatment of HIV-1 infection with highly active antiretroviral therapy has led to sustained viral suppression in the plasma in a large number of children. However, studies have suggested that the integrated provirus in resting CD4+ T lymphocytes could be a source of reactivatable virus and maintain drug-resistant virus. We evaluated the resistance-related mutations in children receiving antiretroviral therapy with prolonged viral suppression. Thirty-two peripheral blood mononuclear cell samples from 16 children with viral loads that had been below detection limits for at least 12 months were obtained at two different time points and the DNAs sequenced. The median CD4 cell count was 1,016 cells/mm3 (347-2,588) and 938 cells/mm3 (440-3,038) at the first and second time points, respectively. The median follow-up time was 15 months (9-27). Six (37.5%) and seven (43.75%) of the 16 patients showed at least one NRTI-associated mutation in the first and second samples, respectively. Two out of 16 (12.5%) had an NNRTI-associated mutation at the first time point and three out of 16 (18.75%) at the second. In addition, 14 out of 16 (87.5%) had at least one PI-associated mutation at both time points. Despite plasma HIV-1 RNA suppression for at least 12 months, resistance-related mutations from previous antiretroviral failures could still be detected in archival virus. Furthermore, viral evolution occurred at the reverse transcriptase region in spite of viral suppression to levels below 400 copies/mL. Persistence of archival resistant virus may be relevant when considering future treatment options.