1 Department of Virology, The National Bacteriological Laboratory, S-105 21 Stockholm, Sweden
2 Division of Gastroenterology, Department of Medicine, Veterans General Hospital, Taipei, Taiwan
3 ...Institut National de Transfusion Sanguine, F-75739 Paris, France
and 4 Experimental Biology Research, Abbott Laboratories, North Chicago, Illinois, U.S.A.
A 681 nucleotide fragment of the hepatitis B virus (HBV) genome was sequenced that corresponded to the complete gene for hepatitis B surface antigen (HBsAg) in 80 HBsAg- and hepatitis B e antigen (HBeAg)-positive sera of diverse geographical origins. These and 42 previously published HBV sequences within the S gene were used for the construction of a dendrogram. In this comparison, each of the 122 HBsAg genes was found to be related to one or other of the six previously identified genomic groups of HBV, A to F. The HBV strains within each genomic group showed a characteristic geographical distribution. Group A genomes were represented by 23 strains mainly originating in northern Europe and sub-Saharan Africa. The group B and C genomes, represented by 17 and 28 strains respectively, were confined to populations with origins in eastern Asia and the Far East. The group D genomes, represented by 38 strains, were found worldwide, but were the predominant strains in the Mediterranean area, the Near and Middle East, and in south Asia. Group E genomes, represented by nine strains, were indigenous to western sub-Saharan Africa as far south as Angola. There were indications that the F group, made up of six strains, represented the genomic group of HBV among populations with origins in the New World. Thus, HBV has diverged into genomic groups according to the distribution of mankind in the different continents. As well as giving information on the genetic relationship of HBV strains of different geographical origin, this study also provides information on the primary structure of HBsAg in different regions of the world. Such data might prove valuable in explaining the reported failures to obtain protection with current HBV vaccines.
Received 17 November 1992;
accepted 18 February 1993.
REASONS FOR PERFORMING THE STUDY: The Réseau d'Epidémio‐Surveillance en Pathologie Equine (RESPE, the French epidemiological network for equine diseases) is a network for epidemio‐surveillance of ...major equine diseases based around sentry veterinarians in France. OBJECTIVE: The aim of this study was to evaluate the contribution of RESPE to efficient surveillance of equine influenza virus (EIV) in France. STUDY DESIGN: Retrospective cross‐sectional study. METHODS: From November 2005 to October 2010, epidemiological and phylogenetic studies were performed on 1426 nasopharyngeal swabs received at the Frank Duncombe Laboratory. Detection was performed by real‐time reverse transcription polymerase chain reaction using original primers and probes designed in the matrix protein gene. Phylogenetic analysis was carried out on the HA1 part of haemagglutinin gene amplified from 47 positive‐testing samples. Epidemiological information was provided with the majority of samples submitted through RESPE. RESULTS: Of the 920 samples submitted by RESPE‐associated veterinarians, 121 (13.1%) from 42 premises were positive for EIV, compared to 26 (5.1%) of the 607 samples received from non‐RESPE associated veterinarians. The most extensive outbreak was observed between February and May 2009, affecting 70 horses on 23 premises, 15 of which were managed by RESPE‐associated veterinarians. All strains belonged to the American lineage, Florida sublineage, Clade 1 and Clade 2. Clade 1 was identified only during the Grosbois episode. CONCLUSION: RESPE improved detection of EIV in France, enabled characterisation of the virus strains, yielded valuable information relating to the epidemiology of the disease and identified vaccine breakdown. POTENTIAL RELEVANCE: Implementation of a similar surveillance network in other countries may reduce the economic losses associated with outbreaks of EIV. The Summary is available in Chinese ‐ see Supporting information.
1 Department of Virology
and 2 Department of Bacteriology, The National Bacteriological Laboratory, S-105 21 Stockholm, Sweden
and 3 Institut National de Transfusion Sanguine, F-75739 Paris, France
...The surface (S) genes of 12 hepatitis B viruses (HBVs) encoding nine different serotypes of hepatitis B surface antigen (HBsAg) were amplified by the polymerase chain reaction and sequenced. These represented the eight strains of HBV, P1 to P8, defined at an international workshop on HBsAg subtypes in Paris in 1975, and the adrq - subtype. The S genes from additional HBV strains, one ayw4 , one adw4 and one ayw1 , of sub-Saharan African origin, were also sequenced. The relationship of these 12 new S gene sequences to those of the 20 published previously was investigated by constructing a phylogenetic tree, which confirmed a previous classification into four groups, designated A to D, based on 18 complete HBV genomes. When relating our sequenced S genes to these genomic groups, ayw1 of African origin and P6 ( adw 2) were both allocated to group A, the reference P1 ( ayw1 of Vietnamese origin) was allocated to group B, P5 ( ayr ), P8 ( adr ) and adrq - were all related to group C, and P2 ( ayw 2) and P3 ( ayw 3) could both be allocated to group D. Interestingly, the S genes of w4 serotype viruses, i.e. P4 ( ayw 4) and P7 ( adw4q - ), differed by 4% or more from both previous groups and from each other, suggesting their classification into two new groups, for which the designations E and F are proposed. Genomes specifying ayw were also found in groups A and B; previously sequenced genomes specifying the ayw subtype have all been confined to group D. There were indications that the epitope for subdeterminants of w resided at amino acid positions 125 to 127. Thus, at positions 125 and 127, ayw1, ayw2 and adw2 had T and P residues, respectively, whereas M and T residues were at the corresponding positions of ayw3 . Both ayw4 and adw4 had L at residue 127, and all strains expressing r , apart from P5, had an I instead of a T residue at position 126.
Received 2 October 1991;
accepted 7 January 1992.
The genomes of six hepatitis B viral (HBV) strains were sequenced from 10 overlapping amplificates obtained by the polymerase chain reaction. Four of the strains, specifying subtypes
ayw4 and
adw4q
...-, represented on the basis of divergency within the S gene two new genomic groups identified by us. The other two strains, encoding
adrq
- and of Pacific origin, belonged to genomic group C. The relation of these genomes to 21 published human, 1 chimpanzee, and 4 rodent hepadnaviral genomes was analyzed by constructing a phylogenetic dendrogram. Thereby, the segregation of human HBV strains into six genomic groups was confirmed. A consistent grouping of the genomes compared was also obtained in dendrograms based on the P and S genes, although the branching order differed from that based on the entire genomes. Each of the two representatives of genomic groups E and F differed by 8.1 to 13.6% and by 12.8 to 15.5% from the genomes of the other groups and by 1.5 and 3.7% from each other. The two Pacific group C strains differed by 2.7% from each other and by 4.1 to 5.4% from other group C genomes, suggesting that they diverged early from the other group C genomes. The F strains formed the most divergent group of HBV genomes, which may be explained by their representing the original strains of the New World. Within the structural gene products, 17 and 34 amino acids unique for human HBV strains were recorded in the sequenced E and F strains, respectively. Most notable is the Ser
81 to Ala
81 substitution in an immunodominant region of HBcAg, and the four extra cysteine residues in HBsAg at residues 19, 183, 206, and 220, which might be engaged in additional disulphide bridges. Five residues shared by E and F strains were also unique for human HBV strains. Two of these, Leu
127 and Ser
140 in HBsAg, were the only substitutions that may explain the
w4 reactivity shared by these HBV strains. Interestingly, the Ser
140 substitution occurs in an immunodominant loop of the a determinant claimed to be important for the protective immune response to HBV vaccination.
Sequences of 234 complete genomes and 631 hepatitis B surface antigen genes were used to assess the worldwide diversity of hepatitis B virus (HBV). Apart from the described two subgenotypes each for ...A and F, also B, C, and D divided into four subgenotypes each in the analysis of complete genomes supported by significant bootstrap values. The subgenotypes of B and C differed in their geographical distribution, with B1 dominating in Japan, B2 in China and Vietnam, B3 confined to Indonesia, and B4 confined to Vietnam, all strains specifying subtype ayw1. Subgenotype C1 was common in Japan, Korea, and China; C2 in China, South-East Asia, and Bangladesh, and C3 in the Oceania comprising strains specifying adrq-, and C4 specifying ayw3 is encountered in Aborigines from Australia. This pattern of defined geographical distribution was less evident for D1-D4, where the subgenotypes were widely spread in Europe, Africa, and Asia, possibly due to their divergence having occurred a longer time ago than for genotypes B and C, with D4 being the first split and still the dominating subgenotype of D in the Oceania. The genetic diversity of HBV and the geographical distribution of its subgenotypes provide a tool to reconstruct the evolutionary history of HBV and may help to complement genetic data in the understanding of the evolution and past migrations of man.
1 Department of Virology, The National Bacteriological Laboratory, S-105 21 Stockholm, Sweden
and 2 Institut National de Transfusion Sanguine, F-75739 Paris, France
Amino acid residues 101 to 180 of ...hepatitis B surface antigen (HBsAg) were predicted by sequencing the corresponding part of the S gene of hepatitis B virus (HBV) DNA in 46 HBsAg-positive sera, which had been subtyped by immunodiffusion with respect to d/y, w/r, w1 to w4 and q . The sequences of the nine different HBV serotypes defined by these specificities were found to be homogeneous proving that they represent consistent variations of HBV at the genomic level. Residue 127 was found to be important as were Pro, Thr and Leu for w1/w2, w3 and w4 , respectively. Five residues were found to differ between ayw1 and ayw2 . These were at positions 134 (Phe instead of Tyr), 143 (Thr instead of Ser), 159 (Ala instead of Gly), 161 (Tyr instead of Phe) and 168 (Val instead of Ala). However, all these residues were shared by ayw1 and adw2 , implying that Arg 122 was also important for w1 expression. All genomes expressing r , apart from one ayr strain, had an Ile 126 , which might explain the pseudo-allelism of w1 to w4 in relation to r , since this substitution might influence the w epitope. There were two regions where adw4q - and adrq - differed from all the q + subtypes. These were located at residues 158 and 159, and at residues 177 and 178, where both the q - subtypes had amino acid substitutions in adjacent positions. The mapping of the epitopes defining these antigenic specificities will help to link information on the world-wide distribution of HBsAg subtypes to future molecular epidemiology with regard to HBV.
Received 1 June 1992;
accepted 24 August 1992.
BACKGROUND: The purpose of this study was to compare the performances of HCV core antigen (HCV Ag) testing with HCV RNA detection during the preseroconversion period.
STUDY DESIGN AND METHODS: Six ...HCV antibody (HCV Ab)‐negative and HCV RNA‐positive blood samples from 6 donors and 135 serial samples from 28 patients who had undergone hemodialysis, collected a mean of 90 days before the detection of HCV Ab, were tested by ELISA for the detection of HCV Ag and by PCR to quantify HCV RNA.
RESULTS: Five of the six donors were positive for HCV Ag. The donor with a negative HCV Ag test had the lowest viral load. In the hemodialysis patients, the 43 first specimens of the series were HCV RNA negative. Of the 92 specimens that were HCV RNA positive, 81 (88%) were positive for HCV Ag. Among the 74 samples with more than 105 RNA copies, 71 (96%) were HCV Ag positive. Average time from first viremic bleed to first HCV Ag‐positive bleed was estimated at 2.0 days and that to first HCV Ab‐positive bleed at 50.8 days.
CONCLUSION: HCV Ag testing permits the detection of an HCV infection about 1.5 months earlier than the HCV Ab screening tests and an average of only 2 days later than quantitative HCV RNA detection in individual specimens.
Background and objectives
Antibodies to the core of hepatitis B virus (anti‐HBc) are considered to be the best serologically reliable markers of hepatitis B virus (HBV) infection. Through a national ...epidemiological survey, two young and first‐time blood donors, originating from HBV‐endemic areas, were identified as HBV carriers with an absence of anti‐HBc reactivity.
Materials and Methods
We followed up these two subjects in order to investigate the evolution of their HBV serological profiles. Nucleotide sequencing was performed of the entire pre‐C/C region of the strains infecting these donors.
Results
The same serological profile of active viral replication with an apparent persistent lack of anti‐HBc and normal alanine aminotransferase (ALT) levels was found for both subjects throughout a follow‐up of 19 months and 4 months, respectively. Neither donor was immunocompromised. Nucleotide sequence analysis of the pre‐C/C region did not show mutations or deletions in encoded proteins.
Conclusion
The hypothesis of an in utero HBV infection responsible for an immune tolerance to HBV seems to be the most probable explanation for this particular immunological situation. Such occurrences in the blood donor population are probably rare as less than 0·1% of hepatitis B surface antigen (HBsAg)‐positive donors exhibit such a profile, in our experience. Moreover, this phenomenon does not impose a risk of HBV transmission by blood donation, as the exclusion of HBV‐infected blood donation is based on HBsAg detection. However, such a risk might be encountered with the hepatitis C virus (HCV) for which at present only antibodies to HCV are screened.
We have conducted a multicenter randomized controlled trial comparing two doses of recombinant human alpha-interferon for efficacy in 60 patients with chronic non-A, non-B hepatitis. The source of ...infection appeared to be transfusion in 30 patients, intravenous drug abuse in 16 patients and was unknown in 14 patients. Patients were randomly assigned to no treatment or to treatment with either 1 or 3 MU of alpha-interferon given three times a week for 24 wk. Forty-five patients (75%) were positive for antibody to hepatitis C virus. During the 24-wk treatment period, mean serum ALT levels decreased in both treatment groups, but the decrease was statistically significant only in the 3 MU group. However, at 24 wk, the proportion of patients with normal ALT levels was similar in the 3 MU group (39%) and the 1 MU group (45%), and both were significantly higher than in controls (0%). Repeat liver biopsy specimens showed a significant decrease in the severity of histological changes in the 3 MU group but not in the 1 MU group or in controls. Responses to alpha-interferon did not correlate with patient's age, gender, source of infection, pretreatment serum ALT, presence of anti-hepatitis C virus or cirrhosis. After treatment, the mean ALT levels rose in both treated groups. The proportion of patients with normal ALT levels at wk 48 was 28% in the 3 MU group and 20% in the 1 MU group. In conclusion, a dose of 3 MU was superior to 1 MU of alpha-interferon given three times weekly for 24 wk in inducing improvements in serum ALT levels and liver histological examinations.
BACKGROUND : Monitoring trends in residual risks of transfusion‐transmitted viral infections (HIV, HTLV, HBV, and HCV) is important to assess improvements in blood safety. In France, theses trends ...were analyzed between 1992 and 2000.
STUDY DESIGN AND METHODS : As risk is predominantly associated with the window period, residual risks were estimated by multiplying incidence rates by the durations of the window periods. Incidence rates were calculated from the data collected by the blood transfusion centers belonging to the Transfusion‐Transmissible Agents Working Group, which currently collects more than 50 percent of the 2.5 million blood samples donated each year in France.
RESULTS : Trend analysis showed a significant decrease in residual risks for HCV (p = 0.01) and HBV (p < 0.001). Although residual risks decreased for HIV and HTLV, the trends were not significant. In 1998 through 2000, residual risks were estimated to be 1 in 470,000 donations for HBV, 1 in 860,000 for HCV, 1 in 1,370,000 for HIV, nil for HTLV, and 1 in 250,000 for the four viruses combined.
CONCLUSION S: In France, the current risk of a blood recipient becoming infected with a retrovirus or a hepatitis virus is extremely low. The implementation of NAT in July 2001 is predicted to reduce the residual risk to 1 in 2,700,000 donations for HIV and 1 in 8,300,000 for HCV.
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