Substitution of the CD81 Binding Site and β-Sandwich Area in E2 of HCV in Cambodia

Unveiling the dynamics of hepatitis C virus transmission among injection drug users and men who have sex with men: A comprehensive study in Japan

AIM

In Japan, despite low nationwide hepatitis C (HCV) incidence, new infections among people who inject drugs (PWID) and men who have sex with men (MSM) hinder HCV elimination. We explored HCV transmission dynamics and screened HCV recombination within these populations.

METHODS

This cross-sectional study recruited HCV-infected patients from Osaka National Hospital, Osaka, Japan, from January 2010 to September 2023. Data from questionnaires and medical records were analyzed. Serum samples collected before anti-HCV treatment underwent HCV RNA extraction, and sequencing of full core (576 bp) and NS5B (267 bp) regions using the Sanger method. Genotype distribution was determined by phylogenetic analysis, and recombinant screening was conducted.

RESULTS

A total of 115 patients were categorized into non-MSM PWID (31), MSM PWID (15), MSM non-PWID (25), and non-MSM non-PWID (44). Positive amplification rates were 99.1% (114/115) for the full-core region, and 96.5% (111/115) for NS5B. No intergenotypic recombination was detected. The predominant genotype in non-MSM PWID was 2a (58%), whereas genotype 1b was most common in MSM PWID, MSM non-PWID, and non-MSM non-PWID groups (79%, 64%, and 68%, respectively). Nucleotide sequence similarity of 94.75%-100% was found in HCV strains from MSM PWID and MSM non-PWID in both full-core and NS5B regions, whereas strains from non-MSM PWID and non-MSM non-PWID were distinct.

CONCLUSION

The findings suggest that the transmission route in PWID is determined by MSM status, whereas MSM groups showed the same transmission route regardless of PWID. HCV control measures should be focused not only on PWID, but also on MSM to achieve HCV elimination in Japan.

Understanding the relationship between HCV infection and progression of kidney disease

Hepatitis C virus (HCV) can cause a range of kidney diseases. HCV is the primary cause of mixed cryoglobulinaemia, which leads to cryoglobulinaemic vasculitis and cryoglobulinaemic glomerulonephritis (GN). Patients with acute cryoglobulinaemic vasculitis often exhibit acute kidney disease due to HCV infection, which typically progresses to acute kidney injury (AKI). HCV also increases the risk of chronic kidney disease (CKD) and the likelihood of developing end-stage renal disease (ESRD). Currently, direct-acting antiviral agents (DAAs) can be used to treat kidney disease at different stages. This review focuses on key findings regarding HCV and kidney disease, discusses the impact of DAAs, and highlights the need for further research and treatment.

Systematic Review of Hepatitis C Virus Prevalence in the WHO Western Pacific Region

BACKGROUND

This review aimed to identify hepatitis C virus (HCV) prevalence estimates among the general population and six key populations (people who inject drugs, men who have sex with men, sex workers, prisoners/detainees, Indigenous people, and migrants) in the World Health Organization Western Pacific Region (WHO WPR).

METHODS

Original research articles published between 2016 and 2020 were identified from bibliographic databases. Publications were retrieved, replicas removed, and abstracts screened. Retained full texts were assessed and excluded if inclusion criteria were not met. Methodological quality was assessed using the Johanna Briggs Institute critical appraisal checklist for prevalence data. Data on HCV exposure and active infection were extracted and aggregated and forest plots generated for each population by country.

RESULTS

There were no HCV prevalence estimates in any population for more than half of WPR countries and territories. Among the 76 estimates, 97% presented prevalence of exposure and 33% prevalence of active infection. General population viraemic prevalence was 1% or less, except in Mongolia. Results confirm the endemic nature of HCV among people who inject drugs, with estimates of exposure ranging from 30% in Cambodia to 76% in Hong Kong.

CONCLUSIONS

Countries require detailed knowledge of HCV prevalence in diverse populations to evaluate the impact of efforts to support WHO HCV elimination goals. Results provide baseline estimates from which to monitor and evaluate progress and by which to benchmark future elimination efforts.

Hepatitis C seroprevalence among people living with HIV/AIDS and pregnant women in four provinces in Cambodia: an integrated bio-behavioral survey

Background

Understanding the extent of viral hepatitis burden in specific subgroups, such as pregnant women and people living with HIV/AIDS (PLWHA), and their geographic distribution is essential for evidence-informed policy and mobilizing resources for targeted treatment and prevention efforts. However, in Cambodia, the epidemiology of hepatitis C remains uncertain. We estimated the hepatitis C virus (HCV) burden and transmission risk factors among PLWHA and pregnant women attending antenatal care (ANC) in Cambodia.

Methods

Between March and April 2016, we conducted a cross-sectional survey in four diverse geographical areas: the capital city of Phnom Penh and three provinces. We collected information on demographic characteristics and risk behaviors and performed HCV antibody (Anti-HCV) testing among pregnant women attending public ANC clinics and among those receiving HIV care at the hospitals. We computed the prevalence of HCV among the two population subsets and performed logistic regression analyses to identify risk factors associated with HCV antibody positivity.

Results

Of 935 participants enrolled, 510 (54.6%) were pregnant women and 425 (45.4%) were PLWHA. Anti-HCV prevalence was significantly higher in PLWHA than in pregnant women (29/425, 6.8% vs 5/510, 0.9%, P < 0.001). Of the geographic regions, Preah Sihanouk province (Southwest) had the highest anti-HCV prevalence among PLWHA (12.0%, P = 0.031). There was no significant geographic difference in anti-HCV prevalence among pregnant women. In multivariable analyses (data subset to PLWHA), HCV infection was significantly associated with having a family member positive for HCV (OR = 7.6 [95% CI: 1.01–57.84], P = 0.048) and a history of intravenous medication injection in the last 5 years (OR = 7.1 [95% CI: 2.79–18.10], P < 0.001).

Conclusions

HCV infection is relatively common among Cambodian PLWHA, likely related to intravenous medication injection and intra-familial viral transmission. Systematic HCV testing and care among PLWHA (and possibly their family members) might be necessary. Setting up a surveillance system for HCV might also be beneficial for some geographical regions and populations.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07163-2.

B, Ouoba S, Akita T, Sugiyama A, Ohisa M, Sakaguchi T, Tahara H, Ohge H, Ohdan H, Kubo T, Kishita E, Kuwabara M, Takahashi K, Tanaka J. Molecular characterization and the mutation pattern of SARS-CoV-2 during first and second wave outbreaks in Hiroshima, Japan

BACKGROUND

In this study, we performed molecular characterization of SARS-CoV-2 strains in Hiroshima and its mutation pattern between the first and second waves of the outbreak.

METHOD

A total of 55 nasal swab samples from the first wave in Hiroshima and 13 from the second wave were examined quantitatively by RT-qPCR and qualitatively by nested PCR using specific primers. Four samples from each wave underwent next-generation sequencing and phylogenetic tree analysis including controls and all sequences retrieved in Japan from GISAID and GenBank. Subsequently, mutations were examined.

RESULTS

Viral load ranged 7.85 × 101-1.42 × 108 copies/ml. Of 68 samples, one was Asian type-O, 65 were European type-GR, and 2 were undetectable. Phylogenetic tree analysis indicated that Japan was infected with various Asian strains (L, S, V, O) from January through April. By second week of March, European strains (G, GH, GR) had appeared, and GR strains became predominant after mid-March. The first case in Hiroshima was classified as Asian strain O, and the rest were GR strains. Then, second wave of GR strains appeared independently with 11-15 base mutations. Comparing the first- and second-wave GR strains, mutation rate was 1.17-1.36 × 10-3 base substitutions per site per year; in addition, amino acid changes occurred at S1361P and P3371S in ORF1a, A314V in ORF1b, and P151L in N. All seven GR strains were D614G variants with R202K and G203R mutations in N. A single-nucleotide insertion in ORF8 that causes a defect in ORF8 protein was found in one isolate (S66) from the second wave.

CONCLUSION

Our findings reveal the evolutionary hierarchy of SARS-CoV-2 in Japan. The predominant D614G variants and a new form of ORF8 deletion in Hiroshima provide the clue for role of viral factor in local outbreaks of SARS-CoV-2.