Hepatitis C virus genotypes in Kenya

Phylogenetic and Phylodynamic Analyses of HCV Strains Circulating among Patients Using Injectable Drugs in Central Italy

Approximately 71 million people worldwide are infected with the hepatitis C virus (HCV). Injectable drug use represents the most common route of transmission in Europe and other developed countries. We studied the molecular characteristics of the HCV infection among mono-infected people who used drugs (PWUD) in Italy. Among 208 PWUD with anti-HCV antibodies, 101 (48.6%) were HCV RNA-positive, the majority (47%) were infected with the HCV genotype (Gt)1a, followed by Gt3a (34.9%), Gt4 (9.1%), Gt1b (4.5%), and Gt2 (4.5%). Bayesian phylogenetic analyses of clustered HCV NS5B sequences from 66 HCV-positive PWUDs with available plasma samples indicated age and neighborhood proximity as the most common characteristics between closely related HCV strains. Population dynamics, as measured by a coalescent Bayesian skyline analysis, revealed an increase in HCV Gt1a infections from the mid-1980s to mid-1990s. While HCV Gt3a infections were first detected in the 1980s, patient numbers with this genotype subtype remained relatively constant. For both Gt1a and Gt3a, Birth–Death Bayesian Skyline analyses produced higher reproduction numbers post 2014. For earlier time intervals, slow growths were observed for both Gt1a and Gt3a with reproduction numbers (Re) of approximately 1. The evolutionary rates for Gt1a and Gt3a were estimated as 2.23 × 10⁻⁴ and 3.85 × 10⁻⁴, respectively.

Seroprevalence and genotypic characterization of HBV among low risk voluntary blood donors in Nairobi, Kenya

Background

Hepatitis B virus (HBV) causes significant morbidity and mortality globally primarily due to its ability to cause hepatitis, liver cirrhosis and hepatocellular carcinoma. The Kenya National Blood Transfusion Services screens for Hepatitis B antibodies using the chemiluminescent microparticle immunoassay method. This test does not inform on the genotypic characteristics of the virus or the actual presence of the virus in blood. This study therefore sought to determine the serologic and genotypic profiles of HBV circulating among the voluntary blood donors in Nairobi.

Methods

Blood samples were collected in plain and EDTA vacutainers and tested for the Hepatitis B surface antigen (HBsAg). HBV DNA was then extracted from plasma, its overlapping P/S gene amplified and sequenced. The resulting sequences were used to analyze for the circulating genotypes and mutations within the P and S genes. Bivariate statistical analysis was used to determine the association between demographic factors and HBV infection.

Results

A seroprevalence of 2.3% (n = 7) was reported. The age group 19–28 years was significantly associated with HBV infection. Nine samples were positive for HBV DNA; these included 2 HBsAg positive samples and 7 HBsAg negative samples. Genotype A, sub genotype A1 was found to be exclusively prevalent while a number of mutations were reported in the “a” determinant segment of the major hydrophilic region of the S gene associated with antibody escape. RT mutations including mutation rt181T in the P gene conferring resistance against Lamivudine and other ʟ-nucleoside drugs were detected.

Conclusion

There is a high prevalence of occult HBV infections among these blood donors and therefore the testing platform currently in use requires revision.

Prevalence, estimated incidence, risk behaviours, and genotypic distribution of hepatitis C virus among people who inject drugs accessing harm-reduction services in Kenya: a retrospective cohort study

BACKGROUND

Sub-Saharan Africa has a large population of people with hepatitis C virus (HCV) infection, yet little is known about HCV among people who inject drugs this region. We assessed the prevalence of HCV mono-infection and HIV-HCV co-infection, and the estimated incidence, genotypes, and risk behaviours associated with HCV among people who inject drugs in Kenya.

METHODS

People aged 18 years or older who were living in Nairobi, coastal Kenya, or western Kenya, had a history of injection drug use, and had used any illicit drugs in the past 12 months were recruited at needle and syringe programme sites using respondent-driven sampling. Participants were screened for the presence of an anti-HCV antibody. Those who were anti-HCV positive underwent confirmatory HCV RNA testing, and those with detectable HCV RNA were genotyped. Participants were interviewed regarding parenteral risk behaviours and exposure to services received at the needle and syringe programme sites. We examined correlates of HCV infection and HIV-HCV co-infection using bivariate and multivariate regression, and estimated HCV incidence.

FINDINGS

Of 2188 enrolled participants, 291 (13%) were anti-HCV positive: 183 (22%) of 842 participants in coastal Kenya, 105 (13%) of 817 in Nairobi, and three (1%) of 529 in western Kenya. 284 anti-HCV-positive participants underwent successful HCV RNA testing, of whom 230 (81%) were viraemic. Estimated incidence rates of anti-HCV positivity per 100 person-years were 6·31 in coastal Kenya, 3·19 in Nairobi, and 0·22 in western Kenya. HCV incidence rate was greater in coastal Kenya compared with Nairobi (incidence rate ratio 1·97 [95% CI 1·35-2·93], p=0·0001) and the western region (28·17 [7·55-236·58], p<0·0001). In the coastal region, history of incarceration, more years injecting, more injections in the past month, and receptive cooker sharing were associated with increased risk of HCV, while female sex, more years injecting, more injections in the past month, and regular use of a syringe with a detachable needle were associated with HCV risk in Nairobi. HCV prevalence among HIV-positive participants was 50% (66 of 131 participants) in coastal Kenya, 35% (42 of 121) in Nairobi, and 4% (one of 23) in western Kenya. Risk factors for HIV-HCV co-infection were similar to those observed for HCV mono-infection. The prevailing genotypes were 1a (51%), 4a (47%), and mixed (2%; three 1a/4a and one 1a/2b).

INTERPRETATION

HCV prevalence, estimated incidence, and risk behaviours among people who inject drugs in Kenya vary with region, with the highest estimated incidence observed in coastal Kenya. These findings should be used to inform focused strategies to reduce HCV transmission, such as expansion of needle and syringe programmes, upscaling of opioid agonist therapy, and treatment as prevention in regions affected by injection drug use and HCV.

FUNDING

National Institute on Drug Abuse.

Screening a nation for hepatitis C virus elimination: a cross-sectional study on prevalence of hepatitis C and associated risk factors in the Rwandan general population

OBJECTIVES

We analysed data collected during programmatic screening activities conducted in 2017 to describe hepatitis C virus (HCV) seroprevalence in the general population and identify associated factors.

DESIGN

We analysed data collected between June and September 2017. For both seroprevalence and viraemia, variations across demographic and geographic factors were assessed and multivariate regression models were fit to identify factors independently associated with each marker. Geospatial data were examined for visualisation.

SETTING

HCV screening was organised within each of the 30 districts in Rwanda. One designated location in each district was selected as the screening site and screening took place for 1 week at each site.

PARTICIPANTS

This study included 124 223 male and female volunteers. Anti-HCV-positive individuals were followed up with HCV RNA viral load (VL) testing for infection confirmation.

MAIN OUTCOME MEASURES

Two markers were examined: the presence of HCV antibodies and HCV RNA VL.

RESULTS

Among 124 223 individuals screened, 11 003 (8.86%, 95% CIs: 8.70% to 9.02%) were positive for anti-HCV. Anti-HCV prevalence varied by age with the oldest age group (>55 year olds) having a prevalence of 16.46% (95% CIs: 16.14% to 16.80%) and the youngest age group (<25 year olds) having a prevalence of 2.20% (95% CIs: 1.93% to 2.50%) (crude OR=8.78). After adjustment for covariates, an association remained between anti-HCV prevalence and age (p<0.001), province (p<0.001) and socioeconomic status (p<0.001). Of the 3771 anti-HCV-positive individuals who had an available HCV RNA VL result, 2099 (55.66%, 95% CI: 54.06% to 57.25%) had a detectable HCV RNA VL. Age was also associated with HCV viraemia (p<0.001).

CONCLUSION

Results suggest that over 55% of individuals who screened positive for HCV-antibodies were chronically infected. Targeted screening for HCV among older individuals is recommended, given the association between age and infection. Further geographical hotspots of HCV infection can also inform targeted screening as Rwanda moves towards HCV elimination.

The Prevalence of Hepatitis C Virus Antibody in HIV-Negative Persons in Kenya, 2007

The prevalence of hepatitis C virus (HCV) infection in the Kenyan population has not been previously determined. We estimated the Kenyan HCV prevalence in HIV-negative persons aged 15-64 years. This is a retrospective cross-sectional study using data from the 2007 Kenya AIDS Indicator Survey-a nationally representative sample of 15,853 persons aged 15-64 years who completed a health interview and provided a blood specimen. Of the 1,091 randomly selected participants, 50 tested positive for HCV antibody using the automated chemiluminescence immunoassay, corresponding to a weighted HCV antibody positivity rate of 4.4% (95% confidence interval: 3.3-5.9%) or 848,000 (range: 634,000-1,100,000) persons. Hepatitis C virus RNA, a marker for current infection, was not detected in any of the tested antibody-positive specimens. The high HCV antibody prevalence together with no current infection suggests that some HCV antibody serologic testing in Kenya may result in false positives whereas others may be because of spontaneous viral clearance.

Low prevalence of hepatitis C virus RNA in blood donors with anti-hepatitis C virus reactivity in Rwanda

BACKGROUND

Hepatitis C virus (HCV) is the leading cause of severe liver disease worldwide and is highly endemic in Africa, where it often has nosocomial spread. Little is known on the HCV prevalence, risk for transfusion-transmitted HCV, and circulating genotypes in Rwanda. This study was performed to investigate the prevalence of anti-HCV among blood donors from all regions of the country and genetically characterize identified HCV strains.

STUDY DESIGN AND METHODS

Data on anti-HCV reactivity for all 45,061 Rwandan blood donations during 2014 were compiled. Samples from 720 blood donors were reanalyzed for anti-HCV in Sweden. Line immunoassay INNO-LIA HCV and detection of HCV RNA by polymerase chain reaction were used to confirm anti-HCV reactivity. The NS5B and core regions were sequenced and phylogenetic analysis was performed.

RESULTS

The anti-HCV prevalence among all first-time blood donors was 1.6%, with the highest occurrence in donors from the eastern region. On further analysis, only 25 of 120 primarily anti-HCV-reactive samples could be confirmed reactive and 15 samples had indeterminate results by INNO-LIA. Confirmed reactivity was more common among females than males (p = 0.03) with no regional difference. Phylogenetic analysis of the sequences showed a predominance of subtypes 4k, 4q, and 4r, with no geographical difference in their distribution.

CONCLUSION

The prevalence of anti-HCV among Rwandan blood donors has probably been overestimated previously due to the high rate of nonconfirmable anti-HCV reactivity. Further study of the involved mechanism is needed to avoid loss of blood products and distress for blood donors and other test recipients.