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The clinical utility of quantifying hepatitis B surface antigen (qHBsAg) levels in African subjects with chronic hepatitis B virus (HBV) infection has been poorly documented. From a multicentre cohort of 944 HBV-infected African patients, we aimed to assess whether qHBsAg alone can accurately identify i) those in a HBeAg-negative chronic HBV infection phase at low risk of liver disease progression and ii) those in need of antiviral therapy according to the 2017 EASL guidelines. We analysed 770 HBV mono-infected treatment-naïve patients, mainly males (61%) from West Africa (92%), median age 35 years (IQR: 30-44), median HBV DNA: 95.6 IU/ml (10.0-1,300.0), median qHBsAg 5,498 IU/ml (1,171-13,000) and HBeAg-pos 38 (5%). A total of 464/770 (60.2%) patients were classified as HBeAg-negative chronic infection (median age 36 years (31-46), median ALT 23 IU/l (18-28), median HBV-DNA 33.5 IU/ml (3.8-154.1), median LSM 4.8 kPa (4.1-5.8)) and qHBsAg levels had poor accuracy to identify these subjects with an AUROC at 0.58 (95%CI: 0.54-0.62), sensitivity 55.0% and specificity 55.6%; 118/770 (15.3%) patients were eligible for treatment according to the 2017 EASL criteria. qHBsAg correlated poorly with HBV DNA and had poor accuracy to select patients for antiviral therapy with an AUROC at 0.54 (0.49-0.60), sensitivity 46.6% and specificity 46.9%. In African treatment-naïve HBV-infected subjects, the clinical utility of qHBsAg to identify subjects in HBeAg-negative infection phase or subjects eligible for antiviral therapy seems futile. Whether qHBsAg levels can be used as a predictor of long-term liver complications in Africa needs to be further investigated., (© 2021 John Wiley & Sons Ltd.)

Hepatocellular carcinoma (HCC) incidence is high in The Gambia, and hepatitis B virus (HBV) infection is the main cause. People coinfected with HBV and hepatitis D virus (HDV) have an even greater risk of HCC and cirrhosis. Using a new HDV quantitative microarray antibody capture (Q-MAC) assay, we evaluated the association between HDV infection and HCC or cirrhosis among participants in The Gambia Liver Cancer Study. In this case-control study, cases had HCC (n = 312) or cirrhosis (n = 119). Controls (n = 470) had no clinical evidence of liver disease and normal serum alpha-foetoprotein. Participants were previously tested for hepatitis B surface antigen (HBsAg); we tested HBsAg+ specimens by HDV Q-MAC, western blot and RNA assays. We evaluated separate cut-offs of the Q-MAC assay for predicting anti-HDV and RNA positivity. Q-MAC correctly identified 29/29 subjects who were western blot-positive (sensitivity = 100%, specificity = 99.4%) and 16/17 who were RNA-positive (sensitivity = 94.1%, specificity = 100%). Compared to controls, cases more often had HBV monoinfection (HBsAg+/HDV RNA-; 54.1% vs 17.0%; odds ratio [OR] = 6.28; P < 0.001) or HBV-HDV coinfection (HBsAg+/HDV RNA+; 3.9% vs 0%; P < 0.001). Risk estimates (for HCC or cirrhosis) based on HDV antibody status and adjusted for covariates (demographics, alcohol, smoking, body mass index, anti-HCV and aflatoxin B1 exposure) yielded consistent results for both HBV monoinfection (adjusted OR = 8.29; 95% confidence interval = 5.74-11.98) and HBV-HDV coinfection (adjusted OR = 30.66; 95% confidence interval = 6.97-134.95). In this Gambian population, HDV Q-MAC had high sensitivity and specificity for both anti-HDV and HDV RNA. HDV infection contributed to the high risk of HCC in The Gambia., (© 2019 John Wiley & Sons Ltd.)

Hepatitis B virus (HBV) is a major cause of chronic liver disease worldwide. HBV infection is diagnosed by serological tests, while real-time polymerase chain reaction (qRT-PCR) assays are used to quantify viral load, which is a crucial parameter to determine viral replication and to monitor antiviral treatments. However, measuring viral load in resource-limited countries remains nonsystematic, due to the high cost of commercial kits. Here, we describe the development, validation and implementation of a low-cost, in-house qRT-PCR assay to monitor HBV viral load in chronic carriers enrolled in the PROLIFICA programme in the Gambia and Senegal. Over 1500 HBsAg-positive patients, including 210 chronically infected HBV patients, who were given antiviral treatment (tenofovir), were monitored by qRT-PCR using the SYBR Green- and HBV-specific primers. Twenty-four tenofovir-treated patients were followed up and their viral load was tested every 3 months over the 12-month experimental time course. Compared to commercial assays, our in-house assay was shown to be (i) highly reliable, with good intra- and interassay reproducibility over a wide range (45-4.5 × 10 8 copies mL -1 ), (ii) very similar in the viral loads detected (R 2  = .90), (iii) highly sensitive, as it detected loads as low as 30 copies mL -1 (~5 IU mL -1 ), (iv) cheaper (2- to 3-fold), (v) easier to implement and (vi) more rapid. Based on our experience, we recommend this assay as a reliable alternative to commercial assays, for monitoring HBV viraemia in resource-limited, highly endemic countries to reduce the cost and technical obstacles associated with commercial kits., (© 2016 John Wiley & Sons Ltd.)

Objective: To estimate the prevalence of antibodies against Coxiella burnetii (Q fever) among children in eight villages in The Gambia, West Africa., Methods: Sera of 796 children aged 1-15 years were tested for presence of antibodies against phase II of C. burnetii by ELISA., Results: IgG and/or IgM phase II antibodies against C. burnetii were detectable in 8.3% (66/796) of all serum samples analysed with significant differences in seroprevalence between villages. Highest prevalence was found in the age group 1-4 years., Conclusions: Exposure to C. burnetii is considerable in the early years of life in The Gambia, and further studies are warranted to estimate the role of Q fever in acute febrile illness in The Gambia and elsewhere in Africa., (© 2013 Blackwell Publishing Ltd.)