The prevalence of hepatitis B virus markers in a cohort of students in Bangui, Central African Republic

Prevalence of hepatitis B virus infection and its associated factors among students in N'Djamena, Chad

INTRODUCTION

Infection by hepatitis B virus (HBV) is a major issue in public health. The prevalence of HBV in Chad is 12.4%, all age groups considered. Here, we aimed to determine the prevalence of HBV and its associated factors among university students in N'Djamena, the country's capital.

METHODS

A cross-sectional survey of students at either the University of N'djamena or Emi Koussi University was conducted from 3 to 23 July 2021. All participating students provided signed, informed consent and were included in the study consecutively. Blood samples were collected, and serum tested for hepatitis B surface antigen (HBsAg) using the Determine HBsAg rapid test kit, with confirmation of positive tests on an Abbott Architect i1000SR analyzer. Descriptive analysis and logistic regression were used to determine associations between the outcome variable and independent/covariate variables.

RESULTS

A total of 457 students with a median age of 24 years were included across different faculties. The prevalence of HBV infection was 14.87% (68/457). Most students (75%) were aged 25 years or less. Unprotected sex was reported by 64.9% of the students and multiple sexual partners by 53.6%. Furthermore, 45.7% of them reported having no knowledge of hepatitis B. Having an HBsAg-positive mother (AOR: 2.11), having a history of transcutaneous medical procedures (AOR: 2.97) and living with a family (AOR: 4.63) were significantly associated with HBV status. Age ≥26 years appeared as a protective factor (AOR = 0.41).

CONCLUSION

Our study detected a high, 14.87% prevalence of HBV infection among students in N'djamena, Chad, and shed light on its associated factors. HBV prevention strategies should include raising awareness among students, making full hepatitis vaccination mandatory before children begin school, promoting mass screening to identify and treat chronic HBV carriers and reduce transmission, and reducing the cost of vaccination.

Toward the elimination of hepatitis B: networking to promote the prevention of vertical transmission of hepatitis B virus through population-based interventions and multidisciplinary groups in Africa

The WHO African Region had 81 million people with chronic hepatitis B in 2019, which remains a silent killer. Hepatitis B virus (HBV), hepatitis delta virus (HDV), and HIV can be transmitted from the mother to child. If the HBV infection is acquired at infancy, it may lead to chronic hepatitis B in 90% of the cases. WHO reports that 6.4 million children under 5 years live with chronic hepatitis B infection worldwide. The prevention of mother-to-child transmission (PMTCT) of HBV is therefore critical in the global elimination strategy of viral hepatitis as we take lessons from PMTCT of HIV programs in Africa. We sought to create a network of multidisciplinary professional and civil society volunteers with the vision to promote cost-effective, country-driven initiatives to prevent the MTCT of HBV in Africa. In 2018, the Mother-Infant Cohort Hepatitis B Network (MICHep B Network) with members from Cameroon, Zimbabwe, and the United Kingdom and later from Chad, Gabon, and Central African Republic was created. The long-term objectives of the network are to organize capacity-building and networking workshops, create awareness among pregnant women, their partners, and the community, promote the operational research on MTCT of HBV, and extend the network activities to other African countries. The Network organized in Cameroon, two "Knowledge, Attitude and Practice" (KAP) surveys, one in-depth interview of 45 health care workers which revealed a high acceptability of the hepatitis B vaccine by families, two in-person workshops in 2018 and 2019, and one virtual in 2021 with over 190 participants, as well as two workshops on grant writing, bioethics, and biostatistics of 30 postgraduate students. Two HBV seroprevalence studies in pregnant women were conducted in Cameroon and Zimbabwe, in which a prevalence of 5.8% and 2.7%, respectively, was reported. The results and recommendations from the MICHep B Network activities could be implemented in countries of the MICHep B Network and beyond, with the goal of providing free birth dose vaccine against hepatitis B in Africa.

The role of dried blood spot tests in the detection of hepatitis B infection: A systematic review

Hepatitis B remains a public health problem worldwide despite vaccine availability. Although the existing diagnostic tools help detect the infection, logistics support and limited resources and technologies affect their usefulness and reliability in developing countries. This systematic review evaluated the performance of dried blood spots (DBS) as a collection and storage tool for diagnosing an hepatitis B virus (HBV) infection. A comprehensive search using OVID, Scopus and CINAHL databases was performed to collate articles published up to April 2023 that detected Hepatitis B infections using DBS. Five reviewers independently performed identification, screening, quality assessment and data extraction. A qualitative synthesis of the included studies was conducted. Of the 402 articles, 78 met the inclusion criteria. The results show that most studies focused on populations with known HBV, HCV and/or HIV status. Approximately half (49%) of the included studies utilized the Whatman Protein Saver Card for DBS collection. The DBS samples were then predominantly stored in room temperature conditions. In line with this, storage conditions influenced the concentration and stability of the analyte from the DBS samples, affecting the accuracy of downstream diagnostic methods. ELISA methods, using hepatitis B surface antigen (HBsAg) as an HBV marker, were the most widely used diagnostic tool for detecting HBV infection in DBS samples. The simplicity and cost-effectiveness of the ELISA technique highlight its potential to be used in low-resource settings. In line with this, the detection of HBsAg using an ELISA immunoassay had higher sensitivity (85.6%-100%), and specificity (95%-100%) ranges as compared to other target molecules and methods. Although this review only performed a qualitative analysis, DBS offers a promising method for collecting and storing blood samples; however, the standardization of sampling, storing conditions and diagnostic techniques is required to ensure sustainable application.

Seroprevalence and factors associated with Hepatitis B virus infection among students in two senior high schools in the Krachi Nchumuru district in Ghana-A cross-sectional study

BACKGROUND

There is paucity of hepatitis B virus (HBV) data among student populations although Ghana is HBV endemic. Screening and identification of factors associated with HBV transmission in schools will support the intervention in the elimination of the virus by 2030. This study assessed the seroprevalence and factors associated with HBV among students in two Senior High Schools in the Krachi Nchumuru District in Ghana.

METHODS

Through cross-sectional design and simple random sampling technique, 300 first-year students were enrolled from selected Senior High Schools. Structured questionnaires were used to collect data on demographic and exposure factors while rapid test kit was used to detect HBV infections. Chi-square/Fisher exact test and multivariable logistic regression were performed to determine the association between the variables at a 95% confidence interval and 0.05 significant level.

RESULTS

Seroprevalence of HBV was 14% (42/300) among the students. The prevalence was significantly (p = 0.001) higher in males 19.4% (34/175) than females 6.4% (8/125). 77.7% (233/300) were aware of HBV infection. Males who were circumcised were 4 times more likely to be infected with HBV (AOR = 4.09, 95%CI = 1.82-9.19) (p = 0.001) compared with those uncircumcised.

CONCLUSION

HBV screening and education on hygienic genital circumcision practices must be prioritized in endemic countries.

Sero-prevalence and associated factors of sexually transmitted infections among youth-friendly services Attendees

BACKGROUND

Worldwide, more than one million peoples acquire sexually transmitted infections (STIs). The burden of STIs and the youth awareness level on the transmission of STIs is under investigated in Sidama Regional State.

OBJECTIVE

To determine the seroprevalence of STIs such as hepatitis B surface antigen (HBsAg), Anti-hepatitis C virus (HCV) antibodies, Human Immunodeficiency virus (HIV) seroprevalence, and syphilis and to determine associated factors among youth-friendly services Attendees at selected health facilities in Hawassa city, Ethiopia.

METHODS

A multicenter cross-sectional study was conducted among 416 randomly selected youth attending youth-friendly services at selected health facilities from May to August 2021. To collect the background characteristics of participants an interviewer-administered questionnaire was used. Blood samples were collected, processed, and tested using Advanced Quality One Step rapid colloidal gold immunochromatographic assay for detection of antibodies for syphilis and hepatitis C virus infection, and hepatitis B virus surface antigen. For the diagnosis of syphilis Rapid Plasma Reagin was also used. HIV1/2 STAT PAK, HIV1/2/O ABON and HIV1/2 SD Bioline were used for testing antibodies for HIV infection. Data entry and analysis were performed using Statistical Package for the Social Sciences (SPSS) version 20.0 software. A crude and adjusted odds ratio with a 95% confidence interval (CI) was computed to identify associated factors.

RESULTS

The overall seroprevalence of STIs was 11.5% (48/422), with a 95% CI: (8.7-14.9). Out of the 48 positive results, the proportions of HBsAg, Anti-HCV, HIV, and syphilis were 56.3% (27/48), 27.1% (13/48), 10.4% (5/48), and 6.3% (3/48) respectively. Out of 416 participants, 17.1% responded that it is safe to have sex without using a condom. The Odds of developing STI among female participants, participants who did not identify alcohol intake as a risk factor for STIs, and those who engaged in transactional sex were (AOR = 2.989: 95% CI: 1.27, 7.02), and (AOR = 2.393, 95% CI: 1.18, 4.81) and practice of transactional sex (AOR = 5.527, 95% CI: 1.62, 18.75).

CONCLUSIONS

STIs are common among youth-friendly services Attendee in Hawassa city The overall STI was significantly associated with sex (females), not able to identify alcohol intake as a risk factor, and practice of transactional sex. High number of (n = 289, 69.5%) participants think that the use of condoms is not effective in preventing STIs and they engage in sexual activity without using condoms.

Diagnostic performances of Exacto® Triplex rapid test for diagnosis of HIV/HCV/HBsAg: a multicenter, cross-sectional, field study in the Central African Republic

INTRODUCTION

the Exacto® Triplex HIV/HCV/HBsAg (Biosynex, Strasbourg, France) consists in lateral flow, immunochromatographic rapid diagnostic test simultaneously detecting human immunodeficiency virus (HIV)-1 and HIV-2 and hepatitis C virus (HCV)- specific antibodies (IgG and IgM) and hepatitis B virus (HBV) surface antigen (HBsAg) in serum, plasma and whole blood. We herein evaluated its diagnostic performances in the Central African Republic (CAR).

METHODS

cross-sectional study was conducted on prospectively collected panel of 550 sera from adult inpatients living in Bangui, including 200 HIV-positive, 100 HBsAg-positive, 50 HCV-positive, 200 negatives to three viruses according to reference immuno-enzymatic serological tests including Murex HCV (Diasorin, Saluggia, Italy) for HCV, Murex HBsAg (Diasorin) for HBV, Genscreen ULTRA HIV Ag-Ab HIV-1/2 Version 2 (Bio-Rad, Marnes-la-Coquette, France) and Murex HIV 1.2.0 Ag/Ab Combination (Diasorin), the 2 tests associated in the parallel algorithm for the reference strategy for the diagnosis of HIV in CAR. Serum samples were tested blindly in duplicate. The findings are reported following the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines.

RESULTS

the Exacto® Triplex showed 99.5% (95% CI; 98.5-100.0), 96.0% [90.6-100.0] and 99.0% [97.1-100.0] sensitivities for HIV, HCV and HBsAg, respectively. The specificity, positive and negative predictive values (PPV and NPV) were 100.0% for all three viruses. The Youden's J index and Cohen's κ coefficient were 0.99 for HIV and HBsAg. For HCV, Youden's J and Cohen's κ coefficient were 0.96 and 0.98, respectively. In the epidemiological context of the CAR, the PPV and NPV for all three viral infections were high (≥99.0% to 100%).

CONCLUSION

taken together, our STROBE-compliant study demonstrates that the Exacto® Triplex HIV/HCV/HBsAg showed high sensitivity and specificity for HIV and HBsAg (≥99.0%), and relatively high sensitivity (96.0%) and high specificity (100%) for HCV. These analytical performances are within the limits required by the WHO (i.e. sensitivity ≥99.0% and specificity ≥98.0%) for HIV and HBV. The Exacto® Triplex HIV/HCV/HBsAg is user-friendly at low cost, and appears highly desirable for routine use in the CAR, and likely other Central African countries.

Hepatitis B among University Population: Prevalence, Associated Risk Factors, Knowledge Assessment, and Treatment Management

Background: Very few studies have been reported on hepatitis B in the State of Azad Jammu and Kashmir, Pakistan, and none of them are specific to the prevalence and causes of hepatitis B spread among educational institutes. This study aimed to estimate the prevalence of hepatitis B infection and its associated risk factors among the University of AJ and K population. Methods: An observational, cross-sectional, and analytical study was conducted with 7015 students and employees. Hepatitis B was detected by rapid immunochromatographic tests (ICTs), enzyme-linked immunosorbent assay (ELISA), and real-time quantitative PCR. A questionnaire and interview method was used to assess the disease knowledge and associated risk factors with hepatitis B through Chi-square, Fisher’s exact test, and paired t-test. Results: Of the participants, 150 (2.13%) were found positive for the hepatitis B surface antigen (57.3% male and 42.7% female). Only 0.3% participants were found fully vaccinated against the hepatitis B virus. Among ethnic groups, the Syed tribe was found more prevalent for hepatitis B infection (40.6%), while use of contaminated mourning blades (95% CI: p = 0.0001) was found as an overlooked risk factor. Hepatitis preventive awareness sessions were found to be very significant (p = 0.0001). Conclusions: The study showed that an overlooked risk factor is playing a key role in the spread of HBV in a tribe living worldwide, which must be addressed globally to eradicate hepatitis B. In Pakistan, a country-wide annual HBV vaccination program should be launched to control hepatitis B.

Italian migrants study: An HCV and HBV micro-elimination pilot project

BACKGROUND

Migrants represent a key target population for viral hepatitis micro-elimination programs and are important targets for specific prevention, screening and treatment programs.

AIMS

To raise awareness on viral hepatitis among migrants and key stakeholders, assess the prevalence of HBV and HCV among migrants, and determine an optimal and scalable viral hepatitis screening and treatment protocol.

MATERIAL AND METHODS

Unselected, consecutive migrants reaching the costs of Italy were screened for HBV, HCV, HDV and HIV markers. Anagraphic and anamnestic information were used to identify viral hepatitis endemic hotspots in the countries of birth or transit. Personal data, including migration route, test results and treatment, were collected and stored in a dedicated database RESULTS: 362 patients were recruited in 2019; median age was 28 years, 71% were male. Most of the patients were African (54%) or Asian (40%). 49% positive for at least one HBV marker: 2.2% HBsAg (asymptomatic carriers with low viremia); 10.6% anti-HBs; 28.5% anti-HBs and anti-HBc, 1.7% anti-HCV, 0.6% anti-HIV, with low or undetectable viral load. Libya was the nexus shared by most of the positive, reactive cases. HCV and HIV markers were only found in migrants already resident in Italy for more than 6-12 months.

CONCLUSION

Low to moderate prevalence of hepatitis B markers were observed in African and Asian first arrival migrants. Migrants positive for HCV and HIV likely acquired the infection after arrival in Italy, suggesting migrants are at risk of contracting viral infections once in Italy, highlighting the importance of ensuring access to prevention for migrant communities.

Applicability of Oral Fluid and Dried Blood Spot for Hepatitis B Virus Diagnosis

Hepatitis B virus (HBV) is one of the major causes of chronic liver disease worldwide; however most of individuals are not aware about the infection. Oral fluid and dried blood spot (DBS) samples may be an alternative to serum to HBV diagnosis to increase the access to diagnosis in remote areas or high-risk groups. The main objective of this review is to give an insight about the usefulness of oral fluid and DBS for detecting HBV markers. Several groups have evaluated the detection of HBsAg, anti-HBc, and anti-HBs markers in oral fluid and DBS samples demonstrating 13 to 100% of sensitivity and specificity according different groups, sample collectors, and diagnosis assays. In the same way, HBV DNA detection using oral fluid and DBS samples demonstrate different values of sensitivity according type of collection, studied group, extraction, and detection methods. Thus, serological and molecular diagnostic tests demonstrated good performance for detecting HBV using oral fluid and DBS according some characteristics and could be useful to increase the access to the diagnosis of HBV.

Usefulness of simultaneous screening for HIV-specific and HCV-specific antibodies and HBsAg by a capillary-based multiplex rapid diagnostic test to strengthen linkage-to-care in sub-Saharan patients attending sexually transmitted infection clinic

Adult outpatients attending the main sexually transmitted infection clinic of Bangui, Central African Republic, were prospectively subjected to a multiplex rapid diagnostic test for human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV). In group I (n = 208) of patients already followed for HIV, 6 (2.9%) were unexpectedly negative, thus corresponding to false positive for HIV by the national HIV algorithm; hepatitis B surface antigen and HCV positivities were high (18.7% and 4.3%, respectively). In group II (n = 71) of patients with unknown HIV status, at least 1 chronic viral disease was diagnosed in 26 (36.6%) patients, including 5 (7.1%) HIV, 17 (23.9%) HBV, and 3 (4.2%) HCV infections.

Hepatitis B and hepatitis D virus infections in the Central African Republic, twenty-five years after a fulminant hepatitis outbreak, indicate continuing spread in asymptomatic young adults

Hepatitis delta virus (HDV) increases morbidity in Hepatitis B virus (HBV)-infected patients. In the mid-eighties, an outbreak of HDV fulminant hepatitis (FH) in the Central African Republic (CAR) killed 88% of patients hospitalized in Bangui. We evaluated infections with HBV and HDV among students and pregnant women, 25 years after the fulminant hepatitis (FH) outbreak to determine (i) the prevalence of HBV and HDV infection in this population, (ii) the clinical risk factors for HBV and/or HDV infections, and (iii) to characterize and compare the strains from the FH outbreak in the 1980s to the 2010 HBV–HDV strains. We performed a cross sectional study with historical comparison on FH-stored samples (n = 179) from 159 patients and dried blood-spots from volunteer students and pregnant women groups (n = 2172). We analyzed risk factors potentially associated with HBV and HDV. Previous HBV infection (presence of anti-HBc) occurred in 345/1290 students (26.7%) and 186/870 pregnant women (21.4%)(p = 0.005), including 110 students (8.8%) and 71 pregnant women (8.2%), who were also HBsAg-positive (p = 0.824). HDV infection occurred more frequently in pregnant women (n = 13; 18.8%) than students (n = 6; 5.4%) (p = 0.010). Infection in childhood was probably the main HBV risk factor. The risk factors for HDV infection were age (p = 0.040), transfusion (p = 0.039), and a tendency for tattooing (p = 0.055) and absence of condom use (p = 0.049). HBV-E and HDV-1 were highly prevalent during both the FH outbreak and the 2010 screening project. For historical samples, due to storage conditions and despite several attempts, we could only obtain partial HDV amplification representing 25% of the full-length genome. The HDV-1 mid-eighties FH-strains did not form a specific clade and were affiliated to two different HDV-1 African subgenotypes, one of which also includes the 2010 HDV-1 strains. In the Central African Republic, these findings indicate a high prevalence of previous and current HBV-E and HDV-1 infections both in the mid-eighties fulminant hepatitis outbreak and among asymptomatic young adults in 2010, and reinforce the need for universal HBV vaccination and the prevention of HDV transmission among HBsAg-positive patients through blood or sexual routes.

In the Central African Republic (CAR), due to 20 years of conflict, the health system has been disorganized. This could contribute to maintenance of high transmission levels of Hepatitis B Virus (HBV) and its satellite Hepatitis Delta Virus (HDV). This work studies the evolution of both infections 25 years after a fulminant hepatitis (FH) outbreak occurring in the mid-1980s associated with HDV superinfection. In young asymptomatic adults, the results show that both HBV and HDV were still actively circulating in CAR in 2010. Indeed, more than one third of HBV-infected individuals were chronic HBV carriers. Furthermore, HDV infection could be spreading among 10% of them through blood and sexual transmission. The past FH outbreak and contemporary infections were both associated with heterogeneous HDV-1 strains, combined with HBV-E. Vaccination against HBV was uncommon among pregnant women and students, even among medical students. The study constitutes warning signals to help CAR health-care reconstruction and underlines the importance of HBV vaccination. The high level of HBV infection creates a background for HDV superinfection. Neonatal HBV vaccination is needed, together with vaccination of unprotected populations. Awareness of health authorities as well as the general public would help reduce HBV and HDV infections.

Prevalence of Hepatitis B virus and Hepatitis D virus Coinfection in Western Burkina Faso and molecular characterization of the detected virus strains

OBJECTIVES

In this study, we monitored the seroprevalence of HBV-HDV co-infection in different population groups in the Western part of Burkina Faso, and described the genetic diversity of the detected virus strains.

METHODS

Between October 2013 and December 2014, venous blood samples were collected from different cohorts (blood donors, pregnant women, outpatients) in the western region of Burkina Faso. Samples were tested for HBsAg and total anti-HDV antibodies. Positive samples were further analysed for HBV-DNA and HDV-RNA. Genotyping of the detected virus strains was done by nucleotide sequencing and phylogenetic analyses.

RESULTS

A total of 841 participants were included in this study. The mean age was 27.45 years (range: 7-89 years). HBsAg was found in 117 (13.9%) participants. Of the HBsAg positive samples, 4 (3.4%) were positive for total anti-HDV antibodies and negative for HDV RNA. Phylogenetic analyses based on the HBV complete genome (n=10) and S fragment sequences (n=35) showed that all strains belonged to genotype E.

CONCLUSIONS

Our study showed a high HBsAg prevalence, but a low rate of HDV co-infection in HBsAg carriers from western Burkina Faso. The predominance of HBV genotype E in the country was confirmed. Our findings contribute to a better understanding of the burden of HBV and HDV infection in western Burkina Faso.

Risk factors for HIV infection among female sex workers in Bangui, Central African Republic

Objective

The aims of the study were i) to categorize female sex workers (FSW) according to socio-anthropologic criteria in Bangui; ii) to examine the association between a selection of demographic and risk variables with the different categories of female sex work as outcome, and iii) to investigate factors associated with HIV status.

Methods

A cross-sectional questionnaire survey was conducted to describe the spectrum of commercial sex work in Bangui among 345 sexually active women. After collection of social and behavioral characteristics, each woman received a physical examination and a blood sample was taken for biological analyses, including HIV testing. The relationships between sociodemographic characteristics, behavioral variables involved in high risk for HIV as well as biological results were investigated by bivariate analysis in relationship with FSW categories as main outcomes, and by bivariate analysis followed by multivariate logistic regression analysis in relationship with HIV as the main outcome. The strength of statistical associations was measured by crude and adjusted Odds ratios (OR) and their 95% confidence intervals.

Results

The typology of FSW comprised six different categories. Two groups were the “official” professional FSW primarily classified according to their locations of work [i) “kata“(18.55%) representing women working in poor neighborhoods of Bangui; ii) “pupulenge” (13.91%) working in hotels and night clubs to seek white men]. Four groups were “clandestine” nonprofessional FSW classified according to their reported main activity [i) “market and street vendors” (20.86%); ii) “schoolgirls or students” (19.13%) involved in occasional transactional sex (during holidays); iii) “housewives or unemployed women” (15.65%); iv) “civil servants” (11.88%) working as soldiers or in the public sector]. The overall prevalence of HIV-1 was 19.12% (66/345). HIV varied according to FSW categories. Thus, among professional FSW, the HIV prevalence was 6-fold higher in "kata" than "pupulenge" (39.13% versus 6.30%; P = 0.001). Among nonprofessional FSW, the "vendors" showed the highest HIV prevalence (31.91%), which was higher than in "students" (6.10%; P = 0.001), "civil servants" (9.83%; P = 0.005), and "housewives" (13.00%; P = 0.01). In bivariate analysis, the following variables showed statistically significant association with risk for HIV infection: nationality; age of first sexual intercourse; self-assessment of HIV risk; knowledge of HIV status; anal sex practice with last clients; irregular condom use in last week; consumption of alcohol; other psycho-active substances; past history of STIs; HBs Ag; HSV-2 and bacterial vaginosis. However, the variable “sex workers categories” dichotomized into professional versus nonprofessional FSW was no longer associated with HIV. In multivariate logistical regression analysis, HIV infection was strongly associated with nationality (15.65% versus 3.77%) [adjusted OR (aOR) 3.39: 95% CI:1.25–9.16, P<0.05]; age of first sexual intercourse (21.10% versus 14.00%) (aOR 2.13: 95% CI: 1.03–4.39, P<0.05); anal sex practice with last clients (43.40% versus 11.50%) (aOR 4.31: 95% CI:2.28–8.33, P<0.001); irregular condom use in past week (33.50% versus 3.00%) (aOR 5.49: 95% CI:1.89–15.98, P<0.001); alcohol consumption before sex (34.70% versus 7.80%) (aOR 2.69: 95% CI:1.22–4.96, P<0.05); past history of STIs (41.00% versus 10.80%) (aOR 2.46: 95% CI:1.22–4.97, P<0.05) and bacterial vaginosis (29.80% versus 4.29%) (aOR 6.36: 95% CI: 2.30–17.72, P<0.001).

Conclusion

Our observations highlight the high level of vulnerability for HIV acquisition of both poor professional “kata” and nonprofessional “street vendor” FSW categories. These categories should be particularly taken into account when designing specific prevention programs for STIs/HIV control purposes.

Hepatitis B virus seroprevalence among Malawian medical students: A cross-sectional study

BACKGROUND

Hepatitis B virus (HBV) predominantly spreads through contact with infected blood or other body fluids and causes liver disease. HBV vaccination for students at the College of Medicine, University of Malawi, is done without screening for the virus. It is important to assess the prevalence of HBV antigens among foundation-year students in order to consolidate evidence in support of HBV screening before vaccination. The aim of this study was to determine the seroprevalence of HBV antigens among 2013-2014 foundation-year students at the University of Malawi College of Medicine.

METHODS

A prospective cross-sectional descriptive study was conducted among 2013-2014 foundation year students at the Malawi College of Medicine. Out of the 234 foundation-year students, written consent was obtained from 89 students. Venous blood samples were collected and tested for HBV surface antigen using SD Bioline immunochromatographic rapid assays.

RESULTS

Out of the 62 (69.7%) male students, none tested HBV-positive, and out of 27 (30.3%) female students, none were seropositive. This suggested the absence of HBsAg among students or presence of HBsAg levels below detectable limits.

CONCLUSIONS

This study showed levels of HBsAg below detectable limits among healthy young adults in Malawi. HBV screening for medical students should further be assessed to ensure adequate protection before they are assigned clinical duties. These findings provide enough grounds to agitate for further surveys to support the establishment of a universal HBV immunisation programme in Malawi.

Serum Dried Samples to Detect Dengue Antibodies: A Field Study

Background

Dried blood and serum samples are useful resources for detecting antiviral antibodies. The conditions for elution of the sample need to be optimized for each disease. Dengue is a widespread disease in Mexico which requires continuous surveillance. In this study, we standardized and validated a protocol for the specific detection of dengue antibodies from dried serum spots (DSSs).

Methods

Paired serum and DSS samples from 66 suspected cases of dengue were collected in a clinic in Veracruz, Mexico. Samples were sent to our laboratory, where the conditions for optimal elution of DSSs were established. The presence of anti-dengue antibodies was determined in the paired samples.

Results

DSS elution conditions were standardized as follows: 1 h at 4°C in 200 µl of DNase-, RNase-, and protease-free PBS (1x). The optimal volume of DSS eluate to be used in the IgG assay was 40 µl. Sensitivity of 94%, specificity of 93.3%, and kappa concordance of 0.87 were obtained when comparing the antidengue reactivity between DSSs and serum samples.

Conclusion

DSS samples are useful for detecting anti-dengue IgG antibodies in the field.

High Prevalence and Diversity of Hepatitis Viruses in Suspected Cases of Yellow Fever in the Democratic Republic of Congo

The majority of patients with acute febrile jaundice (>95%) identified through a yellow fever surveillance program in the Democratic Republic of Congo (DRC) test negative for antibodies against yellow fever virus. However, no etiological investigation has ever been carried out on these patients. Here, we tested for hepatitis A (HAV), hepatitis B (HBV), hepatitis C (HCV), hepatitis D (HDV), and hepatitis E (HEV) viruses, all of which can cause acute febrile jaundice, in patients included in the yellow fever surveillance program in the DRC. On a total of 498 serum samples collected from suspected cases of yellow fever from January 2003 to January 2012, enzyme-linked immunosorbent assay (ELISA) techniques were used to screen for antibodies against HAV (IgM) and HEV (IgM) and for antigens and antibodies against HBV (HBsAg and anti-hepatitis B core protein [HBc] IgM, respectively), HCV, and HDV. Viral loads and genotypes were determined for HBV and HVD. Viral hepatitis serological markers were diagnosed in 218 (43.7%) patients. The seroprevalences were 16.7% for HAV, 24.6% for HBV, 2.3% for HCV, and 10.4% for HEV, and 26.1% of HBV-positive patients were also infected with HDV. Median viral loads were 4.19 × 10⁵ IU/ml for HBV (range, 769 to 9.82 × 10⁹ IU/ml) and 1.4 × 10⁶ IU/ml for HDV (range, 3.1 × 10² to 2.9 × 10⁸ IU/ml). Genotypes A, E, and D of HBV and genotype 1 of HDV were detected. These high hepatitis prevalence rates highlight the necessity to include screening for hepatitis viruses in the yellow fever surveillance program in the DRC.

Seroprevalence of hepatitis B virus surface antigen (HBsAg) among clients visiting 'Tefera Hailu' memorial hospital, Sekota, Northern Ethiopia

Background

Hepatitis B virus is one of the most causative agents of human liver disease, including acute and chronic hepatitis, cirrhosis and hepatocellular carcinoma. The disease is a great health problem worldwide, with estimated of 350 million chronically infected people. Objective: The aim of this study was to determine the prevalence of hepatitis B virus in Tefera Hailu Memorial Hospital (THMH) for the last three years (2013, 2014, 2015) by using secondary data.

Method

A three year retrospective record review was conducted from March 01/2015-July 30/2015. All registered data for hepatitis B virus serological screening of the specified period were included. The data were collected by predesigned data collection sheet. The sample size was calculated by simple statistical estimation to be 149 for each year.

Result

Of 482 subjects, 215 (44.60 %) were females and 267 (55.40 %) were males. The overall prevalence of HBV was 102 (21.16 %). The positivity rate was 69 (14.31 %) in the age group between 15 and 45. There was a decrease in the prevalence of HBV from 2012 up to 2014.

Conclusion

The seroprevalence of HBsAg was higher in males than in females and the yearly prevalence decreases from 2012–2014. But HBV infection is still a public health problem in Ethiopia. Therefore intensification of health education concerning modes of transmission and prevention of HBV, early case finding and treatment is recommended to reduce the spread of the disease.

THE PREVALENCE LIVER FUNCTION AND IMMUNOLOGIC STATUS OF CHILDREN WITH HIV AND HEPATITIS B VIRUS COINFECTION IN ENUGU, NIGERIA

BACKGROUND

Hepatitis B Virus (HBV) co-infection is prevalent among HIV infected individuals because of shared routes and mechanisms of transmission. The multidimensional immunosuppression from HIV infection causes impaired spontaneous recovery from an acute HBV infection, predisposing to chronic infection which is worsened by younger age at infection. Co-infection increases the risk of HBV replication, hepatotoxicity and liver related deaths from Highly Active Antiretroviral Therapy (HAART). The study was undertaken to highlight the burden of co-infection among HIV positive children in Enugu, determine the associated risk factors and compare the effect of co-infection between co-infected and non-co-infected children using liver enzyme and CD4 counts.

MATERIALS AND METHODS

A cross sectional study was carried out among HIV positive children attending the Paediatric ARV clinic of the University of Nigeria Teaching Hospital, Ituku-Ozalla. A total of 140 HIV infected children aged 18 months to 15 years were recruited. An interviewer questionnaire was administered. Hepatitis B surface antigen (HBsAg) was determined using Determine test Kit. Baseline and recent CD4 counts/CD4% were retrieved from the patients' folders.

RESULTS

Fourteen (10%) were positive for HBsAg. The highest prevalence of HBsAg was observed among children aged 11- 15 years. The higher the socioeconomic class the less likely the HBsAg positivity. Seven (50%) of the co-infected children had elevated baseline ALT compared with 57 (45.2%) of non-co-infected children though the difference was not statistically significant (t = 0.6, P = 0.56). After the initiation of HAART, 10 (76.9%) of the co-infected and 18 (15.1%) of the non-co-infected children had elevated ALT. The baseline median CD4 count among children ≥ 6 years was 230 cells/mm³ and 360 cells/mm³ respectively among the co-infected and non- co-infected, (P = 0.67). However, in children ≤ 5 years, it was 25% and 15 % respectively (P = 0.06).

CONCLUSION

HBV co-infection among HIV infected children is common in our environment, and co-infection is associated with impaired immunity and probably liver enzyme derangement.

HBV carriage in children born from HIV-seropositive mothers in Senegal: The need of birth-dose HBV vaccination

Hepatitis B is a major public health problem in Senegal, a country with high prevalence and a transmission occurring mainly during infancy. Only, one 6-8 weeks vaccination campaign was initiated in 2005 and it was part of the expanded program of immunization. The aim of this study was to determine the prevalence of HBsAg in children born from HIV-seropositive mothers by using dried blood specimens. Specimens were collected between July 2007 and November 2012 from children aged 2-48 weeks in Dakar and decentralized sites working on HIV mother-to-child transmission prevention. HBsAg detection was performed using Architect HBsAg Qualitative II kit (Abbott Diagnostics, Ireland) and for all reactive samples confirmation was done using Architect HBsAg Qualitative II Confirmatory kit (Abbott Diagnostics, Ireland). Nine hundred thirty samples were collected throughout the country with 66% out of Dakar, the capital city. The median age was 20 weeks and 88% of children were less than 1 year of age with a sex ratio of 1.27 in favor of boys. HBsAg was detected in 28 cases giving a global prevalence of 3%. According to age, HBsAg prevalences were 5.1% for children less than 6 weeks, 4.1% and 4.6%, respectively, for those aged 12-18 weeks and 18-24 weeks of age. The HIV prevalence was 2.6% with no HIV/HBV co-infection. This study showed a high rate of HBV infection in children under 24 months, highlighting the need to promote birth-dose HBV vaccination as recommended by WHO.

HBV immunization and vaccine coverage among hospitalized children in Cameroon, Central African Republic and Senegal: a cross-sectional study

BACKGROUND

Hepatitis B is a major health concern in Africa. The vaccine against hepatitis B virus (HBV) was introduced into the Expanded Programme on Immunization (EPI) of Cameroon and Senegal in 2005, and of CAR (Central African Republic) in 2008. A cross-sectional study was conducted to assess HBV immunization coverage following the vaccine's introduction into the EPI and factors associated with having been vaccinated.

METHODS

All hospitalized children, regardless of the reasons for their hospitalization, between 3 months and 6 years of age, for whom a blood test was scheduled during their stay and whose condition allowed for an additional 2 mL blood sample to be taken, and who provided the parent's written consent were included. All children anti-HBs- and anti-HBc + were tested for HBsAg. Vaccination coverage was assessed in three different ways: immunization card, maternal recall and serologic anti-HBs profile.

RESULTS

1783 children were enrolled between April 2009 and May 2010. An immunization card was only available for 24 % of the children. The median age was 21 months. Overall HBV immunization coverage based on immunization cards was 99 %, 49 % and 100 % in Cameroon, CAR and Senegal, respectively (p < 0,001). The immunization rate based on maternal recall was 91 %, 17 % and 88 % in Cameroon, CAR and Senegal, respectively (p < 0,001). According to serology (anti-HBs titer ≥ 10 mUI/mL and anti-HBc-), the coverage rate was 68 %, 13 % and 46 % in Cameroon, CAR and Senegal, respectively (p < 0,001). In Senegal and Cameroon, factors associated with having been vaccinated were: mother's higher education (OR = 2.2; 95 % CI [1.5-3.2]), no malnutrition (OR = 1.6; 95 % CI [1.1-2.2]), access to flushing toilets (OR = 1.6; 95 % CI [1.1-2.3]), and < 24 months old (OR = 2.1; 95 % CI [1.3-3.4] between 12 and 23 months and OR = 2.7; 95 % CI [1.6-4.4] < 12 months). The prevalence of HBV-infected children (HBsAg+) were 0.7 %, 5.1 %, and 0.2 % in Cameroon, CAR and Senegal, respectively (p < 0.001).

CONCLUSIONS

Assessing immunization coverage based on immunization cards, maternal recall or administrative data could be usefully reinforced by epidemiological data combined with immunological profiles. Serology-based studies should be implemented regularly in African countries, as recommended by the WHO. Malnutrition, lack of maternal education and poverty are factors associated with vaccine non-compliance. The countries' vaccination programs should actively address these problems.

Seroprevalence of chronic hepatitis B, as determined from dried blood spots, among children and their mothers in central Lao People's Democratic Republic: a multistage, stratified cluster sampling survey

BACKGROUND

There is limited information regarding the prevalence of hepatitis B in Lao PDR, where the hepatitis disease burden is substantial. Thus, reliable seroprevalence data is needed for the disease, based on probability sampling.

METHODS

A stratified, multistage, cluster sampling survey of hepatitis B surface antigen (HBsAg) positivity among children aged 5-9 years and their mothers aged 15-45 years was conducted. Participants were selected randomly from the central region of Lao PDR via probability-proportional-to-size sampling. Blood samples were collected onto filter paper and subsequently analyzed using a chemiluminescent microparticle immunoassay.

RESULTS

A total of 911 mother-and-child pairs were collected; the seroprevalence of HBsAg was estimated to be 2.1% (95% confidence interval 0.8-3.4%) among children and 4.1% (95% confidence interval 2.6-5.5%) in their mothers after taking into account the sampling design and the weight of each sample. The children's HBsAg positivity was positively associated with maternal infection and being born in a non-health facility, while the maternal infection status was not associated with any background characteristic.

CONCLUSIONS

Lao PDR has a relatively lower HBsAg prevalence in the general population compared to surrounding countries. To ensure comparability to other countries and to future data, rapid field tests are recommended for a nationwide prevalence survey.

Incidence of HIV and the prevalence of HIV, hepatitis B and syphilis among youths in Maputo, Mozambique: a cohort study

Background

Prevalence of HIV in Mozambique among individuals aged 15–49 years is 11.5%. The HIV prevalence is higher in women than in men across the country, peaking at ages 25–29 years and 35–39 years, respectively. In this study, we aimed at determining the prevalence and incidence of HIV, prevalence of Hepatitis B (HBV), and prevalence of syphilis in youths. We also characterized a cohort of youths for future participation in phase I/II HIV vaccine trials.

Methods

The study was conducted at a youth clinic in Maputo Central Hospital from August 2009 to October 2011. Youths of both genders aged 18–24 years (n = 1380) were screened for HIV using a sequential algorithm of two immunochromatographic assays, HBV using an enzyme linked immunosorbant test, and syphilis using a treponemal immunochromatographic strip test. The HIV seronegative participants (n = 1309) were followed-up for 12 months with quarterly study visits. The clinical and behavioral data were collected using structured questionnaires. The HIV seroconversions were confirmed by a molecular assay.

Results

The study population was female dominant (76.8%). All participants had a formal education, with 44.6% studying for technical or higher education degrees. The mean age at sexual debut was 16.6 years (SD: ±1.74), with 85.6% reporting more than one sexual partner in life. The screening showed the prevalence of HIV, HBV, and syphilis at 5.1% (95% CI: 3.97–6.31), 12.2% (95% CI 10.5%–14.0%), and 0.36% (95% CI 0.15%–0.84%), respectively. The HIV incidence rate was found to be 1.14/100 person years (95% CI: 0.67–1.92). Retention rates were stable throughout the study being 85.1% at the last visit.

Conclusion

Incidence of HIV in this cohort of youths in Maputo was relatively low. Also, the prevalence of HIV and syphilis was lower than the national values in this age group. However, the HBV prevalence was higher than in previous reports in the country.

Dried blood spots--preparing and processing for use in immunoassays and in molecular techniques

The idea of collecting blood on a paper card and subsequently using the dried blood spots (DBS) for diagnostic purposes originated a century ago. Since then, DBS testing for decades has remained predominantly focused on the diagnosis of infectious diseases especially in resource-limited settings or the systematic screening of newborns for inherited metabolic disorders and only recently have a variety of new and innovative DBS applications begun to emerge. For many years, pre-analytical variables were only inappropriately considered in the field of DBS testing and even today, with the exception of newborn screening, the entire pre-analytical phase, which comprises the preparation and processing of DBS for their final analysis has not been standardized. Given this background, a comprehensive step-by-step protocol, which covers al the essential phases, is proposed, i.e., collection of blood; preparation of blood spots; drying of blood spots; storage and transportation of DBS; elution of DBS, and finally analyses of DBS eluates. The effectiveness of this protocol was first evaluated with 1,762 coupled serum/DBS pairs for detecting markers of hepatitis B virus, hepatitis C virus, and human immunodeficiency virus infections on an automated analytical platform. In a second step, the protocol was utilized during a pilot study, which was conducted on active drug users in the German cities of Berlin and Essen.

Prevention of materno-foetal transmission of hepatitis B in sub-Saharan Africa: the evidence, current practice and future challenges

Hepatitis B (HBV) infection is highly endemic in sub-Saharan Africa (SSA), where more than 8% of the population remain chronic HBV carriers. SSA has one of the highest HBV-related liver cancer rates in the world (CA Cancer J Clin, 55, 2005, 74) and HBV-related liver cancer is the most common cause of premature death in West Africa (Lancet Oncol, 9, 2008, 683; Hepatology, 39, 2004, 211). As such, HBV represents a significant global threat to health in the African continent. Most SSA countries have elected to vaccinate all children against HBV through the WHO-sponsored Expanded Program of Immunization and the current recommendation from WHO-AFRO is for birth-dose HBV vaccination to prevent maternal/child transmission (MFT) and early horizontal transmission of HBV. However, in Africa, HBV vaccine coverage remains low and HBV birth-dose vaccination has not been implemented. HBV transmission from mother to child in the early perinatal period therefore remains a significant contributor to the burden of HBV-related disease in SSA. This review explores the evidence for materno-foetal transmission of HBV in SSA, outlining current practice for HBV MFT prevention and identifying the significant challenges to implementation of HBV prevention in SSA.

Prevalence of HBV, HDV, HCV, and HIV infection during pregnancy in northern Benin

Pregnant women are not screened for HBsAg and anti-HCV antibodies in many African countries. As there are few data concerning the prevalence of HBV, HDV, and HCV serological markers in Benin, the aim of this study was to evaluate their 2011 prevalence in pregnant women undergoing HIV screening in a rural area of north Benin, and compare the data with those reported for the same area in 1986. The sera of 283 women were examined for HBsAg, anti-HBs, anti-HBc, anti-HCV, and anti-HIV 1/2 antibodies. In the case of HBsAg positivity, a search was made for the HBeAg, anti-HDV, and HBV genotypes; in the case of anti-HCV positivity, a search was made for the HCV genotypes. HBsAg, anti-HBs, anti-HBc, anti-HCV, and anti-HIV 1/2 were positive in respectively 44 (15.5%), 82 (29.0%), 234 (82.7%), 21 (7.4%), and nine samples (3.2%). Of the HBsAg-positive samples, five (11.4%) were positive for HBeAg, five (11.4%) for anti-HDV, and 19 for HBV genotype E. Of the anti-HCV-positive samples, five were positive for genotype 2a/2c and one for genotype 1a. The prevalence of anti-HBc alone (HBsAg and anti-HBs negative) was very high (41.3%). In comparison with the 1986 data, the prevalence of HBsAg and anti-HBc remained unchanged, that of HBeAg and anti-HDV had decreased, and that of anti-HIV 1/2 had increased. As these data confirm that HBV and HCV are highly endemic in the study area, it may be appropriate to introduce HBsAg and anti-HCV screening for pregnant women. J. Med. Virol. 86:1281-1287, 2014. © 2014 Wiley Periodicals, Inc.

Characterization of hepatitis delta virus in sub-Saharan Africa

Hepatitis D virus (HDV) is a satellite of hepatitis B virus (HBV), and infection with this virus aggravates acute and chronic liver disease. While HBV seroprevalence is very high across sub-Saharan Africa, much less is known about HDV in the region. In this study, almost 2,300 blood serum samples from Burkina Faso (n=1,131), Nigeria (n=974), Chad (n=50), and the Central African Republic (n = 118) were screened for HBV and HDV. Among 743 HBsAg-positive serum samples, 74 were positive for HDV antibodies and/or HDV RNA, with considerable differences in prevalence, ranging from <2% (pregnant women from Burkina Faso) to 50% (liver patients from Central African Republic). HDV seems to be much more common in chronic liver disease patients in the Central African Republic (CAR) than in similar cohorts in Nigeria. In a large nested mother-child cohort in Burkina Faso, the prevalence of HDV antibodies was 10 times higher in the children than in their mothers, despite similar HBsAg prevalences, excluding vertical transmission as an important route of infection. The genotyping of 16 full-length and 8 partial HDV strains revealed clade 1 (17/24) in three of the four countries, while clades 5 (5/24) and 6 (2/24) were, at least in this study, confined to Central Nigeria. On the amino acid level, almost all our clade 1 strains exhibited a serine at position 202 in the hepatitis D antigen, supporting the hypothesis of an ancient African HDV-1 subgroup. Further studies are required to understand the public health significance of the highly varied HDV prevalences in different cohorts and countries in sub-Saharan Africa.

Assessment of dried blood samples as an alternative less invasive method for detection of Hepatitis E virus marker in an outbreak setting

Hepatitis E virus (HEV) is the causative agent of hepatitis E. It can be asymptomatic, associated with acute self-limiting hepatitis or acute liver failure. The conventional diagnosis of HEV infection relies on anti-HEV IgM serology. The collection of blood samples by venepunture for laboratory confirmation is often difficult during an outbreak. Thus, testing the specimens of dried blood spots (DBS) on filter papers can prove to be a feasible alternative. The present study aimed to evaluate the applicability of anti-HEV IgM detection from DBS samples and the stability of anti-HEV IgM detection at varied time interval, at various storage temperatures. Paired blood and DBS sample were collected from 44 jaundiced patients and eight healthy controls during HEV outbreaks. The DBS were tested for anti-HEV IgM by available ELISA kit with in-house modifications. Three cut offs were determined, that is, the CO1: kit cut-off, CO2: mean of negative controls above 3SD and CO3: area under Receiver operating Curve. The sensitivity of anti-HEV IgM detection ranged from 86-91%. The maximum sensitivity (91%) and specificity (100%) was obtained using CO3. Maximum stability of anti-HEV IgM antibodies (100%) was observed till 65 days at 4°C. Storage at 37°C significantly reduced anti-HEV IgM positivity, wherein 42.85% sample became negative by 45 days. DBS showed good sensitivity and specificity for detecting anti-HEV IgM and can be considered an alternate to serum sample. Moreover, anti-HEV IgM was stable at 4°C, which makes DBS a preferred method for storage and transportation of the sample to reference laboratory.

Detection of hepatitis B virus infection markers in dried plasma spots among patients in Congo-Brazzaville

The detection of hepatitis B virus (HBV) infection markers by using dried plasma spots from 32 patients living in Congo has been assessed. Considering frozen plasma samples as gold standard, the sensitivity and specificity of HBV serologic markers detection in dried plasma eluted from filter paper were 100%. The sensitivity and the specificity of HBV DNA detection reached 96% and 100%, respectively, with plasma samples dried on filter paper compared to standard samples. Dried plasma samples can represent an alternative to conventional sampling for HBV detection and management of the infection in developing countries.

Hepatitis B virus exposure during childhood in Cameroon, Central African Republic and Senegal after the integration of HBV vaccine in the expanded program on immunization

BACKGROUND

More than 2 billion people worldwide have been exposed to hepatitis B virus (HBV). To prevent these infections, Senegal and Cameroon integrated the HBV vaccine into their Expanded Program on Immunization (EPI) in 2005, as did the Central African Republic (CAR) in 2008. We evaluated the prevalence of HBV exposure and infection after the integration of the HBV vaccine in the EPI.

METHODS

An observational cross-sectional study was conducted among the hospitalized children 3 months to 6 years of age in Cameroon, CAR and Senegal. Plasma was collected for the detection of anti-HBc, anti-HBs and hepatitis B surface antigen in children with anti-HBc and anti-HBs.

RESULTS

Between April 2009 and May 2010, 1783 children were enrolled, 19.4% of whom were anti-HBc positive. The percentage of children with anti-HBc was 44.4% among the children younger than 6 months, decreasing after 6 months to reach 18.8% at 12 months. This decline was followed by a rapid increase in anti-HBc positivity rate in CAR observed as early as 12 months of age compared with Cameroon and Senegal, where the anti-HBc increased between 18 and 36 months of age, respectively. The prevalence of hepatitis B surface antigen-positive children was significantly higher in CAR than that in Cameroon and Senegal (5.1% versus 0.7% and 0.2%; P < 0.001). Socioeconomic level, age and country were factors associated with the presence of anti-HBc.

CONCLUSIONS

Passive transfer of anti-HBc maternal antibodies versus HBV exposure could be differentiated as early as 12 months of age. The low prevalence of anti-HBc and hepatitis B surface antigen among children born after the integration of HBV vaccine in the EPI in Cameroon and Senegal suggests a positive impact of HBV vaccination.

Evaluation of commercialized rapid diagnostic testing for some Hepatitis B biomarkers in an area of intermediate endemicity

Hepatitis B virus (HBV) is a major public health threat. Enzyme immune assay (EIA) of HBsAg is the screening method used in most settings, including in blood banks. Other markers are used to evaluate the HBV replication, immunity and the infectious level of the patient. Testing negative for HBsAg, however, does not always mean the absence of infection, and testing other markers using EIA is costly. This study evaluated the diagnostic reliability of commercially available non-HBsAg HBV biomarkers to detect their usefulness to screen for HBV infection. INTEC rapid tests for HBV markers were evaluated in 508 HBsAg negative blood donors and were compared to EIA as a reference method. Only anti-HBs, anti-HBc and anti-HBe could be evaluated. Sensitivities of all tests (64.2, 85.48, and 82.78 respectively) were much lower than those claimed by the manufacturer. The specificities and negative predictive values for all tests exceeded 95% and 93% respectively and were lowest for anti-HBs. Anti-HBe had the highest accuracy (99.02%), while anti-HBs had the lowest (90.16%). It was concluded that the rapid test performance was lower than the manufacturer's reports. They are reliable tools to prove negativity, but less efficient to confirm reactivity. The best performance was for anti-HBe. The positive results of anti-HBs was significantly associated with higher ELISA titer levels, which is therefore recommended to be used for screening of immunity.

Cross-sectional study of hepatitis B virus infection in rural communities, Central African Republic

Background

As most data on hepatitis in resource-poor countries relate to urban communities, surveys in the rural environment are necessary to determine the ‘true’ prevalence of these viral infections. We undertook a survey to determine the prevalence of hepatitis B virus (HBV) infection in an apparently healthy rural population in the Central African Republic (CAR).

Methods

The cross-sectional study was based on dried blood spots (DBS) from 273 people recruited in four prefectures (Lobaye, Nana-Mambéré, Ouham and Ouaka). Eluates from DBS were tested with commercial ELISA kits to detect markers of HBV infection. DBS were directly used for DNA extraction, followed by PCR and genotyping based on preS/S gene sequences.

Results

The overall prevalence of HBc antibodies was 27.1% (Lobaye 29%, Nana-Mambéré 28%, Ouaka 29% and Ouham 23%) and that of HBsAg was 10.6% (Lobaye 9%, Nana-Mambéré 9%, Ouaka 19% and Ouham 8%), with no statistically significant difference among the surveyed communities. Nineteen sequences obtained from 74 anti-HBc-positive patients all belonged to genotype E. Risk factor analysis of HBV infection pointed to sexual transmission of the virus.

Conclusion

The prevalence of HBV is high in rural communities in the CAR and comparable to that observed in urban areas. In addition, genotype E is prevalent in these areas. These findings underline the importance of instituting a programme of active HBV surveillance and vaccination of the population.

Dried cervical spots for human papillomaviruses identification

Financial and operational constraints limit low-resource countries in the screening of high-risk genital human papillomaviruses (HR-HPV), the etiological agents of cervical cancer. With its simple storage, conservation and shipping, dried cervical sample (DCS) could represent an efficient tool. The aim of the study was to evaluate the reliability of HPV genotyping from DCS. Cervical samples were obtained from 50 women infected with HIV-1 in Côte d'Ivoire. After DNA extraction from both DCS and matched liquid cervical samples (LCS), HPV genotyping was performed and the concordance of genotyping results was evaluated. HPV prevalence was 88% in LCS and 78% in DCS. Kappa statistic was 0.51 for the presence of any genotype (95% confidence interval, 0.25-0.77) and 0.73 for HR-HPV (0.45-0.99). Out of 50 samples, 45 were HPV-positive for DCS and/or LCS, and HR-HPV were detected in 37 samples (74%) with 36 HR-HPV multiple infections. Any genotype and HR genotype identification was concordant/compatible in 86% (43/50) and 88% (44/50) of samples, respectively. In most instances, kappa statistics for detection of type-specific HPV was over 0.6 (including HPV-16, -18, -31, -33). An excellent agreement (kappa statistic ≥ 0.81) was found for eight genotypes (HPV-6, -31, -35, -40, -56, -58, -66, and -82). In spite of interfering factors (multiple infections, different HPV loads, amplification competition, different inputs), DCS and LCS led to concordant/compatible results in most cases. DCS could represent an efficient tool for epidemiological field studies in resource-limited settings, and more importantly for improving the screening coverage and care management in women infected with HPV.

Dried blood spot sampling for hepatitis B virus serology and molecular testing

Background & Aims

Dried blood spots (DBS) on filter paper have been successfully used to diagnose and monitor several infectious diseases. The aim was to investigate the performance of DBS in hepatitis B virus (HBV) diagnosis using commercial tests in comparison to standard methods.

Methods

Paired DBS and plasma samples were collected from 200 patients: 100 patients with HBsAg negative status and 100 patients with HBsAg positive status. In the latter patient, HBeAg reactivity was tested. Ten samples of anti-HBs were collected from people vaccinated against HBV. We also studied 50 patients with positive HBV DNA viral load in plasma and 10 HBV DNA negative patients. HBV genotypes and gene polymerase mutations were determined in 10 randomly selected HBV-infected patients. The DBS sample consisted of 50 µL of whole blood, i.e. a 12-mm paper card.

Results

The sensitivity thresholds of HBsAg and anti-HBs antibody were 0.30±0.08 IU/mL and 18.11±6.05 IU/mL, respectively, for DBS with 98% sensitivity and 100% specificity. Sensitivity was 98% and specificity 100% for the detection of HBV DNA on a blotter, considering an HBV DNA threshold of 914.1±157.8 IU/ml. Ten patients had an HBeAg positive status in plasma, all were detected positive using DBS. HBV genotyping and mutation detection were successfully performed on DBS, with full concordance between the 10 paired DBS and plasma samples.

Conclusion

This study shows DBS is a reliable alternative to plasma specimens for quantifying and detecting HBsAg, anti-HBs, HBeAg and genotyping. DBS may increase the opportunities for HBV testing and treatment follow-up in hard-to-reach individuals.

Detection of infections with hepatitis B virus, hepatitis C virus, and human immunodeficiency virus by analyses of dried blood spots--performance characteristics of the ARCHITECT system and two commercial assays for nucleic acid amplification

BACKGROUND

Nowadays, dried blood spots (DBS) are primarily used to obtain diagnostic access to risk collectives such as intravenous drug users, who are prone to infections with hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV). Before DBS analyses can be used in this diagnostic context, however, a comprehensive evaluation of its performance characteristics must be conducted. To the best of our knowledge, the current study presents for the first time such essential data for the Abbott ARCHITECT system, which is currently the worldwide leading platform in this field of infection diagnostics.

METHODS

The investigation comprised 1,762 paired serum/DBS samples and a total of 3,524 determinations with the Abbott ARCHITECT HBsAg, anti-HBc, anti-HBs, anti-HCV and HIV-1-p24-antigen/anti-HIV 1/2 assays as well as with the artus HBV LC PCR and VERSANT HCV RNA qualitative (TMA) tests.

RESULTS

In the context of DBS testing, a specificity of 100% was recorded for the seven serological and molecular biological assays. The analytical sensitivity of HBsAg, anti-HBc, anti-HBs, anti-HCV, HIV-1-p24-antigen/anti-HIV 1/2, HBV DNA, and HCV RNA detections in DBS eluates was 98.6%, 97.1%, 97.5%, 97.8%, 100%, 93%, and 100%, respectively.

DISCUSSION/CONCLUSIONS

The results obtained indicate that it is today possible to reliably detect HBsAg, anti-HBc, anti-HBs, anti-HCV and HIV-1-p24 antigen/anti-HIV 1/2 with state-of-the-art analytical systems such as the Abbott ARCHITECT in DBS eluates even when a comparatively high elution volume of 1,000 μl is used. They also provide evidence for the inherent analytical limits of DBS testing, which primarily concern the anti-HBc/anti-HBs system for individuals with HIV infections and nucleic acid tests with relatively low analytical sensitivity.

Detection of infections with hepatitis B virus, hepatitis C virus, and human immunodeficiency virus by analyses of dried blood spots--performance characteristics of the ARCHITECT system and two commercial assays for nucleic acid amplification

BACKGROUND

Nowadays, dried blood spots (DBS) are primarily used to obtain diagnostic access to risk collectives such as intravenous drug users, who are prone to infections with hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV). Before DBS analyses can be used in this diagnostic context, however, a comprehensive evaluation of its performance characteristics must be conducted. To the best of our knowledge, the current study presents for the first time such essential data for the Abbott ARCHITECT system, which is currently the worldwide leading platform in this field of infection diagnostics.

METHODS

The investigation comprised 1,762 paired serum/DBS samples and a total of 3,524 determinations with the Abbott ARCHITECT HBsAg, anti-HBc, anti-HBs, anti-HCV and HIV-1-p24-antigen/anti-HIV 1/2 assays as well as with the artus HBV LC PCR and VERSANT HCV RNA qualitative (TMA) tests.

RESULTS

In the context of DBS testing, a specificity of 100% was recorded for the seven serological and molecular biological assays. The analytical sensitivity of HBsAg, anti-HBc, anti-HBs, anti-HCV, HIV-1-p24-antigen/anti-HIV 1/2, HBV DNA, and HCV RNA detections in DBS eluates was 98.6%, 97.1%, 97.5%, 97.8%, 100%, 93%, and 100%, respectively.

DISCUSSION/CONCLUSIONS

The results obtained indicate that it is today possible to reliably detect HBsAg, anti-HBc, anti-HBs, anti-HCV and HIV-1-p24 antigen/anti-HIV 1/2 with state-of-the-art analytical systems such as the Abbott ARCHITECT in DBS eluates even when a comparatively high elution volume of 1,000 μl is used. They also provide evidence for the inherent analytical limits of DBS testing, which primarily concern the anti-HBc/anti-HBs system for individuals with HIV infections and nucleic acid tests with relatively low analytical sensitivity.

Hepatitis B surface antigen prevalence among 12,393 rural women of childbearing age in Hainan Province, China: a cross-sectional study

Background

Hepatitis B virus (HBV) infection is highly endemic in China and it threats human health seriously. The hepatitis B surface antigen (HBsAg) prevalence among women of childbearing age plays an important role in mother to child transmission of HBV, as 30% ~50% of chronic carriers can be attributed to maternal-infantile transmission. However, there are few studies which have reported on the prevalence of HBsAg among women of childbearing age in China. This study aimed to determine the prevalence of HBsAg and its associated risk factors among rural women of childbearing age in Hainan, which is the highest hepatitis B virus endemic province in China.

Methods

A cross-sectional, population-based study, which included 12393 rural women aged 15 ~ 49 years, enrolled by a multistage stratified cluster sampling, was carried out in Hainan province, China, from November 2007 to December 2008. Blood samples were obtained from each study participant, and screened for HBsAg.

Results

The overall HBsAg prevalence of childbearing age women was 9.51%. Risk factors for HBsAg positivity among rural women were: lower education level (OR=1.206), lower family monthly income (OR=1.233), having an HBsAg-positive family member (OR=1.300), without an immunization history (OR=1.243), tattooing (OR=1.190), body piercing (OR=1.293), vaginoscopy history (OR=1.103) and history of induced abortion (OR=1.142).

Conclusions

There is a high HBsAg seroprevalence rate among rural women of childbearing age in Hainan province. Hence, it is necessary to take preventive measures to reduce the seroprevalence of HBsAg and to control its associated risk factors.

Epidemiology and molecular characterization of hepatitis B virus infection in isolated villages in the Western Brazilian Amazon

Individuals from three isolated, rural communities in the western Brazilian Amazon were evaluated for serological markers of hepatitis B virus (HBV) infection, HBV genotype, and the presence of risk factors for infection and transmission. Of the 225 individuals studied, 79.1% had serological evidence of HBV infection; 10.2% individuals were chronic carriers for HBV surface antigen (HBsAg-positive). Analysis of risk factors indicates that HBV is transmitted mainly horizontally within the family from a chronic "active" carrier for hepatitis B "e" antigen (HBeAg-positive), though a strong possibility of vertical transmission remains. The predominance of HBV genotype F, with a higher genomic similarity between the isolates, indicated a relatively recent introduction of HBV, from a common source, to the area. This study sheds light on the HBV epidemiology in the Brazilian Amazon region and highlights the need for greater emphasis on HBV control and immunization programs.

[Understanding current practice of clinical medicine in the tropics (II). Bacterial and viral diseases. Malnutrition]

In recent years, a significant number of physicians want to spend part of their medical training in health facilities in developing countries. In this setting, clinical skills are extremely important due to the limited available diagnostic resources. Bacterial diseases are common, but bacterial cultures are rarely accessible. In Africa, tuberculosis affects over 200 cases per 100,000 persons, and more than 22 million people live with HIV infection; both diseases are a serious public health problem. Malnutrition is endemic in many countries in Africa and is compounded by the continuous humanitarian and food crisis. In this paper, basic concepts of epidemiology, clinical features, diagnosis and treatment of major diseases that can be found in a rural health post in the tropics are discussed.

Assessment of dried blood spot samples as a simple method for detection of hepatitis B virus markers

Detection of hepatitis B virus (HBV) serological markers in dried blood spot (DBS) samples by enzyme immunoassay (ELISA) has not yet been fully optimized. In this study, the ability to detect three HBV markers (HBsAg, anti-HBc, and anti-HBs) was evaluated in DBS samples using a modified commercial ELISA. Matched serum and DBS samples were obtained from individuals with or without a past history of HBV infection. Sera samples were tested according to the manufacturer's instructions, but for DBS testing, paper diameters, elution buffer, volume of input sample, and cut-off values were evaluated to optimize the assay. Stability studies were done on DBS stored at for up to 180 days at different temperatures. The absorbance values that yielded the maximum sensitivity and specificity were determined based on the area under the ROC curve (AUROC) and chosen as the cut-off value. Using this parameter, sensitivity was 90.5%, 97.6%, and 78% for anti-HBc, HBsAg, anti-HBs assays, respectively. Specificity was 92.6%, 96.7%, and 97.3% for anti-HBc, HBsAg, and anti-HBs assays, respectively. HBV markers could be detected in DBS samples until 63 days after sample collection at most temperatures, but storage at -20°C yielded more consistent results. These results indicate that modified ELISA can be used to detect HBV markers in DBS samples, particularly if the samples are stored appropriately.

The prevalence of HBV infection in the cohort of IDPs of war against terrorism in Malakand Division of Northern Pakistan

BACKGROUND

Hepatitis B is an important public health problem in the Pakistani population and is the major cause of chronic hepatitis, cirrhosis, fibrosis and hepatocellular carcinoma. High prevalence of HBV infections has been observed especially in areas of low economic status. In spite of effective immunization programs, no significant change has been observed in the epidemiology of HBV in the rural areas of Pakistan (~67.5% of the total population) mainly due to lack of interest from government authorities and poor hygienic measures. The current study was aimed at estimating the prevalence and risk factors associated with HBV infection within internally displaced persons (IDPs) due to war against terrorism in the Malakand Division of Northern Pakistan.

METHODS

Blood samples from 950 IDPs suspected with HBV infection (including both males and females) were collected and processed with commercial ELISA kits for HBsAg, Anti HBs, HBeAg, Anti HBe antibodies. The samples positive by ELISA were confirmed for HBV DNA by real-time PCR analysis.

RESULTS

The overall prevalence of HBV observed was 21.05% of which 78.5% were males and 21.5% were females. Most confirmed HBV patients belong to the Malakand and Dir (lower) district. High-risk of infection was found in the older subjects 29.13% (46-60 years), while a lower incidence (11.97%) was observed in children aged <15 years. Lack of awareness, socioecomic conditions, sexual activities and sharing of razor blades, syringes and tattooing needles were the most common risk factors of HBV infection observed during the cohort of patients.

CONCLUSION

The present study, revealed for the first time a high degree of prevalence of HBV infection in rural areas of Northern Pakistan. The noticed prevalence is gender- and age-dependent that might be due to their high exposures to the common risk factors. To avoid the transmission of HBV infection proper awareness about the possible risk factors and extension of immunization to the rural areas are recommended.

Clinical and epidemiological aspects of a hepatitis E outbreak in Bangui, Central African Republic

Background

Outbreaks of hepatitis E frequently occur in tropical developing countries during the rainy season due to overflowing drains, short-circuiting of networks of clean water and use of contaminated water from wells. Hepatitis E virus (HEV) infections are usually accompanied by general symptoms of acute liver disease. This study was conducted to define the clinical and epidemiological aspects of the HEV outbreak that occurred in May 2004 in Bangui.

Methods

Blood samples were collected from 411 patients aged 1-87 years, most of whom presented with jaundice, asthenia or signs of uncomplicated malaria, for a transversal study from June 2004 to September 2005. Patients were recruited at 11 health care centres, including two referral hospitals, after they had given informed consent. The diagnosis of HEV was made with a commercial ELISA test to detect IgM and/or IgG antibodies. HEV RNA was amplified by RT-PCR to confirm the presence of the viral genome.

Results

The most frequent clinical signs found were jaundice (93.4%), vomiting (50.7%), hepatalgia (47.4%), hepatomegaly (30.9%) and asthenia (26.8%), which are the general clinical signs of hepatic disease. Acute hepatitis E was found in 213 patients (51.8%) who were positive for HEV IgM antibodies. The IgG anti-HEV seroprevalence during this outbreak was high (79.5%). The age group 18-34 years was more frequently infected (91.2%) than those aged 1-17 (78.0%) or over 34 (64.9%) (p < 10^-6). RT-PCR performed on 127 sera from the 213 IgM-HEV-positive patients was amplified, and the presence of the viral genome was found in 65 samples.

Conclusion

Although no specific clinical signs exist for hepatitis E infection, people presenting with jaundice, vomiting, hepatalgia, asthenia, hepatomegaly or distended abdomen with no signs of uncomplicated malaria in tropical developing countries should be sent to a laboratory for testing for hepatitis E.