Hepatitis A and B infections in Yaoundé, Cameroon

Epidemiology of human immunodeficiency virus-1 and hepatitis B virus co-infection and risk factors for acquiring these infections in the Fako division of Southwest Cameroon

Background

Past studies have demonstrated that a large population of Cameroonians are afflicted with human immunodeficiency virus (HIV) and/or hepatitis B virus (HBV) demonstrating a need for better prevention programs. We aim to describe the prevalence of HIV, HBV and HIV/HBV co-infection; examine the association between HIV and HBV; and determine risk correlates associated with HIV and HBV transmission in Southwest Cameroon.

Methods

A cross-sectional, community-based surveillance study was conducted among adults in five hospitals , one in each of the five health districts of  the Fako division of the Southwest region of Cameroon. Participants underwent pre- and post-test counselling, a 30-question survey and blood draw for HIV and HBV serologic testing. To construct a final model, chi-squared tests and logistic regression were used to investigate associations.

Results

Among 761 participants, 40.32 % were male, mean age was 35.21 ± 12.42 years, and the prevalence of HIV, HBV and HIV/HBV co-infection was 10.69 % , 9.86 % , and 1.16 % , respectively. There was no association between HIV and HBV infection. However, there was a statistically significant crude associated (p-value < 0.05) between HIV and three high-risk sexual behaviour variables: condom use, number of lifetime sexual partners, and age at first sexual intercourse. After adjustment, HIV status continued to be associated with number of lifetime sexual partners (adjusted odds ratio (AOR) = 2.26; 95 % confidence interval (CI) =1.22–4.17) and age at first sexual intercourse (AOR = 2.63; 95 % CI =1.44–4.81). In contrast, none of the high-risk sexual behaviours was associated with HBV.

Conclusions

The prevalence of HIV and HBV was relatively high in the Southwest region of Cameroon, emphasizing the importance of intervention and treatment programs in this country. Additionally, the results from this study suggest that unlike HIV, HBV is not associated with sexual risk factors and may provide evidence that HBV is acquired through routes other than sexual transmission, warranting further investigation in this region.

Hepatitis A virus in West Africa: Is an epidemiological transition beginning?

Background:

Studies of hepatitis A virus (HAV) seroprevalence in sub-Saharan Africa have generally found very high anti-HAV IgG seroprevalence rates, but economic development and improved drinking water access may be contributing to decreasing incidence.

Materials and Methods:

This review evaluates all 19 articles that have been published on HAV epidemiology in West Africa.

Results:

Nearly all studies conducted before 1990 found that the majority of preschool-aged children had already developed immunity due to prior infection. However, several recent studies have observed that the age at midpoint of population immunity in some urban populations has shifted to school-aged children.

Conclusion:

There is preliminary evidence that some West-African countries are beginning the transition towards lower hepatitis A endemicity levels. Additional studies of child seroprevalence rates in diverse parts of West Africa are required in order to clarify the extent to which an early transition may be occurring.

HIV, HBV, HCV and T. pallidum infections among blood donors and Transfusion-related complications among recipients at the Laquintinie hospital in Douala, Cameroon

BACKGROUND

Transfusion-transmissible infections (TTIs) pose a major health risk in Cameroon given the high prevalence of such pathogens and increased demands for blood donations in the local communities. This study aims at establishing the prevalence of commonly encountered TTIs among blood donors and transfusion-related complications among recipients in an urban center of Cameroon.

METHODS

A total of 477 blood donors and 83 blood recipients were recruited by consecutive sampling at the Laquintinie Hospital in Douala (LHD), Cameroon. Serum samples from blood donors were tested by quantitative enzyme-linked immunosorbent assays (ELISA) and/or using various Rapid diagnostic test (RDT) for presence of Hepatits B (HBV) viral antigens, and antibodies to human immunodeficiency (HIV-1/2), Hepatits B (HCV) and Treponema pallidum. Recipient's medical records were also analyzed for possible transfusion-associated complications.

RESULTS

The male/female sex ratio of the blood donors was 4/1 with a mean age of 30.2 (Sd = 8.3) years. Of all blood donors, 64/467 (13.7%) were infected by at least one of the four TTIs. Infected volunteer donors represented 8.3% while infected family donors comprised 14.3% of the donor population. The prevalence of HCV, HIV, HBV and T. pallidum were 1.3%, 1.8%, 3.5%, and 8.1%, respectively. More than half of the blood recipients were female (78.3%) and the mean age was 20.6 (SD = 16.1) years. The causes of severe anemia indicative of transfusion in recipients varied with wards (postpartum hemorrhage, caesarean section, uterine or cervical lacerations, abortions, urinary tract infections, severe malaria, vaso-occlusive attacks, wounds and gastrointestinal bleeding). The most frequent complications were chills and hematuria, which represented 46.1% of all observed complications. Other complications such as nausea, vomiting, jaundice, sudden diarrhea, anxiety, tachycardia, or hyperthermia were also found in recipients. Three cases of deaths occurred during the study, including a girl of less than one year.

CONCLUSION

This study confirms the presence of blood-borne infectious diseases in blood donors at the LHD, identifying T. pallidum as the greatest threat to blood safety in the region, and hematuria as the most common immunological complications in blood recipients.

Prevalence, correlates and pattern of Hepatitis B among antenatal clinic attenders in Yaounde-Cameroon: is perinatal transmission of HBV neglected in Cameroon?

BACKGROUND

Few studies have evaluated the prevalence of HBV in the general Cameroonian population or among antenatal attendants. The aim of this study was to determine the prevalence, correlates and patterns of Hepatitis B surface antigen among pregnant women attending antenatal care in Yaounde-Cameroon.

METHODS

This was a cross-sectional multicenter study carried out in a referral hospital and two secondary hospitals in Yaounde, the capital of Cameroon. The study lasted 15 months (March 2011 to June 2012), and recruited 959 pregnant women. Patient recruitment was consecutive. The HBsAg was tested using the Monalisa HBsAg Ultra ELISA kit. Other hepatitis B markers were equally tested.

RESULTS

The prevalence of hepatitis B infection (HBsAg) among antenatal clinic attenders in our setting was 7.7%. Amongst these women, just 5.4% were previously aware of their HBsAg status. The rate of HBV infectivity was high, with 28% of HBsAg positive women having evidence of HBeAg in their plasma, and up to 45.8% of these women lacking antibodies against hepatitis B e antigen (anti-HBe). About 41% of the pregnant women had had previous contact with HBV as evidenced by the positive status for anti-HBc.

CONCLUSION

The prevalence of hepatitis B among pregnant women in Cameroon is high, and the pattern tends towards high infectivity and therefore increased risk of perinatal HBV transmission. These highlight the need to step up preventive efforts against hepatitis B infection and perinatal HBV transmission in our community.

[Prevalence of HBsAg and anti-HCV antibodies in homozygous sickle cell patients at Yaounde Central Hospital]

Introduction

La drépanocytose est un problème de santé publique en Afrique subsahérienne où le portage hétérozygote varie de 20 et 25%. Elle se manifeste essentiellement par des crises vaso-occlusives et/ou hémolytiques et nécessite souvent une thérapeutique transfusionnelle, nonobstant un risque demeuré élevé dans les pays en développement. Le but de cette étude était d’évaluer le portage de l'Ag HBs et de l'Ac anti HCV chez les drépanocytaires homozygotes à l'hôpital central de Yaoundé (HCY).

Méthodes

Pendant une période allant d'août 2008 à janvier 2009, nous avons recruté les patients drépanocytaires régulièrement suivi dans le service d'hématologie de l'HCY. Pour chaque individu, un prélèvement de 5 ml de sang veineux a été effectué. Le sérum était conservé à -20°C jusqu’à l'utilisation pour le dépistage de l'antigène HBs et des anticorps anti-VHC.

Résultats

108 patients drépanocytaires homozygotes ont participé à cette étude. Selon le sexe, 57 soit 52,80% étaient de sexe masculin et 51 soit 47,20% de sexe féminin. Les patients étaient âgés de 5 à 47 ans avec un âge moyen de 21,45 ± 9 ans. Sept (7) patients soit 6,48% étaient positif pour l'Ag HBs, 18 patients soit 16,67% étaient positifs pour l'Ac anti-HCV. Le nombre de patient ayant reçu au moins une transfusion antérieurement était de 93 soit 86.1%. Le nombre de patients ayant reçu plus de 10 transfusions était de 14 soit 13%. Nous avons une prévalence de 42,86% de positivité de l'Ac anti-HCV pour la population drépanocytaire ayant reçu plus de 10 transfusions contre 12,77% pour celle ayant reçu moins de 10 transfusions (P < 0,01).

Conclusion

La prévalence de l'antigène HBs, de l'Ac anti-VHC chez les drépanocytaires homozygotes à Yaoundé est élevée. Cette prévalence croît avec le nombre de transfusions reçues, surtout chez les patients ayant reçu plus de 10 transfusions sanguines. Ces résultats posent le problème de la sécurité transfusionnelle qui doit utiliser les méthodes modernes comme dans les pays développés où le risque résiduel de transfusion sanguine est quasi nul. Les politiques sanitaires des pays africains subsahariens dont le Cameroun, doivent systématiser la vaccination contre l'HVB chez toutes les personnes à risque dont les drépanocytaires.

A low proportion of HBeAg among HBsAg-positive pregnant women with known HIV status could suggest low perinatal transmission of HBV in Cameroon

BACKGROUND

Transmission of hepatitis B virus (HBV) from HBV-positive mothers to their infants is common and usually occurs when the mother is hepatitis B e antigen (HBeAg) positive and/or has a high HBV DNA load. In this study, we determined the prevalence of hepatitis B surface antigen (HBsAg) and HBeAg among pregnant women with known HIV status.

FINDINGS

A total of 650 pregnant women with a mean age of 26.2 years including 301 HIV-positives and 349 HIV-negatives were screened for HBsAg (Monolisa AgHBs Plus Biorad, France). Among the HBsAg-positives, HBeAg and anti-HBe were tested (Monolisa Ag HBe Plus Biorad, France). Overall, 51 (7.85%) were positive for HBsAg. The prevalence of HBsAg was not statistically different between HIV-positive and HIV-negative pregnant women [28/301 (9.3%) vs 23/349 (6.59%); p = 0.2]. None of the 45 HBsAg-positive samples was reactive for HBeAg.

CONCLUSIONS

Our study indicates a high prevalence of HBsAg with very low proportion of HBeAg in Cameroonian pregnant women. Since perinatal transmission of HBV is mostly effective when the mother is also HBeAg-positive, our data could suggest that perinatal transmissions play a minor role in HBV prevalence in Cameroon. In line with previous African studies, these findings further suggests that horizontal transmission could be the most common mechanism of HBV infections in Cameroon.

Detection and characterization of hepatitis B virus strains from wild-caught gorillas and chimpanzees in Cameroon, Central Africa

Previous epidemiological studies have reported a high prevalence of hepatitis B virus (HBV) infection in chimpanzees in Gabon and Congo, Central Africa. There is no data for this species from Cameroon. To date few cases of active HBV infection have been documented in gorillas and only one complete HBV sequence has been described from a wild-caught gorilla originating from Cameroon and housed in Germany. Since gorillas are apes found in Cameroon, we thus investigated the prevalence and genetic relationships of HBV infecting apes in this area. We subjected 185 wild-caught apes' plasmas, including 159 from chimpanzees and 26 from gorillas to ELISA screening for HBV surface antigen (HBsAg). Subsequently, we detected HBV DNA, sequenced the whole HBV genome and performed phylogenetic analysis. Eleven (6.9%) chimpanzees and 3 (11.6%) gorillas plasma were found HBsAg positive, of which 8 and 3 were positive for HBV DNA, respectively. Phylogenetic analyses revealed that the 3 new gorilla HBV sequences grouped together with the single available HBV sequence from gorilla. Evidence of recombination between HBV Pan troglodytes troglodytes and Pan troglodytes vellerosus was observed in two of the Cameroonian strains. Findings from our study show that HBV infection is endemic in wild-born gorillas and chimpanzees in Cameroon, and that there is evidence of recombination between HBV strains circulating in chimpanzees. We demonstrated the existence of gorillas' specific HBV strains distinct but related to those found in chimpanzees living in the same habitat in Cameroon, providing substantial evidence of species association of HBV in NHPs.

Seroprevalence of viral hepatitis in Tanzanian adults

In a cross-sectional study in Dar es Salaam, Tanzania, we determined the seroprevalence of markers for hepatitis A, B, C and E viruses and examined associated risk markers. Among 403 healthy adults, the seroprevalence of antibodies to hepatitis A virus was 99.0% (95% confidence interval: 97.5-99.7). Prior exposure to hepatitis C and E viruses was rare (hepatitis C: 0.7% (0.2-2.1); hepatitis E: 0.2% (< 0.1-1.4)). The prevalence of all markers of hepatitis B was 70.7% (66.0-75.1). Hepatitis B surface antigen was identified in 6.0% (3.9-8.7) of subjects. Independent predictors of hepatitis B infection identified by logistic regression included older age, male gender, Muslim religion and type of abode. Given the high prevalence of hepatitis B and the low prevalence of hepatitis C, the majority of chronic viral hepatitis is likely to be associated with hepatitis B. Control efforts should focus primarily on hepatitis B.

Outbreak of enterically-transmitted hepatitis due to hepatitis A and hepatitis E viruses

BACKGROUND/AIMS

One hundred and eleven patients with acute hepatitis and 61 controls were investigated for hepatitis serological markers in order to determine the viral etiology of cases involved in a waterborne epidemic of hepatitis observed in 1993 in Djibouti, Republic of Djibouti (East Africa). These cases occurred both in indigenous Djiboutians, and in French soldiers and their families in Djibouti. A retrospective study of the viral etiology of acute hepatitis cases observed in French soldiers and relatives living in Djibouti during the 3-year period preceding the epidemic was also undertaken.

METHODS

HAV, HBV and HCV infections were investigated using commercial ELISA tests. HEV infections were investigated by testing IgG and IgM-specific antibodies by means of three different ELISA tests using recombinant proteins or synthetic peptides.

RESULTS

Hepatitis A was observed in 37 (33%) and hepatitis E in 43 (39%) of the 111 cases of acute hepatitis recorded during this epidemic. Hepatitis B represented only 6% of the indigenous cases and hepatitis C was not observed among the cases investigated. Anti-HEV IgG antibodies were also detected in 19% of the indigenous control group.

CONCLUSION

These results suggest that both HAV and HEV were responsible for this waterborne epidemic of acute hepatitis. However, HAV and HEV infections were not equally distributed between French expatriates and Djibouti residents. Whereas HAV infections were mainly observed in French patients, HEV was almost exclusively found in indigenous patients. This study reports for the first time a waterborne outbreak of acute hepatitis simultaneously due to HAV and HEV.

Prevalence of hepatitis C virus and other blood-borne viruses in Pygmies and neighbouring Bantus in southern Cameroon

The prevalences of antibodies to hepatitis C virus (anti-HCV), human immunodeficiency virus (anti-HIV), human T lymphotrophic virus (anti-HTLV) and of hepatitis B surface antigen (HbsAg) were determined in 168 subjects aged 12 years and over (108 Pygmies, 60 Bantus) living in south Cameroon. In 167 subjects, we found an estimated minimal anti-HCV prevalence of 13%. The prevalence was significantly higher in Bantus (31.7%) than in Pygmies (11.1%) and increased with age in both groups, albeit more rapidly in Bantus. The overall prevalence of HBsAg was 7.2% and correlated with neither sex nor ethnic group. No association was found between anti-HCV and HbsAg prevalence rates. No subject was confirmed to be positive for HTLV or HIV. These findings confirm the high prevalence of HCV infection in south Cameroon and indicate that even secluded population groups are affected.

Seroprevalence of hepatitis and HIV infection among rural pregnant women in Cameroon

Since some hepatitis viruses and the human immunodeficiency viruses share common modes of transmission, such as the sexual route, we undertook to investigate the prevalence of antibodies to these and other pathogens among 384 rural pregnant women. Our study was intended to form the basis of infection management policies in pregnancy. Antibodies and other markers of the hepatitis A, B, C, and D viruses (HAV, HBV, HCV, HDV), the human immunodeficiency virus type 1 (HIV-1) and Treponema pallidum were sought. We tested for antibodies to the viruses using the appropriate enzyme-linked immunosorbent assays. HCV and HIV-1 infection were confirmed using standard immunoblotting techniques. Regarding HBV, we tested for the surface antigen (HBsAg), antibody to the surface antigen (anti-HBs) and antibody to the core antigen (anti-HBc). A non-specific test, the rapid plasma reagin test (RPR), was used for estimating Treponema pallidum (syphilis) infection. We found an overall prevalence of antibodies to HAV of 91.4%, to HCV of 6.8%, to HDV of 0%, and to HIV-1 of 3.5%. We found no IgM antibodies to HAV. The incidence of HBV markers was as follows: 5.4% for HBsAg, 61.3% for anti-HBs, and 84.6% for anti-HBc. RPR reactivity was found in 15.8% of the women. These results will be used to establish appropriate management and preventative policies for women attending the antenatal clinic. Prevention and appropriate early treatment of infections in these women will be considered.

Worldwide epidemiology of hepatitis A virus infection

Patterns of hepatitis A virus (HAV) infection and clinical disease differ worldwide, and correlate with socioeconomic conditions (and hygienic and sanitary conditions) of each geographic area. In least developed countries with very poor sanitary and hygienic conditions, HAV spreads readily, and most persons are infected as young children. Because most persons become infected at an age when HAV infection is often asymptomatic, reported disease rates in these areas are low and outbreaks of disease are rare. In developing countries and some regions of developed countries, sanitary conditions are variable, and transmission can predominate in children, adolescents or adults, depending on the geographic region. Paradoxically, since HAV transmission occurs in these areas in older age groups compared with least developed countries where HAV transmission is highly endemic, reported rates of hepatitis A can be higher. In developed countries, sanitation and hygienic conditions are good, and infection rates in children are generally low. Communitywide epidemics can contribute significantly to the burden of disease, as can occasional day care center and common-source outbreaks. In some areas, disease tends to be among specific risk groups, such as travellers to hepatitis A endemic areas, and intravenous drug users among whom hygienic practices may be poor. As countries develop economically with improvement of sanitary conditions, overall endemicity of HAV infection decreases, and disease patterns may change. As the endemicity of HAV transmission decreases, the reported rate of clinical hepatitis A can increase, due to the shift in the average age of infection to an age when clinical illness is more frequent.

Prevalence of infections affecting the child among pregnant women in Yaounde, Cameroon

The prevalence of infections which have deleterious effects to either the mother or the fetus during pregnancy are unknown in Cameroon. To formulate appropriate antenatal screening policies for the Central Mother and Child Clinic in Yaounde, we tested random sera obtained from 1,014 stored samples previously obtained from pregnant women. One hundred and fifty sera were tested for the presence of the hepatitis B surface antigen (HBsAg), 544 for syphilis antibodies, 192 for antibodies to rubella and 192 for antibodies to Toxoplasma gondii. We found the HBsAg in 25.3% (38/150) of the subjects, antibodies against syphilis in 15.9% (87/544), antibodies to the rubella virus in 83.9% (161/192) and evidence of toxoplasma infection in 77.1% (148/192). Of the 38 HBsAg-positive subjects, 5.2% and 55.3% were positive for the HBe antigen and HBe antibody, respectively. We found a high prevalence for these infections in the antenatal clinical attendants. The data will be used to develop an appropriate control strategy for them.

Hepatitis D in Yaounde, Cameroon

Although 10% of the Yaounde population are hepatitis B surface antigen (HBsAg) positive, nothing is known about hepatitis D virus (HDV) infection in them. Sera from 110 HBsAg subjects were tested for HDV infection (antibody and antigen). The subjects were 43 pregnant women, 23 prostitutes, 20 patients with febrile jaundice, 16 multitransfused sickle cell children and 8 medical students. Thirty of the 110 (27.3%) had antibodies to the HDV (HDV-Ab). Two of 91 tested for HDV antigen (2.2%) were positive. The highest HDV-Ab prevalence (62.5%) was obtained from sickle cell children (10/16). Thus, HDV infection was found in about one fifth to one third of the HBsAg-positive subjects we studied and the main route of transmission appears to be by blood transfusion.