Jean Jacques N. Noubiap

Sero-epidemiology of human immunodeficiency virus, hepatitis B and C viruses, and syphilis infections among first-time blood donors in Edea, Cameroon

BACKGROUND Blood safety remains an issue of major concern in transfusion medicine in sub-Saharan Africa. Blood-borne agents such as the human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV), and Treponema pallidum are among the greatest threats to blood safety for the recipient. This study aimed to determine the seroprevalence and risk factors of HIV, HCV, HBV, and syphilis infections among first-time blood donors at the new hospital-based blood bank in Edéa, Cameroon. METHODS We carried out a retrospective analysis of blood donor data recorded between December 2011 and May 2012 at the blood bank of the Edéa Regional Hospital. Antibodies to HIV types 1 and 2 were screened with the Determine and ImmunoComb tests. Hepatitis B surface antigen and antibodies to HCV were detected using DIASpot test strips. Syphilis was diagnosed using the Venereal Disease Research Laboratory (VDRL) test and the Treponema pallidum hemagglutination assay (TPHA). RESULTS A total of 543 blood donors were included, among whom 349 (64.3%) were family replacement donors. One hundred and fifteen donors (21.2%) were infected with at least one pathogen. The overall seroprevalence rates of HIV, HBV, HCV, and syphilis were 4.1%, 10.1%, 4.8%, and 5.7%, respectively. We found a total of 26 dual infections. The most common combinations were HBV-HCV and HBV-HIV. There was a significant association between HIV and HBV infections (adjusted odds ratio (aOR) 3.46, 95% CI 1.29-9.39; p=0.014), and between HBV and HCV infections (aOR 2.81, 95% CI 1.02-10.12; p=0.036). Compared to voluntary donors, family replacement donors were significantly more infected by at least one screened pathogen (aOR 1.81, 95% CI 1.14-2.88; p=0.013), and more infected specifically by HIV (aOR 3.66, 95% CI 1.07-12.55; p=0.039) and syphilis (aOR 2.81, 95% CI 1.05-7.46; p=0.039). CONCLUSIONS Our findings indicate that blood safety remains a major problem in Cameroon where hospital-based blood banks and family replacement donors are predominant. There is an urgent need for a national blood transfusion program in Cameroon that will establish a nationally coordinated blood transfusion service based on the principles of voluntary regular non-remunerated blood donation.

Access to Diagnostic Tests and Essential Medicines for Cardiovascular Diseases and Diabetes Care: Cost, Availability and Affordability in the West Region of Cameroon

Objective To assess the availability and affordability of medicines and routine tests for cardiovascular disease (CVD) and diabetes in the West region of Cameroon, a low-income setting. Methods A survey was conducted on the availability and cost of twelve routine tests and twenty medicines for CVD and diabetes in eight health districts (four urban and four rural) covering over 60% of the population of the region (1.8 million). We analyzed the percentage of tests and medicines available, the median price against the international reference price (median price ratio) for the medicines, and affordability in terms of the number of days’ wages it would cost the lowest-paid unskilled government worker for initial investigation tests and procurement for one month of treatment. Results The availability of tests varied between 10% for the ECG to 100% for the fasting blood sugar. The average cost for the initial investigation using the minimum tests cost 29.76 days’ wages. The availability of medicines varied from 36.4% to 59.1% in urban and from 9.1% to 50% in rural settings. Only metformin and benzathine-benzylpenicilline had a median price ratio of ≤1.5, with statins being largely unaffordable (at least 30.51 days’ wages). One month of combination treatment for coronary heart disease costs at least 40.87 days’ wages. Conclusion The investigation and management of patients with medium-to-high cardiovascular risk remains largely unavailable and unaffordable in this setting. An effective non-communicable disease program should lay emphasis on primary prevention, and improve affordable access to essential medicines in public outlets.

Occupational exposure to blood, hepatitis B vaccine knowledge and uptake among medical students in Cameroon

BackgroundHepatitis B virus (HBV) is the most contagious blood borne pathogen. The risk of occupational exposure to HBV among health care workers is a major concern, especially medical trainees. In this study we describe the knowledge of risk factors for HBV infection, history of accidental exposure to blood, awareness of HBV vaccine and the vaccination status among medical students in Cameroon.MethodsIn April 2012, a cross-sectional survey was carried out using a pretested self-administered questionnaire among 111 medical students.ResultsSixty-two students (55.9%) had had at least one accidental exposure to blood since the beginning of their medical training, with a median of 2 (IQR, 1-3) exposures. There was a good knowledge of the risk factors for HBV infection and awareness of HBV vaccine among participants. However, only 20 (18%) participants had completed the three doses of primary HBV vaccination. Furthermore, only 2 of the 20 (10%) adequately vaccinated participants had a post-vaccination test to confirm a good immune response and thus an effective protection against HBV infection. The main reason for not being vaccinated was lack of money to pay for the vaccine (45.6%). Forty seven (42.3%) participants had been sensitized by their training institutions about the importance of HBV vaccination. These were more likely to be vaccinated compared to those who had not been sensitized (p<0,001).ConclusionThere is a high rate of accidental exposure to blood and a very low HBV vaccination uptake in medical students in Cameroon, leading to a high occupational risk of HBV infection. HBV vaccination should be strongly recommended for medical students and the vaccine made available free of charge at the beginning of their training.

Aetiology of childhood hearing loss in Cameroon (sub-Saharan Africa)

BACKGROUND Severe hearing loss is a global problem affecting particularly developing countries. There is scarcity of recent published data on the epidemiology of childhood deafness in sub-Saharan Africa. OBJECTIVE To determine the etiological profile of severe childhood deafness in Cameroon. METHODS Prospective cross-sectional study of patients with a severe hearing loss that started before the age of 15 years. Detailed family and medical history was obtained; careful clinical, otological and audiological examinations were performed. RESULTS A total of 582 patients with a severe hearing loss were examined. Prelingual deafness accounted for 75.1% (n = 437), with a mean age at medical diagnosis of 3.3 ± 1.2 years. This late presentation may be explained by limited parental awareness of signs raising suspicion of hearing loss, poor access to health care and the absence of neonatal screening for hearing loss in Cameroon. Identified genetic causes accounted for 14.8% (n = 86), putative environmental causes for 52.6% (n = 306) and unknown causes for 32.6% (n = 190). Amongst Genetic causes, the syndromic hearing loss accounted for 13.1% (n = 12) of cases, the rest being non syndromic (n = 74). Consanguineous families accounted for 5.7% (n = 33) of the whole sample, and 15.1% (n = 13) of genetic cases. No union between deaf parents was observed. CONCLUSION These data highlight the possible predominance of putative environmental causes of childhood deafness in Cameroon, and emphasize the need for improved policies for prevention of infectious diseases and for neonatal hearing screening. However, further molecular analyses and targeted CT scan investigations are required to more accurately gauge the contribution of genetics etiologies.

Prevalence and Risk Factors of Hypertension in Urban Areas of Cameroon: A Nationwide Population-Based Cross-Sectional Study.

Accurate estimates of the prevalence rate of hypertension and determinants in Cameroon are crucial to inform efficient prevention and control policies. The authors carried out a cluster‐specific cross‐sectional survey in urban areas of the 10 regions of Cameroon to assess the prevalence and risk factors of hypertension in Cameroonian adults using the WHO STEPwise approach to Surveillance (STEPS). Sociodemographic data were collected and blood pressure and glycemia were measured using standardized methods. Participants were adults of both sexes aged 16 years or older. A total of 15,470 participants were surveyed. The age‐standardized prevalence rate of hypertension was 29.7%. The awareness rate was 14.1%. Independent correlates of hypertension included higher age, male sex, obesity, hyperglycemia, and living in the Savannah zone. The prevalence of hypertension is high in urban areas of Cameroon, with very low awareness. Prevention and control strategies should emphasize on improvement and vulgarization of population opportunistic screening and education.

Aspirin for primary prevention of cardiovascular disease

Although aspirin has a well-established role in preventing adverse events in patients with known cardiovascular disease (CVD), its benefit in patients without a history of CVD remains under scrutiny. Current data have provided insight into the risks of aspirin use, particularly bleeding, compared with its benefits in primary CVD prevention. Although aspirin is inexpensive and widely available, especially in developing countries, there is lack of evidence that the benefits outweigh the adverse events with continuous aspirin use in primary CVD prevention. Therefore, the decision to initiate aspirin therapy should be an individual clinical judgment that weighs the absolute benefit in reducing the risk of a first cardiovascular event against the absolute risk of major bleeding, and tailored to the patient’s CVD risk. This risk must be calculated, based on accurate and cost-benefit locally developed risk assessment tools, the most discriminating threshold be identified. Additionally, patients preferences should be taken into account when making the decision to initiate aspirin therapy in primary prevention of CVD or not. Physicians should continuously be trained to calculate their patients CVD risk, and concomitant strategies be emphasized.

Prevalence and correlates of depressive symptoms in HIV-positive patients: a cross-sectional study among newly diagnosed patients in Yaoundé, Cameroon

BackgroundDepression is one of the most common neuropsychiatric complications of HIV disease, and in turn it is associated with worse HIV-related outcomes. Data on depression among HIV-infected patients in Cameroon are scarce. In this study, we report the prevalence and correlates of depressive symptoms among newly diagnosed HIV-infected patients in Yaoundé, Cameroon.MethodsInterviews were conducted with 100 newly diagnosed HIV-infected patients at three referral hospitals of Yaoundé. Depression was assessed using the nine-item Patient Health Questionnaire (PHQ-9). A positive depression screen was defined as PHQ-9 score greater than 9.ResultsThe overall prevalence of depressive symptoms was 63% (95% CI: 53.2 to 71.8), the majority having symptoms corresponding to moderate depression. Multiple logistic regression analysis showed that probable depressed patients were more likely than those who were not depressed to have had experience of alcohol abuse (OR: 19.03, 95% CI 3.11-375.85; p = 0.0083), and a 100 CD4 cells/mm3 fewer was associated with a 2.9 times increase of the odds of probable depression (95% CI 1.88-4.84; p < 0.0001).ConclusionsOur findings indicate a high prevalence of depressive symptoms in newly diagnosed HIV-infected patients in our setting, and their association with alcohol abuse and severe immunosuppression. This study also highlights the necessity to integrate mental health interventions into routine HIV clinical care in Cameroon.

Is air pollution a risk factor for rheumatoid arthritis

Rheumatoid arthritis is a chronic inflammatory debilitating disease triggered by a complex interaction involving genetic and environmental factors. Active smoking and occupational exposures such as silica increase its risk, suggesting that initial inflammation and generation of rheumatoid arthritis-related autoantibodies in the lungs may precede the clinical disease. This hypothesis paved the way to epidemiological studies investigating air pollution as a potential determinant of rheumatoid arthritis. Studies designed for epidemiology of rheumatoid arthritis found a link between traffic, a surrogate of air pollution, and this disease. Furthermore, a small case–control study recently found an association between wood smoke exposure and anticyclic citrullinated protein/peptide antibody in sera of patients presenting wood-smoke-related chronic obstructive pulmonary disease. However, reports addressing impact of specific pollutants on rheumatoid arthritis incidence and severity across populations are somewhat conflicting. In addition to the link reported between other systemic autoimmune rheumatic diseases and particulate matters/gaseous pollutants, experimental observation of exacerbated rheumatoid arthritis incidence and severity in mice models of collagen-induced arthritis after diesel exhaust particles exposure as well as hypovitaminosis D-related autoimmunity can help understand the role of air pollution in rheumatoid arthritis. All these considerations highlight the necessity to extend high quality epidemiological researches investigating different sources of atmospheric pollution across populations and particularly in low-and-middle countries, in order to further explore the biological plausibility of air pollution’s effect in the pathogenesis of rheumatoid arthritis. This should be attempted to better inform policies aiming to reduce the burden of rheumatoid arthritis.

Prevalence, infectivity and correlates of hepatitis B virus infection among pregnant women in a rural district of the Far North Region of Cameroon

BackgroundEpidemiological data on hepatitis B virus (HBV) infection among pregnant women in Cameroon are very scarce, especially in the rural milieu. The purpose of this study was to determine the prevalence and factors associated with HBV infection, and the infectivity of rural pregnant women in the Far North Region of Cameroon.MethodsA cross-sectional study was conducted in three rural health facilities of the Guidiguis health district between December 2013 and March 2014. We consecutively recruited 325 pregnant women attending antenatal consultations. A pretested questionnaire was used to collect socio-demographic data and factors associated with HBV infection. The presence of hepatitis B surface antigen (HBsAg), hepatitis B e antigen (HBeAg) and human immunodeficiency virus (HIV) were determined using commercial test strips. Regression analyses were used to assess correlates of HBV infection.ResultsThe mean age was 24.4 (SD5.6) years. Most women were married (97.2%) and housewives (96.4%), with less than secondary education level (80%). Only 4 women (1.2%) had been vaccinated against HBV. Thirty-three women (10.2%) were HBsAg-positive, of whom 4 (12.1%) were positive to HBeAg. The prevalence of HIV infection was 2.5% (8/325). Overall, 5 (1.5%) women were co-infected with HIV and HBV. Independent correlates of HBV infection included history of blood transfusion (adjusted odd ratio 12.59, 95% CI 1.46-108.89; p = 0.021) and concurrent infection by HIV (adjusted odd ratio 22.53, 95% CI 4.76-106.71; p < 0.0001).ConclusionThe prevalence of HBV infection among pregnant women in this rural milieu is high. History of blood transfusion and HIV infection are highly associated with HBV infection. The relative low rate of women positive to both HBsAg and HBeAg suggests that perinatal transmission of HBV might not be the prevailing mode of HBV transmission in this area.

What is the best strategy for the prevention of transfusion-transmitted malaria in sub-Saharan African countries where malaria is endemic?

The transmission of malaria by blood transfusion was one of the first recorded incidents of transfusion-transmitted infections (TTIs). Although the World Health Organization (WHO) recommends that blood for transfusion should be screened for TTIs, malaria screening is not performed in most malaria-endemic countries in sub-Saharan Africa (SSA). The transfusion of infected red blood cells may lead to severe post-transfusion clinical manifestations of malaria, which could be rapidly fatal. Ensuring that blood supply in endemic countries is free from malaria is highly problematical, as most of the donors may potentially harbour low levels of malaria parasites. Pre-transfusion screening within endemic settings has been identified as a cost-effective option for prevention of transfusion-transmitted malaria (TTM). But currently, there is no screening method that is practical, affordable and suitably sensitive for use by blood banks in SSA. Even if this method was available, rejection of malaria-positive donors would considerably jeopardize the blood supply and increase morbidity and mortality, especially among pregnant women and children who top the scale of blood transfusion users in SSA. In this context, the systematic prophylaxis of recipients with anti-malarials could constitute a good alternative, as it prevents any deferral of donor units as well as the occurrence of TTM. With the on-going programme, namely the Affordable Medicine Facility - Malaria, there is an increase in the availability of low-priced artemisinin-based combination therapy that can be used for systematic prophylaxis. It appears nonetheless an urgent need to conduct cost-benefit studies in order to evaluate each of the TTM preventive methods. This approach could permit the design and implementation of an evidence-based measure of TTM prevention in SSA, advocating thereby its widespread use in the region.