Theresa Nkuo-Akenji

Enteric viruses in healthy children in Cameroon: viral load and genotyping of norovirus strains.

Data regarding prevalence of noroviruses (NoVs) among asymptomatic persons are scarce. The current study carried out on samples from Cameroon describes the asymptomatic shedding of NoVs and other enteric viruses in healthy children and in adults infected with HIV but lacking symptoms of gastroenteritis. Enteric viruses were common with a prevalence of 53.7% in the children, and 35.5% in the adult participants. Multiple enteric viruses (2–5 agents) were detected in fecal samples from 65% of the children, and co‐infection with NoV was demonstrated in almost all cases of multiple infections. NoV viral loads in the healthy children were within disease causing range and significantly higher than those observed in the adults (P < 0.01). Sequencing and genotyping of NoV strains by phylogeny showed a marked diversity within two distinct genogroups, GI and GII, and strains clustered with genotypes GI.3, GII.17, GII.8, and GII.4. Genetic similarities to recent outbreak strains from other continents suggest a rapid circulation of NoVs that includes healthy children, who may constitute a reservoir for pathogenic NoVs. J. Med. Virol. 83:2135–2142, 2011.

Malaria and helminth co-infection in children living in a malaria endemic setting of mount cameroon and predictors of anemia

A study was carried out with 425 children aged 0–14 yr residing in Bolifamba, Cameroon, to investigate the effect of Plasmodium falciparum malaria and intestinal helminth coinfection on anemia and to identify significant predictors of anemia in the community. Blood was collected by finger prick to determine malaria parasitemia and packed cell volume (PCV). The Kato-Katz technique was used to assess the prevalence and egg load of intestinal helminths. The prevalence of P. falciparum malaria, intestinal helminth infections, and coinfection was 64.2%, 38.3%, and 24.7%, respectively. Coinfections in which heavy helminth loads were detected had corresponding high mean P. falciparum parasite loads >5,000/μl compared with coinfections involving light helminth burden. The overall prevalence of anemia was 30.8%. Anemia prevalence increased significantly with P. falciparum parasite load >5,000/μl compared with lower densities (χ2 = 6.734, P = 0.034). Anemia prevalence was significantly higher in febrile children compared with nonfebrile children (χ2 = 6.041, P = 0.014). Children infected exclusively with P. falciparum recorded the highest prevalence of anemia compared with uninfected children, those with coinfections, and those harboring only helminths. This difference in prevalence was significant (χ2 = 6.734, P = 0.031). Multiple regression analysis exposed fever (P > 0.001) and age (P = 0.004) as significant predictors of anemia.

An update on concurrent malaria and typhoid fever in Cameroon.

Malaria and typhoid fever are endemic diseases in Cameroon, with overlapping signs and symptoms. While the high prevalence of malaria is an established fact, it is only within the past 5 years that an unusually high number of illnesses have been diagnosed as malaria co-existing with typhoid fever. The Widal test is widely used as the sole laboratory test for the diagnosis of typhoid fever. To investigate the extent of the malaria and typhoid fever association, we used blood and stool cultures as additional diagnostic tests for typhoid fever. We report that, of 200 patients presenting with fever, 17.0% had concurrent malaria and typhoid fever (Salmonella typhi) based on bacteriological proven diagnosis as compared with 47.9% based on the Widal test. A higher proportion of patients (32.5%) had malaria coexisting with S. typhimurium when compared to S. paratyphi (2%) and S. typhi (P < 0.05). We conclude that the number of fever cases diagnosed as malaria co-existing with typhoid fever is overestimated.

Molecular typing reveals substantial Plasmodium vivax infection in asymptomatic adults in a rural area of Cameroon

BackgroundMalaria in Cameroon is due to infections by Plasmodium falciparum and, to a lesser extent, Plasmodium malariae and Plasmodium ovale, but rarely Plasmodium vivax. A recent report suggested “Plasmodium vivax–like” infections around the study area that remained unconfirmed. Therefore, molecular and antigenic typing was used to investigate the prevalence of P. vivax and Duffy in asymptomatic adults resident in Bolifamba.MethodsA cross-sectional study was conducted from July 2008 to October 2009. The status of all parasite species was determined by nested PCR in 269 blood samples collected. The P. falciparum and P. vivax anti-MSP/CSP antibody status of each subject was also determined qualitatively by a rapid card assay. Parasite DNA was extracted from a sample infected with three parasite species, purified and sequenced. The Duffy antigen status of 12 subjects infected with P. vivax was also determined by sequencing. In silico web-based tools were used to analyse sequence data for similarities and matches to reference sequences in public DNA databases.ResultsThe overall malaria parasite prevalence in 269 individuals was 32.3% (87) as determined by PCR. Remarkably, 14.9% (13/87) of infections were caused either exclusively or concomitantly by P. vivax, established both by PCR and microscopic examination of blood smears, in individuals both positive (50%, 6/12) and negative (50%, 6/12) for the Duffy receptor. A triple infection by P. falciparum, P. vivax and P. malariae, was detected in one infected individual. Anti-MSP/CSP antibodies were detected in 72.1% (194/269) of samples, indicating high and continuous exposure to infection through mosquito bites.DiscussionThese data provide the first molecular evidence of P. vivax in Duffy positive and negative Cameroonians and suggest that there may be a significant prevalence of P. vivax infection than expected in the study area. Whether the P. vivax cases were imported or due to expansion of a founder effect was not investigated. Notwithstanding, the presence of P. vivax may complicate control efforts if these parasites become hypnozoitic or latent as the liver stage.ConclusionsThese data strongly suggest that P. vivax is endemic to the south-west region of Cameroon and should be taken into account when designing malaria control strategies.

High prevalence of HIV and malaria co-infection in urban Douala, Cameroon

A prospective cohort study was undertaken among 684 adult hospital attendees in Douala, Littoral Province, Cameroon. The objectives were to determine the prevalence of HIV/malaria co-infection and to determine and compare the prevalence of some parasitological, haematological and clinical parameters between co-infection and mono-infection with HIV or malaria in the study population. Information was collected on HIV serostatus, and malaria parasitaemia was assessed from blood smears by microscopy. Haemoglobin concentration was measured using the STANBIO STAT-Site MHgb Test System®, and CD4 cell counts were obtained using the Partec CyFlow Counter®. The prevalence of HIV/malaria co-infection in the sample was 29.4%. Geometric mean parasitaemia was significantly higher in co-infected patients than in malaria patients (9 868 parasites/μL blood versus 6 134 parasites/μL blood; F = 3.44, p = 0.018). Anaemia was more prevalent in cases of co-infection (43.3%) than in cases of HIV mono-infection (36.8%) or malaria mono-infection (20.4%) (χ2 = 12.38, p = 0.006). The mean CD4 cell count between the groups of co-infected and HIV-mono-infected patients was not significantly different (F = 0.004, p = 1.000), but more patients with dual infections had CD4 cell counts corresponding to the chronic and advanced stages of HIV infection. A total of 105 individuals were successfully followed up for six months; twelve deaths were recorded within this period, nine of which were co-infected patients. Our results add to the existing pool of data from similar studies showing that HIV/malaria co-infections have a significant effect on a patients clinical outcome. The data provide a basis for more elaborate studies with a larger sample size and follow-up of longer duration in the study region.

Prevalence of metabolic syndrome in human immunodeficiency virus - infected patients from the South-West region of Cameroon, using the adult treatment panel III criteria.

BackgroundSeveral studies have reported that the metabolic syndrome (MS) is more common in subjects with HIV infection than in HIV-negative individuals. HIV infection and the use of Highly Active Antiretroviral Therapy (HAART) have been shown to predispose HIV-infected persons to MS. In this study, we report the prevalence of MS in Cameroonian HIV-infected subjects receiving different combinations of HAART as well as HIV patients who have never received antiretroviral drugs.MethodsIn this cross-sectional study, 173 treated and untreated HIV-infected out-patients (aged 18–70 years) managed at the Buea and Limbe Regional Hospitals and 50 seronegative individuals (controls) were recruited after obtaining their consent. Ethical approval for this study was obtained from the National Ethics Committee of Cameroon. Metabolic syndrome prevalence was examined using the U.S. National Cholesterol Education Program Adult Treatment Panel III (ATPIII) criteria. Data was analyzed using SPSS® (Statistical Package for the Social Sciences, SPSS Inc., Chicago, IL, USA) version 16. Statistical significance was set at p < 0.05.Results and discussionThe prevalence of MS among the HIV patients was 15.6% (27/173) and 8% (4/50) among the controls and the difference was significant (p = 0.022). MS was more prevalent in HIV-infected patients on HAART than in ART-naive patients and seronegative individuals. Overall, the prevalence of MS was significantly higher (p = 0.003) in females (28/153; 18.3%) than in males (3/70; 4.3%). The patients on first-line drugs demonstrated the highest MS prevalence (15/62; 24.2%) followed by the ART-naïve group of patients (7/61; 11.5%) and the lowest prevalence was among the patients on protease inhibitors (5/50; 10%). Patients on the drug combination Lamivudine/Stavudine/Nevirapine had the highest prevalence of MS (50%).ConclusionsIn this study, HAART but not HIV disease plays a significant role in the development of MS. The metabolic complications as a result of treatment with HAART may predispose HIV patients to developing cardiovascular diseases and diabetes, in spite of improvements in morbidity and mortality conferred by immune reconstitution as a result of HAART treatment.

Genetic diversity of Plasmodium falciparum in Bolifamba, on the slopes of Mount Cameroon: influence of MSP1 allelic variants on symptomatic malaria and anaemia

Abstract The influence of the genetic diversity of Plasmodium falciparum infection on the clinical presentation of human malaria was investigated in rural Bolifamba, Cameroon. Parasite DNA was obtained from the blood of 208 children (aged 1–15 years) with malarial infection. The prevalences of anaemia and symptomatic and asymptomatic malaria among these children were 57.7%, 51.4% and 48.6%, respectively. The frequencies of parasites carrying each of the block-2 allelic variants (MAD20, K1 and RO33) of merozoite surface protein 1 (MSP1) were compared among the symptomatic and asymptomatic cases of malaria, the anaemic and non-anaemic subjects, and in various age groupings. Although all three allelic variants were found in Bolifamba, 32.7% of the children investigated were co-infected with parasites carrying the RO33 and K1 variants. There was a significant difference in the prevalence of each MSP1 allelic variant both between age-groups and between the various categories of anaemia considered (P<0.0001 for each), with the highest number of alleles occurring in the children with severe anaemia. The combination of RO33/K1 co-infection and anaemia was detected in most (57.7%) of the children aged 3–<6 years. The RO33/K1 co-infection was also strongly associated with both fever and high levels of parasitaemia (P<0.0001 for each). Although the children of Bolifamba are exposed to all three allelic variants of MSP1, which occur either singly or in varying combinations in the infected children, RO33/K1 co-infections are particularly associated with fever and this association appears independent of age and parasite density. The preliminary data presented here should facilitate the design of future research towards the development and testing of malaria candidate vaccines in the study area.

Drug Resistance Profiles of Mycobacterium tuberculosis Complex and Factors Associated with Drug Resistance in the Northwest and Southwest Regions of Cameroon

Background Anti-tuberculosis drug resistance continues to be a major obstacle to tuberculosis (TB) control programmes with HIV being a major risk factor in developing TB. We investigated anti-TB drug resistance profiles and the impact of socioeconomic as well as behavioural factors on the prevalence of TB and drug resistance in two regions of Cameroon with such data paucity. Methods This was a hospital-based study in which 1706 participants, comprising 1133 females and 573 males consecutively enrolled from selected TB and HIV treatment centres of the Northwest and Southwest regions. Demographic, clinical and self-reported risk behaviours and socioeconomic data were obtained with the consent of participants using questionnaires. Culture and drug resistance testing were performed according to standard procedures. Results The prevalence of resistance to at least one anti-TB drug was 27.7% and multi-drug resistance was 5.9%. Smoking, concurrent alcohol consumption and smoking, being on antiretroviral therapy for ≤ 12 months and previous household contact with TB patient were independently associated with tuberculosis prevalence, while only previous tuberculosis infection was associated with drug resistance in a univariate analysis. Conclusion The study showed a high prevalence of drug resistance TB in the study population with only previous TB infection associated with drug resistance in a univariate analysis. It also provides evidence in our context, of the role of alcohol and smoking in increasing the risk of developing TB, which is more likely in people living with HIV/AIDS. Therefore, it is important for public health authorities to integrate and intensify alcohol/smoking abstention interventions in TB and HIV control programs in Cameroon.

Public health implications of contamination of Franc CFA (XAF) circulating in Buea (Cameroon) with drug resistant pathogens.

BackgroundStudies in different parts of the world have implicated money as a vehicle for transmission of pathogens. Such information which is necessary to facilitate infection control strategies is lacking in many sub-Saharan countries including Cameroon. This study analyzed the Franc de la Communauté Financiere d’Afrique (Franc CFA), the currency used in Cameroon and other countries in the Central African sub-region, as a potential vehicle for transmission of pathogenic bacteria and fungi, particularly drug-resistant strains, to generate findings which could create awareness on currency contamination and serve as a guide when formulating health policies on currency.MethodsTwo hundred and thirteen currency samples representing various denominations of notes and coins randomly collected from diverse sources in Buea, Cameroon were analyzed for bacteria and fungi. The sensitivity of bacterial isolates to antibiotics was tested using the disc diffusion method. The relationship between contamination and physical state, source or denomination of currency was assessed using the χ2 test. All statistics were discussed at 0.05 significance level.ResultsTwo hundred (93.9%) samples were contaminated with notes (96.6%) showing higher contamination than coins (88.2%). Uncirculated (mint) samples showed no contamination. There was a significant difference (P˂0.05) in contamination with respect to currency denomination, physical state and source. All samples from butchers and patients/personnel in hospitals were contaminated. Lower denominations showed significantly higher (P = 0.008) levels of contamination than higher denominations. Dirty currency was more contaminated than clean currency. Nine bacterial species were isolated. Coagulase-negative Staphylococcus (CoNS) (54.9%) and Staphylococcus aureus (20.1%) predominated. Among the fungi detected, Aspergillus sp (17.3%) and Penicillium sp (15.9%) showed higher frequency of occurrence. Bacteria were susceptible (100%) to ceftriaxone, gentamicin, norfloxacin and ofloxacin. Susceptibility to amoxicillin, penicillin, ampicillin, vancomycin and cotrimoxazole was low. Staphylococci were resistant (100%) to vancomycin, penicillin G, and amoxicillin. CoNS in addition showed resistance (100%) to cotrimoxazole.ConclusionsThe CFA franc circulating in Buea could serve as a vehicle for transmission of drug resistant pathogenic or potential organisms and contamination could be due to currency usage and handling as mint notes were not contaminated. Hygiene practices during or after handling currency is greatly encouraged to prevent infection.

Knowledge of HIV/AIDS, sexual behaviour and prevalence of sexually transmitted infections among female students of the University of Buea, Cameroon

The study investigates the cognitive effect of knowledge and protective practices on the prevalence of HIV and some sexually transmitted infections (STIs) among female students of the University of Buea, Cameroon. A cross-sectional study involving the analysis of a questionnaire completed by 522 female students and the voluntary testing of 108 sexually active females for HIV, syphilis, Chlamydia and gonorrhoea was carried out. Knowledge of the protective effects of abstinence, condom-use and fidelity were independent of sexual practices (OR = 0.86, p = 0.611, φ = 0.22; OR = 1.26, p = 0.213, φ = 0.05; and OR = 1.18, p = 0.344, φ = 0.029, respectively). The prevalence of HIV, syphilis, Chlamydia and gonorrhoea among the participants tested was 3.9%, 6.1%, 24.1% and 30.1%, respectively. We conclude that relatively high prevalence of STIs among female students of the University of Buea stems from inadequate knowledge of the major modes of STI/HIV transmission and inadequate use of preventive methods.