Epidemiological factors associated with HBV infection and uptake of testing in south west region of Cameroon: What can be done to scale up HBV testing in our setting?

Hepatitis B infection affects millions of people globally, partly due to its high degree of transmissibility and asymptomatic nature. This study was aimed at identifying prevailing epidemiological factors associated with HBV infection and testing uptake in the South West region of Cameroon. This hospital-based case-control study enrolled HBV infected participants and "healthy" controls ≥18 years old. Venous blood collected from participants was used to conduct HBV panel test (HBsAg, anti-HBs, HBeAg, anti-HBe, anti-HBc). Data on demographic and behavioral risk factors as well as reasons for taking the HBV test for the first time were collected using a questionnaire. A total of 424 participants were enrolled (212 "healthy" controls and 212 HBV infected cases). Male sex (odds ratio [OR] = 2.08, p = 0.010), ≤ secondary education level (OR = 4.83, p<0.001), low-income level (OR = 3.79, p<0.001), rural settlement (OR = 2.17, p = 0.031), history of sexually transmitted infections (STI) (OR = 4.24, p<0.001) and ignorance of sexual partners HBsAg status (OR = 2.70, p = 0.003) all had an independent and significant association with HBV infection. Top 3 reasons for doing HBsAg test were free screening (40.3%), blood donation (15.0%) and administrative requirements (14.9%). HBV testing uptake and early detection can be improved if more sensitization and free/opportunistic screenings are implemented. A significant drop in the cost of HBV test could encourage more people to get tested.

Evaluation of the performance of an in-house duplex PCR assay targeting the IS6110 and rpoB genes for tuberculosis diagnosis in Cameroon.

BACKGROUND: Tuberculosis (TB) remains a major public health concern in many low-income countries accounting for approximately two-thirds of deaths in people living with human immunodeficiency virus (HIV) infection. With prompt, accurate and appropriate treatment, almost all TB disease can be cured. The present study was to evaluate the diagnostic performance of an in-house duplex PCR (D-PCR) using IS1610 and rpoB specific primers in sputum samples from TB suspected patients. METHODS: A hospital-based cross-sectional study was conducted at the Limbe and Buea Regional Hospitals of the South West Region of Cameroon from June 2016 to April 2017. Sputum samples, decontaminated with hypertonic saline/sodium hydroxide solution were centrifuged and pellets processed for smear microscopy, culture and DNA extraction. Suspected inhibition was resolved by serial dilution of genomic DNA. Results were compared to culture as gold standard as well as a Composite Reference Standard (CRS). RESULTS: A total of 129 participants aged between 5 to 82 years were enrolled in to the study. The median age of the participants was 37 years (interquartile range, IQR: 27-50 years), with 54.3% being male. Forty-seven samples (36.4%) were positive by direct sputum microscopy, 49 (38%) by microscopy after concentration, 51 (39.5%) by culture and 62 (40.1%) by D-PCR. PCR inhibition was resolved in 85.7% (18/21) of the samples that had inhibition. The overall sensitivity, specificity, positive and negative predictive values, positive and negative likelihood ratios and area under the curve AUC) of the D-PCR was 93.5, 94, 94, 94%, 15.6, 0.005 and 89.0% respectively using CRS as reference. The sensitivities of D-PCR observed among different sample categories were 95.7, 87.5 and 87.5% for smear-and culture-positives, smear-negative/culture-positive, and clinically diagnosed cases respectively. CONCLUSION: IS1610 and rpoB duplex PCR using relatively cheap decontamination and DNA extraction methods in addition to simple serial dilutions to resolve PCR inhibition shows high sensitivity in the diagnosis of paucibacillary tuberculosis.

Case report on a swift shift in uropathogens from Shigella flexneri to Escherichia coli: a thin line between bacterial persistence and reinfection.

BACKGROUND: Urinary tract infections (UTI) are mostly caused by bacteria. Urine cultures are usually a definitive measure to select the appropriate antibiotics for the elimination of a uropathogen and subsequent recovery from the infection. However, the preferred antibiotics as determined by urine culture and sensitivity may still not eliminate the infection and would require further examination to ascertain the cause of treatment failure which could be unresolved bacteriuria, bacterial persistence, immediate reinfection with a different uropathogen or misdiagnosis. CASE PRESENTATION: A 2-years 7 months-old female was admitted in the Regional hospital of Buea following persistent fever. An auto medication with amoxicillin was reported. Urinalysis was done on the first day and the sediment of the cloudy urine revealed many bacteria and few pus cells. Ceftriaxone was prescribed as empirical treatment and a request for urine and blood culture was made. Three days after admission, the temperature and CRP were 39.0 °C and 96 mg/l, respectively. The urine culture results (> 105 CFU/ml of Shigella flexneri sensitive to ofloxacin) were presented to the doctor on the 4th day of admission. Patient was put on ofloxacin. Three days after, the temperature (38.5 °C) and CRP (24 mg/l) were still elevated. The blood culture result came out negative. A second urine culture was requested which came back positive (> 105 CFU/ml of Escherichia coli resistant to ofloxacin and sensitive to meropenem and amikacin). Ofloxacin was discontinued and the patient put on meropenem and amikacin. The third urine culture recorded no significant growth after 48 h of incubation. The patient was discharged looking healthy once more with a normal body temperature. CONCLUSION: Antibiotics tailored towards the elimination of a particular bacterial species may as well provide a favorable environment for other bacterial species that are resistant to it in the course of treating a UTI episode. This apparent treatment failure may first of all require a second urine culture for confirmation rather than considering the possibilities of a misdiagnosis.

Genetic diversity and antiretroviral resistance-associated mutation profile of treated and naive HIV-1 infected patients from the Northwest and Southwest regions of Cameroon.

BACKGROUND: Antiretroviral therapy (ART) has improved the survival of HIV infected persons. However, rapid scale-up of ART and the high HIV-1 genetic variability, has greatly influenced the emergence of drug-resistant strains. This constitutes a potential threat to achieving the UNAIDS' 90-90-90 goals by 2020. We investigated the prevalent HIV-1 genotypes, drug resistance-associated mutations and assessed some predictors of the occurrence of these mutations. METHODS: This was a hospital-based cross-sectional study conducted between October 2010 and June 2012. Participants were consecutively enrolled from selected HIV treatment centers of the Southwest and Northwest regions of Cameroon. Viral load was determined with the automated Abbott Real-time HIV-1 m2000rt System. HIV genotyping and antiretroviral resistance mutations analysis were performed using Bayer's HIV-1 TRUGENE™ Genotyping Kit and OpenGene DNA Sequencing system. The drug resistance mutation was interpreted with the Stanford HIV database. Epidemiological data were obtained using pre-tested semi-structured questionnaires. RESULTS: Of the 387 participants, 239 were successfully genotyped. The median age of these participants was 33 years (interquartile range, IQR: 28-40 years), and a majority (65.7%) were female. A total of 29.3% of the participants were receiving ART. The median duration of ART was 10.5 months (IQR: 4-17.25 months). The median CD4 count and log10 viral load of study participants were 353.5 cells/ml (IQR:145-471) and 4.89 copies/ml (IQR: 3.91-5.55) respectively. CRF02 (A/G) (69%) was the most prevalent subtype followed by G (8.2%) and F (6.7%). Overall, resistance mutations were present in 37.1% of ART-experienced and 10.7% of ART-naive patients. Nucleoside reverse transcriptase inhibitors (NRTI) mutations occurred in 30% of ART-experienced and 2.4% of ART-naïve patients, while non-nucleoside reverse transcriptase inhibitors (NNRTI) mutations occurred in 34.2% of ART-experienced and 10.1% of -naïve patients. M184V (8.4%, 20/239) and K103N (5.4%, 13/239) were the most prevalent mutations. Major protease inhibitor mutations occurred in 3 (1.3%) out of the 239 sequences. The duration of ART independently predicted the occurrence of resistance mutation among ART-experienced patients. CONCLUSION: The high resistance to NNRTIs, which are the main support to the backbone (NRTIs) first-line antiretroviral regimen in Cameroon, has prompted the need to rollout an integrase strand transfer inhibitor regimen (containing Dolutegravir) with a higher genetic barrier to resistance as the preferred first line regimen.

HBV Transmission Risk Assessment in Healthcare Workers, Household and Sexual Contacts of HBV Infected Patients in the Southwest Region of Cameroon.

OBJECTIVES: Hepatitis B virus (HBV) is known to be highly transmissible via the body fluids of an infected person. We investigated the transmission risks, awareness, and prevalence among healthcare workers (HCWs), household contacts (HHCs), and sexual partners (SPs) of HBV infected individuals. METHODS: We conducted a cross-sectional study of HCWs, HBV infected individuals as well as their corresponding HHCs and SPs. Data related to some transmission risks and HBV awareness was obtained from each participant using a questionnaire. Blood samples were collected from each participant and tested for hepatitis B surface antigen (HBsAg), hepatitis B e-antigen, and anti-hepatitis B core (anti-HBc). HBV viral load measurement was done for the HBV infected participants. RESULTS: A total of 596 participants were enrolled (127 HCWs, 128 HHCs, 138 SPs, and 203 HBV infected participants). HHCs (odds ratio (OR): 3.85, confidence interval (CI): 1.89-7.81), and SPs (OR: 3.04, CI: 1.51-6.17) were more associated with HBsAg/anti-HBc positivity compared to HCWs. Age, years spent with HBV infected partner, unprotected sex, and marriage were not identified as risk factors for HBV sexual transmission but cohabiting with an HBV infected SP was significantly (p = 0.005) associated with transmission (OR: 3.56, CI: 1.46-8.72). Female HHCs (OR: 2.48, CI: 1.06-5.80) and SPs (OR: 2.64, CI: 0.95-7.30) were more associated with HBsAg/anti-HBc positivity. The mean viral load (log IU) of HBV infected individuals (3.9±2.0) with HBsAg positive SPs was significantly higher than that of HBV infected individuals (2.8±1.0) with HBsAg negative SPs (p < 0.001). CONCLUSIONS: HHCs and SPs of HBV infected patients are more associated with HBV infection compared to HCWs. Horizontal transmission can as well be implicated among SPs since unprotected sex was not identified as a risk factor for transmission, but cohabitation was. Prompt management and preventive measures could be implemented if HHCs and SPs of HBV infected patients are identified, sensitized, and screened.

Characterization and assessment of HBV chronically infected patients: Identification of those eligible for treatment in the South West region of Cameroon.

BACKGROUND: The management of patients with chronic hepatitis B infection is quite complex because it requires an in-depth knowledge of the natural history of the disease. This study was aimed at characterizing HBV infected patients in order to determine the phase of the infection and identify the proportion eligible for treatment using 3 different guidelines. METHODS: HBV chronically infected patients (negative for HIV and HCV) were enrolled and the following tests were done for them: ALT, AST, HBV viral load, HBV serologic panel and Full blood count. APRI score was calculated for all patients. These patients were classified into immunotolerant, immune clearance, immune control and immune escape phases of the infection. The WHO and the 2018 AASLD criteria was also used to identify those who need treatment. Patients were clinically examined for signs and symptoms. Questionnaire was administered to all participants to ascertain their treatment status. Statistical analysis was done using SPSS version 21. RESULTS: A total of 283 participants (101 females and 182 males) with a mean age of 31.3±8.5 were enrolled. Fifty-two (18.4%) were eligible for treatment (Immune clearance and immune escape phases) and they recorded a significantly higher mean APRI score (0.71±0.51) as compared to those in the immune control and immune tolerant phase (0.43±0.20). Based on WHO and AASLD criteria, 12(4.2%) and 15 (5.3%) were eligible for treatment respectively and these were all subsets of the 52 cases mentioned above. Six (2.1%) and 29 (10.2%) of those identified under the immune control phase were on tenofovir and traditional medication respectively. CONCLUSION: Considering treatment for patients in the immune clearance and immune escape phases of the infection can be a reliable strategy to implement in our setting as this may probably tie with considerations from other treatment guidelines. Fifty-two (18.4%) patients were eligible for treatment and none of them were among the 2.1% of patients put on Tenofovir based treatment. This calls for the need for more trained health experts to periodically assess patients, implement an adequate treatment guideline and place the right patients on treatment in Cameroon.

Vaccine uptake and immune responses to HBV infection amongst vaccinated and non-vaccinated healthcare workers, household and sexual contacts to chronically infected HBV individuals in the South West Region of Cameroon.

BACKGROUND: HBV infection affects about 257 million people globally and Sub-Saharan Africa has the highest burden. The disease still constitutes a major public health problem despite the advent of preventive measures like the HBV vaccine. This study was aimed at identifying factors that influence vaccine uptake and the efficacy of administered vaccines among people at high risk of HBV infection. METHODS: This was a cross-sectional study conducted between January 2016 and December 2017. A pretested semi-structured questionnaire was used to capture information on sociodemographic and vaccination status from healthcare workers, household and sexual contacts to HBV infected people. HBV serological panel as well as quantitative anti-HBs ELISA test was done for all participants. Additional information was obtained from the institutions that administered the vaccines. RESULTS: A total of 265 participants with a mean age of 32.1±8.7 were enrolled. Eighty (30.2%) of them had received at least 1 dose of the HBV vaccine while 185 (69.8%) were unvaccinated. Healthcare workers were the most vaccinated (37%). Ignorance, negligence, fear of injection and the cost of the vaccine all contributed to poor vaccine uptake in the study population. Natural immunity was seen in 9 (3.4%) of the participants. Only 64.9% of the vaccinated participants attained the desirable level of anti-HBs (≥10mIU/ml) 1-2 months after ≥ 3 doses of the vaccine. Age, gender, obesity, alcohol and smoking were not significantly associated with poor immune responses. No standardized protocol was followed by the institutions administering the vaccine. CONCLUSION: This study revealed very poor vaccine uptake and poor immune responses to the HBV vaccine in the study population and this should urge the health sector in Cameroon to intensify their sensitization on HBV vaccine, standardize the protocol for storing and administering the vaccine, subsidize the cost of the vaccine especially amongst healthcare workers and encourage anti-HBs post vaccination testing.

Comparative evaluation of a rapid diagnostic test, an antibody ELISA, and a pLDH ELISA in detecting asymptomatic malaria parasitaemia in blood donors in Buea, Cameroon.

BACKGROUND: In malaria endemic areas, infected blood donors serve as a source of infection to blood recipients, which may adversely affect their prognosis. This necessitates the proper screening of blood to be used for transfusion in these areas. The purpose of this study was to determine the prevalence of malaria parasitaemia in blood donors in Buea, Cameroon, and to evaluate the performance of a rapid diagnostic test (RDT), a malaria antibody enzyme-linked immunosorbent assay (ELISA), and a Plasmodium lactate dehydrogenase (pLDH) ELISA in the detection of asymptomatic malaria parasitaemia in the target population. METHODS: In a prospective study conducted between September 2015 and June 2016, 1 240 potential blood donors were enrolled. The donors were screened for malaria parasites using Giemsa microscopy (GM) and a RDT. A sub-sample of 184 samples, comprising 88 positive and 96 negative samples, were selected for the evaluation of the pLDH ELISA and the antibody ELISA. The chi-square test and correlation analysis were performed as part of the statistical analyses. The statistical significance cut-off was set at P < 0.05. RESULTS: The prevalence of malaria parasitaemia in this study was found to be 8.1% (95% CI: 6.6 - 9.7). The prevalence was not observed to be dependent on the age or sex of the participants. The RDT had a sensitivity (88.0%), specificity (99.1%), and negative predictive value (99.0%) higher than the ELISAs. The performance of the pLDH ELISA, which demonstrated the highest positive predictive value (91.6%), was generally comparable to the RDT. The sensitivity was lowest with the antibody ELISA (69.9%), which also demonstrated the highest false positive and false negative rates. The detection threshold for the pLDH (three parasites/µl) was lower compared to the RDT (50 - 60 parasites/µl). Non-significant positive correlations were observed between the parasite density and the pLDH titers and malaria antibody titers. CONCLUSIONS: Overall, the RDT and the pLDH ELISA demonstrated a perfectly correlated agreement with GM, meanwhile the antibody ELISA demonstrated a substantially correlated agreement with GM. The pLDH is therefore recommended for mass screening of blood (to detect malaria parasitaemia) for transfusions in the study area. However, where this is not feasible, an RDT will suffice.

Identification of the Plasmodium species in clinical samples from children residing in five epidemiological strata of malaria in Cameroon.

BACKGROUND: Malaria in Cameroon was previously known to be caused solely by Plasmodium falciparum but today, evidence points to other Plasmodium species including P. vivax, P. ovale and P. malariae. The purpose of this study was to identify the Plasmodium species in clinical samples from children residing in five epidemiological strata of malaria in Cameroon, so as to advise control policies. METHODS: One thousand six hundred nine febrile children (≤15 years) were recruited from five epidemiological strata of malaria including the Sudano-sahelian (SS) strata, the High inland plateau (HIP) strata, the South Cameroonian Equatorial forest (SCEF) strata, the High western plateau (HWP) strata and the Coastal (C) strata. Malaria parasites were detected by Giemsa microscopy (GM) while a multiplex polymerase chain reaction (PCR) was used to identify the Plasmodium species. Statistical analysis performed included the Pearson chi-square test, and statistical significance was set at p < 0.05. RESULTS: The PCR-adjusted prevalence of malaria was 17.6%. The detection rate of PCR was higher than GM (p = 0.05). However, GM demonstrated a high sensitivity (85.5%) and specificity (100%) and, overall, a perfectly correlated agreement with PCR (97.5%). The prevalence of malaria was significantly higher in children between 60 and 119 months (p < 0.001) and in Limbe (in the Coastal strata) (p < 0.001). Contrariwise, the prevalence of malaria was not associated with gender (p = 0.239). P. falciparum was identified in all (100%) the cases of malaria; P. ovale, P. vivax, P. malariae and P. knowlesi were all absent. No case of mixed infection was identified. CONCLUSIONS: P. falciparum was the only species causing clinical malaria in the target population, which is contrary to studies that have reported P. vivax, P. malariae and P. ovale as causing clinical malaria in Cameroon.

Genetic diversity, viraemic and aminotransferases levels in chronic infected hepatitis B patients from Cameroon.

BACKGROUND: HBV infection annually accounts for 1 million deaths worldwide as a result of cirrhosis, liver failure, and hepatocellular carcinoma. In addition to varying responses to antiviral therapy, HBV genotypes have also been shown to be associated with different pattern of disease progression. Despite a high HBV prevalence of >8%, very few studies have been carried out in Cameroon to determine the genotype distribution across the country. The aim of this study was to determine the prevalent genotypes, level of viraemia and correlate these parameters with liver enzymes known to be the most affordable and widely used biomarkers for monitoring disease progression in Cameroon. METHODS: This was a hospital-community based study in which 81 participants who had been previously diagnosed of HBV were recruited and screened for HIV, HCV (for exclusion) and HBsAg for confirmation. Fifty known negative cases for HIV, HBV and HCV were tested and recruited to be used as healthy controls. Viral load and genotyping was performed only for HBV-mono infected cases using the Abbott RealTime HBV automated m2000 system and INNO-LiPA HBV Genotyping assay respectively. Liver enzymes were measured by spectrophotometry on both hepatitis B positive and healthy control cases. RESULTS: The mean alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were significantly higher (p < 0.001) in HBV infected patients than "healthy controls". Of the 81 HBV infected cases viral load was detected in 76 (93.8%) with mean viral load of 120,807 IU/ml ± 440,159 SD. Mean viral load was significantly different in patients with abnormal AST and ALT when compared with patients who had normal ALT and AST. The identified genotypes in order of prevalence were A (47.4%), E (39.5%), C/E (3.9%) A/C (2.6%), A/E (2.6%), B (1.3%), A/B (1.3%) and B/C (1.3%). CONCLUSION: Genotype E was significantly associated with higher mean viral load and mean AST levels. However, aminotransferase levels may not be a good marker for HBV disease progression as some patients could have normal levels but still present with very high viral loads and therefore, remain active HBV infection with possible high transmission.