Effect of hepatitis B vaccination on HBV-infection among school children in Yaounde; ten years after the introduction of HBV vaccine into routine Immunization Program in Cameroon.

Introduction: since the introduction of the anti-HBV vaccine into the Expanded Program on Immunization (EPI) in 2005 in Cameroon, vaccination coverage has reached 99.0%. This coverage would indicate an increase in the number of children immune to Hepatitis B Virus (HBV) and a decrease in susceptibility to HBV-infection. This study was conducted to evaluate the effect of the HBV vaccine on pediatric HBV-infection in Yaounde, Cameroon. Methods: this school-based cross-sectional study was conducted from February to May 2016 among 180 children from Nkomo public school. The study population was stratified into two groups: vaccinated (n=95) versus (vs) unvaccinated (n=85). Screening for HBV biomarkers was done using a rapid panel test for detection (HBsAg, HBeAg and anti-HBc) and anti-HBs titer using enzyme linked immunosorbent assay (ELISA). Statistical analyses were done using SPSS v. 22 with p < 0.05 considered significant. Results: the mean age was 9.65 years. HBsAg (p=0.019) and anti-HBc (p=0.001) rates were detected in children aged ≥10 years and children aged < 10 years (95.95% [71/74]) were vaccinated vs 22.64% (24/106) for those aged ≥10 years (OR: 80.86; 95% CI: 23.36%-279.87%, p < 0.0001). According to anti-HBV vaccination status, HBsAg rate varied from [9.41% (8/85) to 1.05% (1/95), p=0.025], HBeAg rate varied from [2.35% (2/85) to 0% (0/95), p= 0.42] and anti-HBc rate ranged from [12.94% (11/85) to 2.10% (2/95), p= 0.011]. Conclusion: despite the variability of the anti-HBs titer, vaccination against HBV has a positive effect on the reduction of HBV-infection in children in tropical settings such as Cameroon.

Plasma IL-33 levels and immune activation in HIV-TB coinfection: a cross-sectional study in Yaoundé, Cameroon.

Introduction: HIV-1 and Mtb are characterized by immune activation and unbalances production of cytokines, but the expression of IL33 in HIV/TB coinfection remain understudied. This study aimed to evaluate the level of IL-33 in plasma of HIV and M. tuberculosis (HIV/TB) coinfected patients compared to patients with respective mono infections in Yaoundé. Methods: a cross-sectional study was conducted among patients attending the pneumology service and HIV treatment center of the Yaoundé Jamot Hospital. Plasma samples of 157 HIV/TB coinfected patients (n =26, 50% males and 50% females, mean age 39), HIV-1 monoinfected patients (n = 41, 41% males and 59% females, mean age 35), TB monoinfected patients (n = 48, 56% males and 44% females, mean age 37) and healthy controls (n = 42, 29% males and 71% females, mean age 32) were examined by enzyme-linked immunoassay (ELISA) to detect the levels of IL-33 cytokine. Results: plasma level of IL-33 were higher in HIV/TB coinfected (33.1±30.9 pg/ml) and TB monoinfected individuals (15.1±2.9 pg/ml) compared to healthy controls (14.0±3.4 pg/ml) and could not be detected in most of the HIV-1 monoinfected individuals (12.6±8.7 pg/ml). Interestingly, the increased plasma level of IL-33 in HIV/TB coinfected patients showed a statistically significant difference between healthy controls (33.1±30.9 pg/ml vs 14.0±3.4 pg/ml, P<0.0001) and HIV-1 monoinfected patients (33.1±30.9 pg/ml vs 12.6±8.7 pg/ml, P=0.0002). We further found that IL-33 was higher in patients with high viral load group (40.6±59.7 pg/ml vs 12.6±1.8 pg/ml), P= 0.47) whereas patients under highly active antiretroviral therapy (HAART) showed decreased level of IL-33 concentration as the number of years under ART increased. Our data showed a positive association between plasma IL-33 and viral load in the context of HIV/TB coinfection in our study population with a positive Pearson coefficient of r=0.21. Conclusion: this study indicates that plasma level of IL-33 differs among HIV/TB coinfected patients and respective monoinfections patients. The increased level of plasma IL-33 reveals that IL-33 measurement in HIV-1 monoinfected patients may represent an early predictor of development of tuberculosis.

Seroprevalence of SARS-CoV-2 antibodies and associated risk factors during the second wave of infection in a university community in Cameroon.

Background: The COVID-19 pandemic has caused a public health emergency in all sectors of society, including universities and other academic institutions in Cameroon. However, little is known concerning the real prevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections among student communities during the second wave of infection in Cameroon. This study aimed to estimate SARS-CoV-2 antibodies seroprevalence among participants in a university community in Cameroon. Methodology: A cross-sectional study was conducted from March to April 2021 in 547 students aged ≥18 years during a mass diagnostic campaign at the School of Health Sciences of the Catholic University of Central Africa (ESS/UCAC). The anti-SARS-CoV-2 antibody screening was done using the Panbio™ COVID-19 IgG/IgM Rapid Diagnostic Test. Results: The overall seroprevalence of SARS-CoV-2 antibodies was 27%, of which 89.9% (n = 133) was IgG, 6.7% (n = 10) IgM and 3.4% (n = 5) IgG/IgM positive. The undergraduate students represented 79% (432/547) of the total population and were highly positive with anti-SARS-CoV-2 antibodies 30% (130/432) as compared with postgraduate students 20% (23/115). The total antibody seropositivity was higher in males (34.4%) than females (24.9%). Several factors were associated with an increased risk of SARS-CoV-2 seroprevalence including the male gender (OR: 1.61 [95% confidence interval, CI 1.0-2.4]), specialization to medical laboratory (OR: 2.8 [95% CI 1.1-7.1]) and nursing sciences (OR: 2.6 [95% CI 1.1-6.2]). Conclusion: Our findings point to extensive and underreported circulation of SARS-CoV-2 in a university community during the second wave of infection in Cameroon, which likely resulted in artificially low case counts.

An ultrasound-based referential of body height-adjusted normal liver organometry in school children from Bokito in rural Cameroon.

The grading system for ultrasonographic assessment of Schistosoma mansoni morbidity is crucial for evaluation of control programs. This requires prior definition of normal liver organometric ranges in the population from the endemic area. A cross-sectional study was conducted in a S. mansoni endemic area in rural Cameroon. 1002 Participants were screened and 234 of them, free from all common liver-affecting diseases in the area (schistosomiasis, malaria, hepatitis B and C) and with no ultrasonographic signs of liver disease were selected and their liver parameters measured by ultrasonography. All statistics were considered significant for p-values < 0.05. Normal dimensions of livers lobe sizes, portal vein wall thickness and portal vein diameters are reported. The liver organometric data are presented for the entire study population as a whole and separately for males and females as prediction plots, with observed values and fitted regression line with 95% confidence. Reference ranges for liver parameters (size, portal vein thickness and diameter) adjusted for body height established in the current study are novel for Cameroon. The prediction plots generated should improve the accuracy of the assessment of liver morbidity by ultrasonography in the region.

Cytokine levels of interleukin-2 and 7 amongst antiretroviral therapy success and failure HIV patients attending the University Teaching Hospital, Yaoundé, Cameroon.

BACKGROUND: Immune reconstitution complications (IRC) are a major problem faced by HIV treated patients world wide. Interleukin (IL)-2 and IL-7 play vital roles in peripheral T-cell homeostasis. Our study objective was to measure and compare the blood plasma levels of IL-2 and IL-7 amongst antiretroviral therapy (ART) patients attending the Yaoundé University Teaching Hospital, Cameroon. METHODS: We performed a cross-sectional study with 296 HIV positive patients enrolled between July 2017 and May 2018 at the Yaoundé University Teaching Hospital. IL-2, IL-7, T-cell profile counts and plasma viral load were measured on whole blood specimens. Data obtained were analyzed using Graph Pad Prism 5.0 and Epi info 7.0. Software. RESULTS: IL-2 and IL-7 plasma concentration levels were higher in patients with ART failure compared to ART success, with a mean SD of 19.4±8 and 17.1±6 pg /ml, 35.26±11 and 21.5±5 pg/ml, with p < 0.001 and < 0.001. There was a direct and significant correlation between viral load, IL-2 and IL-7 with p values = 0.028, and 0.020, respectively. There was an association between IL-2, IL-7 and viral load in relation to the duration on treatment (DT), with p values = 0.003 (R2=0.041, CI= 0.069 - 0.34) ,0.017 (R2=0.027, CI=-0.30 - 0.030), and 0.001 (R2=0.048, CI=-0.047-0.76). CONCLUSION: Considering that limited surrogate markers are availiable for monitoring immune reconstitution and high associated mortality rates, IL-2 and IL-7 could be a good immunological predictor for ART failure and success in HIV infected individuals.

[Determinants of survival of HIV-infected children aged 6 months to 15 years on follow-up in the town of Ebolowa, Cameroon from 2008 to 2018]. / Déterminants de la survie des enfants âgés de 6 mois à 15 ans, infectés par le VIH et suivis dans la ville d'Ebolowa au Cameroun de 2008 à 2018.

INTRODUCTION: survival of HIV-infected children is a challenge in developing countries. In Cameroon, HIV-related mortality among children under the age of 15 in 2018 was 20%. Paradoxically, the Southern Cameroon region, despite high seroprevalence among children (4.1%) and low antiretroviral therapy coverage (around 64%), is not among the regions of Cameroon most affected by HIV/AIDS-related pediatric mortality. The purpose of this study was to calculate survival rate and to identify its determinants in HIV-infected children aged 6 months-15 years. METHODS: we conducted a retrospective, prospective cohort study data-collection in three health care facilities specialized in treating HIV-positive children in Ebolowa, South Cameroon from January 2008 to December 2018. The study was conducted in two phases, a retrospective collection phase for the selection of medical records of HIV-positive children that met inclusion criteria in consultation registries and a prospective collection phase in which we collected information from parents about the future of children. Informed parental consent was obtained during this second phase. Socio-demographic, clinical, paramedical, therapeutic data as well as data about the future of children were collected. Mean survival time and factors associated with survival were determined using the Kaplan Meier model. Cox proportional hazards regression allowed for the identification of survival determinants. Evaluation criterion was the death. Significance level was set at 5%. RESULTS: a total of 186 patients were enrolled in the study: the average follow-up period was 18.5 months. Survival rate was 66.7%. The majority of deaths (67%) occurred before the sixth month of follow-up. After multivariate analysis, an age less than 2 years [aHR: 18.6 (6.48-53.59); p=0.001), severe anemia [aHR: 7.69 (1.02-57.9); p=0.04) and the presence of opportunistic infections [aHR: 4.52 (2.51-8.14); p=0.05] were independently and significantly associated with survival. CONCLUSION: in addition to early antiretroviral therapy, good clinical and paraclinical monitoring is needed to improve the survival of HIV-infected children.

Observed HIV drug resistance associated mutations amongst naïve immunocompetent children in Yaoundé, Cameroon.

INTRODUCTION: The emergence of drug resistance mutations (DRMs) has been a major threat for successful lifelong combination antiretroviral therapy (cART), especially for HIV-vertically infected children within the context of the prevention of mother-to-child transmission (PMTCT). This study aimed to evaluate DRMs amongst immune competent treatment-naïve children in Cameroon. METHODS: A cross-sectional study was conducted between 2015 and 2016 amongst 55 proxy consented HIV-1 positive children, aged 9 months to 6 years. They were all immune competent, cART naïve and with unknown history of PMTCT. CD4 cell counts and genotypic drug resistance testing were performed using standard methods. RESULTS: Levels of DRMs to protease (PR) inhibitors (PIs), nucleoside reverse transcriptase inhibitors (NRTIs) and non-NRTIs were 27.6%, 3.7% and 40.7%, respectively. Only minor DRMs were observed for PR. The observed mutations for NRTI were K65R, T215I and K219E (33.0% each) and for NNRTI: V106M, Y181C and Y188H (6.0% each). Only minor accessory mutations were found in the integrase (IN) region. CONCLUSION: Despite widely available cART we still observe naïve HIV children, especially from the rural communities. We observe that a proportion of study participants had HIV-1 drug resistance associated mutations (RAMs). Data generated could help strengthen the current PMTCT programmes within the country. There is a need to upscale approaches for drug resistance testing for children in Cameroon and many other resource-limited settings.

Resistance pattern of enterobacteriaceae isolates from urinary tract infections to selected quinolones in Yaoundé.

INTRODUCTION: It is estimated that 150 million urinary tract infections (UTIs) occur yearly worldwide, resulting in more than 6 billion dollar in direct healthcare cost. The etiology of UTIs is predictable, with Escherichia coli, an Enterobacteriaceae being the principal pathogen. Quinolones are usually the drug of choice. In this study, we report the resistance pattern of Enterobacteriaceae isolates from UTIs to quinolones among in-patients and out-patients at the Yaoundé Reference Hospital in Cameroon. METHODS: A cross-sectional descriptive study was carried out for a ten-month period. Consecutive clean-catch mid-stream urine samples were collected from 207 in and out-patients. Identification was done using the Api 20E, and susceptibility testing using the Kirby Bauer's disc diffusion method and the MIC was done using the E-test. RESULTS: Out of the 207 isolates, 58(28.0%) were found to be resistant to all the quinolones used in the study. The resistances observed by species were in the order: Enterobacter 4(30.8%); Klebsiella 19(29.7%); Escherichia 25 (29.4%); Proteus 2(11.8%); Serratia 4(25.0%). Quinolone resistance for Escherichia was 42.9% for In-Patients (IP) and 16.3% for Out-Patient (OP) (P-value=0.006); Klebsiella 35.9% for IP and 20% for OP; Proteus 11.1% for IP and 12.5% for OP; Serratia 18.2% for IP and 40% for OP; Enterobacter 22.2 for IP and 50% for OP. CONCLUSION: High resistance rates to quinolones were observed not only for in-patients but also for out-patients with urinary tract enterobacterial infections. These findings demonstrate the importance of antibiotics susceptibility testing in improving quinolones prescription practices in Cameroon.

Relationship between multiple drug resistance and biofilm formation in Staphylococcus aureus isolated from medical and non-medical personnel in Yaounde, Cameroon.

INTRODUCTION: Monitoring the prevalence of nasal carriage of multiple drug resistance (MDR) Staphylococcus aureus (SA) strains in hospital personnel is essential. These strains when transmitted from hospital personnel to patients with already weakened immune states or in-built medical devices, may limit the latter's treatment options. This study aimed at assessing the potential exposure of patients to these MDR SA in a resource-limited hospital setting by assessing the prevalence and relationship between antimicrobial susceptibility and biofilm forming capacity of SA isolates from hospital personnel. METHODS: A total of 59 bacteria isolates phenotypically identified as Staphylococcus aureus obtained from medical (39) and non-medical personnel (20) in Yaounde were used in the study. Multiple drug resistance defined as resistance to four or more of twelve locally used antibiotics were determined by Kirby Bauer disc diffusion technique whereas quantification of biofilm production was by the microtitre plate method. RESULTS: Among the 59 SA isolates, the prevalence of MDR was 50.9%. Among medical personnel 48.7% had MDR as against 55.9% for non-medical personnel (p-value=0.648). The overall percentage of weak biofilm producers was 35.6%. Although the prevalence of weak biofilm formers was higher in isolates from non-medical personnel (40%) than medical personnel (33.3%) the difference was not statistically significant (p-value= 0.246). Slightly less than half (42.9%) of the weak biofilm producers were MDR. CONCLUSION: Considering the high rates of MDR and that slightly less than half of biofilm formers were MDR, these trends need to be monitored regularly among hospital personnel in Yaounde.

Proportion of extended-spectrum ß-lactamase-producing Enterobacteriaceae in community setting in Ngaoundere, Cameroon.

BACKGROUND: There is no information regarding the resistance mechanisms of extended-spectrum ß-lactamase (ESBL)-producing Enterobacteriaceae in community setting in Cameroon. The current study aimed to determine the proportion of ESBLs in Enterobacteriaceae isolated in the community and to analyse some risk factors associated with ESBL carriage. METHODS: Faecal samples were collected from 208 different outpatients and 150 healthy student volunteers between 3 January and 3 April 2009. Enterobacterial isolates resistant to third-generation cephalosporins were screened for ESBL production by the double-disk synergy test. Presumptive ESBL-producing isolates with positive synergy test were identified by Mass Spectrometry using the BioTyper MALDI-TOF. For such ESBL positive isolates, antibiotic susceptibility was determined by the Vitek 2 system. PCR and sequencing were performed for the detection of different types of ESBL genes in presumptive ESBL-producing isolates. Statistical methods were used for the univariate calculation of risk factors. RESULTS: During the study period, a total of 358 faecal samples were analysed; 58 of such samples (16%) showed an ESBL phenotype and were confirmed by PCR. The proportion of ESBL producers in faecal carriage was statistically different between outpatients and student volunteers (23.1% vs. 6.7%: p < 0.000). According to a univariate analysis, previous use of antibiotics (ciprofloxacin) appeared to be a risk factor for ESBL carriage (p < 0.05).Escherichia coli was the species most frequently isolated among the ESBL producers in outpatients (66.7%) and student volunteers (90%). Isolates showed additional resistance to gentamicin, ciprofloxacin and trimethoprim/sulfamethoxazole but none of them was resistant to temocillin, amikacin or meropenem. Most of the strains (97%) produced a CTX-M group 1 enzymes [CTX-M-15 (98%) or CTX-M-1 (2%)] and the remaining strains produced SHV-12 enzyme (3%). CONCLUSIONS: The use of drugs such as amoxicillin, ciprofloxacin and trimethoprim/sulfamethoxazole does not seem appropriate for empirical treatment because of emerging resistance. The implementation in Cameroon or in other African countries of methods of screening ESBL-producing organisms in routine laboratories is of great importance in order for us to offer patients appropriate treatment and for infection control efforts to succeed.