The effect of climatic factors on the number of malaria cases in an inland and a coastal setting from 2011 to 2017 in the equatorial rain forest of Cameroon.

BACKGROUND: Weather fluctuation affects the incidence of malaria through a network of causuative pathays. Globally, human activities have ultered weather conditions over time, and consequently the number of malaria cases. This study aimed at determining the influence of humidity, temperature and rainfall on malaria incidence in an inland (Muyuka) and a coastal (Tiko) settings for a period of seven years (2011-2017) as well as predict the number of malaria cases two years after (2018 and 2019). METHODS: Malaria data for Muyuka Health District (MHD) and Tiko Health District (THD) were obtained from the Regional Delegation of Public Health and Tiko District Health service respectively. Climate data for MHD was obtained from the Regional Delegation of Transport while that of THD was gotten from Cameroon Development Coorporation. Spearman rank correlation was used to investigate the relationship between number of malaria cases and the weather variables and the simple seasonal model was used to forecast the number of malaria cases for 2018 and 2019. RESULTS: The mean monthly rainfall, temperature and relative humidity for MHD were 200.38 mm, 27.050C, 82.35% and THD were 207.36 mm, 27.57 °C and 84.32% respectively, with a total number of malaria cases of 56,745 and 40,160. In MHD, mean yearly humidity strongly correlated negatively with number of malaria cases (r = - 0.811, p = 0.027) but in THD, a moderate negative yearly correlation was observed (r = - 0.595, p = 0.159). In THD, the mean seasonal temperature moderately correlated (r = 0.599, p = 0.024) positively with the number of malaria cases, whereas MHD had a very weak negative correlation (r = - 0.174, p = 0.551). Likewise mean seasonal rainfall in THD moderately correlated (r = - 0.559, p = 0.038) negatively with malaria cases, contrary to MHD which showed a very weak positive correlation (r = 0.425, p = 0.130). The simple seasonal model predicted 6,842 malaria cases in Muyuka, for 2018 and same number for 2019, while 3167 cases were observed in 2018 and 2848 in 2019. Also 6,738 cases of malaria were predicted for MHD in 2018 likewise 2019, but 7327 cases were observed in 2018 and 21,735 cases in 2019. CONCLUSION: Humidity is the principal climatic variable that negatively influences malaria cases in MHD, while higher seasonal temperatures and lower seasonal rain fall significantly increase malaria cases in THD.

The current status of malaria epidemiology in Bolifamba, atypical Cameroonian rainforest zone: an assessment of intervention strategies and seasonal variations.

BACKGROUND: Global malaria has been on the decline over the past decade due to expansion of interventions. The present study aimed at determining the current status of malaria epidemiology in the context of sustained interventions and seasonal variations in Bolifamba, which represents a typical semi-urban malaria endemic community in the Cameroonian rainforest. METHODS: A monthly cross-sectional survey was carried out in Bolifamba, a multi ethnic semi-urban locality on the eastern flanks of Mt Cameroon, for a year during which blood samples were collected from participants and examined for malaria parasites by microscopy. Correlation analysis of seasonal/monthly malaria prevalence was done with weather data from Ekona, a nearby village with a meteorological station. Intervention strategy such as use of Insecticide Treated Bed Net (ITBN) and risk factors such as duration of stay in the locality, age and housing type were also investigated. RESULTS: The results revealed a malaria prevalence of 38.3 % in the rainy season, which was significantly higher than 24.4 % observed in the dry season (P < 0.0001). A high prevalence of asymptomatic malaria which was more than double the prevalence of symptomatic malaria on a monthly basis was observed, 30.7 % vs 17.8 % in the rainy and dry season respectively (p < 0.0001) and asymptomatic malaria was significantly associated with anemia (p < 0.005). April was the peak month of malaria prevalence and coincided with peak periods of both asymptomatic and symptomatic malaria. The Plasmodium falciparum parasite rates in the 2- up to 10-years age group (PfPR(2-10)) was 40.8 %. The regular use of ITBN was significantly associated with low prevalence of 31.7 % as opposed to irregular or non-usage of ITBN 38.2 % (p < 0.05). Log of parasite load was found to initially increase to 2.49 with less than 5 years of stay, and decreased gradually with increasing duration of stay in the locality (p = 0.046). Climatic factors were significantly and positively associated with monthly malaria prevalence and the strongest predictors of malaria prevalence were rainfall and minimum temperature with r values of 0.563 and 0.6 respectively. CONCLUSIONS: The study highlights the role of seasonal change in modifying malaria prevalence during the year and the beneficial effect of ITBN. It also underscores a sublime problem of asymptomatic malaria associated with anemia, and indicates that partial immunity is acquired with prolonged stay in Bolifamba. This preliminary result is the basis of ongoing work to identify the antigens involved in acquired immunity.

Empowering adolescents living with perinatally-acquired HIV: tailored CD4+ count assessment for optimized care, the EDCTP READY-study.

Background: The elevated rate of AIDS-related mortality in Sub-Saharan Africa among adolescents living with HIV (ALHIV) is influenced by various factors, notably immunosuppression, within a framework of limited therapeutic alternatives. We aimed to enhance the management of pediatric HIV by assessing the immune response and associated factors in perinatally-infected ALHIV on antiretroviral therapy (ART) in Cameroon. Methods: A cohort study was conducted from 2018-2020 among 271 ART-experienced ALHIV in Cameroon. Sociodemographic data, immunological (CD4), and virological (plasma viral load, PVL) responses were measured at enrolment (T0), 6-months (T1), and 12-months (T2) using PIMA CD4 (Abbott/Pantech (Pty) Ltd) and Abbott Applied Biosystem platform (Real-Time PCR m2000RT) respectively. Immunological failure (IF) was defined as absolute CD4 < 250 cells/mm3, and Virological failure (VF) as PVL ≥ 1,000 copies/ml. A linear mixed-effects model with R version 4.4.1 was used to estimate both fixed and random effects, with significance set at p < 0.05. Results: Of the 271 perinatally-infected ALHIV enrolled over three phases, females were predominant (55.7, 55.1, and 56.0%); median age was 14 (IQR: 12-17); majority of the participants were followed-up in urban areas (77.5, 74.5, and 78.6%); and the age distribution favored older adolescents (48.7, 61.2, and 58.5%). Most participants achieved clinical success (93.1, 89.7, 88.9%), predominantly on first-line ART (80.8, 66.2, and 53.0%), with good adherence (64.2, 58.9, and 64.5%). Most participants had secondary education (67.2, 70.1, and 67.5%). Median CD4+ counts fluctuated overtime, with values of 563 (IQR: 249.0-845.0), 502 (IQR: 319.0-783.5), and 628 (IQR: 427.5-817.5), respectively. Of note, being male was linked to a reduction in CD4+ count compared to females, [-200.63 (-379.32 to -21.95), p = 0.028]. Similarly, late adolescence was associated with lower CD4+ counts compared to early adolescence, [-181.08 (-301.08 to -61.09), p = 0.003]. Moreover, participants experiencing VF showed significantly lower CD4+ counts compared to those with undetectable viral loads, [-353.08 (-465.81 to -240.36), p < 0.001]. Additionally, there was a marginally significant interaction between male gender and secondary educational level, [209.78 (-6.94-426.51), p = 0.058]. Conclusion: Among perinatally-infected ALHIV, age, gender, educational level, and virological status are key factors influencing their immune health and treatment outcomes. Prioritizing targeted interventions and close monitoring within these subgroups is crucial for optimal management, employing holistic care strategies that consider not only medical interventions but also psychosocial support and education.

Knowledge, attitude and practices of community health workers on managing and preventing childhood malaria and diarrhea in Fako Division, South West Region, Cameroon; A mixed method study.

In developing countries, childhood malaria and diarrhea are among the 5 leading causes of death among children under five years; the use of community health workers (CHWs) to manage these diseases has shown some degree of success. A descriptive cross-sectional study was conducted to assess knowledge, attitude and practices (KAP) of CHWs on the management and prevention of childhood malaria and diarrhea in Fako Division, South-West Region, Cameroon. A pretested questionnaire was administered to eighty CHWs in Fako Division. Three focus group discussions (FGDs) were conducted with 29 CHWs. The Chi-Square and Spearman Correlation tests were used to investigate the association between socio-demographic characteristics with CHWs' KAP on childhood malaria and diarrhea management and prevention. A total of 52.5% of the participants had good knowledge, negative attitudes (65.0%), and carried out poor practices (60.0%) on the management and prevention of childhood malaria. Up to 8.75% CHWs did not know the first-line antimalarial drug used in Cameroon. More than half (57.5%) of participants had poor knowledge, 70.0% had a negative attitude and 82.25% carried out good practices on the management and prevention of childhood diarrhea. 47.6% of CHWs used a mixture of guava leaves and 'masepo' (Ocimum gratissimum) as treatment for childhood diarrhea. Level of education (p = 0.028) and Health District (p = 0.026) were significantly associated with practices on management and prevention of childhood diarrhea. CHWs had inadequate knowledge, poor attitude, and practices on childhood malaria management. Even though a majority of CHWs carried out good practices for diarrhea management, their knowledge and attitude were poor. Therefore, there is a need for training to improve CHWs' knowledge, attitude and practices on childhood malaria and diarrhea management.

The influence of COVID-19 barrier measures on the positivity rate of typhoidal salmonellosis and amoebiasis in the Buea Health District, South West Region of Cameroon.

Typhoidal salmonellosis and amoebiasis are prevalent in the Buea Health District (BHD) and it is evident that hand hygiene can reduce the transmissibility of these diseases. The barrier measures enforced by the government, in the wake of the corona virus disease 2019 (COVID-19) pandemic has led to behavioural changes which may have had an influence on the positivity rate of these diseases. This study seeks to determine the influence of COVID-19 barrier measures and the implementation of COVID-19 vaccination on the positivity rate of typhoidal salmonellosis and amoebiasis in the BHD. A retrospective study, with purposive and random sampling methods were used to select health facilities in BHD, whose laboratory records were reviewed using a data extraction form to obtain health information of patients who tested for typhoidal salmonella and/or Entamoeba histolytica from June 1, 2018 to December 31, 2021. Chi-square test was used to compare the positivity rate in the pre-and-COVID-19 and in the pre-and-vaccination era. The positivity rate of typhoidal salmonellosis and amoebiasis dropped from 57.8% and 2.7% in the pre-COVID-19 era to 34% and 1.8% in the COVID-19 era respectively, which were significant (χ2 = 945.8; P<0.001 and χ2 = 11.8; P = 0.001 respectively). Within the COVID-19 era, the positivity rate of salmonellosis and amoebiasis decreased from 39% and 2.6% before the implementation of COVID-19 vaccination to 27.7% and 0.8% respectively in the COVID-19 vaccination era and these differences were significant (χ2 = 149.1; P<0.001 and χ2 = 33.8; P<0.001 respectively). However, the positivity rate of salmonellosis between the rainy (43.5%) and the dry (42.8%) seasons and amoebiasis between the rainy (2.2%) and the dry (2%) seasons were not significantly different (χ2 = 0.6; P = 0.429 and χ2 = 0.54; P = 0.463 respectively). A significant decline in the positivity rate of typhoidal salmonellosis and amoebiasis was observed after the implementation of COVID-19 barrier measures and vaccination.

A cross-sectional study on the prevalence and drug susceptibility pattern of methicillin-resistant Staphylococcus aureus isolated from patients in the Buea Health District, Cameroon.

Introduction: Staphylococcus aureus, which is part of the normal flora accounts for most acute and chronic infections in humans, and treatment options are greatly limited, when infection is caused by methicillin-resistant Staphylococcus aureus (MRSA). This study was to determine the prevalence and antimicrobial susceptibility pattern of MRSA from clinical samples obtained randomly from patients in Buea Health District. Methods: a total of 264 wounds, nasopharynx, and urine samples were collected from patients from different hospitals in Buea and transported to the laboratory in the University of Buea, for analysis. Samples were inoculated on mannitol salt agar for S. aureus isolation, characterized morphologically by gram staining and biochemically by catalase, coagulase, and hemolysis tests. Diagnosis of S. aureus was confirmed by molecular identification of the nuc gene. MRSA was identified from S. aureus by oxacillin screening and confirmed by molecular identification of the mecA gene. The data were analyzed using SPSS version 17.0. Results: S. aureus was isolated from 70 (26.52%) and all were confirmed molecularly by nuc gene amplification. MRSA by oxacillin screening was 36 (13.64%) while MRSA detected by mecA gene amplification was 34 (12.88%). Antimicrobial susceptibility testing revealed 100% resistance to ampicillin, 88.24% to cefixime and 70.59% to ceftriaxone while low resistance was observed to meropenem (11.76%), doxycycline (14.71%), and vancomycin (17.67%). Conclusion: MRSA isolated from Buea Health District are resistant to ampicillin, cefixime, and ceftriaxone. The antimicrobials (meropenem, doxycycline, and vancomycin) should be used to treat MRSA infections in Buea Health District.

Genotypic resistance testing improves antiretroviral treatment outcomes in a cohort of adolescents in Cameroon: Implications in the dolutegravir-era.

Acquired drug resistance (ADR) is common among adolescents living with perinatal HIV (APHI) in sub-Saharan Africa (SSA). Personalized management has the potential to improve pediatric antiretroviral therapy (ART), even in the presence of long-term treatment and HIV-1 subtype diversity. We sought to evaluate the effect of HIV-1 mutational profiling on immuno-virological response and ADR among APHI. A cohort-study was conducted from 2018-2020 among 311 APHI receiving ART in Cameroon. Clinical, immunological and virological responses were measured at enrolment (T1), 6-months (T2) and 12-months (T3). Immunological failure (IF: CD4 #x003C;250 cells/mm3), VF (viremia ≥1,000 copies/ml), and ADR were analyzed, with P#x003C;0.05 considered significant. Mean age was 15(±3) years; male-female ratio was 1:1; median [IQR] ART-duration was 36[21-81] months. At T1, T2, and T3 respectively, adherence-level was 66.4, 58.3 and 66.5%; 14 viral clades were found, driven by CRF02_AG (58.6%); ADR-mutations favored increased switch to second-line ART (16.1, 31.2, and 41.9%, P#x003C;0.0001). From T1-T3 respectively, there were declining rates of IF (25.5, 18.9, and 9.83%, P#x003C;0.0001), VF (39.7, 39.9, and 28.2%, P=0.007), and HIVDR (96.4, 91.7, and 85.0%, P=0.099). Predictors of ADR were being on first-line ART (P=0.045), high viremia at enrolment (AOR=12.56, P=0.059), and IF (AOR=5.86, P=0.010). Of note, optimized ART guided by mutational profile (AOR=0.05, P=0.002) was protective. Moreover, full Tenofovir+Lamivudine+Dolutegravir efficacy was predicted in 77 and 62% of APHI respectively after first- and second-line failure. Among APHI in this SSA setting, viral mutational profiling prompts the use of optimized Dolutegravir-based ART regimens, leading to improved immuno-virological response and declining ADR burdens. Thus, implementing personalized HIV medicine in this vulnerable population would substantially improve ART response and the achievement of the 95-95-95 goals in these underserved populations.

HIV-1 subtype diversity and immuno-virological outcomes among adolescents failing antiretroviral therapy in Cameroon: A cohort study.

OBJECTIVE: We sought to evaluate the variability of HIV-1 and its effect on immuno-virological response among adolescents living with perinatally acquired HIV (APHI). METHODS: A cohort study was conducted from 2018-2020 among 311 APHI receiving antiretroviral therapy (ART) in Cameroon. Sequencing of protease and reverse transcriptase regions was performed for participants experiencing virological failure, VF, (Plasma viral load, PVL ≥ 1000 RNA copies/ml). HIV-1 subtypes were inferred by phylogeny; immuno-virological responses were monitored at 3-time points (T1-T3). Cox regression modeling was used to estimate adjusted hazard ratios (aHRs) of progression to: CD4 < 250, and PVL > 5log10, adjusted for acquired drug resistance, gender, ART line, adherence, and duration on treatment; p < 0.05 was considered statistically significant. RESULTS: Of the 141 participants in VF enrolled, the male-female ratio was 1:1; mean age was 15 (±3) years; and median [IQR] duration on ART was 51 [46-60] months. In all phases, 17 viral clades were found with a predominant CRF02_AG (58.2%, 59.4%, and 58.3%). From T1-T3 respectively, there was an increasing CD4 count (213 [154-313], 366 [309-469], and 438 [364-569] cells/mm3) and decline log10 PVL (5.23, 4.43, and 4.43), similar across subtypes. Among participants with CRF02_AG infection, duration of treatment was significantly associated with both rates of progression to CD4 < 250, and PVL > 5log10, aHR = 0.02 (0.001-0.52), and aHR = 0.05 (0.01-0.47) respectively. Moreover, four potential new HIV-1 recombinants were identified (CRF02_AG/02D, CRF02_AG/02A1F2, D/CRF02_AG, and AF2/CRF02_AG), indicating a wide viral diversity. CONCLUSION: Among APHI in settings like Cameroon, there is a wide genetic diversity of HIV-1, driven by CRF02_AG and with potential novel clades due to ongoing recombination events. Duration of treatment significantly reduces the risk of disease progression.

Plasmodium falciparum histidine-rich protein 2 and 3 gene deletion in the Mount Cameroon region.

Objective: Plasmodium falciparum produces histidine-rich protein 2/3 (Pfhrp2/3) genes that accumulate to high levels in the bloodstream and serve as a diagnostic and prognostic marker for falciparum malaria. Pfhrp2/3 gene deletions may lead to false-negative rapid diagnostic test (RDT) results. We aimed to determine the prevalence of pfhrp2/3 gene deletions in P. falciparum isolates and the implications for RDT use in the Mount Cameroon region. Methods: A cross-sectional hospital-based study with malaria diagnosis performed using microscopy, RDT and nested polymerase chain reaction (nPCR). In total, 324 P. falciparum microscopy positive individuals were enrolled and their samples confirmed positive for P. falciparum using 18SrRNA PCR. Samples that gave false-negative RDT results were analyzed to detect pfhrp2/3 exon 2 deletions. Results: Of 324 positive microscopic and nPCR samples, 16 gave RDT false-negative results. Among the 324 P. falciparum positive isolates, exon 2 deletions were observed in 2.2% (7 of 324); 3 were negative for pfhrp2 gene, 2 for pfhrp3, and 2 for both pfhrp2 and pfhrp3 (double deletions). Conclusion: P. falciparum isolates with pfhrp2/3 gene deletion were present in the parasite populations and may contribute to the RDT false-negative results in the Mount Cameroon region.

Trends in malaria prevalence and risk factors associated with the disease in Nkongho-mbeng; a typical rural setting in the equatorial rainforest of the South West Region of Cameroon.

Globally, malaria in recent years has witnessed a decline in the number of cases and death, though the most recent world malaria report shows a slight decrease in the number of cases in 2018 compared to 2017 and, increase in 2017 compared to 2016. Africa remains the region with the greatest burden of the disease. Cameroon is among the countries with a very high burden of malaria, with the coastal and forest regions carrying the highest burden of the disease. Nkongho-mbeng is a typical rural setting in the equatorial rain forest region of Cameroon, with no existing knowledge of the epidemiology of malaria in this locality. This study aimed at determining the current status of malaria epidemiology in Nkongho-mbeng. A cross-sectional survey was conducted, during which blood samples were collected from 500 participants and examined by microscopy. Risk factors such as, age, sex, duration of stay in the locality, housing type, environmental sanitation and intervention strategies including use of, LLINs and drugs were investigated. Trends in malaria morbidity were also determined. Of the 500 samples studied, 60 were positive, giving an overall prevalence of 12.0% with the prevalence of asymptomatic infection (10.8%), more than quadruple the prevalence of symptomatic infections (1.2%) and, fever burden not due to malaria was 1.4%. The GMPD was 6,869.17 parasites/µL of blood (95% C.I: 4,977.26/µL- 9,480.19/µL). A LLINs coverage of 84.4% and 77.88% usage was observed. Unexpectedly, the prevalence of malaria was higher among those sleeping under LLINs (12.56%) than those not sleeping under LLINs (8.97%), though the difference was not significant (p = 0.371). Being a male (p = 0.044), being unemployed (p = 0.025) and, living in Mbetta (p = 0.013) or Lekwe (p = 0.022) and the presence bushes around homes (p = 0.002) were significant risk factors associated with malaria infection. Trends in proportion demonstrated that, the prevalence of malaria amongst patients receiving treatment in the health center from 2015 to 2019 decreased significantly (p < 0.001) and linearly from 9.74% to 3.08% respectively. Data generated from this study can be exploited for development of a more effective control measures to curb the spread of malaria within Nkongho-mbeng.

Investigating the risk factors for seroprevalence and the correlation between CD4+ T-cell count and humoral antibody responses to Toxoplasma gondii infection amongst HIV patients in the Bamenda Health District, Cameroon.

BACKGROUND: Toxoplasmosis is caused by an obligate intracellular tissue protozoan parasite, Toxoplasma gondii that infect humans and other warm-blooded animals. Transmission to humans is by eating raw or inadequately cooked infected meat or through ingestion of oocysts that cats have passed in faeces. Studies have shown life-threatening and substantial neurologic damage in immunocompromised patients; however, 80% of humans remain asymptomatic. The aim of this study was to determine the seroprevalence of Toxoplasma gondii infection in HIV positive patients and the risk factors associated with the infection, and to investigate the correlation between CD4+ T-cell count and toxoplasma specific antibodies as possible predictors of each other amongst HIV patients in the Bamenda Health District of the North West Region of Cameroon. METHODS: A cross-sectional study was conducted, in which 325 HIV patients were recruited for administration of questionnaire, serological diagnosis of T. gondii and measurement of CD4+ T-cell count. Bivariate and multivariate logistic regression was used to identify risk factors associated with T. gondii infection while the linear regression was used to investigate the relationship between CD4+ T-cell count and antibody levels against T. gondii. RESULTS: The findings showed that, majority (45.8%) of HIV patients suffered from chronic (IgG antibody) infection, and 6.5% from acute (IgM and IgM/IgG antibody) toxoplasma infection. The overall sero-prevalence of T. gondii infection amongst HIV patients was 50.5%. On the whole, 43 men (45.7%) and 127 women (55%) presented with anti- T. gondii antibodies; however, there was no significant difference amongst males and females who were positive to T. gondii infection (p = 0.131). Marital status (p = 0.0003), contact with garden soil (p = 0.0062), and garden ownership (p = 0.009), were factors that showed significant association with T. gondii infection. There was no significant difference (p = 0.909) between the mean CD4+ T-cell count of HIV patients negative for toxoplasma infection (502.7 cells/mL), chronically infected with T. gondii (517.7 cells/mL) and acutely infected with T. gondii (513.1 cells/mL). CD4+ T-cell count was neither a predictor of IgM antibody titer (r = 0.193, p = 0.401), nor IgG antibody titer (r = 0.149, p = 0.519) amongst HIV patients acutely infected with T. gondii. CONCLUSION: The findings from this study underscore the need to implement preventive and control measures to fight against T. gondii infection amongst HIV patients in the Bamenda Health District.