Plasmodium vivax, susceptibility factors and pharmacogenetics of treatment among febrile patients in the West and South Regions of Cameroon

Thanks to the implementation of molecular detection techniques, Plasmodium vivax (Pv) infections have been reported in several sub-Saharan African countries recently, including Duffy-negative populations of West and Central Africa. This work aimed to assess the possible circulation of Pv and factors linked to the susceptibility to Pv and the pharmacogenetics of its treatment (Duffy antigen, G6PD deficiency, CYP450 genetic variability) among outpatients of Santchou, Dschang and Ambam Health Districts. A cross-sectional descriptive and analytical study was performed in 4 healthcare facilities (HCFs). Data was collected in two different periods, the rainy season in Santchou (August 2016-December 2016) and rainy season in Dschang and Kyé-ossi/Ambam (May 2017September 2017). Interviews were conducted using a structured questionnaireand consenting febrile patients were consecutively recruited and drops of blood were collected on dried blood spots and smears. All samples were analysed by molecular and microscopic methods. All data was analysed using Microsoft Excel 2013 and Epi info version 7.2. In total, 1001 samples were collected and Plasmodium spp parasite DNA was detected in 486 (48.6%) samples. In particular, 441 cases of Plasmodium mono-infections (287 P. falciparum, 146 P. vivax, 2 P. ovale, 6 P. malariae) and 45 cases of mixed-infections (37 falciparum/vivax, 2 falciparum/ovale, 4 falciparum/malariae, 2 vivax/malariae) were detected. Globally, Pv has been detected in 185 cases (38.1% of positive samples), mainly from Dschang (n=181) than Santchou (n=2) and Ambam (n=2). Pv occurrence appeared to be linked with environmental factors more than biological factors. Locally used malaria diagnosis methods had less specificity and sensibility to respect to PCR. Duffy blood group genotyping showed alleles frequencies of 0.30% (2/666) positive (-33TC) and 99.70% (664/666) negative (-33CC). All the Pv positive cases have shown a Duffy-negative genotype (-33CC). G6PD 968 SNP did not show any variability (968 A+, TT). G6PD deficiency prevalence was 2.78% (5/180) evaluated according to 202G>A SNP. The deficient allele frequency (G6PD 202A) among females was 2.72%. Two (2) Pv infected people were G6PD heterozygous (202GA; A+/-). Looking at CYP2D6 gene variability, the mutant alleles found were *2 (56.71%), *17 (13.63%) and *4 (4.24%). Most of them were normal metabolizers (98.82%; 504/510). Twelve (12) Pv infected people were intermediate and normal-slow metabolizers. These data show a relatively high circulation of Pv in the West Region of Cameroon among Duffy-negative autochthonous individuals, with a prevalence possibly depending from altitude and seasonality. Further study are necessary, in order to assess the real Pv local circulation and transmission, as well as to identify Duffy-independent Pv erythrocyte invasion pathway. It is important to improve the local malaria control program in Dschang taking in account the challenges of Pv malaria management (therapeutic toxicity, attacks and relapses)

The Ebola virus disease outbreak in Tonkolili district, Sierra Leone: a retrospective analysis of the Viral Haemorrhagic Fever surveillance system, July 2014–June 2015

In Sierra Leone, the Ebola virus disease (EVD) outbreak occurred with substantial differences between districts with someone even not affected. To monitor the epidemic, a community event-based surveillance system was set up, collecting data into the Viral Haemorrhagic Fever (VHF) database. We analysed the VHF database of Tonkolili district to describe the epi- demiology of the EVD outbreak during July 2014–June 2015 (data availability). Multivariable analysis was used to identify risk factors for EVD, fatal EVD and barriers to healthcare access, by comparing EVD-positive vs. EVD-negative cases. Key-performance indicators for EVD response were also measured. Overall, 454 EVD-positive cases were reported. At multivariable analysis, the odds of EVD was higher among those reporting contacts with an EVD-positive/ suspected case (odds ratio (OR) 2.47; 95% confidence interval (CI) 2.44–2.50; P < 0.01) and those attending funeral (OR 1.02; 95% CI 1.01–1.04; P < 0.01). EVD cases from Kunike chief- dom had a lower odds of death (OR 0.22; 95% CI 0.08–0.44; P < 0.01) and were also more likely to be hospitalised (OR 2.34; 95% CI 1.23–4.57; P < 0.05). Only 25.1% of alerts were gen- erated within 1 day from symptom onset. EVD preparedness and response plans for Tonkolili should include social-mobilisation activities targeting Ebola/knowledge-attitudes-practice dur- ing funeral attendance, to avoid contact with suspected cases and to increase awareness on EVD symptoms, in order to reduce delays between symptom onset to alert generation and consequently improve the outbreak-response promptness

Effects of environmental, living space and climate variability on the utilization of impregnated bed nets in west Cameroon: A community based survey for policy implementation

Background: Despite the fact that Long Lasting Impregnated Mosquito Net (LLIN) represents one of the most effective tools in fighting malaria, its use remains limited. Our study aimed at determining how environmental, household characteristics and climate affect bed net use. Methodology: A cross sectional descriptive and analytic study was carried out from January to April 2014 in Mifi health district. Data collected were collected in households during a face to face interview with standard household questionnaires, entered and analyzed using Epi Info software version 3.5.3. Graphics and tables were obtained using MS Excel and Word. Results: Of the 317 participants interviewed, average age was 33.23 years (SD = 10.80) and female sex predominant (85.2%). Most participants had attended secondary education 53.6% (n= 170), married marital status was most represented (58.1%; n= 185).75.4% (n=239) of households had at least 1 LLIN and average district coverage estimated to 1 LLIN for 3.3 persons. 78% of occupants in households with at least one LLIN had slept under the night before the survey. The presence of a ceiling in a house reduced net usage by 2.5% (p = 0.67) compared to house lacking ceiling. Standing waters around the compound increased net utilization rate to 16.6% (p = 0.03), whereas the presence of a covered well decreased the rate by 1.4% (p = 0.86). The dry season was identified as the period during which 86.8% (n= 239) of respondents sleep less under a net. Heat (57.60% n = 138/239), increased choking (2.5%), reduction in vector breeding sites (39.90%; n = 95) were cited as main reasons. Conclusion: Although classified as zone of continuous transmission, our findings indicate that bed net usage by our study population depends on environmental, household characteristics and climate. There is therefore an urgent need to develop strategic communication and sensitization campaigns coupled to environmental management to help scale up and optimize malaria burden reductio

Human cytochrome P450 2B6 genetic variability in Botswana: a case of haplotype diversity and convergent phenotypes

Identification of inter-individual variability for drug metabolism through cytochrome P450 2B6 (CYP2B6) enzyme is important for understanding the di erences in clinical responses to malaria and HIV. This study evaluates the distribution of CYP2B6 alleles, haplotypes and inferred metabolic phenotypes among subjects with di erent ethnicity in Botswana. A total of 570 subjects were analyzed for CYP2B6 polymorphisms at position 516G>T (rs3745274), 785A>G (rs2279343) and 983T>C (rs28399499). Samples were collected in three districts of Botswana where the population belongs to Bantu (Serowe/Palapye and Chobe) and San-related (Ghanzi) ethnicity. The three districts showed di erent haplotype composition according to the ethnic background but similar metabolic inferred phenotypes, with 59.12%, 34.56%, 2.10% and 4.21% of the subjects having, respectively, an extensive, intermediate, slow and rapid metabolic pro le. The results hint at the possibility of a convergent adaptation of detoxifying metabolic phenotypes despite a di erent haplotype structure due to the di erent genetic background. The main implication is that, while there is substantial homogeneity of metabolic inferred phenotypes among the country, the response to drugs metabolized via CYP2B6 could be individually associated to an increased risk of treatment failure and toxicity. These are important facts since Botswana is facing malaria elimination and a very high HIV prevalence

Molecular evidence of Plasmodium vivax infection in Duffy negative symptomatic individuals from Dschang, West Cameroon

Background: Plasmodium vivax infection is known to be rare in West/Central Africa, the most accepted explanation being the lack of expression of erythroid Duffy antigen in the local human populations. Duffy negativity prevents the parasite to exploit the entry mechanism on the red blood cell surface. However, there are a growing number of reported vivax infections in Duffy-negative individuals. Data on P. vivax circulation in Cameroon are limited. The aim of the study was to evaluate the P. vivax presence, and its association with the Duffy genotype in West Cameroon. Results: Overall, 484 blood samples were collected consecutively from febrile outpatients attending the Dschang’s Hospital (West Cameroon) during a 3-months period. Plasmodium vivax infection was detected by PCR in 5.6% (n = 27/484) of the cases, representing 38.6% (n = 27/70) of all Plasmodium infections detected. All P. vivax infected individuals showed a Duffy-negative genotype, and the frequency of Duffy-positive individuals in the whole tested population was 1.7%. Conclusions: The results of this study confirm the circulation of P. vivax in Cameroon, as well as that the lack of expression of Duffy-antigen does not confer full protection against vivax malaria acquisition

Nutritional outcomes in HIV Exposed Infants in the Mingha Program, Dschang-Cameroon (2003-2011)

Background: Prevention of Mother to Child Transmission (PMTCT) is a set of interventions that contribute in reducing the risk of HIV transmission from mother (parents) to the child. The infant feeding choice in the HIV context remains a key item of PMTCT. This study aimed at evaluating the nutritional status of children followed by the Mingha / PMTCT program in the Dschang Health District (DHD) during 09 years of activities. We used a descriptive study based on retrospective data from an intervention conducted at the DHD between 2003 and 2011 on a group of mother-child pairs in the PMTCT (Mingha/PMTCT) facilitation program. The intervention was the formula feeding given to the children from birth till 18 months. The data collected was analyzed using SPSS Version 18 software. Results: Among 328 children accessed, we had a sex ratio of 0.83 with more boys than girls. Severe wasting was found only within 11 boys (3.26%) and only <6 months old children were concerned. Moderate wasting was found among 6 girls (1.74%) and 5 boys (1.52%) and <6 months old children were highly concerned 10 (3.17%). Overweight (3.26%) was highly predominant among 8 boys (2.24%) and except those of <6 months, all the other age groups were concerned. There were no cases of obesity or stunting. Conclusions: The nutritional status of the Mingha/PMTCT program children was quite satisfactory. It characterizes the hope for a suitable nutritional follow up of children in HIV context. Therefore programs like Mingha/PMTCT should be promoted and transferred to other Health Districts and even resource-limited countries

Performance of the SD Bioline rapid diagnostic test as a good alternative to the detection of human African trypanosomiasis in Cameroon

Background: Case detection is essential for the management of human African trypanosomiasis (HAT), which is caused by Trypanosoma brucei gambiense. Prior to parasitological confirmation, routine screening using the card agglutination test for trypanosomiasis (CATT) is essential. Recently, individual rapid diagnostic tests (RDTs) for the serodiagnosis of HAT have been developed. Objective: The purpose of this study was to evaluate the contribution of SD Bioline HAT to the serological screening of human African trypanosomiasis in Cameroonian foci.Methods. Between June 2014 and January 2015, blood samples were collected during surveys in the foci of Campo, Yokadouma, and Fontem. The sensitivity (Se) and specificity (Sp) of SD Bioline HAT were determined using the CATT as the gold standard for the detection of specific antibodies against Trypanosoma brucei gambiense. Results: A total of 88 samples were tested: 59.1% (n=52) in Campo, 31.8% (n=28) in Yokadouma, and 9.1% (n=8) in Fontem. There were 61.4% (n=54) males and 38.4% (n=34) females, and the average age was 35.4 19.0 years. In probed foci, the overall seroprevalence was 11.4% (95% confidence interval: 6.3-19.7) with the CATT method and 18.2% (95% confidence interval: 11.5-27.2%) with the SD Bioline HAT RDT method. The SD Bioline HAT's Se and Sp were 80.0% and 89.7%, respectively. Conclusions: This study demonstrated that the overall performance of the SD Bioline HAT was comparable to that of the CATT, with high specificity in the serological detection of HAT

Awareness against STIs/HIV/AIDS among youth in developing countries: case of the mobile caravan project of Dschang, Cameroon.

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Sensibilisation des jeunes sur les IST/VIH et sida dans les établissements d’enseignement secondaire de la Commune de Dschang.

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