Species Composition and Plasmodium falciparum Infection Rates of Anopheles gambiae s.l. Mosquitoes in Six Localities of Kwara State, North Central, Nigeria

Entomological data gathering is essential for monitoring malaria vector disease risks and selection of appropriate interventions for the protection of exposed human populations. This study assessed the relative abundance, species composition, and sporozoite infection rates of indoor resting An. gambiae s.l. malaria vectors in six communities across 3 Local Government Areas in Kwara State, Nigeria. Total number of mosquitoes collected by Pyrethrum Spray Catch method over a period of eighth months were correlated with rainfall values in the area. Plasmodium falciparum sporozoite infection rates and sibling species identification of collected An. gambiae s.l. mosquito samples were determined by ELISA and PCR respectively. Results showed a positive correlation (r = 0.639, p = 0.08) between rainfall and numbers of Anopheles mosquitoes in the study areas. The overall composition of the An. gambiae s.l sibling species in the collected samples from all the six communities showed the predominance of An. gambiae s.s 298 (75.3%) compared to An. coluzzii 94(23.7%) and An. arabiensis 4(1.0%). However, the sporozoite infection rate of An. coluzzii (22.3%) was higher compared to An. gambiae s.s (12.8%) and An. arabiensis (0%). Mean numbers of An. gambiae s.l mosquitoes were significantly higher in Ilorin west LGA compared to Asa (F = 17.81, P < 0.001) and Ilorin East LGAs (F = 22.81, P < 0.001). Sporozoite rates of both An. gambiae s.s and An. coluzzii sibling species were higher in Ilorin West communities (Aiyede 21%, Ogundele 32%) compared to Asa (Idi Emi 11.1%, Lasoju 5.1%) and Ilorin East (Oke Oyi 2.4%, Ote-efan 0%) communities. Prevalence of sporozoite-infected An. gambiae s.s and An. coluzzii indoors highlight the need for effective insecticide treated bed-nets interventions to protect the residents from malaria risks. Higher numbers of An. coluzzii in the swampy rice marshed Ilorin West LGA communities require larval source management as an additional strategy for effective malaria vector control

A decade of innovation to deepen the understanding of infectious diseases of poverty and foster their control and elimination

[Image: see text

Ethnic variations in duration of untreated psychosis: report from the CRIS-FEP study

Objectives:  There is inconsistent evidence on the influence of ethnicity on duration of untreated psychosis (DUP). We investigated ethnic differences in DUP in a large epidemiological dataset of first episode psychosis patients in an inner city area of south London, UK. Methods:  We analysed data on 558 first episode psychosis patients at the South London and Maudsley NHS Trust, between 2010 and 2012. We performed multivariable logistic regression to estimate the odds of a short DUP (≤ 6 months) by ethnic group, controlling for confounders. Results:  There was no evidence that ethnicity is associated with duration of untreated psychosis. However, we found evidence that a short DUP was strongly associated with age, living circumstances, and pathways to care variables (involuntary admission, out of office hour contact, accident and emergency referral, criminal justice agency referral and family involvement in help-seeking). Conversely, a long DUP was associated with report of social isolation, living alone, being single and General Practitioner referral. Conclusion:  Our findings suggest that indicators of social isolation were associated with long DUP. Our data also show that pathways into care characteristics play significant role in DUP. Thus, the challenge of tackling the issue of timely access to EI under the new Access and Waiting Time standard for psychosis requires a multilevel approach, including joint working with communities, public awareness of psychosis, less restrictive referral pathways and adequate resourcing of early intervention for psychosis services. These will go a long way in addressing patients’ needs rather than be determined by service structures

Evaluation of the efficacy and safety of artemether-lumefantrine in the treatment of acute uncomplicated Plasmodium falciparum malaria in Nigerian infants and children

<p>Abstract</p> <p>Background</p> <p>The six-dose regimen of artemether-lumefantrine (AL) is now considered the gold standard for the treatment of uncomplicated <it>Plasmodium falciparum </it>malaria. There are few reports evaluating co-artemether in very young Nigerian infants and children. Results of the evaluation of the six-dose regimen in very young infants and children in Nigeria are presented in this report.</p> <p>Methods</p> <p>As part of a larger African study, this open label, non-comparative trial, assessed the efficacy and safety of six-dose regimen of AL tablets in 103 Nigerian infants and children weighing between five and 25 kg suffering from acute uncomplicated malaria. Treatment was administered under supervision over three days with children as in-patients. 12-lead ECG tracings were taken pre-treatment and at day 3.</p> <p>Results</p> <p>Ninety-three infants and children completed the study as stipulated by the protocol. Mean fever and parasite clearance times for the intent to treat population (ITT) were 24.9 h ± (1.28) and 26 h ± (4.14) and the corresponding figures for the per-protocol population (PP) were 19.24 h ± 13.9 and 25.62 h ± 11.25 respectively. Day 14 cure rates for the ITT and PP were 95.1% and 100% respectively while day 28 cure rates were 91.3% and 95.7% respectively. The overall PCR corrected day 28 cure rate was 95.1% for the ITT. The six-dose regimen of AL was well tolerated with no drug-related serious adverse events. Although six patients recorded a QTc prolongation of > 60 ms on D3 over D0 recording, no patient recorded a QTc interval > 500 ms.</p> <p>Conclusion</p> <p>The six-dose regimen of AL tablets is safe and effective for the treatment of acute uncomplicated malaria in Nigerian infants and children weighing between five and 25 kg.</p> <p>Trial registration</p> <p>NCT00709969</p

A high performance liquid chromatographic assay of Mefloquine in saliva after a single oral dose in healthy adult Africans

<p>Abstract</p> <p>Background</p> <p>Mefloquine-artesunate is a formulation of artemisinin based combination therapy (ACT) recommended by the World Health Organization and historically the first ACT used clinically. The use of ACT demands constant monitoring of therapeutic efficacies and drug levels, in order to ensure that optimum drug exposure is achieved and detect reduced susceptibility to these drugs. Quantification of anti-malarial drugs in biological fluids other than blood would provide a more readily applicable method of therapeutic drug monitoring in developing endemic countries. Efforts in this study were devoted to the development of a simple, field applicable, non-invasive method for assay of mefloquine in saliva.</p> <p>Methods</p> <p>A high performance liquid chromatographic method with UV detection at 220 nm for assaying mefloquine in saliva was developed and validated by comparing mefloquine concentrations in saliva and plasma samples from four healthy volunteers who received single oral dose of mefloquine. Verapamil was used as internal standard. Chromatographic separation was achieved using a Hypersil ODS column.</p> <p>Results</p> <p>Extraction recoveries of mefloquine in plasma or saliva were 76-86% or 83-93% respectively. Limit of quantification of mefloquine was 20 ng/ml. Agreement between salivary and plasma mefloquine concentrations was satisfactory (r = 0.88, <it>p </it>< 0.001). Saliva:plasma concentrations ratio was 0.42.</p> <p>Conclusion</p> <p>Disposition of mefloquine in saliva paralleled that in plasma, making salivary quantification of mefloquine potentially useful in therapeutic drug monitoring.</p

Evaluation of a PfHRP2 and a pLDH-based Rapid Diagnostic Test for the Diagnosis of Severe Malaria in 2 Populations of African Children

This comparative study in 1898 children in 2 different African population shows that a pfHRP2-based rapid diagnostic test is a reliable diagnostic for diagnosing severe falciparum malaria in these settings and performs better than routine microscopy or a pLDH based test

Pregnancy Outcome and Placenta Pathology in Plasmodium berghei ANKA Infected Mice Reproduce the Pathogenesis of Severe Malaria in Pregnant Women

Pregnancy-associated malaria (PAM) is expressed in a range of clinical complications that include increased disease severity in pregnant women, decreased fetal viability, intra-uterine growth retardation, low birth weight and infant mortality. The physiopathology of malaria in pregnancy is difficult to scrutinize and attempts were made in the past to use animal models for pregnancy malaria studies. Here, we describe a comprehensive mouse experimental model that recapitulates many of the pathological and clinical features typical of human severe malaria in pregnancy. We used P. berghei ANKA-GFP infection during pregnancy to evoke a prominent inflammatory response in the placenta that entails CD11b mononuclear infiltration, up-regulation of MIP-1 alpha chemokine and is associated with marked reduction of placental vascular spaces. Placenta pathology was associated with decreased fetal viability, intra-uterine growth retardation, gross post-natal growth impairment and increased disease severity in pregnant females. Moreover, we provide evidence that CSA and HA, known to mediate P. falciparum adhesion to human placenta, are also involved in mouse placental malaria infection. We propose that reduction of maternal blood flow in the placenta is a key pathogenic factor in murine pregnancy malaria and we hypothesize that exacerbated innate inflammatory responses to Plasmodium infected red blood cells trigger severe placenta pathology. This experimental model provides an opportunity to identify cell and molecular components of severe PAM pathogenesis and to investigate the inflammatory response that leads to the observed fetal and placental blood circulation abnormalities

Confirmation of emergence of mutations associated with atovaquone-proguanil resistance in unexposed Plasmodium falciparum isolates from Africa

BACKGROUND: In vitro and in vivo resistance of Plasmodium falciparum to atovaquone or atovaquone-proguanil hydrochloride combination has been associated to two point mutations in the parasite cytochrome b (cytb) gene (Tyr268Ser and Tyr268Asn). However, little is known about the prevalence of codon-268 mutations in natural populations of P. falciparum without previous exposure to the drug in Africa. METHODS: The prevalence of codon-268 mutations in the cytb gene of African P. falciparum isolates from Nigeria, Malawi and Senegal, where atovaquone-proguanil has not been introduced for treatment of malaria was assessed. Genotyping of the cytb gene in isolates of P. falciparum was performed by PCR-restriction fragment length polymorphism and confirmed by sequencing. RESULTS: 295 samples from Nigeria (111), Malawi (91) and Senegal (93) were successfully analyzed for detection of either mutant Tyr268Ser or Tyr268Asn. No case of Ser268 or Asn268 was detected in cytb gene of parasites from Malawi or Senegal. However, Asn268 was detected in five out of 111 (4.5%) unexposed P. falciparum isolates from Nigeria. In addition, one out of these five mutant Asn268 isolates showed an additional cytb mutation leading to a Pro266Thr substitution inside the ubiquinone reduction site. CONCLUSION: No Tyr268Ser mutation is found in cytb of P. falciparum isolates from Nigeria, Malawi or Senegal. This study reports for the first time cytb Tyr268Asn mutation in unexposed P. falciparum isolates from Nigeria. The emergence in Africa of P. falciparum isolates with cytb Tyr268Asn mutation is a matter of serious concern. Continuous monitoring of atovaquone-proguanil resistant P. falciparum in Africa is warranted for the rational use of this new antimalarial drug, especially in non-immune travelers

An overview of anti-diabetic plants used in Gabon: Pharmacology and Toxicology

© 2017 Elsevier B.V. All rights reserved.Ethnopharmacological relevance: The management of diabetes mellitus management in African communities, especially in Gabon, is not well established as more than 60% of population rely on traditional treatments as primary healthcare. The aim of this review was to collect and present the scientific evidence for the use of medicinal plants that are in currect by Gabonese traditional healers to manage diabetes or hyperglycaemia based here on the pharmacological and toxicological profiles of plants with anti-diabetic activity. There are presented in order to promote their therapeutic value, ensure a safer use by population and provide some bases for further study on high potential plants reviewed. Materials and methods: Ethnobotanical studies were sourced using databases such as Online Wiley library, Pubmed, Google Scholar, PROTA, books and unpublished data including Ph.D. and Master thesis, African and Asian journals. Keywords including ‘Diabetes’ ‘Gabon’ ‘Toxicity’ ‘Constituents’ ‘hyperglycaemia’ were used. Results: A total of 69 plants currently used in Gabon with potential anti-diabetic activity have been identified in the literature, all of which have been used in in vivo or in vitro studies. Most of the plants have been studied in human or animal models for their ability to reduce blood glucose, stimulate insulin secretion or inhibit carbohydrates enzymes. Active substances have been identified in 12 out of 69 plants outlined in this review, these include Allium cepa and Tabernanthe iboga. Only eight plants have their active substances tested for anti-diabetic activity and are suitables for further investigation. Toxicological data is scarce and is dose-related to the functional parameters of major organs such as kidney and liver. Conclusion: An in-depth understanding on the pharmacology and toxicology of Gabonese anti-diabetic plants is lacking yet there is a great scope for new treatments. With further research, the use of Gabonese anti-diabetic plants is important to ensure the safety of the diabetic patients in Gabon.Peer reviewedFinal Accepted Versio