Papers by Hesham Mahyoub Al-Mekhlafi
Malaria Journal
Background Despite significant progress in eliminating malaria from the Kingdom of Saudi Arabia, ... more Background Despite significant progress in eliminating malaria from the Kingdom of Saudi Arabia, the disease is still endemic in the southwestern region of the country. Artesunate plus sulfadoxine–pyrimethamine (AS + SP) has been used in Saudi Arabia since 2007 as a first-line treatment for uncomplicated Plasmodium falciparum malaria. This study aimed to investigate the prevalence of mutations associated with resistance to artemisinin and sulfadoxine–pyrimethamine (SP) resistance in P. falciparum parasites circulating in Jazan region, southwestern Saudi Arabia. Methods A total of 151 P. falciparum isolates were collected between April 2018 and March 2019 from 12 of the governorates in Jazan region. Genomic DNA was extracted from dried blood spots and amplified using nested PCR. Polymorphisms in the propeller domain of the P. falciparum k13 (pfkelch13) gene and point mutations in the P. falciparum dihydrofolate reductase (pfdhfr) and dihydropteroate synthase (pfdhps) genes were ident...
Malaria Journal
Background Saudi Arabia and Yemen are the only two countries in the Arabian Peninsula that are ye... more Background Saudi Arabia and Yemen are the only two countries in the Arabian Peninsula that are yet to achieve malaria elimination. Over the past two decades, the malaria control programme in Saudi Arabia has successfully reduced the annual number of malaria cases, with the lowest incidence rate across the country reported in 2014. This study aims to investigate the distribution of residual malaria in Jazan region and to identify potential climatic drivers of autochthonous malaria cases in the region. Methods A cross-sectional study was carried out from 1 April 2018 to 31 January 2019 in Jazan region, southwestern Saudi Arabia, which targeted febrile individuals attending hospitals and primary healthcare centres. Participants’ demographic data were collected, including age, gender, nationality, and residence. Moreover, association of climatic variables with the monthly autochthonous malaria cases reported during the period of 2010–2017 was retrospectively analysed. Results A total of...
Pathogens and Global Health
Journal of Herbal Medicine
Iranian journal of parasitology
This study evaluated the performance of routine permanent stain and cultivation method in compari... more This study evaluated the performance of routine permanent stain and cultivation method in comparison with polymerase chain reaction assay as the reference technique to detect sp. A cross-sectional study was conducted among aboriginal populations that reside in Pahang, Peninsular Malaysia in Feb to Mar 2015. A total of 359 stool samples were examined using Wheatley's trichrome stain, in-vitro cultivation in Jones' medium and PCR assay. Positive amplicons were subjected to sequencing and phylogenetic analysis. Fifty-six (15.6%) samples were detected positive with sp. by Wheatley's trichrome stain and 73 (20.3%) by in-vitro culture, while PCR assay detected 71 (19.8%) positive samples. Detection rate of sp. was highest in combination of microscopic techniques (27.9%). The sensitivity and specificity of Wheatley's trichrome staining and in-vitro culture techniques compared to PCR assay were 49.3% (95% CI: 37.2-61.4) and 92.7% (95% CI: 89.1-95.4) and 39.4% (95% CI: 28.0-5...
The Southeast Asian journal of tropical medicine and public health, 2016
The epidemiology and environmental factors affecting transmission of human microsporidiosis are p... more The epidemiology and environmental factors affecting transmission of human microsporidiosis are poorly understood. We conducted the present study to determine the prevalence and risk factors associated with asymptomatic intestinal microsporidiosis among aboriginal school children in the Kuala Krau District, Pahang State, Malaysia. We collected stool samples from 255 school children and examined the samples using Gram-chromotrope Kinyoun stain. We also collected demographic, socioeconomic, environmental and personal hygiene information using a pre-tested questionnaire. Sixty-nine of the children was positive for microsporidia: 72.5% and 27.5% were low (1+) and moderate (2+) excretions of microsporidia spores, respectively. Univariate and multivariate analyses showed being aged 10 years (p = 0.026), using an unsafe water supply as a source for drinking water (p = 0.044) and having close contact with domestic animals (p = 0.031) were all significantly associated with microsporidial inf...
Asian Pacific Journal of Tropical Medicine
Asian Pacific Journal of Tropical Medicine
Tropical medicine & international health : TM & IH, Apr 2, 2017
To investigate the molecular epidemiology of Entamoeba histolytica, E. dispar and E. moshkovskii ... more To investigate the molecular epidemiology of Entamoeba histolytica, E. dispar and E. moshkovskii infections among rural communities in Yemen. In a community-based study, faecal samples were collected from 605 participants and examined by wet mount, formalin-ether sedimentation, trichrome staining and nested multiplex PCR techniques. Demographic, socio-economic and environmental information was collected using a pre-tested questionnaire. Overall, 324 (53.6%) of the samples were positive for Entamoeba cysts and/or trophozoites by microscopic examination. Molecular analysis revealed that 20.2%, 15.7% and 18.2% of the samples were positive for E. histolytica, E. dispar and E. moshkovskii, respectively. Multivariate analysis showed different sets of species-specific risk factors among these communities. Educational level was identified as the significant risk factor for E. histolytica; age and gender were the significant risk factors for E. moshkovskii; and sources of drinking water and ...
The American journal of tropical medicine and hygiene, 2016
In this study, the seroprevalence of sparganosis and its relationship with sociodemographic facto... more In this study, the seroprevalence of sparganosis and its relationship with sociodemographic factors in northern Tanzania have been assessed. A total of 216 serum samples from two rural districts, Monduli and Babati, were tested for sparganosis using an enzyme-linked immunosorbent assay. The seroprevalence of anti-sparganum IgG antibodies was 62.5% (95% confidence interval [CI] = 56.1-68.9) in all age groups. There were significant associations between district (relative risk [RR] = 1.95, 95% CI = 1.42-2.69), education (RR = 1.40, 95% CI = 1.15-1.70), and pet ownership with seropositivity (RR = 1.48, 95% CI = 1.02-2.16) based on univariate analysis. However, only the district was significantly associated with seropositivity (odds ratio = 4.20, 95% CI = 1.89-9.32) in binary logistic regression analysis. Providing health education to people residing in sparganosis-endemic areas is likely to improve the efficacy of preventative measures and reduce human disease burden.
The Southeast Asian journal of tropical medicine and public health, 2015
Dientamoeba fragilis is a trichomonad parasite that can infect the gastrointestinal tract of huma... more Dientamoeba fragilis is a trichomonad parasite that can infect the gastrointestinal tract of humans causing gastrointestinal disease. Little is known about its epidemiology. We evaluated the prevalence of D. fragilis by conducting a cross sectional study of an Orang Asli population in rural Malaysia. We examined stool samples from 150 participants for D. fragilis using Wheatley's trichrome stain and collected demographic data from each participant using a structured questionnaire. Five participants (3.3%) had D. fragilis in their stool; four of these were aged < 15 years; 3 were male and 2 were female. All participants with positive stool sample for D. fragilis were symptomatic; 3 had diarrhea and 2 had other gastrointestinal symptoms. D. fragilis is present in the study population. Further studies are needed to determine the virulence, pathogenicity and mode of transmission of D. fragilis in the study population.
PLOS ONE, 2016
Visceral leishmaniasis (VL) is a debilitating, often fatal disease caused by Leishmania donovani ... more Visceral leishmaniasis (VL) is a debilitating, often fatal disease caused by Leishmania donovani complex; however, it is a neglected tropical disease. L. donovani complex comprises two closely related species, L. donovani that is mostly anthroponotic and L. infantum that is zoonotic. Differentiation between these two species is critical due to the differences in their epidemiology and pathology. However, they cannot be differentiated morphologically, and their speciation using isoenzyme-based methods poses a difficult task and may be unreliable. Molecular characterization is now the most reliable method to differentiate between them and to determine their phylogenetic relationships. The present study aims to characterize Leishmania species isolated from bone marrows of Yemeni pediatric patients using sequence analysis of the ribosomal internal transcribed spacer-1 (ITS1) gene. Out of 41 isolates from Giemsa-stained bone marrow smears, 25 isolates were successfully amplified by nested polymerase chain reaction and sequenced in both directions. Phylogenetic analysis using neighbor joining method placed all study isolates in one cluster with L. donovani complex (99% bootstrap). The analysis of ITS1 for microsatellite repeat numbers identified L. infantum in 11 isolates and L. donovani in 14 isolates. These data suggest the possibility of both anthroponotic and zoonotic transmission of VL-causing Leishmania species in Yemen. Exploring the possible animal reservoir hosts is therefore needed for effective control to be achieved.
The American journal of tropical medicine and hygiene
ABSTRACT
Previous research has shown the beneficial effects of aqueous extract of Piper sarmentosum (P.s) ... more Previous research has shown the beneficial effects of aqueous extract of Piper sarmentosum (P.s) on atherosclerosis. The first stage in atherosclerosis is the formation of foam cell. The aim of this study was to investigate the effect of the methanol extract of P.s on fatty streaks by calculating neointimal foam cell infiltration in rabbits fed with high cholesterol diet. Thirty six male New Zealand white rabbits were divided equally into six groups: (i) C: control group fed normal rabbit chow; (ii) CH: cholesterol diet (1 % cholesterol); (iii) PM1: 1 % cholesterol with methanol extract of P.s (62.5 mg/kg); (iv) PM2: 1 % cholesterol with methanol extract of P.s (125 mg/kg); (v) PM3: 1 % cholesterol with methanol extract of P.s (250 mg/kg); (vi) SMV group fed 1 % cholesterol supplemented with Simvistatin drug (1.2 mg/kg). All animals were treated for 10 weeks. At the end of the treatment, the rabbits were fasted and sacrificed and the aortic tissues were collected for histological st...
Asia Pacific journal of clinical nutrition, 2007
We conducted a cross sectional study to examine the association of intestinal parasitic infection... more We conducted a cross sectional study to examine the association of intestinal parasitic infections and protein energy malnutrition (PEM) with iron-status indicators and anaemia among Orang Asli children in Selangor, Malaysia. A total of 281 children aged 2 - 15 years were studied. The data were collected using structured questionnaires, anthropometric measurements and laboratory analysis for blood and faecal samples. All children were infected either by A. lumbricoides, T. trichiura or hookworm and almost 19%, 26% and 3% of the children had severe infection of ascariasis, trichuriasis and hookworm infection respectively. The prevalence of giardiasis among them was 24.9%. Overall, 41.5% of the children were anaemic (haemoglobin < 11.0 g/dL). Of these 61.0% of the children had iron deficiency and 36.5% had iron deficiency anaemia (IDA), which accounted for 88.0% of anaemia in this population. Severe trichuriasis had the most significant correlation with anaemia and iron deficiency ...
Transactions of the Royal Society of Tropical Medicine and Hygiene, 2008
A cross-sectional study to determine the current prevalence of anaemia and iron deficiency anaemi... more A cross-sectional study to determine the current prevalence of anaemia and iron deficiency anaemia (IDA) and to investigate the possible risk factors for IDA was carried out on 241 aboriginal schoolchildren (120 boys, 121 girls) aged 7-12 years and living in remote areas in Pos Betau, Pahang, Malaysia. Haemoglobin (Hb) level was measured and serum iron status was assessed by serum ferritin (SF), serum iron (SI) and total iron binding capacity measurements. Socioeconomic data were collected using pre-tested questionnaires. All children were screened for intestinal parasitic infections. Overall, 48.5% (95% CI 42.3-54.8) of children were anaemic (Hb&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;12 g/dl). The prevalence of IDA was 34% (95% CI 28.3-40.2), which accounted for 70.1% of the anaemia cases. The prevalence of IDA was significantly higher in females than males. Low levels of mothers&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; education and low household income were identified as risk factors for IDA. Severe trichuriasis also found to be associated with low SF and SI. Logistic regression confirmed low levels of mothers&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; education and gender as significant risk factors for IDA. Improvement of socioeconomic status and health education together with periodic mass deworming should be included in public health strategies for the control and prevention of anaemia and IDA in this population.
Journal of Ethnopharmacology, 2010
Ethnopharmacological relevance: Various plants species are used in the traditional medicine for t... more Ethnopharmacological relevance: Various plants species are used in the traditional medicine for the treatment of malaria. This is the first community based ethnobotanical study in Peninsular Malaysia. Aim of the study: To investigate the plants traditionally used in the treatment of malaria in Malaysia. Materials and methods: An ethnobotanical survey was carried out among 233 Aboriginal and rural households, and traditional healers in malaria endemic areas in Peninsular Malaysia. Data were collected using a pre-tested questionnaire. Results: Nineteen species belonging to 17 families were identified. Twelve plant species have not previously been documented for the treatment of malaria in Malaysia. Conclusions: Findings of this study can be used as an ethnopharmacological basis for selecting plants for further anti-malarial phytochemical and pharmaceutical studies.
Rapid diagnostic tests (RDTs) have been widely used for malaria diagnosis and become an indispens... more Rapid diagnostic tests (RDTs) have been widely used for malaria diagnosis and become an indispensable tool for malaria case-management, control and elimination worldwide, especially in rural endemic areas without or with low laboratory capacity. In 2009, Yemen has introduced histidine rich protein 2 (HRP2)-based RDT to the malaria diagnosis platform for diagnosing falciparum malaria infections. Data on RDT evaluation and genetic variation of the pfhrp2 is not available yet. Hence, the present study aims to investigate both RDT diagnostic performance and the genetic variation of the pfhrp2 gene in falciparum malaria isolates from high endemic areas, Yemen and its possible impact on the efficacy of the currently used pfhrp2-based RDTs. A serial dilution of Plasmodium falciparum isolate with known parasite density of asexual forms was examined using CareStartTM Malaria HRP2 based-RDT. Moreover, blood samples from 622 individuals were examined using both RDT and microscopy. Sensitivity,...
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Papers by Hesham Mahyoub Al-Mekhlafi