Genetic diversity of Plasmodium falciparum isolates from Pahang, Malaysia based on MSP-1 and MSP-2 genes

<p>Abstract</p> <p>Background</p> <p>Malaria is still a public health problem in Malaysia especially in the interior parts of Peninsular Malaysia and the states of Sabah and Sarawak (East Malaysia). This is the first study on the genetic diversity and genotype multiplicity of <it>Plasmodium falciparum </it>in Malaysia.</p> <p>Methods</p> <p>Seventy-five <it>P. falciparum </it>isolates were genotyped by using nested-PCR of <it>MSP-1 </it>(block 2) and <it>MSP-2 </it>(block 3).</p> <p>Results</p> <p><it>MSP-1 </it>and <it>MSP-2 </it>allelic families were identified in 65 blood samples. RO33 was the predominant <it>MSP-1 </it>allelic family identified in 80.0% (52/65) of the samples while K1 family had the least frequency. Of the <it>MSP-2 </it>allelic families, 3D7 showed higher frequency (76.0%) compared to FC27 (20.0%). The multiplicity of <it>P. falciparum </it>infection (MOI) was 1.37 and 1.20 for <it>MSP-1 </it>and <it>MSP-2</it>, respectively. A total of seven alleles were detected; of which three <it>MSP-1 </it>allelic families (RO33, MAD20 and K1) were monomorphic in terms of size while <it>MSP-2 </it>alleles were polymorphic (two 3D7 and two FC27). Heterozygosity (H_E) was 0.57 and 0.55 for <it>MSP-1 </it>and <it>MSP-2</it>, respectively.</p> <p>Conclusions</p> <p>The study showed that the MOI of <it>P. falciparum </it>is low, reflected the low intensity of malaria transmission in Pahang, Malaysia; RO33 and 3D7 were the most predominant circulating allelic families. The findings showed that <it>P. falciparum </it>has low allelic diversity with a high frequency of alleles. As a result, antimalarial drug efficacy trials based on MSP genotyping should be carefully interpreted.</p

Nutritional and socio-economic determinants of cognitive function and educational achievement of Aboriginal schoolchildren in rural Malaysia

A community-based cross-sectional study was carried out among Aboriginal schoolchildren aged 7–12 years living in remote areas in Pos Betau, Pahang, Malaysia to investigate the potential determinants influencing the cognitive function and educational achievement of these children. Cognitive function was measured by intelligence quotient (IQ), while examination scores of selected school subjects were used in assessing educational achievement. Blood samples were collected to assess serum Fe status. All children were screened for soil-transmitted helminthes. Demographic and socio-economic data were collected using pre-tested questionnaires. Almost two-thirds (67·6 %) of the subjects had poor IQ and most of them (72·6 %) had insufficient educational achievement. Output of the stepwise multiple regression model showed that poor IQ was significantly associated with low household income which contributed the most to the regression variance (r2 0·059; P = 0·020). Low maternal education was also identified as a significant predictor of low IQ scores (r2 0·042; P = 0·043). With educational achievement, Fe-deficiency anaemia (IDA) was the only variable to show significant association (r2 0·025; P = 0·015). In conclusion, the cognitive function and educational achievement of Aboriginal schoolchildren are poor and influenced by household income, maternal education and IDA. Thus, effective and integrated measures to improve the nutritional and socio-economic status of rural children would have a pronounced positive effect on their education

High Seroprevalence of Echinococossis, Schistosomiasis and Toxoplasmosis among the Populations in Babati and Monduli Districts, Tanzania.

BackgroundThe neglected tropical diseases, echinococcosis, schistosomiasis and toxoplasmosis are all globally widespread zoonotic diseases with potentially harmful consequences. There is very limited data available on the prevalence of these infections, except for schistosmiasis, in underdeveloped countries. This study aimed to determine the seroprevalence of Echinococcus multilocularis, Schistosoma mansoni, and Toxoplasma gondii antibodies in populations from the Monduli and Babati districts in Tanzania.MethodsA total of 345 blood samples were collected from 160 and 185 randomly selected households from Babati and Monduli districts, Tanzania between February and May of 2012 and analyzed them using the enzyme linked immunosorbent assay. The antibodies were determined using the NovaLisa® Toxoplasma gondii IgG, NovaLisa® Schistosoma Mansoni IgG, NovaLisa® Echinococcus IgG and NovaLisa® Toxoplasma gondii IgM kits (Novatec, Germany).ResultsThe seropositivity estimated for E. multilocularis, S. mansoni, and T. gondii IgG was 11.3% (95% confidence interval (CI): 7.96 - 14.6), 51.3% (95% CI: 46.0 - 56.5), and 57.68% (95% CI: 52.5 - 62.9), respectively. The seropositivity for T. gondii IgM was 11.3% (95% CI: 7.96 - 14.6). Living in the Monduli district was found to be the main risk factor for IgG seropositivity for both schistosomiasis (OR =1.94; 95% CI: 1.23 - 3.08; p =0.005) and toxoplasmosis (OR =2.09; 95% CI: 1.31-3.33; p =0.002).ConclusionsThese results suggest that restricting disease transmission, implementing control measures, and introducing training projects to increase public awareness are imperative, particularly for the Monduli district

Changes in the vascular cell adhesion molecule-1, intercellular adhesion molecule-1 and c-reactive protein following administration of aqueous extract of piper sarmentosum on experimental rabbits fed with cholesterol diet

Background: Inflammation process plays an important role in the development of atherosclerosis. Hypercholesterolemia is one of the major risk factors for atherosclerosis. The present study aimed to evaluate the effect of aqueous extract of Piper sarmentosum (P.s) on inflammatory markers like vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), and C-reactive protein (CRP). Methods: Forty two male New Zealand white rabbits were divided equally into seven groups; (i) C-control group fed normal rabbit chow (ii) CH-cholesterol diet (1 cholesterol) (iii) X1-1 cholesterol with water extract of P.s (62.5 mg/kg) (iv) X2-1 cholesterol with water extract of P.s (125 mg/kg (v) X3-1 cholesterol with water extract of P.s (250 mg/kg) (vi) X4-1 cholesterol with water extract of P.s (500 mg/kg) and (vii) SMV group fed with 1 cholesterol supplemented with simvistatin drug (1.2 mg/kg). All animals were treated for 10 weeks. Blood serum was taken for observing the inflammatory markers at the beginning and end of the experiment. Results: Rabbits fed with 1 cholesterol diet (CH) showed significant increase in the level of VCAM-1, ICAM-1 and CRP compared to the C group. The levels of VCAM-1, ICAM-1 and CRP in the 1 cholesterol group and supplemented with P.s (500 mg/kg) were significantly reduced compared to the cholesterol group. Similar results were also reported with simvistatin group. Conclusion: These results suggest that the supplementation of Piper sarmentosum extract could inhibit inflammatory markers which in turn could prevent atherosclerosis

Prevalence and associated factors of Schistosomiasis among children in Yemen: implications for an effective control programme

BACKGROUND Schistosomiasis, one of the most prevalent neglected tropical diseases, is a life-threatening public health problem in Yemen especially in rural communities. This cross-sectional study aims to determine the prevalence and associated risk factors of schistosomiasis among children in rural Yemen. METHODS/FINDINGS Urine and faecal samples were collected from 400 children. Urine samples were examined using filtration technique for the presence of Schistosoma haematobium eggs while faecal samples were examined using formalin-ether concentration and Kato Katz techniques for the presence of S. mansoni. Demographic, socioeconomic and environmental information were collected via a validated questionnaire. Overall, 31.8% of the participants were found to be positive for schistosomiasis; 23.8% were infected with S. haematobium and 9.3% were infected with S. mansoni. Moreover, 39.5% of the participants were anaemic whereas 9.5% had hepatosplenomegaly. The prevalence of schistosomiasis was significantly higher among children aged >10 years compared to those aged ≤ 10 years (P<0.05). Multivariate analysis confirmed that presence of other infected family member (P<0.001), low household monthly income (P = 0.003), using unsafe sources for drinking water (P = 0.003), living nearby stream/spring (P = 0.006) and living nearby pool/pond (P = 0.002) were the key factors significantly associated with schistosomiasis among these children. CONCLUSIONS/SIGNIFICANCE This study reveals that schistosomiasis is still highly prevalent in Yemen. These findings support an urgent need to start an integrated, targeted and effective schistosomiasis control programme with a mission to move towards the elimination phase. Besides periodic drug distribution, health education and community mobilisation, provision of clean and safe drinking water, introduction of proper sanitation are imperative among these communities in order to curtail the transmission and morbidity caused by schistosomiasis. Screening and treating other infected family members should also be adopted by the public health authorities in combating this infection in these communities

High frequency of Plasmodium falciparum chloroquine resistance marker (pfcrt T76 mutation) in Yemen: An urgent need to re-examine malaria drug policy

<p>Abstract</p> <p>Background</p> <p>Malaria remains a significant health problem in Yemen with <it>Plasmodium falciparum </it>being the predominant species which is responsible for 90% of the malaria cases. Despite serious concerns regarding increasing drug resistance, chloroquine is still used for the prevention and treatment of malaria in Yemen. This study was carried out to determine the prevalence of choloroquine resistance (CQR) of <it>P. falciparum </it>isolated from Yemen based on the <it>pfcrt </it>T76 mutation.</p> <p>Methods</p> <p>A cross-sectional study was carried out among 511 participants from four governorates in Yemen. Blood samples were screened using microscopic and species-specific nested PCR based on the 18S rRNA gene to detect and identify <it>Plasmodium </it>species. Blood samples positive for <it>P. falciparum </it>were used for detecting the <it>pfcrt </it>T76 mutation using nested-PCR.</p> <p>Results</p> <p>The prevalence of <it>pfcrt </it>T76 mutation was 81.5% (66 of 81 isolates). Coastal areas/foothills had higher prevalence of <it>pfcrt </it>T76 mutation compared to highland areas (90.5% <it>vs </it>71.8%) (p = 0.031). The <it>pfcrt </it>T76 mutation had a significant association with parasitaemia (p = 0.045). Univariate analysis shows a significant association of <it>pfcrt </it>T76 mutation with people aged > 10 years (OR = 9, 95% CI = 2.3 - 36.2, p = 0.001), low household income (OR = 5, 95% CI = 1.3 - 19.5, p = 0.027), no insecticide spray (OR = 3.7, 95% CI = 1.16 - 11.86, p = 0.025) and not sleeping under insecticide treated nets (ITNs) (OR = 4.8, 95% CI = 1.38 - 16.78, p = 0.01). Logistic regression model confirmed age > 10 years and low household income as predictors of <it>pfcrt </it>T76 mutation in Yemen <it>P. falciparum </it>isolates.</p> <p>Conclusions</p> <p>The high prevalence of <it>pfcrt </it>T76 mutation in Yemen could be a predictive marker for the prevalence of <it>P. falciparum </it>CQR. This finding shows the necessity for an in-vivo therapeutic efficacy test for CQ.<it> P. falciparum </it>CQR should be addressed in the national strategy to control malaria.</p

Mapping and modelling the geographical distribution of soil-transmitted helminthiases in Peninsular Malaysia : implications for control approaches

Soil-transmitted helminth (STH) infections in Malaysia are still highly prevalent, especially in rural and remote communities. Complete estimations of the total disease burden in the country has not been performed, since available data are not easily accessible in the public domain. The current study utilised geographical information system (GIS) to collate and map the distribution of STH infections from available empirical survey data in Peninsular Malaysia, highlighting areas where information is lacking. The assembled database, comprising surveys conducted between 1970 and 2012 in 99 different locations, represents one of the most comprehensive compilations of STH infections in the country. It was found that the geographical distribution of STH varies considerably with no clear pattern across the surveyed locations. Our attempt to generate predictive risk maps of STH infections on the basis of ecological limits such as climate and other environmental factors shows that the prevalence of Ascaris lumbricoides is low along the western coast and the southern part of the country, whilst the prevalence is high in the central plains and in the North. In the present study, we demonstrate that GIS can play an important role in providing data for the implementation of sustainable and effective STH control programmes to policy-makers and authorities in charge

New insights into the genetic diversity of Schistosoma mansoni and S. haematobium in Yemen

Background: Human schistosomiasis is a neglected tropical disease of great importance that remains highly prevalent in Yemen, especially amongst rural communities. In order to investigate the genetic diversity of human Schistosoma species, a DNA barcoding study was conducted on S. mansoni and S. haematobium in Yemen. Methods: A cross-sectional study was conducted to collect urine and faecal samples from 400 children from five provinces in Yemen. The samples were examined for the presence of Schistosoma eggs. A partial fragment of the schistosome cox1 mitochondrial gene was analysed from each individual sample to evaluate the genetic diversity of the S. mansoni and S. haematobium infections. The data was also analysed together with previous published cox1 data for S. mansoni and S. haematobium from Africa and the Indian Ocean Islands. Results: Overall, 31.8 % of participants were found to be excreting schistosome eggs in either the urine or faeces (8.0 % S. mansoni and 22.5 % S. haematobium). Nineteen unique haplotypes of S. mansoni were detected and split into four lineages. Furthermore, nine unique haplotypes of S. haematobium were identified that could be split into two distinct groups. Conclusion: This study provides novel and interesting insights into the population diversity and structure of S. mansoni and S. haematobium in Yemen. The data adds to our understanding of the evolutionary history and phylogeography of these devastating parasites whilst the genetic information could support the control and monitoring of urogenital and intestinal schistosomiasis in these endemic areas

Detection of Schistosoma mansoni and Schistosoma haematobium by Real-Time PCR with High Resolution Melting Analysis

The present study describes a real-time PCR approach with high resolution melting-curve (HRM) assay developed for the detection and differentiation of Schistosoma mansoni and S. haematobium in fecal and urine samples collected from rural Yemen. The samples were screened by microscopy and PCR for the Schistosoma species infection. A pair of degenerate primers were designed targeting partial regions in the cytochrome oxidase subunit I (cox1) gene of S. mansoni and S. haematobium using real-time PCR-HRM assay. The overall prevalence of schistosomiasis was 31.8%; 23.8% of the participants were infected with S. haematobium and 9.3% were infected with S. mansoni. With regards to the intensity of infections, 22.1% and 77.9% of S. haematobium infections were of heavy and light intensities, respectively. Likewise, 8.1%, 40.5% and 51.4% of S. mansoni infections were of heavy, moderate and light intensities, respectively. The melting points were distinctive for S. mansoni and S. haematobium, categorized by peaks of 76.49 ± 0.25 °C and 75.43 ± 0.26 °C, respectively. HRM analysis showed high detection capability through the amplification of Schistosoma DNA with as low as 0.0001 ng/µL. Significant negative correlations were reported between the real-time PCR-HRM cycle threshold (Ct) values and microscopic egg counts for both S. mansoni in stool and S. haematobium in urine (p < 0.01). In conclusion, this closed-tube HRM protocol provides a potentially powerful screening molecular tool for the detection of S. mansoni and S. haematobium. It is a simple, rapid, accurate, and cost-effective method. Hence, this method is a good alternative approach to probe-based PCR assays