Displaying publications 21 - 40 of 56 in total

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  1. Vythilingam I, Nitiavathy K, Yi P, Bakotee B, Hugo B, Singh B, et al.
    PMID: 10928352
    Dried Anopheles farauti mosquitos caught in Solomon Islands in 1990 were examined for malaria sporozoites by ELISA and nested polymerase chain reaction (PCR). Only heads and thoraces were used. Plasmodium genus-specific nested PCR amplifications were carried out on all samples. Of the 402 pools of mosquitos that were processed, 30 were positive for malaria. Nest 1 products of positive samples were subjected to further PCR amplifications with species-specific primers for P. falciparum and P. vivax. Twenty pools were positive for P. vivax by PCR while only 7 were positive by ELISA. For P. falciparum 2 pools were positive by both ELISA and PCR, and one of these was a pool which was positive for P. vivax by PCR and ELISA. Thus the sensitivity of PCR for P. vivax was 100% while the specificity was 96.7%. For P. falciparum the sensitivity and specificity were 100%. The PCR technique is highly sensitive and can be used on dried mosquitos which makes it a valuable tool for determining sporozoite rates of mosquitos, even in remote areas.
    Matched MeSH terms: Plasmodium falciparum/isolation & purification*
  2. Chang MS, Matusop A, Sen FK
    PMID: 10774651
    Anopheles mosquitos were surveyed using three trapping technics in four longhouse settlements and their respectively farming zone in western Sarawak, Malaysia. The study area was mountainous with tropical rain forest. An. leucosphyrus and An. donaldi were predominant in the farm huts. An. tessellatus and An. subpictus were more abundant in the village settlements. In both ecotypes, human baited traps yielded a significantly greater proportion of Anopheles mosquito than CDC light traps and landing biting catches. Circumsporozoite antigen positively rate, mosquito survival rate and parasite rate showed that malaria transmission is more intense in farm huts than in longhouse settlements. The entomological inoculation rate of An. donaldi and An. leucosphyrus in farm huts was 0.035 and 0.023, respectively. No sporozoite infections were observed in the main settlements.
    Matched MeSH terms: Plasmodium falciparum/isolation & purification
  3. Chang SP, Kramer KJ, Yamaga KM, Kato A, Case SE, Siddiqui WA
    Exp Parasitol, 1988 Oct;67(1):1-11.
    PMID: 3049134
    The gene encoding the 195,000-Da major merozoite surface antigen (gp195) of the FUP (Uganda-Palo Alto) isolate of Plasmodium falciparum, a strain widely used for monkey vaccination experiments, has been cloned and sequenced. The translated amino acid sequence of the FUP gp195 protein is closely related to the sequences of corresponding proteins of the CAMP (Malaysia) and MAD-20 (Papua New Guinea) isolates and more distantly related to those of the Wellcome (West Africa) and K1 (Thailand) isolates, supporting the proposed allelic dimorphism of gp195 within the parasite population. The prevalence of dimorphic sequences within the gp195 protein suggests that many gp195 epitopes would be group-specific. Despite the extensive differences in amino acid sequence between gp195 proteins of these two groups, the hydropathy profiles of proteins representative of both groups are very similar. The conservation of overall secondary structure shown by the hydropathy profile comparison indicates that gp195 proteins of the various P. falciparum isolates are functionally equivalent. This information on the primary structure of the FUP gp195 protein will enable us to evaluate the possible roles of conserved, group-specific and variable epitopes in immunity to the blood stage of the malaria parasite.
    Matched MeSH terms: Plasmodium falciparum/isolation & purification
  4. Seleena P, Lee HL, Chooi KH, Junaidih S
    PMID: 15272747
    A pilot study was undertaken to determine the effectiveness of space application of insecticides for the control of malaria in Ranau, a district in Sabah. A village each was treated monthly: with chemical adulticide--alpha cypermethrin (Fendona SC(R)/10SC(R)) at 2 g a.i./10,000 m2 in Pahu; with biological larvicides--Bacillus thuringiensis israelensis (Vectobac 12AS(R)) at 500 ml/10,000 m2 or B. sphaericus (Vectolex WG(R)) at 500 g/10,000 m2 in Pinawantai; and with a mixture of chemical adulticide and biological larvicide in Togop Laut. All sprayings were conducted using a portable mist blower. During the study period all villages, including Tarawas the untreated village, received the conventional malaria control measures. Entomological and epidemiological surveillance was used to measure the effectiveness of the space application. The entomological surveillance indicated that the An. balabacensis population was significantly reduced by alpha cypermethrin in Pahu and Togop Laut and B. sphaericus in Pinawantai; but was not reduced by B.t.i. in Pinawantai. There was a significant reduction in the number of malaria cases and in the slide positivity rate in the treated villages during the study period. The pilot study does indicate that space application of larvicides/adulticides or a mixture of both is able to reduce the malaria vector population and the malaria transmission. A larger scale study needs to be undertaken in a malarious village/province to determine whether space application of insecticides together with other malaria control measures will be able to eradicate malaria.
    Matched MeSH terms: Plasmodium falciparum/isolation & purification
  5. Khairul MF, Min TH, Low JH, Nasriyyah CH, A'shikin AN, Norazmi MN, et al.
    Jpn J Infect Dis, 2006 Oct;59(5):329-31.
    PMID: 17060702
    Fluoxetine (FLX), a P-glycoprotein inhibitor with antimalarial activity, is promising candidate for reversing chloroquine/mefloquine (CQ/MQ) resistance. The Dd2 strain of CQ- and MQ-resistant Plasmodium falciparum was synchronized and assayed with various concentrations of CQ/MQ individually and in combination with FLX or verapamil (VPL). Our results indicated the 50% inhibitory concentration values of CQ and MQ were greatly lowered when FLX was used simultaneously. Isobolograms indicated that CQ-FLX combinations are more synergistic (mean fractional inhibitory concentration [FIC] index 0.55) than MQ-FLX (mean FIC index 0.64), and their synergistic effect was better than or at par with CQ-VPL (mean FIC index 0.88) and MQ-VPL (mean FIC index 0.60) combinations. We conclude that the FLX potentiates the CQ and MQ response on multidrug-resistant P. falciparum at clinically achievable concentrations.
    Matched MeSH terms: Plasmodium falciparum/isolation & purification
  6. Hussin N, Lim YA, Goh PP, William T, Jelip J, Mudin RN
    Malar J, 2020 Jan 31;19(1):55.
    PMID: 32005228 DOI: 10.1186/s12936-020-3135-x
    BACKGROUND: To date, most of the recent publications on malaria in Malaysia were conducted in Sabah, East Malaysia focusing on the emergence of Plasmodium knowlesi. This analysis aims to describe the incidence, mortality and case fatality rate of malaria caused by all Plasmodium species between Peninsular Malaysia and East Malaysia (Sabah and Sarawak) over a 5-year period (2013-2017).

    METHODS: This is a secondary data review of all diagnosed and reported malaria confirmed cases notified to the Ministry of Health, Malaysia between January 2013 and December 2017.

    RESULTS: From 2013 to 2017, a total of 16,500 malaria cases were notified in Malaysia. The cases were mainly contributed from Sabah (7150; 43.3%) and Sarawak (5684; 34.4%). Majority of the patients were male (13,552; 82.1%). The most common age group in Peninsular Malaysia was 20 to 29 years (1286; 35.1%), while Sabah and Sarawak reported highest number of malaria cases in age group of 30 to 39 years (2776; 21.6%). The top two races with malaria in Sabah and Sarawak were Bumiputera Sabah (5613; 43.7%) and Bumiputera Sarawak (4512; 35.1%), whereas other ethnic group (1232; 33.6%) and Malays (1025; 28.0%) were the two most common races in Peninsular Malaysia. Plasmodium knowlesi was the commonest species in Sabah and Sarawak (9902; 77.1%), while there were more Plasmodium vivax cases (1548; 42.2%) in Peninsular Malaysia. The overall average incidence rate, mortality rate and case fatality rates for malaria from 2013 to 2017 in Malaysia were 0.106/1000, 0.030/100,000 and 0.27%, respectively. Sarawak reported the highest average incidence rate of 0.420/1000 population followed by Sabah (0.383/1000). Other states in Peninsular Malaysia reported below the national average incidence rate with less than 0.100/1000.

    CONCLUSIONS: There were different trends and characteristics of notified malaria cases in Peninsular Malaysia and Sabah and Sarawak. They provide useful information to modify current prevention and control measures so that they are customised to the peculiarities of disease patterns in the two regions in order to successfully achieve the pre-elimination of human-only species in the near future.

    Matched MeSH terms: Plasmodium falciparum/isolation & purification
  7. Boush MA, Djibrine MA, Mussa A, Talib M, Maki A, Mohammed A, et al.
    Sci Rep, 2020 07 30;10(1):12822.
    PMID: 32733079 DOI: 10.1038/s41598-020-69756-8
    In remote areas of malaria-endemic countries, rapid diagnostic tests (RDTs) have dramatically improved parasitological confirmation of suspected malaria cases, especially when skilled microscopists are not available. This study was designed to determine the frequency of Plasmodium falciparum isolates with histidine-rich protein 2 (pfhrp2) gene deletion as one of the possible factors contributing to the failure of PfHRP2-based RDTs in detecting malaria. A total of 300 blood samples were collected from several health centres in Nyala City, Western Sudan. The performance of PfHRP2-based RDTs in relation to microscopy was examined and the PCR-confirmed samples were investigated for the presence of pfhrp2 gene. A total of 113 out of 300 patients were P. falciparum positive by microscopy. Among them, 93.81% (106 out of 113) were positives by the PfHRP2 RDTs. Seven isolates were identified as false negative on the basis of the RDTs results. Only one isolate (0.9%; 1/113) potentially has pfhrp2 gene deletion. The sensitivity and specificity of PfHRP2-based RDTs were 93.81% and 100%, respectively. The results provide insights into the pfhrp2 gene deletion amongst P. falciparum population from Sudan. However, further studies with a large and systematic collection from different geographical settings across the country are needed.
    Matched MeSH terms: Plasmodium falciparum/isolation & purification
  8. O'Holohan DR
    J Trop Med Hyg, 1976 Sep;79(9):191-6.
    PMID: 794512
    In the context of this study the ethnic origin of the patients revealed no noteworthy difference in the clinical reaction to the parasite; neither did age or sex of the patients. Any minor differences whcih appeared in length of history before seeking treatment and frequency of repeat attacks were more a reflection of the cultural pattern of response to illness (i.e. resort to traditional medicines) and the distance between the patient's home and the doctor rather than any altered response on the part of the host to the parasite. However, the fact that about 35 per cent of all the episodes had a history of eight or more days (about 10 per cent more than 30 days) suggest that more "malaria consciousness" is called for in what is after all an endemic malaria area. The value (and necessity) of repeated examination of the blood to detect the parasite is confirmed but it is also encouraging to note that in 84% of cases a single careful examination of the blood revealed the parasite. Since in 49% of our malaria episodes the patient was afebrile when the parasite was discovered, it is obvious that in outpatient practice especially blood should be examined when the patient presents for treatment, irrespective of the presence or absence of pyrexia. As always, a prerequisite to the diagnosis of malaria is an awareness of its possible presence.
    Matched MeSH terms: Plasmodium falciparum/isolation & purification
  9. Clyde DF, McCarthy VC, Gilman RH, Miller RM
    J Trop Med Hyg, 1973 Sep;76(9):226-30.
    PMID: 4582746
    Matched MeSH terms: Plasmodium falciparum/isolation & purification*
  10. Beshir KB, Grignard L, Hajissa K, Mohammed A, Nurhussein AM, Ishengoma DS, et al.
    Am J Trop Med Hyg, 2020 08;103(2):558-560.
    PMID: 32553046 DOI: 10.4269/ajtmh.20-0467
    Rapid diagnostic tests (RDTs) play a critical role in malaria diagnosis and control. The emergence of Plasmodium falciparum parasites that can evade detection by RDTs threatens control and elimination efforts. These parasites lack or have altered genes encoding histidine-rich proteins (HRPs) 2 and 3, the antigens recognized by HRP2-based RDTs. Surveillance of such parasites is dependent on identifying false-negative RDT results among suspected malaria cases, a task made more challenging during the current pandemic because of the overlap of symptoms between malaria and COVID-19, particularly in areas of low malaria transmission. Here, we share our perspective on the emergence of P. falciparum parasites lacking HRP2 and HRP3, and the surveillance needed to identify them amid the COVID-19 pandemic.
    Matched MeSH terms: Plasmodium falciparum/isolation & purification*
  11. Mu AK, Bee PC, Lau YL, Chen Y
    Int J Mol Sci, 2014;15(11):19952-61.
    PMID: 25372941 DOI: 10.3390/ijms151119952
    Malaria is caused by parasitic protozoans of the genus Plasmodium and is one of the most prevalent infectious diseases in tropical and subtropical regions. For this reason, effective and practical diagnostic methods are urgently needed to control the spread of malaria. The aim of the current study was to identify a panel of new malarial markers, which could be used to diagnose patients infected with various Plasmodium species, including P. knowlesi, P. vivax and P. falciparum. Sera from malaria-infected patients were pooled and compared to control sera obtained from healthy individuals using the isobaric tags for relative and absolute quantitation (iTRAQ) technique. Mass spectrometry was used to identify serum proteins and quantify their relative abundance. We found that the levels of several proteins were increased in pooled serum from infected patients, including cell adhesion molecule-4 and C-reactive protein. In contrast, the serum concentration of haptoglobin was reduced in malaria-infected individuals, which we verified by western blot assay. Therefore, these proteins might represent infectious markers of malaria, which could be used to develop novel diagnostic tools for detecting P. knowlesi, P. vivax and P. falciparum. However, these potential malarial markers will need to be validated in a larger population of infected individuals.
    Matched MeSH terms: Plasmodium falciparum/isolation & purification
  12. Abdullah NR, Norahmad NA, Jelip J, Sulaiman LH, Mohd Sidek H, Ismail Z, et al.
    Malar J, 2013;12:198.
    PMID: 23758930 DOI: 10.1186/1475-2875-12-198
    Sulphadoxine-pyrimethamine (SP) has been in use for the treatment of uncomplicated falciparum malaria in Malaysia since the 1970s and is still widely employed in spite of widespread clinical resistance. Resistance to SP is known to be mediated by mutations in the pfdhfr and pfdhps genes. The aim of the present study was to investigate the distribution of pfdhfr and pfdhps gene polymorphism in Plasmodium falciparum field isolates from Kalabakan, Sabah, in northern Borneo.
    Matched MeSH terms: Plasmodium falciparum/isolation & purification
  13. Srinivasan V, Mohamed M, Zakaria R, Ahmad AH
    Infect Disord Drug Targets, 2012 Oct;12(5):371-9.
    PMID: 23082960
    Malaria, one of the most deadly diseases of our time affects more than 200 million people across the globe and is responsible for about one million deaths annually. Until recently Plasmodium falciparum has been the main cause for malarial infection in human beings but now Plasmodium knowlesi from Malaysia remains as one of the most virulent parasite spreading fast not only in Malaysia but in different parts of the world. Hence there is urgent need for the global fight to control malaria. Global malaria eradication program by use of insecticide spraying has resulted in good response in the past. Treatment of malaria infected patients with anti-malarial drugs has helped to eliminate malarial infections successfully but with increased resistance displayed by malarial parasites to these drugs there is resurgence of malaria caused both by drug resistance as well as by infection caused by new malarial species like Plasmodium knowlesi. With recent advances on molecular studies on malarial parasites it is now clear that the pineal hormone melatonin acts as a cue for growth and development of Plasmodium falciparum. Same may be true for Plasmodium knowlesi also. Hence treatment modalities that can effectively block the action of melatonin on Plasmodium species during night time by way of using either bright light therapy or use of melatonin receptor blocking can be considered as useful approaches for eliminating malarial infection in man.
    Matched MeSH terms: Plasmodium falciparum/isolation & purification
  14. Atroosh WM, Al-Mekhlafi HM, Mahdy MA, Surin J
    Malar J, 2012;11:251.
    PMID: 22853645 DOI: 10.1186/1475-2875-11-251
    Malaria is still a public health problem in Malaysia with chloroquine (CQ) being the first-line drug in the treatment policy of uncomplicated malaria. There is a scarcity in information about the magnitude of Plasmodium falciparum CQ resistance. This study aims to investigate the presence of single point mutations in the P. falciparum chloroquine-resistance transporter gene (pfcrt) at codons 76, 271, 326, 356 and 371 and in P. falciparum multi-drug resistance-1 gene (pfmdr1) at codons 86 and 1246, as molecular markers of CQ resistance.
    Matched MeSH terms: Plasmodium falciparum/isolation & purification
  15. Norahmad NA, Abdullah NR, Yaccob N, Jelip J, Dony JF, Ruslan KF, et al.
    PMID: 22299399
    Chloroquine (CQ) remains the first line drug for the prevention and treatment of malaria in Malaysia in spite of the fact that resistance to CQ has been observed in Malaysia since the 1960s. CQ-resistance is associated with various mutations in pfcrt, which encodes a putative transporter located in the digestive vacuolar membrane of P. falciparum. Substitution of lysine (K) to threonine (T) at amino acid 76 (K76T) in pfcrt is the primary genetic marker conferring resistance to CQ. To determine the presence of T76 mutation in pfcrt from selected areas of Kalabakan, Malaysia 619 blood samples were screened for P. falciparum, out of which 31 were positive. Blood samples were collected on 3 MM Whatman filter papers and DNA was extracted using QIAmp DNA mini kit. RFLP-PCR for the detection of the CQ-resistant T76 and sensitive K76 genotype was carried out. Twenty-five samples were shown to have the point mutation in pfcrt whereas the remaining samples were classified as CQ-sensitive (wild-type). In view of the fact that CQ is the first line anti-malarial drug in Malaysia, this finding could be an important indication that treatment with CQ may no longer be effective in the future.
    Matched MeSH terms: Plasmodium falciparum/isolation & purification
  16. Mohd Abd Razak MR, Sastu UR, Norahmad NA, Abdul-Karim A, Muhammad A, Muniandy PK, et al.
    PLoS One, 2016;11(3):e0152415.
    PMID: 27023787 DOI: 10.1371/journal.pone.0152415
    Malaysia has a national goal to eliminate malaria by 2020. Understanding the genetic diversity of malaria parasites in residual transmission foci can provide invaluable information which may inform the intervention strategies used to reach elimination targets. This study was conducted to determine the genetic diversity level of P. falciparum isolates in malaria residual foci areas of Sabah. Malaria active case detection was conducted in Kalabakan and Kota Marudu. All individuals in the study sites were screened for malaria infection by rapid diagnostic test. Blood from P. falciparum-infected individuals were collected on filter paper prior to DNA extraction. Genotyping was performed using merozoite surface protein-1 (MSP-1), merozoite surface protein-2 (MSP-2), glutamate rich protein (GLURP) and 10 neutral microsatellite loci markers. The size of alleles, multiplicity of infection (MOI), mean number of alleles (Na), expected heterozygosity (He), linkage disequilibrium (LD) and genetic differentiation (FST) were determined. In Kalabakan, the MSP-1 and MSP-2 alleles were predominantly K1 and FC27 family types, respectively. The GLURP genotype VI (751-800 bp) was predominant. The MOI for MSP-1 and MSP-2 were 1.65 and 1.20, respectively. The Na per microsatellite locus was 1.70. The He values for MSP-1, MSP-2, GLURP and neutral microsatellites were 0.17, 0.37, 0.70 and 0.33, respectively. In Kota Marudu, the MSP-1 and MSP-2 alleles were predominantly MAD20 and 3D7 family types, respectively. The GLURP genotype IV (651-700 bp) was predominant. The MOI for both MSP-1 and MSP-2 was 1.05. The Na per microsatellite locus was 3.60. The He values for MSP-1, MSP-2, GLURP and neutral microsatellites were 0.24, 0.25, 0.69 and 0.30, respectively. A significant LD was observed in Kalabakan (0.495, p<0.01) and Kota Marudu P. falciparum populations (0.601, p<0.01). High genetic differentiation between Kalabakan and Kota Marudu P. falciparum populations was observed (FST = 0.532). The genetic data from the present study highlighted the limited diversity and contrasting genetic pattern of P. falciparum populations in the malaria declining areas of Sabah.
    Matched MeSH terms: Plasmodium falciparum/isolation & purification
  17. Ravichandran M, Doolan DL, Cox-Singh J, Hoffman SL, Singh B
    Parasite Immunol., 2000 Sep;22(9):469-73.
    PMID: 10972854
    Considerable effort is directed at the development of a malaria vaccine that elicits antigen-specific T-cell responses against pre-erythrocytic antigens of Plasmodium falciparum. Genetic restriction of host T-cell responses and polymorphism of target epitopes on parasite antigens pose obstacles to the development of such a vaccine. Liver stage-specific antigen-1 (LSA-1) is a prime candidate vaccine antigen and five T-cell epitopes that are degenerately restricted by HLA molecules common in most populations have been identified on LSA-1. To define the extent of polymorphism within these T-cell epitopes, the N-terminal non-repetitive region of the LSA-1 gene from Malaysian P. falciparum field isolates was sequenced and compared with data of isolates from Brazil, Kenya and Papua New Guinea. Three of the T-cell epitopes were completely conserved while the remaining two were highly conserved in the isolates examined. Our findings underscore the potential of including these HLA-degenerate T-cell epitopes of LSA-1 in a subunit vaccine.
    Matched MeSH terms: Plasmodium falciparum/isolation & purification
  18. Lim PK, Looareesuwan S, Chindanond D, Saleh AM, Tan SK
    PMID: 10437950
    Matched MeSH terms: Plasmodium falciparum/isolation & purification
  19. Hii JL, Chee KC, Vun YS, Awang J, Chin KH, Kan SK
    PMID: 9185261
    The district of Kudat has one of the highest and most persistent malaria transmission levels in Sabah, Malaysia, with annual parasite incidence of 102 per 1,000 inhabitants per year. Due to this situation and the failure of DDT spraying to control malaria, a community participation health program (Sukarelawan Penjagaan Kesihatan Primer or SPKP) was developed as an adjunct to current anti-malarial measures during 1987-1991. SPKP is made up of unpaid community workers known as village health volunteers (VHVs). VHVs are selected by a village development and security committees training and supervision a member of the Vector-Borne Diseases Control Program (VBDCP). The beneficiaries of SPKP consisted primarily of Runggus people and other remote, and mobile populations who visit the home of a VHV for diagnosis and treatment. This group of febrile patients and their children who attend a participating school submit finger prick blood and personal details to the VHV. and receive a presumptive treatment for malaria. Thick and thin blood smears are examined by a VBDCP microscopist who then prepare and forward a radical or curative treatment to the VHV so that it can be administered to the microscopically-positive patient free of charge. Between June 1987 to June 1991, VHVs from 32 kampungs (villages) and 22 schools collected 56,245 slides representing 24.7% of total slide collection compared to 74.9% collected by passive case detection (PCD) posts in health centers and district hospital. The average volunteer treated 11.8 (range 10.4-13.4) and 31.4 (range 26-49) patients per month in kampungs and schools respectively. In contrast, non-SPKP posts in a district hospital, health centers and flying doctor service treated an average of 616.3 patients per month (range 134.8-1032.8). The slide positivity rate of blood smears taken by VHVs was 8.43% compared with 7.37% for non-SPKP posts. Average slide collection and slide positivity rates varied considerably from one community to another, despite their close geographic proximity. The monthly number of VHV-diagnosed patients from the school and kampungs communities and the monthly number of true malaria patients in the two groups were significantly correlated. Sustainability of SPKP was linked to an ongoing process of social change which involved co-operative networking between the government health sector and the community. This in turn provided a stimulus for malaria abatement efforts. When Runggus people themselves control and maintain ownership of community-based malaria programs, the function of SPKP as a malaria surveillance system and an antimalarial drug distribution network is vastly improved.
    Matched MeSH terms: Plasmodium falciparum/isolation & purification
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