Displaying publications 101 - 120 of 210 in total

Abstract:
Sort:
  1. Li MI, Mailepessov D, Vythilingam I, Lee V, Lam P, Ng LC, et al.
    PLoS Negl Trop Dis, 2021 Jan;15(1):e0009110.
    PMID: 33493205 DOI: 10.1371/journal.pntd.0009110
    Plasmodium knowlesi is a simian malaria parasite currently recognized as the fifth causative agent of human malaria. Recently, naturally acquired P. cynomolgi infection in humans was also detected in Southeast Asia. The main reservoir of both parasites is the long-tailed and pig-tailed macaques, which are indigenous in this region. Due to increased urbanization and changes in land use, there has been greater proximity and interaction between the long-tailed macaques and the general population in Singapore. As such, this study aims to determine the prevalence of simian malaria parasites in local macaques to assess the risk of zoonosis to the general human population. Screening for the presence of malaria parasites was conducted on blood samples from 660 peridomestic macaques collected between Jan 2008 and Mar 2017, and 379 wild macaques collected between Mar 2009 and Mar 2017, using a Pan-Plasmodium-genus specific PCR. Positive samples were then screened using a simian Plasmodium species-specific nested PCR assay to identify the species of parasites (P. knowlesi, P. coatneyi, P. fieldi, P. cynomolgi, and P. inui) present. All the peridomestic macaques sampled were tested negative for malaria, while 80.5% of the 379 wild macaques were infected. All five simian Plasmodium species were detected; P. cynomolgi being the most prevalent (71.5%), followed by P. knowlesi (47.5%), P. inui (42.0%), P. fieldi (32.5%), and P. coatneyi (28.5%). Co-infection with multiple species of Plasmodium parasites was also observed. The study revealed that Singapore's wild long-tailed macaques are natural hosts of the five simian malaria parasite species, while no malaria was detected in all peridomestic macaques tested. Therefore, the risk of simian malaria transmission to the general human population is concluded to be low. However, this can be better demonstrated with the incrimination of the vectors of simian malaria parasites in Singapore.
    Matched MeSH terms: Malaria/epidemiology*
  2. Balami AD, Said SM, Zulkefli NAM, Norsa'adah B, Audu B
    Malar J, 2021 Jan 21;20(1):55.
    PMID: 33478529 DOI: 10.1186/s12936-021-03586-5
    BACKGROUND: The prevalence of malaria in pregnancy and its complications, remain very high in Nigeria. This study aimed to determine the effects of a malaria health educational intervention based on the information-motivation-behavioural skills (IMB) model on malaria preventive practices and pregnancy outcomes.

    METHODS: The study was a randomized controlled parallel-group study, where 372 randomly selected antenatal care attendees were randomly assigned to one of either two groups after collecting baseline data. The intervention group then received a four-hour health education intervention in Hausa language, which was developed based on the IMB model, while the control group received a similarly designed health education on breastfeeding. Follow up data were then collected from the participants at a first (2 months post-intervention) and second (4 months post-intervention) follow up, and at the end of their pregnancies.

    RESULTS: For both groups, reported ITN use had increased from baseline (Intervention: Often-14.0%, Almost always-9.1; Control: Often-12.4%; Almost always 16.1%) to the time of second follow up (Intervention: Often -28.10%, Almost always-24.5; Control: Often-17.2%; Almost always 19.5%). Reported IPTp uptake at second follow up was also higher for the intervention group (Intervention: Two doses-59.0%, Three doses 22.3%; Control group: Two doses-48.4%, Three doses-7.0%). The drop in the haematocrit levels was greater for the control group (32.42% to 30.63%) compared to the intervention group (33.09% to 31.93%). The Generalized Linear Mixed Models (GLMM) analysis revealed that the intervention had significantly improved reported ITN use, reported IPTp uptake, and haematocrit levels, but had no significant effect on the incidence of reported malaria diagnosis or babies' birth weights.

    CONCLUSIONS: The intervention was effective in improving ITN use, IPTp uptake, and haematocrit levels. It is, therefore, recommended for the modules to be adopted and incorporated into the routine antenatal care programmes in health centres with predominantly Hausa speaking clients.

    TRIAL REGISTRATION: Pan African Clinical Trial Registry, PACTR201610001823405. Registered 26 October 2016, www.pactr.org .

    Matched MeSH terms: Malaria/epidemiology
  3. Al-Mekhlafi AM, Al-Mekhlafi HM, Mahdy MA, Azazy AA, Fong MY
    Ann Trop Med Parasitol, 2011 Apr;105(3):187-95.
    PMID: 21801497 DOI: 10.1179/136485911X12987676649421
    Between June 2008 and March 2009, a cross-sectional study of human malaria was carried out in four governorates of Yemen, two (Taiz and Hodiedah) representing the country's highlands and the others (Dhamar and Raymah) the country's coastal plains/foothills. The main aims were to determine the prevalences of Plasmodium infection among 455 febrile patients presenting for care at participating health facilities and to investigate the potential risk factors for such infection. Malarial infection was detected in 78 (17·1%) of the investigated patients and was more likely to be detected among the febrile patients from the highlands than among those presenting in the coastal plains/foothills (22·6% v.13·9%; χ(2)=10·102; P=0·018). Binary logistic-regression models identified low household income [odds ratio (OR)=13·52; 95% confidence interval (CI)=2·62-69·67; P=0·002], living in a household with access to a water pump (OR=4·18; CI=1·60-10·96; P=0·004) and living in a household near a stream (OR=4·43; CI=1·35-14·56; P=0·014) as significant risk factors for malarial infection in the highlands. Low household income was the only significant risk factor identified for such infection in the coastal plains and foothills (OR = 8·20; CI=1·80-37·45; P=0·007). It is unclear why febrile patients in the highlands of Yemen are much more likely to be found to have malarial infection than their counterparts from the coastal plains and foothills. Although it is possible that malarial transmission is relatively intense in the highlands, it seems more likely that, compared with those who live at lower altitudes, those who live in the highlands are less immune to malaria, and therefore more likely to develop febrile illness following malarial infection. Whatever the cause of the symptomatic malarial infection commonly found in the highlands of Yemen, it is a matter of serious concern that should be addressed in the national strategy to control malaria.
    Matched MeSH terms: Malaria/epidemiology*
  4. Divis PC, Lin LC, Rovie-Ryan JJ, Kadir KA, Anderios F, Hisam S, et al.
    Emerg Infect Dis, 2017 04;23(4):616-624.
    PMID: 28322705 DOI: 10.3201/eid2304.161738
    Multilocus microsatellite genotyping of Plasmodium knowlesi isolates previously indicated 2 divergent parasite subpopulations in humans on the island of Borneo, each associated with a different macaque reservoir host species. Geographic divergence was also apparent, and independent sequence data have indicated particularly deep divergence between parasites from mainland Southeast Asia and Borneo. To resolve the overall population structure, multilocus microsatellite genotyping was conducted on a new sample of 182 P. knowlesi infections (obtained from 134 humans and 48 wild macaques) from diverse areas of Malaysia, first analyzed separately and then in combination with previous data. All analyses confirmed 2 divergent clusters of human cases in Malaysian Borneo, associated with long-tailed macaques and pig-tailed macaques, and a third cluster in humans and most macaques in peninsular Malaysia. High levels of pairwise divergence between each of these sympatric and allopatric subpopulations have implications for the epidemiology and control of this zoonotic species.
    Matched MeSH terms: Malaria/epidemiology
  5. Kantele A, Marti H, Felger I, Müller D, Jokiranta TS
    Emerg Infect Dis, 2008 Sep;14(9):1434-6.
    PMID: 18760013 DOI: 10.3201/eid1409.080170
    In 2007, a Finnish traveler was infected in Peninsular Malaysia with Plasmodium knowlesi, a parasite that usually causes malaria in monkeys. P. knowlesi has established itself as the fifth Plasmodium species that can cause human malaria. The disease is potentially life-threatening in humans; clinicians and laboratory personnel should become more aware of this pathogen in travelers.
    Matched MeSH terms: Malaria/epidemiology*
  6. Ali WN, Ahmad R, Nor ZM, Ismail Z, Lim LH
    PMID: 21710845
    Mosquitoes in malaria endemic areas needs to be monitored constantly in order to detect demographic changes that could affect control measures. A 12-month mosquito population survey was conducted in several malaria endemic areas in Pos Lenjang, Kuala Lipis, Pahang, Malaysia. Collection of mosquitoes using a human landing catch technique was carried out indoors and outdoors for 12 hours from 7:00 PM to 7:00 AM for 42 nights. Anopheles maculatus Theobald (31.0%), Armigeres flavus Leicester (11.3%), Armigeres annulitarsis Leicester (11.0%), Culex vishnui Theobald (9.6%) and Aedes albopictus Skuse (7.0%) were the predominant species caught in the study area. The salivary gland and midgut of all anopheline mosquitoes were dissected to determine the presence of malaria parasites but none were positive. A high rate of human biting by An. maculatus was detected during December, but the rate was lower in January. Mosquito larvae were carried by the rapid current of the river downstream causing a decrease in the larvae population. Of the five predominant species, only Ar. annulitarsis exhibited a significant positive correlation in numbers with monthly rainfall (p < 0.05). An. maculatus biting activity peaked during 10:00 PM to 11:00 PM. Ae. albopictus, Ar. annulitarsis, and Ar. flavus exhibited similar activities which peaked during 7:00 PM to 8.00 PM.
    Matched MeSH terms: Malaria/epidemiology*
  7. Hii J, Alexander N, Chuan CK, Rahman HA, Safri A, Chan M
    PMID: 8629079
    Matched MeSH terms: Malaria/epidemiology
  8. Yong HS, Chiang GL, Loong KP, Ooi CS
    PMID: 3238481
    Starch-gel electrophoretic studies on nine gene-enzyme systems comprising 14 loci revealed a fair level of genetic variation in two population samples of Anopheles maculatus from Peninsular Malaysia. The proportion of polymorphic loci was 0.36 for the Fort Bertau sample and 0.29 for the Gua Musang sample, while the mean heterozygosity value was 0.09 for Fort Bertau and 0.07 for Gua Musang. The values of genetic similarity (I = 0.98) and genetic distance (D = 0.02) were of the rank of geographical populations.
    Matched MeSH terms: Malaria/epidemiology
  9. Baimai V
    PMID: 3238480
    Until recently, very little was known of Anopheles species complexes and their relationships to epidemiology and malaria transmission in Southeast Asia. During the past eight years, extensive studies on the genetics of natural populations of anopheline mosquitoes in this region, involving the interdisciplinary efforts of taxonomists, operational entomologists and biologists, have revealed groups of cryptic species of Anopheles vectors, particularly the An. leucos phyrus group. This species group comprise seventeen species and two subspecies widely distributed in the forested areas of Southeast Asia. Among these species. An. dirus Peyton and Harrison, has been shown by cytogenetic and morphological studies to be a complex of at least seven isomorphic species, provisionally designated species A, B, C, D, E, F and takasagoensis, on the Southeast Asian mainland. Cytological identification of these species is based on distinct banding patterns of salivary gland polytene chromosomes as well as heterochromatin differences in mitotic karyotypes. The five species found in Thailand (A-D, F) exhibit distinct geographic distributions. Species A is widespread throughout Thailand except in the south. Species B had been found in sympatry with species C in southern Thailand and both seem to show north-south clinal geographic variation. Species D is common on the west side of southern Thailand and along the Thai-Burmese border in sympatry with species A. Species F, An. nemophilous Peyton and Ramalingam, has been found in a population at the Thai-Malaysian border in this study although it was known to be common in southern and western Thailand and Peninsular Malaysia. Species E is known only from western India. The five species found in Thailand also exhibit seasonal variation in relative abundance and different nocturnal biting cycles. Chromosomal polymorphisms have been observed in mitotic and polytene chromosomes of An. dirus A and D. Species B and C also show heterochromatin variation in the sex chromosomes, but are monomorphic for the standard sequence in polytene chromosomes. These biological characteristics of the An. dirus complex may have implications for understanding the epidemiology of malaria in Southeast Asia. Recent cytogenetic studies of wild-caught samples of An. leucosphyrus from Sumatra, Kalimantan and southern Thailand have revealed the presence of two distinct species within this taxon. Species A is widely distributed in southern Thailand, East Malaysia and Kalimantan, while species B is confined to Sumatra. The two isomorphic species are vectors of human malaria within their range of distribution.(ABSTRACT TRUNCATED AT 400 WORDS)
    Matched MeSH terms: Malaria/epidemiology
  10. Kaur G
    PMID: 19842399
    An epidemiological cross-sectional study was undertaken to determine the prevalence of clinical malaria among the Orang Asli population of Raub, Pahang, Malaysia. The study was conducted on a representative sample of 520 Orang Asli. Malariometric and clinical measurements were taken. The overall parasitemic rate was 24.2% (95% CI 20.7-28.1). Twenty-three point four percent (95% CI 19.5-26.9) of respondents age two years and above were clinically febrile. The prevalence of fever, chills, perspiration and body aches during a one month period prior to the survey among the same group ranged between 4.2% (95% CI 2.7-6.4) and 13.5% (95% CI 10.6-16.7). Children 2-12 years old were more likely to present with fever, and symptoms of malaria than older children. Gender was not significantly associated with fever or any of the other malaria symptoms. Presence of clinical fever and history of malaria symptoms were all strongly associated with current infection. The association was significant even after controlling for age (adjusted OR 2.8-5.1, 95% CI 1.1-8.3). Orang Asli children significantly experienced greater morbidity due to malaria compared to adults. Control and treatment of malaria should focus on children, while further research should explore the effects of malaria morbidity on the quality of life of these children.
    Matched MeSH terms: Malaria/epidemiology*
  11. Rohani A, Wan Najdah WM, Zamree I, Azahari AH, Mohd Noor I, Rahimi H, et al.
    PMID: 21073056
    In Peninsular Malaysia, a large proportion of malaria cases occur in the central mountainous and forested parts of the country. As part of a study to assess remote sensing data as a tool for vector mapping, we conducted entomological surveys to determine the type of mosquitoes, their characteristics and the abundance of habitats of the vector Anopheles maculatus in malaria endemic areas in Pos Senderot. An. maculatus mosquitoes were collected from 49 breeding sites in Pos Senderot. An. maculatus preferred to breed in water pockets formed on the bank of rivers and waterfalls. The most common larval habitats were shallow pools 5.0-15.0 cm deep with clear water, mud substrate and plants or floatage. The mosquito also preferred open or partially shaded habitats. Breeding habitats were generally located at 100-400 m from the nearest human settlement. Changes in breeding characteristics were also observed. Instead of breeding in slow flowing streams, most larvae bred in small water pockets along the river margin.
    Matched MeSH terms: Malaria/epidemiology*
  12. Nimir AR, Isa NH, Eugene CB, Ghauth IM, Salleh FM, Rahman RA
    PMID: 17333723
    The age distribution, types of infection and clinical patterns of malaria were compared in patients admitted to an urban and a rural hospital. Analysis of the cases seen in urban setting characteristically indicated a relatively low transmission rate of the disease, whereas the mean inoculation rate in patients from the rural hospital was found to be at least twenty folds higher. Plasmodium vivax was the predominant causative species in the urban hospital (p = 0.01), infecting mostly adult (p = 0.001) males (p = 0.01). The geometric mean parasite count at 3432/microl among the urban patients was significantly higher than that in the rural patients at 1422/microl (p = 0.04). Coma and death were more common among the cases seen in the urban hospital (p = 0.003), while severe anemia was the significant complication in the rural setting. Overall, the provisional diagnosis of malaria was relatively low in the urban hospital (p = 0.02). The results from this study highlighted the need to define the extent of malaria in urban areas. This report attempts to identify the non-climatic determinants of the infection and, furthermore, to provide a more informed basis to describe the burden of the disease.
    Matched MeSH terms: Malaria/epidemiology*
  13. Jamaiah I, Rohela M, Nissapatorn V, Mohamad Azlan H, Nor Adli AR, Shahrul Rizan I, et al.
    PMID: 17547040
    This was a five-year retrospective study (1999-2004) on the prevalence of malaria at the Aborigine Hospital, Gombak, Malaysia. A total of 94 malaria cases was analysed. The highest case reports were for the year 2000, with 32 cases (34%), and the lowest was in 2004, with only 1 (1%). The majority of cases reported were among the Semai tribe (44%), followed by the Temiar tribe (34%) and the unspecified tribe (s) (20%). Females (53%) were more commonly affected than males (47%). The majority of cases were within the age group 1-5 years (51%). Plasmodium falciparum was the most common species reported in this study, at 57%, followed by Plasmodium vivax (38%) and 5% mixed infection of P. falciparum and P. vivax. Most patients (27%) stayed for more than one month in hospital. Most patients came from Kuala Lipis, Pahang, (78%). The most common complication was anemia (38%) followed by splenomegaly (18%); only 2% had cerebral malaria. All patients were treated with the standard anti-malarial drugs. No deaths were reported in this study.
    Matched MeSH terms: Malaria/epidemiology*
  14. Matsuo M, Nishiyama K, Shirakawa T, Padilla CD, San LP, Suryantoro P, et al.
    PMID: 15906715
    Glucose-6-phosphate dehydrogenase (G6PD) deficiency is common in malaria endemic regions and is estimated to affect more than 400 million people worldwide. Deficient subjects are mostly asymptomatic but clinical manifestations range from neonatal jaundice due to acute hemolytic anemia to chronic non-spherocytic hemolytic anemia. To date, biochemical parameters allowed more than 400 different G6PD variants to be distinguished thereby suggesting a vast genetic heterogeneity. So far, only a small portion of this heterogeneity has been confirmed at the DNA level with the identification of about 90 different point mutations in the G6PD coding sequence. To determine the molecular background of G6PD deficiency in Southeast Asian countries, we conducted molecular analyses of G6PD patients from the Philippines, Malaysia, Singapore, Vietnam and Indonesia. The most prevalent mutation identified differs from country to country, thus suggesting independent mutational events of the G6PD gene.
    Matched MeSH terms: Malaria/epidemiology
  15. Jamaiah I, Rohela M, Nissapatorn V, Khoo BL, Khoo PS, Radhiyah M, et al.
    PMID: 16438181
    Malaria is still one of the most important vector-borne diseases in Malaysia, particularly in remote areas. This retrospective study was carried out to find the prevalence of malaria among patients admitted to UMMC Kuala Lumpur, from 1994-2003. A total of 86 malaria cases were analyzed. Most cases occurred among foreigners [57% (49 cases)] while Malaysians constituted 43% (37 cases). Among foreigners, Indonesians constituted the most [57% (28 cases)]. Among Malaysians, most cases occurred among the Chinese [35% (13 cases)] followed by the Malays [30% (11 cases)]. Males [70%(60 cases)] were more commonly affected. The majority of cases were within the 20-39 year age group (69%). Three species of malaria parasites were reported, of which Plasmodium vivax constituted the most [55%( 47 cases)], followed by Plasmodium falciparum [29% (25 cases)], and only four cases (5%) of Plasmodium malariae. Nine percent (8 cases) were mixed infections. In this study, 12%(10 cases) developed chloroquine resistance: 7 cases of P. falciparum, and 3 cases of P. vivax. The most common complications were jaundice and anemia [77% (23 cases)], followed by blackwater fever [13% (4 cases)] and cerebral malaria [10% (3 cases)]. Most of the complications were due to P. falciparum [43% (13 cases)]. There were no reported deaths. This new source of malaria coming from foreigners must be given serious attention, as it has great potential of increasing malaria cases in urban Malaysia.
    Matched MeSH terms: Malaria/epidemiology*
  16. Arasu GD
    PMID: 1341845
    The risk behavior in malaria has been identified as one of the factors contributing to malaria in Malaysia. The occurrence of malaria among illegal immigrants and indigenous groups, staying in risk prone areas where conditions are favorable for transmission, highlights the behavior pattern of these groups. In these areas the usual anti-malarial activities are less effective and thus there is a need to identify control measures suited to that particular condition and environment and to community groups. Some of the determinants contributing to the increase in malaria cases like man-vector contact, non-compliance to drugs, complications of the disease, and factors interfering with malaria control measures, factors favoring transmission and proposals to modify risk behavior, which can be applied in an endeavor to control the diseases, have been discussed.
    Matched MeSH terms: Malaria/epidemiology
  17. Dondero TJ, Parsons RE, O'Holohan DR
    PMID: 775652
    Chloroquine pressure was applied over a 22 month period on a somewhat isolated, malarious rubber estate by examination of residents at 4-week intervals and treatment of parasitaemias with chloroquine. During this time the monthly attack rate for P. falciparum rose four-fold to an average of nearly 18% per month, while that of P. vivax remained relatively constant at about 8%. Eight in vivo chloroquine resistance studies, which allowed both detection of late recrudescing R-I resistance and estimation of the risk of reinfection, showed an apparent rise in the drug resistance rate, from 12% to 20% prior to the study to the range of 40-50%. Virtually all resistance encountered was R-I in nature. There was no convincing evidence of chloroquine resistance among 148 tested P. vivax infections.
    Matched MeSH terms: Malaria/epidemiology
  18. Muul I, Yap LF, Lim BL
    PMID: 4203491
    Matched MeSH terms: Malaria/epidemiology
Filters
Contact Us

Please provide feedback to Administrator ([email protected])

External Links