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  1. Importance of Theranostics in Rare Brain-Eating Amoebae Infections
    Anwar A, Siddiqui R, Khan NA
    ACS Chem Neurosci, 2019 01 16;10(1):6-12.
    PMID: 30149693 DOI: 10.1021/acschemneuro.8b00321
    Pathogenic free-living amoebae including Acanthamoeba spp., Balamuthia mandrillaris, and Naegleria fowleri cause infections of the central nervous system (CNS), which almost always prove fatal. The mortality rate is high with the CNS infections caused by these microbes despite modern developments in healthcare and antimicrobial chemotherapy. The low awareness, delayed diagnosis, and lack of effective drugs are major hurdles to overcome these challenges. Nanomaterials have emerged as vital tools for concurrent diagnosis and therapy, which are commonly referred to as theranostics. Nanomaterials offer highly sensitive diagnostic systems and viable therapeutic effects as a single modality. There has been good progress to develop nanomaterials based efficient theranostic systems against numerous kinds of tumors, but this field is yet immature in the context of infectious diseases, particularly parasitic infections. Herein, we describe the potential value of theranostic applications of nanomaterials against brain infections due to pathogenic amoebae.
    Matched MeSH terms: Brain/parasitology*
  2. Clinically Approved Drugs against CNS Diseases as Potential Therapeutic Agents To Target Brain-Eating Amoebae
    Anwar A, Rajendran K, Siddiqui R, Raza Shah M, Khan NA
    ACS Chem Neurosci, 2019 01 16;10(1):658-666.
    PMID: 30346711 DOI: 10.1021/acschemneuro.8b00484
    Central nervous system (CNS) infections caused by free-living amoebae such as Acanthamoeba species and Naegleria fowleri are rare but fatal. A major challenge in the treatment against the infections caused by these amoebae is the discovery of novel compounds that can effectively cross the blood-brain barrier to penetrate the CNS. It is logical to test clinically approved drugs against CNS diseases for their potential antiamoebic effects since they are known for effective blood-brain barrier penetration and affect eukaryotic cell targets. The antiamoebic effects of clinically available drugs for seizures targeting gamma-amino butyric acid (GABA) receptor and ion channels were tested against Acanthamoeba castellanii belonging to the T4 genotype and N. fowleri. Three such drugs, namely, diazepam (Valium), phenobarbitone (Luminal), phenytoin (Dilantin), and their silver nanoparticles (AgNPs) were evaluated against both trophozoites and cysts stage. Drugs alone and drug conjugated silver nanoparticles were tested for amoebicidal, cysticidal, and host-cell cytotoxicity assays. Nanoparticles were synthesized by sodium borohydride reduction of silver nitrate with drugs as capping agents. Drug conjugated nanoconjugates were characterized by ultraviolet-visible (UV-vis) and Fourier transform infrared (FT-IR) spectroscopies and atomic force microscopy (AFM). In vitro moebicidal assay showed potent amoebicidal effects for diazepam, phenobarbitone, and phenytoin-conjugated AgNPs as compared to drugs alone against A. castellanii and N. fowleri. Furthermore, both drugs and drug conjugated AgNPs showed compelling cysticidal effects. Drugs conjugations with silver nanoparticles enhanced their antiacanthamoebic activity. Interestingly, amoeba-mediated host-cell cytotoxicity was also significantly reduced by drugs alone as well as their nanoconjugates. Since, these drugs are being used to target CNS diseases, their evaluation against brain-eating amoebae seems feasible due to advantages such as permeability of the blood-brain barrier, established pharmacokinetics and dynamics, and United States Food and Drug Administration (FDA) approval. Given the limited availability of effective drugs against brain-eating amoebae, the clinically available drugs tested here present potential for further in vivo studies.
    Matched MeSH terms: Blood-Brain Barrier/parasitology; Central Nervous System Diseases/parasitology; Acanthamoeba castellanii/parasitology*; Metal Nanoparticles/parasitology
  3. Future Priorities in Tackling Infections Due to Brain-Eating Amoebae
    Khan NA, Anwar A, Siddiqui R
    ACS Chem Neurosci, 2017 11 15;8(11):2355.
    PMID: 28933530 DOI: 10.1021/acschemneuro.7b00343
    Brain-eating amoebae (Acanthamoeba spp., Balamuthia mandrillaris, and Naegleria fowleri) can cause opportunistic infections involving the central nervous system. It is troubling that the mortality rate is more than 90% despite advances in antimicrobial chemotherapy over the last few decades. Here, we describe urgent key priorities for improving outcomes from infections due to brain-eating amoebae.
    Matched MeSH terms: Opportunistic Infections/parasitology
  4. Toxoplasma gondii excretory secretory antigenic proteins of diagnostic potential
    Saadatnia G, Mohamed Z, Ghaffarifar F, Osman E, Moghadam ZK, Noordin R
    APMIS, 2012 Jan;120(1):47-55.
    PMID: 22151308 DOI: 10.1111/j.1600-0463.2011.02810.x
    Infection with Toxoplasma gondii is widespread and important in humans, especially pregnant women and immunosuppressed patients. A panel of tests is usually required for diagnosis toxoplasmosis. Excretory secretory antigen (ESA) is highly immunogenic, and thus it is a good candidate for investigation into new infection markers. ESA was prepared from tachyzoites of RH strain of T. gondii by mice intraperitoneal infection. Sera were obtained from several categories of individuals who differed in their status of anti-Toxoplasma IgM, IgG and IgG avidity antibodies. The ESA was subjected to SDS-PAGE, two-dimensional gel electrophoresis and Western blot analysis. Antigenic bands of approximate molecular weights of 12, 20 and 30 kDa, when probed with anti-human IgM-HRP and IgA-HRP, showed good potential as infection markers. The highest sensitivity of the bands was 98.7% with combination of IgM and IgA blots with sera of patients with anti-Toxoplasma IgM+ IgG+. The specificities were 84% and 70% with sera from other infections and healthy controls in IgM blots and IgA blots respectively. By mass spectrometry, the 12 kDa protein was identified as thioredoxin. The two top proteins identified for 20 kDa molecule were microneme protein 10 and dense granule protein 7; whereas that for 30 kDa were phosphoglycerate mutase 1 and phosphoglycerate mutase.
    Matched MeSH terms: Toxoplasmosis/parasitology; Pregnancy Complications, Parasitic/parasitology
  5. Role of fine needle aspiration cytology in detection of microfilariae: report of 2 cases
    Sivakumar S
    Acta Cytol., 2007 Sep-Oct;51(5):803-6.
    PMID: 17910352 DOI: 10.1159/000325846
    BACKGROUND: Filariasis is a major public health problem in developing countries, and the diagnosis is conventionally made by demonstrating microfilariae in the peripheral blood smear. However, microfilariae have been incidentally detected in fine needle aspirates of various lesions in clinically unsuspected cases of filariasis with absence of microfilariae in the peripheral blood.

    CASES: In case 1, a 21-year-old woman presented with multiple left axillary lymphadenopathy of 3 months' duration. In case 2, a 32-year-old woman presented with a thyroid nodule of 7 months' duration. Fine needle aspiration smears from both cases showed sheathed microfilariae of Wuchereria bancrofti. In both cases, microfilariae could not be demonstrated in the peripheral blood smears and the blood eosinophil counts were within normal limits. The histopathologic examination showed neither microfilariae nor adult worm.

    CONCLUSION: Although microfilariae in cytologic material are considered incidental findings, these cases illustrate the value of routine fine needle aspiration cytology in the detection of asymptomatic and clinically unsuspected cases of bancroftian filariasis. Absence of microfilariae in the peripheral blood does not exdude filarial infection.
    Matched MeSH terms: Lymph Nodes/parasitology
  6. Detection of toxoplasmosis in environmental samples at a wet market of a capital city centre
    Nimir AR, Linn TC
    Acta Medica (Hradec Kralove), 2011;54(3):107-10.
    PMID: 22250479
    The local Chow Kit market is the largest wet market in the city of Kuala Lumpur. It is very close to the biggest government hospital in the city centre. However, the level of cleanliness in this area is always questionable and a matter of concern. The aim of this study was to identify the prevalence of T. gondii oocyst in water samples used by hawkers in that market and tissue cysts in rats' brains captured from the same area. Water samples were taken to the parasitology laboratory at the National Universtiy of MalaysiaUniversity and a sugar flotation concentration method was used. Supernatant microscopical examination was then performed. A total of 752 slides were screened for the presence of T. gondii oocyst. A hundred rats wandering in the same area were also captured by the hawkers using mousetraps. After each animal was sacrificed, and an electric microtome was used to cut out serial sections 5 microm thick from the rat brains. The de-waxed tissue sections were stained by the progressive Haematoxylin and Eosin (H&E) stain for microscopical examination. A total of 1000 slides were screened under a light microscope to detect the presence of T. gondii brain cysts. All the water samples were found to be negative for T. gondii oocyst. Out of the 100 rats captured, three rats were found to possess T. gondii cysts in their brains. Water samples reflect minimal or no solid food contamination, while the 3% of positive brain cysts influence the researchers to broaden their investigations for future projects.
    Matched MeSH terms: Water/parasitology*; Food Parasitology*; Rats/parasitology
  7. Gastrointestinal parasites in rural dogs and cats in Selangor and Pahang states in Peninsular Malaysia
    Ngui R, Lee SC, Yap NJ, Tan TK, Aidil RM, Chua KH, et al.
    Acta Parasitol, 2014 Oct;59(4):737-44.
    PMID: 25236287 DOI: 10.2478/s11686-014-0306-3
    To estimate the current prevalence of gastrointestinal (GI) parasites in dogs and cats, a total of 105 fresh faecal samples were collected from rural areas in Peninsular Malaysia. Each faecal sample was examined for the presence of GI parasites by microscopic examination after formalin-ether concentration technique and for protozoa, trichrome and Ziehl-Neelsen staining were employed. The overall prevalence of GI parasitic infection was 88.6% (95% CI = 82.5-94.7) in which 88.3% of dogs and 89.3% of cats were infected with at least one parasites species, respectively. There were 14 different GI parasites species (nematodes, cestodes and protozoa) detected, including Ancylostoma spp. (62.9%), Toxocara spp. (32.4%), Trichuris vulpis (21.0%), Spirometra spp. (9.5%), Toxascaris leonina (5.7%), Dipylidium caninum (4.8%), Ascaris spp. (2.9%), Hymenolepis diminuta (1.0%) and others. General prevalence of GI parasites showed a significant difference between helminth (84.4%) and protozoa (34.3%) infections. Monoparasitism (38.1%) was less frequent than polyparasitism (46.7%). As several of these GI parasites are recognized as zoonotic agents, the results of this investigation revealed that local populations may be exposed to a broad spectrum of zoonotic agents by means of environmental contamination with dogs and cats faeces and this information should be used to mitigate public health risks. Prevention and control measures have to be taken in order to reduce the prevalence rates especially in socioeconomically disadvantaged communities where animals live in close proximity to people, poor levels of hygiene and overcrowding together with a lack in veterinary attention and zoonotic awareness.
    Matched MeSH terms: Cat Diseases/parasitology*; Dog Diseases/parasitology*; Gastrointestinal Diseases/parasitology; Helminthiasis, Animal/parasitology*
  8. New species of Bakeria (Nematoda; Strongylida; Molineidae), new species of Falcaustra (Nematoda; Ascaridida; Kathlaniidae) and other helminths in Cnemaspis mcguirei (Sauria; Gekkonidae) from Peninsular Malaysia
    Bursey CR, Goldberg SR, Grismer LL
    Acta Parasitol, 2014 Oct;59(4):643-52.
    PMID: 25236275 DOI: 10.2478/s11686-014-0299-y
    Two new nematode species, Bakeria schadi sp. nov. and Falcaustra malaysiaia sp. nov. from the gastrointestinal tract of McGuire's rock gecko, Cnemaspis mcguirei (Sauria: Gekkonidae) collected in Peninsular Malaysia are described. The two species now assigned to Bakeria are separated on the bases of male bursa type and location of the excretory pore: type II in B. schadi sp. nov. and type I in B. bakeri; location of excretory pore, anterior to nerve ring in B. schadi sp. nov. and posterior to nerve ring in B. bakeri. Falcaustra malaysiaia sp. nov. is most similar to F. chabaudi, F. concinnae, F. condorcanquii, F. barbi, F. dubia, and F. tchadi in that these 7 species possess 1 pseudosucker, 1 median papilla plus 10 pairs caudal papillae, and spicules with lengths between 1 and 2 mm. F. barbi and F. tchadi lack adcloacal papillae; the remaining 5 species possess 1 pair of adcloacal papillae. Falcaustra chabaudi is known from Nearctic salamanders; F. concinnae from Nearctic turtles; F. condorcanquii from Neotropical frogs, F. dubia from Oriental frogs, and F. malaysiaia sp. nov. from Oriental geckos. Two additional species of Nematoda were found, Cosmocerca ornata and Meteterakis singaporensis. Cnemaspis mcguirei represents a new host record for Cosmocerca ornata and Meteterakis singaporensis.
    Matched MeSH terms: Gastrointestinal Diseases/parasitology; Helminthiasis, Animal/parasitology*; Lizards/parasitology*
  9. The Morphological and Molecular Description of Acanthogyrus (Acanthosentis) fusiformis n. sp. (Acanthocephala: Quadrigyridae) from the Catfish Arius sp. (Ariidae) in the Pacific Ocean off Vietnam, with Notes on Zoogeography
    Amin OM, Chaudhary A, Heckmann RA, Ha NV, Singh HS
    Acta Parasitol, 2019 Dec;64(4):779-796.
    PMID: 31332657 DOI: 10.2478/s11686-019-00102-3
    BACKGROUND: Most (82%) of the 46 recognized species of Acanthogyrus (Acanthosentis) Verma and Datta, 1929 are known from Asian freshwater fishes. Only three species of Acanthosentis are known from marine or brackish water fishes from India and Pakistan. We have discovered another marine species of Acanthosentis in the Pacific Ocean, off Vietnam.

    PURPOSE: The purpose is to describe the new species morphologically and molecularly and provide new information of its evolutionally relationships with other species of the subgenus.

    METHODS: Standard methods of collection and examination of marine hosts, processing and illustrating of specimens, and taxonomic identification of parasites using the extensive collection of the lead author were used. Specimens were further studied using energy-dispersive X-ray analysis and ion sectioning of hooks, SEM analysis, and molecular sequencing. Type specimens were deposited at the Harold W. Manter Lab. collection, Lincoln, Nebraska.

    RESULTS: Acanthogyrus (Acanthosentis) fusiformis n. sp. is described from the catfish, Arius sp. (Ariidae: Siluriformes) off the Pacific Coast of Vietnam at Bac Lieu in the Gulf of Thailand. The three other marine Indian species include A. (A.) arii Bilqees, 1971 which is also described from a similar catfish, Arius serratus Day off the Karachi coast in the Arabian Sea, Indian Ocean. Our new species from Vietnam is distinguished from the other 46 species by a combination of characters including a small fusiform trunk, complete circles of small hollow spines covering the entire trunk, prominent double apical organs often extending posteriorly past posterior hooks, middle and posterior hooks of equal size slightly smaller than anterior hooks, large neck continuous with the outline of the proboscis without distinct separation, big drop-shaped cephalic ganglion, extension of the proboscis receptacle anteriorly past the base of the proboscis up to the insertion point of the posterior hooks, presence of two para-receptacle structures (PRSs), free unattached thick lemnisci, short female reproductive system with filamentous attachment of the distal end of the uterine bell to the ventral body wall, and small narrowly ellipsoid eggs with thickened polar ends. Partial sequences of the 18S and internal transcribed spacers (ITS1-5.8S-ITS2) of ribosomal RNA were generated and used for phylogenetic analyses to confirm the taxonomic identity of Acanthogyrus (Acanthosentis) fusiformis n. sp.

    CONCLUSIONS: We describe unique morphological features of A. fusiformis never before known in the subgenus Acanthosentis. The uniqueness of A. fusiformis is further demonstrated by its EDXA fingerprint characterized by high levels of calcium and phosphorous in hooks. The zoogeography of species of Acanthosentis is elucidated in the Indian subcontinent, the Caribbean, China, and Africa. Molecular data have been available only in few species of Acanthogyrus (Acanthosentis) to date on GenBank database. For 18S, only two sequences from unknown Acanthosentis sp. from India are available, while for the ITS1-5.8S-ITS2 region, only sequences of A. cheni from China and of two unidentified species from Malaysia are available. Additional studies of species of Acanthosentis based on morphological and molecular genetic data will be needed to reconstruct the evolutionary history and phylogenetic affinities of this group of acanthocephalans.

    Matched MeSH terms: Catfishes/parasitology*; Fish Diseases/parasitology*; Helminthiasis, Animal/parasitology*
  10. Molecular Prevalence and Epidemiology of Trypanosoma evansi Among Cattle in Peninsular Malaysia
    Ola-Fadunsin SD, Gimba FI, Abdullah DA, Abdullah FJF, Sani RA
    Acta Parasitol, 2020 Mar;65(1):165-173.
    PMID: 31797192 DOI: 10.2478/s11686-019-00150-9
    BACKGROUND: Animal trypanosomiasis (Surra) caused by Trypanosoma evansi (T. evansi) is known to be one of the important haemoprotozoan parasites that causes great economical loss on animal production due to mortality and loss of condition.

    METHODS: A cross-sectional study was designed to evaluate the prevalence and risk factors associated with T. evansi infection among cattle in Peninsular Malaysia. Polymerase chain reaction (PCR) was employed on 1045 blood samples collected from 43 farms. A well-structured questionnaire was used to collect data on risk factors associated with T. evansi prevalence. The RoTat 1.2 set of primers was used to amplify products of 205 base pair.

    RESULTS: The overall prevalence was found to be 17.9% (187/1045; 95% CI = 15.66-20.31). Trypanosoma evansi was detected among cattle in all the States of Peninsular Malaysia. Breeds of cattle and closeness to waste area, where the risk factors significantly (p 

    Matched MeSH terms: Cattle Diseases/parasitology
  11. Identification of Host Proteins Interacting with Toxoplasma gondii SAG1 by Yeast Two-Hybrid Assay
    Lai MY, Abdul-Majid N, Lau YL
    Acta Parasitol, 2019 Sep;64(3):575-581.
    PMID: 31165984 DOI: 10.2478/s11686-019-00066-4
    Toxoplasma gondii is one of the most successful human pathogens. To eliminate the infection, identification of receptors or binding partners from humans is indeed urgent. T. gondii surface antigen is the ultimate component involved during the attachment of parasite into host cell. However, mechanism of invasion between SAG and host-cell membrane remains unclear. Yeast two-hybrid experiment was used to identify the binding partners from cDNA human library by using T. gondii SAG1 as bait. Mated yeast cells were plated on DDO/X plates to confirm only prey plasmid that expressing interacting protein was selected. We detected 39 clones interacted with SAG1 based on a series of the selection procedures. After colony PCR, only 29 clones were positive and subsequently sent for sequencing. The yeast plasmids for true positive clones were rescued by transformation into E. coli TOP 10F' cells. Twenty-two clones were further examined by small-scale Y2H experiment. The results indicated that a strong interaction existed between Homo sapiens lysine-rich coil-coiled and SAG1 protein, which could activate the expressions of the reporter genes in diploid yeast. Co-immunoprecipitation experiment result indicated the binding between this prey and SAG1 protein was significant (Mann-Whitney U test, Z = - 1.964, P = 0.05). H. sapiens lysine-rich coil-coiled protein was found to be interacted with SAG1. This prey protein may serve as the potential drug target in vaccination study.
    Matched MeSH terms: Toxoplasmosis/parasitology
  12. Genetic characterization of the partial mitochondrial cytochrome oxidase c subunit I (cox 1) gene of the zoonotic parasitic nematode, Ancylostoma ceylanicum from humans, dogs and cats
    Ngui R, Mahdy MA, Chua KH, Traub R, Lim YA
    Acta Trop, 2013 Oct;128(1):154-7.
    PMID: 23774318 DOI: 10.1016/j.actatropica.2013.06.003
    Ancylostoma ceylanicum is the only zoonotic hookworm species that is able to produce patent infections in humans with the majority of cases reported in South East Asia. Over the past few years, there have been an increasing number of studies investigating the prevalence of this parasitic zoonosis using molecular diagnostic tools and a single genetic locus as marker for species identification. As there can be limitations in using a single genetic locus for epidemiological studies and genetic discrimination, the complementary use of a more variable locus will provide additional evidence to support the zoonotic exchange of hookworm species between humans and animals. In the present study, the cytochrome c oxidase subunit 1 (cox 1) sequence of A. ceylanicum from positive human and animal fecal samples were determined and compared with published reference sequences. Phylogenetic analysis demonstrated that isolates of A. ceylanicum were divided into two clusters, one consisting 3 human isolates and the other comprising 19 isolates of human and animal origin from different geographical locations within Malaysia. The two groups of A. ceylanicum could be distinguished from one another through five fixed nucleotide differences at locations 891, 966, 1008, 1077 and 1083. The detection of genetically distinct groups and considerable level of genetic variation within the cox 1 sequence of A. ceylanicum might suggest potential haplotype-linked differences in zoonotic, epidemiological and pathobiological characteristics, a hypothesis that still needs further investigation.
    Matched MeSH terms: Ancylostomiasis/parasitology*
  13. Plasmodium knowlesi: the emerging zoonotic malaria parasite
    Antinori S, Galimberti L, Milazzo L, Corbellino M
    Acta Trop, 2013 Feb;125(2):191-201.
    PMID: 23088834 DOI: 10.1016/j.actatropica.2012.10.008
    Plasmodium knowlesi was initially identified in the 30s as a natural Plasmodium of Macaca fascicularis monkey also capable of experimentally infecting humans. It gained a relative notoriety in the mid-30s as an alternative to Plasmodium vivax in the treatment of the general paralysis of the insane (neurosyphilis). In 1965 the first natural human infection was described in a US military surveyor coming back from the Pahang jungle of the Malaysian peninsula. P. knowlesi was again brought to the attention of the medical community when in 2004, Balbir Singh and his co-workers reported that about 58% of malaria cases observed in the Kapit district of the Malaysian Borneo were actually caused by P. knowlesi. In the following years several reports showed that P. knowlesi is much more widespread than initially thought with cases reported across Southeast Asia. This infection should also be considered in the differential diagnosis of any febrile travellers coming back from a recent travel to forested areas of Southeast Asia. P. knowlesi can cause severe malaria with a rate of 6-9% and with a case fatality rate of 3%. Respiratory distress, acute renal failure, shock and hyperbilirubinemia are the most frequently observed complications of severe P. knowlesi malaria. Chloroquine is considered the treatment of choice of uncomplicated malaria caused by P. knowlesi.
    Matched MeSH terms: Anopheles/parasitology; Insect Vectors/parasitology*; Malaria/parasitology*; Thrombocytopenia/parasitology; Zoonoses/parasitology*; Communicable Diseases, Emerging/parasitology
  14. Giardia intestinalis genotypes: Risk factors and correlation with clinical symptoms
    Mohammed Mahdy AK, Surin J, Wan KL, Mohd-Adnan A, Al-Mekhlafi MS, Lim YA
    Acta Trop, 2009 Oct;112(1):67-70.
    PMID: 19560431 DOI: 10.1016/j.actatropica.2009.06.012
    This study was conducted to identify genotypes related risk factors of Giardia intestinalis in an Orang Asli (aboriginal) community in Pahang, Malaysia. Stool samples were collected from 321 individuals aged between 2 and 76 years old, of whom 160 were males and 161 were females. Faecal samples were processed with trichrome staining technique for the primary identification of G. intestinalis. Molecular identification was carried out by the amplification of a partial SSU rRNA gene using nested PCR. PCR products were purified and genotyped. 42 samples successfully amplified from the 76 positive faecal samples, only 1 was Assemblage A, the rest were Assemblage B. Risk analysis based on the detected genotypes of Giardia using univariate analysis and logistic regression identified three significant risk factors of giardiasis caused by assemblage B which included children =12 years (OR=13.56, 95% CI=1.79-102.64, p=0.012), females (OR=2.52, 95% CI=1.11-5.75, p=0.027) and eating fresh fruits (OR=7.78, 95% CI=1.01-60.00, p=0.049). Assemblage B infection was significantly correlated with clinical symptoms of giardiasis (OR=2.4, 95% CI=1.13-5.12, p=0.019). Females infected with Assemblage B were at higher risk of manifesting gastroenteritis signs and symptoms (OR=3.9, 95% CI=1.50-10.31, p=0.004). It has been concluded that giardiasis is still a public health problem in Orang Asli community and most commonly caused by assemblage B. The dynamic of transmission is most probably anthroponotic which is human to human either directly or indirectly through contaminated food. This route of transmission should be considered in the control strategy of the disease. Mass treatment together with health education could be the most practical intervention for reducing the infection. Those at high risk should receive more attention from public health authorities.
    Matched MeSH terms: Feces/parasitology; Giardiasis/parasitology*
  15. Pattern and predictors of soil-transmitted helminth reinfection among aboriginal schoolchildren in rural Peninsular Malaysia
    Hesham Al-Mekhlafi M, Surin J, Atiya AS, Ariffin WA, Mohammed Mahdy AK, Che Abdullah H
    Acta Trop, 2008 Aug;107(2):200-4.
    PMID: 18582430 DOI: 10.1016/j.actatropica.2008.05.022
    Data on soil-transmitted helminth (STH) infections and reinfection among Orang Asli (aborigine) schoolchildren and their nutritional and socioeconomic status were analyzed to investigate the pattern and the possible predictors of STH reinfection. In this longitudinal study, 120 (60 males and 60 females) Orang Asli primary schoolchildren aged 7-12 years and living in remote areas in Pos Betau, Kuala Lipis, Pahang were screened for the presence of STH using modified cellophane thick smear and Harada Mori techniques. The overall prevalence of ascariasis, trichuriasis and hookworm infections were 65.8, 97.5 and 10.8%, respectively. After complete deworming with a 3-day course of 400mg/daily of albendazole tablets, children were re-examined at 3 and 6 months from baseline. The reinfection rate, by one or more of STH species, at 3 months after deworming was high (49.5%) while 79.6% of the children were reinfected at 6 months after deworming. Logistic regression analyses showed that females, stunted children and those living in houses without toilets had significantly higher reinfection rates than others at 3 months (P<0.05). At 6 months, maternal employment status emerged as another predictor where children of working mothers had significantly higher reinfection rates (P=0.026). In conclusion, reinfection rate of STH is high and thus necessitates frequent and periodic deworming among children. Public health personnel need to re-look at the current control measures and identify innovative and integrated ways in order to reduce STH significantly in the rural communities.
    Matched MeSH terms: Ascariasis/parasitology; Feces/parasitology; Helminthiasis/parasitology; Hookworm Infections/parasitology; Soil/parasitology*; Trichuriasis/parasitology
  16. Comparison of IgG-ELISA and IgG4-ELISA for Toxocara serodiagnosis
    Noordin R, Smith HV, Mohamad S, Maizels RM, Fong MY
    Acta Trop, 2005 Jan;93(1):57-62.
    PMID: 15589798
    Diagnosis of human toxocariasis, caused by Toxocara canis or Toxocara cati, normally relies on a combination of the presence of clinical signs and symptoms backed by positive serology. The use of Toxocara excretory-secretory antigen (TES) in ELISA assays increases the test specificity. However, in tropical countries where soil-transmitted helminths are endemic, cross-reactivity from antibodies to these intestinal parasites poses a significant limitation for Toxocara serodiagnosis. To increase the specificity of serodiagnosis, we compared the use of IgG-ELISA to the use of IgG4-ELISA using commercially manufactured TES-coated plates. The sensitivity of the IgG-ELISA was 97.1%, while that of the IgG4-ELISA was 45.7%; the specificities were 36.0 and 78.6%, respectively. The study shows that employing both assays can improve the serodiagnosis of toxocariasis. An IgG4 immunoassay would also be useful in the secondary screening of antigen clones in the effort to develop improved serological tests for toxocariasis.
    Matched MeSH terms: Toxocariasis/parasitology
  17. The prevalence and intensity of Amblyomma javanense infestation on Malayan pangolins (Manis javanica Desmarest) from Peninsular Malaysia
    Hassan M, Sulaiman MH, Lian CJ
    Acta Trop, 2013 May;126(2):142-5.
    PMID: 23416121 DOI: 10.1016/j.actatropica.2013.02.001
    A parasitological survey of 16 pangolins, confiscated from the Department of Wildlife and Nature Park Peninsular Malaysia (DWNP) at Kelantan and Pulau Pinang, Malaysia was conducted in 2011. Amblyomma javanense (family: Ixodidae) was the only ectoparasite found on the pangolins. The prevalence, intensity and life cycle of A. javanense were observed together with the respective pangolins' age and sex. It was found that 68.8% of the pangolins were infected, and significant difference, χ(2)(1, N=16)=4.02, p=0.05 were observed with males higher in infestation (88.9%) as compared to the females (42.9%). However, the mean intensity was higher on females (72) as compared to males (31.6). In addition, significant difference, χ(2) (2, N=16)=6.73, p=0.05 was recorded between adults and juveniles with juveniles found to be 100% infected as compared to adult (63.6%). Nevertheless, the mean intensity was slightly higher on adults (47) than juveniles (35). Adult ticks were found in higher numbers as compared to the nymph and larvae with number of male ticks higher (236) as compared to the females (53). Similarly, a high significant difference χ(2)(2, N=469)=203.47, p=0.05 was recorded in the composition of the tick's life stages with a higher number of adult ticks (61.6%) followed by nymph (30.3%) and larvae (8.1%). As such, the results of this study revealed a picture of the A. javanense life cycle which is related to the age and gender of the Malayan Pangolin.
    Matched MeSH terms: Mammals/parasitology*; Tick Infestations/parasitology
  18. The impact of development and malaria control activities on its vectors in the Kinabatangan area of Sabah, East Malaysia
    Vythilingam I, Chan ST, Shanmugratnam C, Tanrang H, Chooi KH
    Acta Trop, 2005 Oct;96(1):24-30.
    PMID: 16076459
    A study was carried out from July 2001 until January 2003 in the Kinabatangan area of Sabah, part of Borneo island, where malaria used to be mesoendemic. Vector surveys determined that Plasmodium falciparum was the predominant species and Anopheles balabacensis the primary vector. Malaria cases have dropped drastically over the years but P. falciparum is still predominant. In the present study, Anopheles donaldi was the predominant species and was positive for sporozoites. Although An. balabacensis was present, none were infective. An. donaldi bite more outdoors than indoors and have a peak biting time from 18:00 to 19:00 h when most people are still out of their homes. An integrated malaria control programme along with area development has helped in the control of malaria and its vector.
    Matched MeSH terms: Anopheles/parasitology*
  19. Survey of chloroquine-resistant mutations in the Plasmodium falciparum pfcrt and pfmdr-1 genes in Hadhramout, Yemen
    Bamaga OA, Mahdy MA, Lim YA
    Acta Trop, 2015 Sep;149:59-63.
    PMID: 26001972 DOI: 10.1016/j.actatropica.2015.05.013
    Malaria is still a major public health problem in Yemen. More than 95% of the malaria cases are due to Plasmodium ‎falciparum‎. Recently in Yemen, the antimalarial treatment policy was changed from chloroquine (CQ) to artemisinin combination therapy (ACTs). However, CQ is still available and prescribed in the Yemeni market. The persistence of CQ resistance will be prolonged if the shift to ACT and the simultaneous withdrawal of CQ are not rigorously implemented. The aim of the current survey is to detect chloroquine-resistant mutations in P. falciparum chloroquine-resistance transporter (pfcrt) and P. falciparum multi-drug resistance-1 (pfmdr1) genes. These data will be important for future monitoring and assessment of antimalarial drug policy in Yemen. Blood specimens were collected from 735 individuals from different districts of the Hadhramout province, Yemen by house-to-house visit. Mutation-specific nested polymerase chain reaction (PCR) and restriction fragment length polymorphism (PCR-RFLP) methods were used to investigate the mutations in the pfmdr1(codons 86 and 1246) and pfcrt (codons 76, 271, 326, 356 and 371) genes. The overall prevalence of pfcrt mutations at codons 76, 271, 326 and 371 were 50.4%, 58.7%, 54.3% and 44.9%, respectively. All isolates had wild-type pfcrt 356 allele. The majority of pfmdr1 86 alleles (83.3%) and all pfmdr1 1246 alleles were wild type. There was no association between pfcrt mutations and symptomatology, gender and age groups. In conclusion, point mutations in codons 76, 271, 326 and 371 of pfcrt of P. falciparum are high suggesting a sustained high CQ resistance even after 4 years of shifting to ACTs. These findings warrant complete withdrawal of CQ use from the Yemeni market for P. falciparum and careful usage of CQ for treating Plasmodium vivax.
    Matched MeSH terms: Malaria, Falciparum/parasitology*
  20. Draft genome of neurotropic nematode parasite Angiostrongylus cantonensis, causative agent of human eosinophilic meningitis
    Yong HS, Eamsobhana P, Lim PE, Razali R, Aziz FA, Rosli NS, et al.
    Acta Trop, 2015 Aug;148:51-7.
    PMID: 25910624 DOI: 10.1016/j.actatropica.2015.04.012
    Angiostrongylus cantonensis is a bursate nematode parasite that causes eosinophilic meningitis (or meningoencephalitis) in humans in many parts of the world. The genomic data from A. cantonensis will form a useful resource for comparative genomic and chemogenomic studies to aid the development of diagnostics and therapeutics. We have sequenced, assembled and annotated the genome of A. cantonensis. The genome size is estimated to be ∼260 Mb, with 17,280 genomic scaffolds, 91X coverage, 81.45% for complete and 93.95% for partial score based on CEGMA analysis of genome completeness. The number of predicted genes of ≥300 bp was 17,482. A total of 7737 predicted protein-coding genes of ≥50 amino acids were identified in the assembled genome. Among the proteins of known function, kinases are the most abundant followed by transferases. The draft genome contains 34 excretory-secretory proteins (ES), a minimum of 44 Nematode Astacin (NAS) metalloproteases, 12 Homeobox (HOX) genes, and 30 neurotransmitters. The assembled genome size (260 Mb) is larger than those of Pristionchus pacificus, Caenorhabditis elegans, Necator americanus, Caenorhabditis briggsae, Trichinella spiralis, Brugia malayi and Loa loa, but smaller than Haemonchus contortus and Ascaris suum. The repeat content (25%) is similar to H. contortus. The GC content (41.17%) is lower compared to P. pacificus (42.7%) and H. contortus (43.1%) but higher compared to C. briggsae (37.69%), A. suum (37.9%) and N. americanus (40.2%) while the scaffold N50 is 42,191. This draft genome will facilitate the understanding of many unresolved issues on the parasite and the disorder it causes.
    Matched MeSH terms: Eosinophilia/parasitology*; Meningoencephalitis/parasitology*
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