Molecular Identification of Human Hookworm Infections in Economically Disadvantaged Communities in Peninsular Malaysia

Ngui, Romano; Lee, Soo Ching; Kai, Tan; Roslan, Muhammad Aidil; Lim, Yvonne A. L.

doi:10.4269/ajtmh.2012.11-0446

Cited by 41 publications

(40 citation statements)

References 29 publications

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“…Prevalence of other intestinal parasites detected in these humans were as reported in our previous study [26]. As for domestic carnivores, Toxocara canis infection (33/105, 31.4%) was the highest, followed by Trichuris vulpis (21/105, 19.7%), Entamoeba spp.…”

Section: Resultssupporting

confidence: 84%

Epidemiological and Genetic Data Supporting the Transmission of Ancylostoma ceylanicum among Human and Domestic Animals

et al. 2012

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BackgroundCurrently, information on species-specific hookworm infection is unavailable in Malaysia and is restricted worldwide due to limited application of molecular diagnostic tools. Given the importance of accurate identification of hookworms, this study was conducted as part of an ongoing molecular epidemiological investigation aimed at providing the first documented data on species-specific hookworm infection, associated risk factors and the role of domestic animals as reservoirs for hookworm infections in endemic communities of Malaysia.Methods/FindingsA total of 634 human and 105 domestic canine and feline fecal samples were randomly collected. The overall prevalence of hookworm in humans and animals determined via microscopy was 9.1% (95% CI = 7.0–11.7%) and 61.9% (95% CI = 51.2–71.2%), respectively. Multivariate analysis indicated that participants without the provision of proper latrine systems (OR = 3.5; 95% CI = 1.53–8.00; p = 0.003), walking barefooted (OR = 5.6; 95% CI = 2.91–10.73; p<0.001) and in close contact with pets or livestock (OR = 2.9; 95% CI = 1.19–7.15; p = 0.009) were more likely to be infected with hookworms. Molecular analysis revealed that while most hookworm-positive individuals were infected with Necator americanus, Ancylostoma ceylanicum constituted 12.8% of single infections and 10.6% mixed infections with N. americanus. As for cats and dogs, 52.0% were positive for A. ceylanicum, 46.0% for Ancylostoma caninum and 2.0% for Ancylostoma braziliense and all were single infections.ConclusionThis present study provided evidence based on the combination of epidemiological, conventional diagnostic and molecular tools that A. ceylanicum infection is common and that its transmission dynamic in endemic areas in Malaysia is heightened by the close contact of human and domestic animal (i.e., dogs and cats) populations.

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Section: Resultssupporting

confidence: 84%

Epidemiological and Genetic Data Supporting the Transmission of Ancylostoma ceylanicum among Human and Domestic Animals

et al. 2012

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“…The results obtained were compared to iodine stained direct smear and conventional semi-nested PCR as reported previously [2], [34]. The study protocol (MEC Ref.…”

Section: Methodsmentioning

confidence: 99%

Rapid Detection and Identification of Human Hookworm Infections through High Resolution Melting (HRM) Analysis

2012

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Background Hookworm infections are still endemic in low and middle income tropical countries with greater impact on the socioeconomic and public health of the bottom billion of the world's poorest people. In this study, a real-time polymerase chain reaction (PCR) coupled with high resolution melting-curve (HRM) analysis was evaluated for an accurate, rapid and sensitive tool for species identification focusing on the five human hookworm species. Methods Real-time PCR coupled with HRM analysis targeting the second internal transcribed spacer (ITS-2) of nuclear ribosomal DNA as the genetic marker was used to identify and distinguish hookworm species in human samples. Unique and distinct characteristics of HRM patterns were produced for each of the five hookworm species. The melting curves were characterized by peaks of 79.24±0.05°C and 83.00±0.04°C for Necator americanus , 79.12±0.10°C for Ancylostoma duodenale , 79.40±0.10°C for Ancylostoma ceylanicum , 79.63±0.05°C for Ancylostoma caninum and 79.70±0.14°C for Ancylostoma braziliense . An evaluation of the method's sensitivity and specificity revealed that this assay was able to detect as low as 0.01 ng/µl hookworm DNA and amplification was only recorded for hookworm positive samples. Conclusion The HRM assay developed in this study is a rapid and straightforward method for the diagnosis, identification and discrimination of five human hookworms. This assay is simple compared to other probe-based genotyping methods as it does not require multiplexing, DNA sequencing or post-PCR processing. Therefore, this method offers a new alternative for rapid detection of human hookworm species.

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“…These findings confirmed the previous epidemiological survey indicating that individuals who had close contact with dogs were more likely to be infected with A. ceylanicum. [33][34][35] Although the notion of zoonotic transmission of A. lumbricoides and T. trichiura between humans and dogs is still largely unclear, these animals may act as significant mechanical transmitter of ascariasis in the human population especially in communities where the habit of indiscriminate defecation exist. Molecular-based tool studies have shown that dogs act as disseminators and environmental contaminators of A. lumbricoides in communities where indiscriminate defecation is common.…”

Section: Discussionmentioning

confidence: 99%

“…33,34 Moreover, more studies are reporting on the zoonotic ancylostomiasis caused by A. ceylanicum in humans in endemic areas in Southeast Asia. 23,[34][35][36] A recent genetic study to provide further evidence on zoonotic transmission of A. ceylanicum between humans and animals in Malaysia showed that some of the A. ceylanicum strains from both the human and animal host in the same geographical location are clustered together within the same group. 37 This provides evidence that dogs and humans share genetically similar genotypes of A. ceylanicum within the same geographical location.…”

Section: Discussionmentioning

confidence: 99%

Patterns and Risk Factors of Soil-Transmitted Helminthiasis Among Orang Asli Subgroups in Peninsular Malaysia

Ngui¹,

Shafie²,

Chua³

et al. 2015

The American Society of Tropical Medicine and Hygiene

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Abstract. A cross-sectional study was conducted to provide comprehensive data on the patterns and associated risk factors of soil-transmitted helminth (STH) infections among five Orang Asli subgroups in Peninsular Malaysia. The overall prevalence of STH infections was 59.9% (95% confidence interval [CI] = 56.1-63.7%). Trichuris trichiura (54.3%; 95% CI = 50.4-58.2%) was the predominant species followed by Ascaris lumbricoides (26.7%; 95% CI = 23.3-30.1%) and hookworm (9.1%; 95% CI = 6.9-11.3%). This study showed diversity for STH infections by subgroup with poverty and personal sanitary behavior as important risk factors for infection. Risk profile analyses indicating that Orang Kuala subgroup who has a generally well-developed infrastructure and better quality of life had a low rate of infection. There is a need for poverty reduction and promotion of deworming programs along with mass scale campaigns to create awareness about health and hygiene to reduce STH infections.

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Molecular Identification of Human Hookworm Infections in Economically Disadvantaged Communities in Peninsular Malaysia

Cited by 41 publications

References 29 publications

Epidemiological and Genetic Data Supporting the Transmission of Ancylostoma ceylanicum among Human and Domestic Animals

Epidemiological and Genetic Data Supporting the Transmission of Ancylostoma ceylanicum among Human and Domestic Animals

Rapid Detection and Identification of Human Hookworm Infections through High Resolution Melting (HRM) Analysis

Patterns and Risk Factors of Soil-Transmitted Helminthiasis Among Orang Asli Subgroups in Peninsular Malaysia

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