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Fulltext Zoonotic Ancylostoma ceylanicum infection detected by endoscopy

Ngui R, Lim YA, Ismail WH, Lim KN, Mahmud R

Am J Trop Med Hyg, 2014 Jul;91(1):86-8.
PMID: 24891471 DOI: 10.4269/ajtmh.13-0756

We report a case of Ancylostoma ceylanicum infection detected by endoscopy. It was diagnosed and confirmed using polymerase chain reaction (PCR) and DNA sequencing. The patient is a 58-year-old Malaysian woman who lives in a rural area, where uncontrolled populations of stray and semidomesticated dogs live in close proximity with humans.

Matched MeSH terms: Ancylostoma/isolation & purification*
Repeat endoscopy for recurrent iron deficiency anemia: an (un)expected finding from southeast Asia

Mahadeva S, Qua CS, Yusoff W, Sulaiman W

Dig Dis Sci, 2007 Feb;52(2):523-5.
PMID: 17219070
Matched MeSH terms: Ancylostoma/isolation & purification*
Fulltext Rapid detection and identification of human hookworm infections through high resolution melting (HRM) analysis

Ngui R, Lim YA, Chua KH

PLoS One, 2012;7(7):e41996.
PMID: 22844538 DOI: 10.1371/journal.pone.0041996

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.

Matched MeSH terms: Ancylostoma/isolation & purification
Fulltext Epidemiological surveys of, and research on, soil-transmitted helminths in Southeast Asia: a systematic review

Dunn JC, Turner HC, Tun A, Anderson RM

Parasit Vectors, 2016 Jan 27;9:31.
PMID: 26813007 DOI: 10.1186/s13071-016-1310-2

Soil-transmitted helminth (STH) infections of humans fall within the World Health Organization's (WHO) grouping termed the neglected tropical diseases (NTDs). It is estimated that they affect approximately 1.4 billion people worldwide. A significant proportion of these infections are in the population of Southeast Asia. This review analyses published data on STH prevalence and intensity in Southeast Asia over the time period of 1900 to the present to describe age related patterns in these epidemiological measures. This is with a focus on the four major parasite species affecting humans; namely Ascaris lumbricoides, Trichuris trichiura and the hookworms; Necator americanus and Ancylostoma duodenale. Data were also collected on the diagnostic methods used in the published surveys and how the studies were designed to facilitate comparative analyses of recorded patterns and changes therein over time. PubMed, Google Scholar, EMBASE, ISI Web of Science, Cochrane Database of Systematic Reviews and the Global Atlas of Helminth Infections search engines were used to identify studies on STH in Southeast Asia with the search based on the major key words, and variants on, "soil-transmitted helminth" "Ascaris" "Trichuris" "hookworm" and the country name. A total of 280 studies satisfied the inclusion criteria from 11 Southeast Asian countries; Brunei, Cambodia, Indonesia, Lao People's Democratic Republic (Lao PDR), Malaysia, Myanmar, Philippines, Singapore, Thailand, Timor-Leste and Vietnam. It was concluded that the epidemiological patterns of STH infection by age and species mix in Southeast Asia are similar to those reported in other parts of the world. In the published studies there were a large number of different diagnostic methods used with differing sensitivities and specificities, which makes comparison of the results both within and between countries difficult. There is a clear requirement to standardise the methods of both STH diagnosis in faecal material and how the intensity of infection is recorded and reported in future STH research and in monitoring and evaluation (M&E) of the impact of continuing and expanding mass drug administration (MDA) programmes.

Matched MeSH terms: Ancylostoma/isolation & purification
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: Ancylostoma/isolation & purification
Fulltext Epidemiological and genetic data supporting the transmission of Ancylostoma ceylanicum among human and domestic animals

Ngui R, Lim YA, Traub R, Mahmud R, Mistam MS

PLoS Negl Trop Dis, 2012;6(2):e1522.
PMID: 22347515 DOI: 10.1371/journal.pntd.0001522

BACKGROUND: Currently, 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/FINDINGS: A 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.
CONCLUSION: This 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.

Matched MeSH terms: Ancylostoma/isolation & purification*
Levels of Ancylostoma infections and phylogenetic analysis of cox 1 gene of A. ceylanicum in stray cat faecal samples from Guangzhou, China

Hu W, Yu XG, Wu S, Tan LP, Song MR, Abdulahi AY, et al.

J Helminthol, 2016 Jul;90(4):392-7.
PMID: 26123649 DOI: 10.1017/S0022149X15000413

Ancylostoma ceylanicum is a common zoonotic nematode. Cats act as natural reservoirs of the hookworm and are involved in transmitting infection to humans, thus posing a potential risk to public health. The prevalence of feline A. ceylanicum in Guangzhou (South China) was surveyed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). In total, 112 faecal samples were examined; 34.8% (39/112) and 43.8% (49/112) samples were positive with hookworms by microscopy and PCR method, respectively. Among them, 40.8% of samples harboured A. ceylanicum. Twelve positive A. ceylanicum samples were selected randomly and used for cox 1 sequence analysis. Sequencing results revealed that they had 97-99% similarity with A. ceylanicum cox 1 gene sequences deposited in GenBank. A phylogenetic tree showed that A. ceylanicum isolates were divided into two groups: one comprising four isolates from Guangzhou (South China), and the other comprising those from Malaysia, Cambodia and Guangzhou. In the latter group, all A. ceylanicum isolates from Guangzhou were clustered into a minor group again. The results indicate that the high prevalence of A. ceylanicum in stray cats in South China poses a potential risk of hookworm transmission from pet cats to humans, and that A. ceylanicum may be a species complex worldwide.

Matched MeSH terms: Ancylostoma/isolation & purification
Fulltext Molecular identification of human hookworm infections in economically disadvantaged communities in Peninsular Malaysia

Ngui R, Ching LS, Kai TT, Roslan MA, Lim YA

Am J Trop Med Hyg, 2012 May;86(5):837-42.
PMID: 22556084 DOI: 10.4269/ajtmh.2012.11-0446

Species identification of human hookworm infections among eight communities in rural areas of Peninsular Malaysia was determined during 2009-2011. Fecal samples were examined by microscopy and subsequently, the internal transcribed spacer 2 and 28S ribosomal RNA region of Necator americanus and Ancylostoma spp. were sequenced. Overall, 9.1% (58 of 634) were identified positive by microscopy for hookworm infection, and 47 (81.0%) of 58 were successfully amplified and sequenced. Sequence comparison found that N. americanus (87.2%) was the most predominant hookworm identified, followed by Ancylostoma ceylanicum (23.4%). No A. duodenale infection was detected in this study. Detection of A. ceylanicum in humans highlighted the zoonotic transmission among humans living near dogs. Thus, implementation of effective control measures for hookworm infections in future should seriously consider this zoonotic implication.

Matched MeSH terms: Ancylostoma/isolation & purification