We report here for the first time horsehair worms (Nematomorpha) from Hong Kong (China). Most specimens belong to the genus Chordodes, and can be assigned to C. bipilus, C. caledoniensis and to C. cf. moutoni. Two specimens have a cuticular pattern resembling the South American species C. peraccae or C. bouvieri, but for Southeast Asia this pattern is new. These two specimens are reported here as Chordodes sp. Additionally, Gordionus chinensis was found. One new species, Acutogordius koljai, is described from Malaysia. It has a characteristically-structured region posterior to the postcloacal crescent which sets it apart from previously described species in this genus.
A second case of a gordian worm (hairworm) "parasitic" in man is recorded from Malaya. A previous literature is critically discussed especially in regard to the mode of human infection. It is suggested that water-borne larvae reach the gut, invade the tissues and are finally voided with the faeces or passed with urine. Other modes of infection are considered less likely by the authors.
Soil-transmitted intestinal worms known as helminths colonize over 1.5 billion people worldwide. Although helminth colonization has been associated with altered composition of the gut microbiota, such as increases in Clostridia, individual species have not been isolated and characterized. Here, we isolate and sequence the genome of 13 Clostridia from the Orang Asli, an indigenous population in Malaysia with a high prevalence of helminth infections. Metagenomic analysis of 650 fecal samples from urban and rural Malaysians confirm the prevalence of species corresponding to these isolates and reveal a specific association between Peptostreptococcaceae family members and helminth colonization. Remarkably, Peptostreptococcaceae isolated from the Orang Asli display superior capacity to promote the life cycle of whipworm species, including hatching of eggs from Trichuris muris and Trichuris trichiura. These findings support a model in which helminths select for gut colonization of microbes that support their life cycle.
A helminthological examination of 367 wood rats, Rattus tiomanicus, in an oil-palm. estate 24 miles north of Kuala Lumpur conducted during 1973 revealed 8 species of helminths: 5 nematodes. Angiostrongylus malaysiensis (54.2% of the rats infected), Hepatojarakus malayae (48.5%), Nippostrongylus braziliensis (48.0%), Gongylonema neoplasticum (0.3%), Syphacia muris (17.7%); 3 cestodes, Hymenolepis diminuta (6.0%), Hymenolepis nana (7.6%), Hydatigera taeniaeformis (cysticercus) (12.0%) and 1 pentastomid, Armillifer sp. (nymph) (0.8%). Overall helminthic infection rates seemed to be higher than those previously reported in this host species.
The above survey based on a study of single stool specimens from 569 patients, drawn from a hospital population belonging to different ethnic groups and having different cultural backgrounds, failed to indicate an association between intestinal helminth infection and eosinophilic lung. The higher prevalence of eosinophilic lung in Indians than in the other ethnic groups, as reported previously, cannot be explained on a basis of differences in the prevalence of the intestinal helminths, Ascaris lumbricoides, hookworm, Trichuris trichiura and Strongyloides stercoralis.
Orang Asli, the indigenous people of Peninsular Malaysia, is a minority population and placed behind in terms of socioeconomy, education and health. The Malaysian government has supported Orang Asli since the second Malaysia Plan in the 1970s, resulting in changes in their living standard, access to health, education and occupation. Hence, this review aims to assess the recent prevalence of diseases among Orang Asli in Peninsular Malaysia. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) review protocol guided this systematic review. The research question was formulated based on Population, Interest, Comparison and Outcome (PICO). The selected databases include Web of Science, Scopus, Ovid and EBSCOhost. The process of identification, screening and inclusion identified 33 articles. The mixed methods appraisal tool (MMAT) was then used to rank the quality of the articles. Selangor is the most frequent state involved in this review (12 studies), followed by Perak (10 studies), Pahang (10 studies) and Kedah (one study). We categorised into four categories of diseases, namely neglected tropical disease (n = 20), non-communicable disease (n = 6), nutritional status (n = 5), and hepatic disease (n = 2). The prevalence of diseases among Orang Asli is higher than in the general population, especially for soil-transmitted helminth (STH) and malnutrition. There is increasing research on non-communicable diseases due to an increasing trend in the socioeconomic status and lifestyle of the Orang Asli. Government agencies and private organisations must work together to empower Orang Asli with a healthy lifestyle, improve their socioeconomic status, and enhance food security, all of which will improve Orang Asli's health and reduce the prevalence of diseases.
Many species of helminths and protozoa caused intestinal parasitic infections (IPIs). It belongs to neglected tropical diseases (NTDs) and remains a major public health problem in several Southeast Asian countries. The present study aimed to investigate the prevalence of IPIs and associated risk factors among the population in Kratie Province in northeastern Cambodia and Phnom Penh is the capital that locates in southern Cambodia. Fecal specimens (n=366) were collected in 10 villages in Kratie Province and Phnom Penh from 2019 to 2021. They were processed using the formalin ethyl-acetate concentration technique (FECT) to investigate parasites at egg and cyst stages and then examined under a light microscope. The results revealed that the prevalence of IPIs among the population in Kratie Province (n=317) and Phnom Penh (n=49) was 16.12% (n=59); of Kratie Province (n=50, 13.66%) and Phnom Penh (n=9, 2.46%), 12.02% (n=44) were helminths and 4.10% (n=15) were protozoa. The parasitic infection rate was higher in males (9.02%) than in females (7.10%) and more likely to be due to helminths (7.38%) than protozoa (1.64%). Prevalence of Opisthorchis viverrini was the highest (5.74%), followed by those of Entamoeba coli (4.10%), hookworm (3.83%), Ascaris lumbricoides (1.10%), Hymenolepis nana (1.09%), Taenia spp. (0.54%), Trichuris trichiura (0.55%), and Enterobius vermicularis (0.27%), respectively. Moreover, O. viverrini infection was the most common infection in the <20-year age group in Kratie Province. In addition, the bivariate and multivariate analyses showed that the association between gender. Gender was a significant risk factor positively associated with O. viverrini and hookworm infections (ORadj=0.318, 95% CI=0.122-0.8270, P=0.019 and ORadj=0.085, 95% CI=0.017-0.436, P=0.003, respectively). In conclusion, the IPIs were highly prevalent, especially O. viverrini and hookworm infections, among the population in Cambodia. These IPIs impact the public health burden but can be prevented by education regarding good sanitary practices in this community.
Much effort has been devoted by the World Health Organization (WHO) to eliminate soil-transmitted helminth (STH) infections by 2030 using mass drug administration targeted at particular risk groups alongside the availability to access water, sanitation and hygiene services. The targets set by the WHO for the control of helminth infections are typically defined in terms of the prevalence of infection, whereas the standard formulation of STH transmission models typically describe dynamic changes in the mean-worm burden. We develop a prevalence-based deterministic model to investigate the transmission dynamics of soil-transmitted helminthiasis in humans, subject to continuous exposure to infection over time. We analytically determine local stability criteria for all equilibria and find bifurcation points. Our model predicts that STH infection will either be eliminated (if the initial prevalence value, y(0), is sufficiently small) or remain endemic (if y(0) is sufficiently large), with the two stable points of endemic infection and parasite eradication separated by a transmission breakpoint. Two special cases of the model are analysed: (1) the distribution of the STH parasites in the host population is highly aggregated following a negative binomial distribution, and (2) no density-dependent effects act on the parasite population. We find that disease extinction is always possible for Case (1), but it is not so for Case (2) if y(0) is sufficiently large. However, by introducing stochastic perturbation into the deterministic model, we discover that chance effects can lead to outcomes not predicted by the deterministic model alone, with outcomes highly dependent on the degree of worm clumping, k. Specifically, we show that if the reproduction number and clumping are sufficiently bounded, then stochasticity will cause the parasite to die out. It follows that control of soil-transmitted helminths will be more difficult if the worm distribution tends towards clumping.
The currently known diversity of horsehair worms (Nematomorpha) from India is only 17 species. We report here two female specimens found on two occasions on a terrace paddy field in Tsupo, Viswema, Kohima, Nagaland, India. Although found at the same location, both species differ in their cuticular structures. One is determined as Chordodes moutoni, a species known from China, Malaysia and India. The other specimen shows a new type of cuticular structure, the areoles, which combines characters of both simple areoles and tubercle areoles. This specimen is described as a new species, C. combiareolatus. Both specimens show arrangements on the cuticle, in which a circle of areoles surrounds a region of "naked" cuticle. We interpret these regions as artifacts caused by the breaking off of the central crowned areoles, leaving only the circumcluster areoles behind.