Intestinal parasites of importance to man are Enterobius vermicularis, the soil-transmitted helminthes (STH)--Ascaris lumbricoides Tricburis trichiura, bookworms (Necator americans/Ancylostoma duodenale) and Strongyloides stercoralis and the protozoa Entamoeba histolytica and Giardia duodenalis. Other protozoa such as Cryptosporidium sp. and Isopora sp. are becoming important in causing prolonged diarrhea in immunocompromised patients. It is estimated that almost 1 billion, 500 million and 900 million people worldwide are infected by the major nematode species--A. lumbricoides, T. trichiura and hookworms respectively. Most of the infections are endemic and widely distributed throughout poor and socio-economically deprived communities in the tropics and subtropics. Environmental, socio-economic, demographic and health-related behavior is known to influence the transmission and distribution of these infections. In giardiasis, one study indicates that age < or = 12 years and the presence of family members infected with Giardia were risk factors for infection. Most of the infections occur in children and both genders are equally affected. Epidemiological studies of STH infections have shown that the prevalence and intensity of infection are highest among children 4-15 years of age. The frequency of distribution of STH infections is over-dispersed and highly aggregated. areas reinfection can occur as early as 2 months post-treatment, and by 4 months, almost half of the population treated become reinfected. By 6 months the intensity of infection was similar to pretreatment level.
A study conducted in. all the government schools in Wilayah to find the prevalence rate of worm infection in. urban schools revealed that 50 percent of the 7,682 school children. examined suffered from helminthiasis. More than 50 percent had mixed infections, worm infection was more prevalent among Malays and Indians. Both males and females had an equal prevalence of worm infection. Schools near the squatter areas had high infection rates. This was attributed to poverty, cultural factors, and environmental sanitation in the squatter areas.
In the past year, stool specimens of 1,732 alien laborers were examined for intestinal parasites. There was no significant difference in the positive rate between males and females. All alien laborers were examined in 3 hospitals and the positive rates were 24.8% (191/769), 13.6% (109/804) and 12.6% (20/159). Broken down by nationality, the positive rates in laborers from Thailand, Indonesia, the Philippines and Malaysia were 23.9% (192/803), 20.3% (62/305), 12.1% (60/498) and 4.8% (6/126) respectively. Of all alien laborers, 17.2% (297/1,732) had single infections of parasites and 1.3% (23/1,732) had multiple infections. Opisthorchis viverrinii was the most prevalent parasite found in infected alien laborers. 91.5% of alien laborers were aged from 21 to 40-years-old and had positive rates of parasites reaching 91.0%. The time of arrival in Taiwan had an effect in all alien laborers examined for parasites. The positive rate in laborers arriving during April to June was 22.7% which was significantly higher than the 16.3% for laborers arriving in other months.
A prevalence study for intestinal parasites among 305 infants and young children was conducted at the Paediatric wards of the General Hospital Kuala Lum.pur, Malaysia. 40.8 percent of children were infected with at least one type of intestinal parasites: 39 percent were found to be infected with intestinal helminths and 4.26 percent with intestinal protozoa. Ascaris formed 17.38 percent of the infestation followed by Trichuris (14.75 percent) and hookworm (2.95 percent); 0.3 percent of the cases had Strongyloides stercoralis; 2.30 percent and 2.62 percent of the children had Entamoeba histolytica and Giardia lamblia respectively. Indian children were the predominant group found infected, followed by the Chinese and Ma lays. A significant drop in infestation rate of soil-transmitted helminths was detected among the Malays. The significance of the changing pattern in the epidemiology of soil-transmitted helminths is
discussed. A brief review of literature is also presented.
We reviewed the epidemiology of STH in Malaysia from the 1970s to 2009. High prevalence rates persist among the rural Aborigines, estate workers and in urban slums and squatter areas. Trichuris trichiura is the most prevalent helminth in Malaysia ranging from 2.1% to 98.2%. Ascaris lumbricoides follows closely with a prevalence rate of 4.6-86.7%, while hookworm is the least prevalent (0-37.0%). A countrywide control program with special emphasis on school-based intervention is highly recommended among aboriginal people.
Parasitic intestinal infections are still among socioeconomic problems in the world, especially in developing countries like Iran. Food-handlers that directly deal with production and distribution of foods between societies are one of the most important sources to transmit parasitic infections to humans. The aim of this study was to determine the prevalence of intestinal parasitic infections among food-handlers in Shiraz, Iran.
Intestinal parasitic infection among five interior communities at Bakun Valley, upper Rejang River, Sarawak, Malaysia, was investigated as part of a public health impact assessment of the proposed US$ 3 billion Bakun Hydroelectric Project. Coproparasitological examination of 355 stool samples from 7 of 16 villages representing 5 of 7 tribes in the area revealed infection rate of 41%. A higher infection rate was found among the settled Kayans (56%) than the seminomadic Penans (29%). Infection rate was high (68%) among children less than 14 years old. Trichuris trichiura accounted for more than 90% of all infections; less common were Ascaris lumbricoides, hookworms and Strongyloides stercoralis. Polyparasitism was found in 8% of the individuals surveyed with dual infection due to T. trichiura and A. lumbricoides being more common than dual infection with T. trichiura and hookworm. Women had higher infection rates (57%) than men (33%).
Faecal worm egg counts of goats from two farms in Penang Island, West Malaysia, were monitored over a period of 14 months. The faecal egg count pattern followed that of total rainfall. The humid tropical environment was favourable for the development of various species of trichostrongylid nematodes, namely Haemonchus contortus, Trichostrongylus spp., Oesophagostomum spp. and Cooperia spp. Generally, H. contortus was observed to be the predominant species, more so in the monsoon months of the year.
This paper describes the first Malaysian case of oesophagostomiasis. The patient was an 8-year-old Malay boy who presented to Ipoh General Hospital, Perak with abdominal pain and weight loss. Examination revealed multiple cavitated pseudotumours of the colon. A hemicolectomy was performed. Examination of the lesions revealed Oesophagostomum worms in the necrotic centres. The differential diagnoses and the pathology caused by Oesophagostomum are discussed. A brief review of the available literature is presented.
Faecal samples of 56 common house crows (Corvus splendens Vieillot) were collected from the Petaling Jaya and Kelang districts of Selangor, peninsular Malaysia, and examined for coccidia. Intestinal tracts of 8 of the above crows wee histologically examined under light microscopy to determine the site of coccidial infection and the endogenous stages present. Fifty three (94.6%) crows had coccidial oocysts morphologically conforming to only one species of Isospora in their faeces at the time they were examined. The sporulated oocysts were found to be Isospora corviae (Ray et al. 1952) which has been emended to I. corvi. These oocysts are redescribed in greater detail. Corvus splendens is a new host record for I. corvi. Coccidial infection was observed in all the intestinal tracts and generally confined to the anterior two thirds of the intestine. The parasites occurred within intestinal epithelial cells, located usually above the host cell nucleus. Developmental stages of both the asexual and sexual phases were found in the epithelium, and are deemed to be the endogenous stages of I. corvi on the basis of the oocysts recovered from the same crows used for histological study. These stages are described here for the first time. The prevalence of I. corvi, its relationship with the host C. splendens, and its probable transmission from C. macrorhynchus are discussed.
A new species of parasitic nematode, Paracapillaria malayensis n. sp. (Capillariidae), is described from the small intestine of the toad Duttaphrynus melanostictus imported from the Malayan Peninsula to the Czech Republic. The new species differs from the only other congeneric species, Paracapillaria spratti, mainly in the shape and structure of the spicular proximal end (with a lobular rim), smaller eggs (45-51 x 21-24 microm), longer spicule (336 microm), and the number (37-38) of stichocytes in gravid females; whereas P. spratti parasitizes frogs of the Microhylidae in Papua New Guinea, P. malayensis is a parasite of Bufonidae in the Malayan Peninsula. Other Paracapillaria spp. are parasites of fishes, birds, or mammals and they mostly differ from P. malayensis in the structure of eggs and some other morphological features.