Prevalence and some risk factors of Giardia duodenalis infection in a rural community in Malaysia.

A study on prevalence and risk factors of Giardia duodenalis infection was conducted in rural communities of Malaysia. A total of 917 individuals between 2-70 years old (431 males and 486 females), participated in this study. The overall prevalence of G. duodenalis infection was 19.2%. The prevalence was significantly different between different age groups, but not genders. Our study indicated that age < or = 12 years old and the presence of family members infected with G. duodenalis were the risk factors of infection. Person-to-person contact within the family members was the possible mode of transmission. Health education on personal hygiene, together with the treatment of the infected people, may help in reducing and controlling this infection in these communities.

Efficacy of single dose albendazole on the prevalence and intensity of infection of soil-transmitted helminths in Orang Asli children in Malaysia.

The efficacy of a single-dose 400 mg albendazole to treat Ascaris, Trichuris and hookworm infection was studied in Orang Asli community. Kato-Katz examination was performed on fecal samples which were collected before treatment, 1 and 4 months after treatment. A total of 123 children were involved in all three surveys. The cure rate of Ascaris infection was 97.4% and the egg reduction after treatment was 99.9%. The cure rate for hookworm infection was 93.1% with 96.6% egg reduction. Although the cure rate was low in Trichuris infection (5.5%), egg reduction was more evident (49.1%). The reinfection rate at 4 months after treatment was 54.5%, 3.6% and 10.3% for Ascaris, Trichuris and hookworm infection, respectively. Within 4 months after treatment almost one-fifth children with Ascaris and hookworm infection reached pre-treatment intensity infection. In Trichuris infection, however more than half of the children reached their pre-treatment intensity infection at 4 months after treatment. Findings suggest that 4-monthly targeted periodic treatment with 400 mg single-dose albendazole in highly endemic areas can have a significant impact on intensity infection of Ascaris and hookworm, but not on Trichuris infection.

The prevalence of Trichuris, Ascaris and hookworm infection in Orang Asli children.

A community study on the age and sex related prevalence, intensity infection and frequency distribution of Ascaris, Trichuris and hookworm was carried out in 205 Orang Asli (Aborigines) children (95 boys, 110 girls) aged 1-13 years. The overall prevalence of Ascaris, Trichuris and hookworm was 62.9%, 91.7% and 28.8%, respectively. Almost two-thirds of the children were infected with moderate and severe intensity infection of Trichuris, 46.3% had moderate to severe intensity infection of Ascaris. However only 1.5% had moderate intensity of hookworm infection. The prevalence and mean intensity infection (measured by eggs per g) of Ascaris was age-dependent; lower in age group 1-4 years reached peak and stable at age group 5 years and above. The prevalence of Trichuris was high in all age groups and it fluctuated with age; the mean intensity of infection of Trichuris (measured by eggs per g) was age-dependent. Hookworm infection also rose with age and reached peak at 5-6 years, following that the prevalence declined. The frequency distributions of Ascaris, and hookworm were overdispersed. A strong positive correlation (p < 0.001) were observed between Ascaris and Trichuris and between hookworm and Trichuris. A positive correlation (p < 0.01) were also observed between Ascaris and hookworm.

Cockroaches from urban human dwellings: isolation of bacterial pathogens and control.

A study was carried out to determine the distribution of cockroaches in two different housing areas with central sewerage or individual septic tanks in an urban area in Kuala Lumpur, Malaysia. Six species of cockroaches were present and of these Periplaneta americana and Periplaneta brunnea were found in greater abundance. Seventeen species of bacteria were isolated and of these Escherichia coli and Klebsiella p. pneumoniae were isolated in greatest numbers. Control measures carried out using lambda cyhalothrin showed that there was no significant difference between treated and control sites.

Enterobius vermicularis infection among children aged 1-8 years in a rural area in Malaysia.

The infection rate and relationship of enterobiasis with socio-economic status were determined in children aged 1-8 years, living in a rural area in Malaysia. Of the 178 subjects 40.4% were infected with Enterobius vermicularis. The distribution of enterobiasis among these children were analyzed in relation to age groups and sex. The rate of infection was significantly higher in older children (5-7 years). The association of enterobiasis with other factors studied such as number of persons per house, household income per months and mother's employment status were not significant. The sensitivity of three successive days anal swabs compared to a single swab was found to be statistically significant.

Host tissue reaction to Gnathostoma malaysiae (Nematoda: Gnathostomidae) in Rattus surifer Miller.

The occurrence of adult Gnathostoma malaysiae in Rattus surifer and R. tiomanicus in Malaysia has been reported but there are no known reports on the host tissue reactions. This paper reports on the gross pathology caused by G. malaysiae in a red spiny forest rat, R. surifer and the tissue reactions caused. A tumor-like growth was located on the mid-stomach wall in a female rat captured in Gunung Bachock, Kelantan, Malaysia. This growth consisted of four tunnel-like structures containing sanguinopurulent fluid and leukocytes and this structure led into a central canal. The tissue surrounding the tumor was greatly inflamed and there was localized gastritis. The tunnel-like structure was surrounded by dense fibrotic tissue. The stomach wall was devoid of superficial epithelium and smooth muscle but mucinous glands were present. The midregion of the fibrotic scar contained eggs of G. malaysiae which had evoked a strong tissue reaction and were surrounded by pus. Blood vessels were empty, dilated and had undergone vasculitis and thrombosis.

Detection of circulating antigens and parasite specific antibodies in filariasis.

In Peninsular Malaysia, only Wuchereria bancrofti and Brugia malayi are reported to cause human filariasis. Brugia pahangi infects many of the same animal hosts as the zoonotically transmitted subperiodic B. malayi. There is a well-recognized need for improved diagnostic techniques for lymphatic filariasis. Parasite antigen detection is a promising new approach, and it will probably prove to be more sensitive and specific than clinical, microscopic and antibody-based serological methods. We recently generated monoclonal antibodies (MAb XC3) from in vitro culture products of adult B. pahangi (B.p. IVP). Filarial antigenemia was quantitated in various hosts including the sera from 6 Malaysian Aborigines with acute lymphatic filariasis. In hosts infected with brugian filariasis and dirofilariasis, antigenemia was scored ranging from 90 ng/ml to 960 ng/ml. None of the control animal and human sera had antigenemia above 90 ng/ml. In addition, MAb XC3 and B.p. IVP were applied in several seroepidemiological surveys among household cats in Kuala Selangor in order to correlate information gathered for future studies of possible cases of human infection. Out of the 81 cats surveyed, 10 (12.35%) and 5 (6.17%) were parasitologically positive for B. pahangi and B. malayi, respectively. However, 21 (25.92%) were antigenemia positive when serologically investigated with MAb XC3. Antifilarial antibodies to B.p. IVP by direct ELISA showed very high cross-reactivity with non-filarial gut worm infections. 16 (19.75%) cats had reciprocal titers ranging from 320 to 2,560. Only 1 (1.23%) cat from this group was antigenemic.

Prevalence of Enterobius vermicularis amongst adults living in hostels by six successive day examination.

The prevalence of Enterobius vermicularis in four groups of adults, all trainee public health inspectors or public health nurses, aged 18-35 years and all living in hostels on campus was studied. The modified scotch tape technique was used and the subjects were taught to do the examination on themselves to detect the presence of eggs over a period of 6 successive mornings. Each was given an elaborately illustrated diagram on how and when to take the samples and given demonstration in groups. The samples were examined by trained people. Most of the subjects took samples on 6 consecutive days. Of the 119 subjects who returned samples, the overall prevalence of E. vermicularis was 9.2% and this was thought to be high for this particular age group. This was due to the higher prevalence (19.4%) in one group, whereas in the others the range was 3.5-8.0%. Based on the samples returned on the first day none of the subjects were detected as having the infection. After examination on 3 successive days (109 subjects) 10.1% were found to be infected (chi 2 = 10.704; d. f. = 1) and after examination on 6 successive days (72 subjects) 13.9% were found to be infected (chi 2 = 3.026; d. f. = 1). There was no significance between examination over 3 successive days and 6 consecutive days (chi 2 = 0.296; d. f. = 1). There was no difference in the prevalence between males and females.(ABSTRACT TRUNCATED AT 250 WORDS)