Mice were chronically infected with cysts of ME49 strain of Toxoplasma gondii. At different periods post-infection, their spleens were removed and single cell suspensions were made. Lymphocyte transformation experiments were performed on the lymphocyte suspensions using three different kinds of antigens of ME49 strain of T. gondii, namely soluble, excretory/secretory and cystic forms. The results showed that the pattern of lymphocyte responsiveness was dependent on the kind of antigen employed for induction of the blastogenesis. Using soluble and cystic forms of the antigen, different periods of lymphocyte suppression and lymphocyte proliferation were demonstrated. However, with the use of excretory/secretory antigen, no significant suppression of lymphocyte stimulation was noted throughout the course of infection. Thus excretory/secretory antigen may be the best form of antigen for stimulation of the cell-mediated immune response and hence it appears to be a good candidate for vaccine in toxoplasmosis.
A cross-sectional survey of the nutritional status of children aged 1-10 years old from the Kuala Betis resettlement villages was carried out. A total of 620 children were examined, of which 329 were preschool children and 291 were schoolchildren. The age was determined and anthropometric measurements such as weight, height and MUAC were taken. The nutritional status was assessed by looking at the distributions of the z-scores of weight-for-age (WAZ), height-for-age (HAZ) and weight-for-height (WHZ) in relation to the growth charts of the National Center for Health Statistics reference population. It was found that the nutritional status of the Orang Asli children was poor, with a prevalence of 33.7-65.3% underweight, 55.3-74.4% stunting and 4.4-29.7% wasting based on the NCHS reference values. The prevalence of malnutrition among the Malay children was lower, underweight--7.3-34.1%, stunting--9.8-34.1% and wasting--1.7-17.1%. The nutritional status of the Orang Asli children were poorer compared to the Malay children. More preschool Orang Asli children were stunted compared to the Orang Asli schoolchildren. This may be due to the poor economic base of the Orang Asli community during the transformation period after resettlement. A comprehensive primary health care program is essential, especially targeting the preschool Orang Asli children in these resettlement villages.
A total of 136 patients, 67 HIV, 69 diabetes mellitus (DM) with or without (+/-) end-stage renal disease (ESRD), were registered for tuberculosis treatment at the National Tuberculosis Center (NTBC) from May to December, 2003. Ages ranged from 21-78 years (median 57.7 years) in TB/DM patients, and 21-62 (mean 37.6 +/- 8.3 years) in TB/HIV patients. TB was significantly found in younger and single HIV patients, but in older and married DM patients (p<0.05). Male patients in both groups were strongly associated with TB, while females more commonly had TB with DM (p<0.05). The majority of these patients were Malays, unemployed, and resided in Kuala Lumpur territory; however, no statistically significant difference was found between the 2 groups. Smoking, IVDUs and hepatitis C virus (HCV) infection were more significantly found in TB/HIV patients and further analysis showed that pulmonary TB was strongly associated with HCV infection in these patients (p<0.05). Pulmonary TB (62; 89.9%) was the most common type found in both groups and was a markedly more common disease location in TB/DM patients, while extrapulmonary TB (21; 31.3%) and miliary TB (14; 21%) were significantly higher in TB/HIV patients. Cough with or without sputum, fever and loss of appetite and/or weight were common clinical presentations in both groups. Nevertheless, fever (54; 80.6%) and lymphadenopathy (17; 25.4%) were significantly related to TB/HIV patients (p<0.05). Interestingly, the presence of BCG vaccination and positive tuberculin skin test were stronger in TB/HIV (27; 40.3%) and TB/DM (20; 29%) patients, respectively (p<0.05). Overall, regular 6-, 9- and 12-months' anti-tubercular therapy (ATT) were routine practice, and EHRZ+B6 was the most common regimen used. The highest percentage of patients with treatment success were in both groups with 6 months' ATT; however, a significantly higher percentage was found in TB/DM (24; 34.8%) than TB/HIV (13; 19.4%) (p<0.05). A success rate of 15 (21.7%) was noted for TB/DM patients with 9 months' ATT, which was similar to both groups with the 12-month regimen. A higher percentage failure rate (lost to follow-up) was seen in TB/HIV (19; 28.4%) patients. Nine patients were reported to have anti-tubercular-drug side-effects, such as drug-induced hepatitis, blurred vision, and skin rash. No cases of drug resistance or death were notified among these patients.
This retrospective study was conducted at the National Tuberculosis Center (NTBC) where 252 HIV-positive patients coexisting with tuberculosis (TB/HIV) were examined. We found that patients with pulmonary (PTB) and extrapulmonary tuberculosis (EPT) had similar mean age. A higher sex ratio between male to female (10.7:1) was observed in patients with PTB. The other characteristics of patients with pulmonary and extrapulmonary tuberculosis were not statistically different from each other. Cough (88%) and hemoptysis were the most common presenting symptoms, significantly related to patients with PTB. Lymphadenopathy (33.5%) was the most common sign in patients with EPT. The majority of patients with pulmonary and extrapulmonary tuberculosis had CD4 cell counts of less than 200 cells/mm3 (range 0-1,179 with a median of 57 cells/mm3). Lung (89%) and miliary (55.6%) forms were the most frequent disease locations in patients with PTB and EPT, respectively. A higher percentage of patients with PTB (42%) were treated successfully with short-course (6 months) therapy, whereas in patients with EPT (43%) needed a longer period (9 months) for successful treatment. Of the patients who defaulted treatment, a higher proportion (87%) had PTB. No MDR-TB or relapse cases were found in this study.
The shedding pattern of the protozoan parasite, Blastocystis hominis, is investigated in man and in experimental animal infections. The shedding pattern of the vacuolar and cystic forms of Blastocystis hominis in infected individuals have been shown in the present study to be irregular. The study shows that there is marked fluctuation in the shedding of the parasite from day to day, varying from as high as 17 to 0 per x40 microscopic field. The cystic stages when estimated in 8 Blastocystis-infected individuals ranged from as high as 7.4x10(5) cysts per gram of stool to 0. The shedding of cystic and vacuolar forms observed over a period of 20 days in experimentally-infected Wistar rats were not only shown to be irregular but the amount varied from host to host. The study has important diagnostic implications in that the stool samples must be collected more than once from patients showing clinical signs and symptoms to eliminate the cause of it to Blastocystis. The study also shows that there are asymptomatic individuals who pass a large amount of cysts as such individuals should be treated to prevent transmission to others.
Stool examination, height and weight measurements were undertaken on 249 early primary school children at two schools in North-eastern Peninsular Malaysia. Helminth infected children were treated and follow-up anthropometric measurements and stool examination undertaken on all (n = 100) children at one of the schools 16 months later; to observe the relationship between acquisition of infection and growth. Baseline Ascaris prevalence rates at the two schools were 16.0% (23/144) and 47.6% (50/105) respectively whilst Trichuris rates were 33.3% (48/144) and 52.4% (55/105). Hookworm infection was uncommon. There was no difference in weight or height for age between infected and uninfected children at any time. Acquisition of worm infection over the initial 16 month follow-up period was not associated with significant decreases in growth rates. However the small subsets of children with heavy Ascaris infection were consistently lighter and shorter at all evaluation times. They also gained significantly less weight and tended to have reduced linear growth rates between measurements. Further interventional studies are required to determine if this association is one of cause and effect or largely incidental.
An IgG4 ELISA based on a novel recombinant antigen was evaluated for detection of Brugia malayi infection, using 2487 sera from various institutions: 2031 samples from Universiti Sains Malaysia, 276 blinded sera from 2 other institutions in Malaysia, 140 blinded sera from India and 40 blinded sera from Thailand. These sera were from various groups of individuals, i.e., microfilaraemics, chronic patients, endemic normals, non-endemic normals and individuals with other parasitic and bacterial infections. Based on a cut-off optical density reading of 0.300, the IgG4 ELISA demonstrated specificity rates of 95.6-100%, sensitivity rates of 96-100%, positive predictive values of 75-100% and negative predictive values of 98.9-100%. These evaluation studies demonstrated the high specificity and sensitivity of this test for the detection of active B. malayi infection. Thus, the IgG4 ELISA would be very useful as a tool in diagnosis and in elimination programmes for brugian filariasis.
The present study investigated whether people working closely with animals were at higher risk of getting infected with Blastocystis hominis. The prevalence of the parasite was determined in two population groups, i.e., animal handlers and normal healthy individuals who did not work with animals. In all, 105 stool samples were collected from animal handlers from 2 local research institutions, a local zoo, and a local abattoir and 163 stool samples were collected from normal healthy individuals residing in high-rise flats in the city. The in vitro culture method used in the study detected that 41% of 105 animal handlers and 17% of 163 flat-dwellers in the city were positive for Blastocystis. This statistically significant finding (P = 0.0000313) shows that people who work closely with animals do stand at risk of acquiring Blastocystis infection.
A total of 200 pregnant women were recruited in this cross-sectional study. The overall seroprevalence of toxoplasmosis in pregnant women was found to be 49%, in which 39%, 4% and 6% for anti-Toxoplasma IgG, IgM and both anti-Toxoplasma IgG and IgM antibodies, respectively. We found the differences in Toxoplasma seroprevalence rates among the races were significant: the highest rate was in the Malays (55.7%), followed by the Indian (55.3%) and the Chinese (19.4%) (P<0.05) populations. An increase in Toxoplasma seroprevalence with increasing parity was detected (P<0.05). Women with no children had a prevalence of 39.7%, while women with one or more than two children had a prevalence of 44.2% and 62.9%, respectively. In this study, there was no significant association between Toxoplasma seroprevalence and various possible risk factors in pregnant women (P>0.05). When multivariate analysis was performed, no significant association between Toxoplasma seroprevalence and history of contact with cats, consumption of undercooked meat and blood transfusion was found (P>0.05). We did not find any newly diagnosed cases of acute acquired toxoplasmosis in pregnancy during the study period.