C57BL/6 mice were orally infected with different doses of cysts of ME49 strain of Toxoplasma gondii to produce groups of acutely and chronically infected mice. Sera were obtained at different periods post-infection. SDS-PAGE was ran with excretory/secretory antigens of ME49 and RH strains of T. gondii, followed by Western blot analyses using the above sera and anti- IgA, IgM, IgG as conjugates. The SDS-PAGE profiles of the two antigens were similar. However the antigenic bands showed variations in all blots, most evidently in IgA blots of chronic sera. IgG blots showed greatest similarities in reactive bands. In IgM blots, more common bands were shown in chronic sera than in acute sera. Variations and similarities in prominence of some bands and time of their appearance were also noted, especially in IgM and IgG blots of chronic sera. Thus antigenic variations and similarities are present in excretory/secretory products of different strains of T. gondii.
A study was carried out on 49 H. pylori-positive and 11 H. pylori-negative patients to determine the reactivity of peripheral blood lymphocytes (PBL) to phytohemagglutinin (PHA) and acid glycine extract (AGE) of H. pylori, and to identify cells responsible for imunosuppression. Based on response to PHA stimulation, cell-mediated immunity of all patients were competent. In some patients, however, response to AGE of H. pylori was suppressed by plastic adherent cells. This study provided evidence of the presence of plastic adherent suppressor cells which suppressed PBL response to AGE of H. pylori but not to PHA suggesting that immunosuppression is antigen specific. There is also an indication that immunosuppression may be species-specific as PBL devoid of plastic adherent cells only responded to stimulation by AGE of H. pylori but not that to AGE of C. jejuni.
Faecal samples from patients admitted to the District Hospital in Balik, Pulau, Penang revealed high infection rates for Ascaris lumbricoides, Trichuris trichiura and hookworms. The prevalence rates were Trichuris trichiura 51.7%, Ascaris lumbricoides 31.9% and hookworm 37.2%. The overall highest infection is among the Malays (79%), the least being among the Chinese (61.1%). The prevalence of Ascaris lumbricoides was highest in the 11-20 age group. The prevalence of Trichura was highest in the 51-60 age group, Ascaris and Trichuris infections is higher among the males but hookworm infection is higher among the females. 72.6% of the patients were infected with at least one type of helminth and 32.9% of the patients were infected with at least 2 types of helminths.
We retrospectively reviewed 205 HIV-infected patients, who came at first entry from January 2001 to December 2002 to the Hospital Kuala Lumpur, Kuala Lumpur, Malaysia. The aged range was 21-69 years [mean 37.25 years (+/- SD) 8.1]. Subjects were mainly in the age group 35-44 years. The majority of patients were male (82%), Chinese (55.1%), single (55.6%), resided in Kuala Lumpur (55.1%), and were unemployed (57.1%). The most frequent routes of transmission were sexual contact (78.5%), followed by IDUs (30%), blood transfusion (5%), and unknown (0.5%). Oral candidiasis was the most common mucocutaneous disease and significant co-existence was found with the main opportunistic systemic diseases, such as TB, PCP, toxoplasmic encephalitis, penicillosis, and CMV retinitis (p < 0.05). In this study, the range of CD4 counts was 0-910, with a median of 35 cells/mm3. Significant associations between a CD4 level less than 100 cells/mm3 at the time of diagnosis, and the occurrence of major opportunistic diseases, such as candidiasis, TB, PCP, TE, herpes simplex infection, CMV retinitis, penicillosis, and histoplasmosis were found (p < 0.05) in this study.
A cross-sectional study of the nutritional status of schoolchildren aged 7-10 years from the Kuala Betis Resettlement Scheme in Gua Musang, Kelantan was done. A total of 291 schoolchildren were examined but only 183 (62.9%) fecal samples were returned for geo-helminth infection analysis. The prevalence of stunting was 40.4% and underweight was 28.4%. A total of 127 schoolchildren (69.4%) were positive for at least one of the 3 geo-helminth infections. The most common geo-helminth was Ascaris lumbricoides (62.8%), followed by Trichuris trichiura (38.9%), and hookworm infection was relatively low (12.6%). All the anthropometric indices measured were lower in the geo-helminth infected children compared to the uninfected childen, except for the weight-for-height z-score. However the differences were insignificant Geo-helminth infections may not be a significant factor in malnutrition of these schoolchildren. However, with the availability of safe, efficacious and cheap broad spectrum anthelmintics, regular mass treatment should be given in selected areas where the prevalence of geo-helminth infections is still high, so that these schoolchildren will be able to achieve their growth potential during their school years.
Two commercial serological kits, Pylori-set (Orion Diagnostica, Finland) and Helico-G (Cambridge Biomedical Ltd, UK), and an in-house ELISA were evaluated with sera from 24 Helicobacter pylori-positive and 146 H. pylori-negative dyspeptic patients. Sensitivity, specificity, positive and negative predictive values of Pylori-set were lower than that of Helico-G and in-house ELISA. Helico-G was more sensitive (91.7%) than in-house ELISA (83.3%) and both had comparable negative predictive values of 98.3% and 97.3%, respectively. However, specificity (97.9%) and positive predictive value (86.9%) of an in-house ELISA were much higher than specificity (80.1%) and positive predictive value (43.1%) of Helico-G. Kappa index of agreement between the three serological tests (Pylori-set, Helico-G or in-house ELISA) and the presence of H. pylori in antral biopsies was very low (k = 0.13; z = 1.9; p > 0.05), moderate (k = 0.49; z = 7.1; p < 0.0001), or substantial (k = 0.82; z = 10.8; p < 0.0001), respectively. Overall, statistical evaluations demonstrated that both commercial kits were not as reliable as the in-house ELISA for serodiagnosing H. pylori infection.
Filariasis, a parasitic infection endemic in parts of India, Myanmar, islands of the South Pacific, West and East Africa and Saudi Arabia can be diagnosed from various types of cytopathological specimens. This case documents the detection of filarial infection from hydrocele fluid cytology in a 30-year-old Myanmar migrant worker in Malaysia.
Over a period of ten years (1983-1992), 134 malaria cases admitted to University Hospital, Kuala Lumpur (UHKL) were analysed. Malays constituted 27.6%, Chinese 29.8%, Indians 9.7%, Indonesians 16.4% and other foreigners 16.4%. Therefore, of the total number of cases, foreigners constituted 32.8% (44) of all the malaria cases admitted to UHKL. Fifteen of these foreigners had chloroquine-resistant strains of malarial parasites. Three species of malaria were reported of which Plasmodium falciparum constituted the most (46.3%) (80% of these developed resistance to chloroquine). Plasmodium vivax was confirmed in 44.8% (10% of these developed resistance to chloroquine) and there was only one case of Plasmodium malarie infection.
Acanthamoeba sp. is a free-living amoeba known to cause chronic central nervous system infection or eye infection in humans. Many cases remain undetected for want of a good detection system. We report for the first time a rapid staining method to facilitate the identification of Acanthamoeba sp. using the modified Field's staining technique. A. castellanii, which was used in the present experiment, is maintained in our laboratory in mycological peptone medium (Gibco). The cultures were pooled together and smears were made on glass slides for staining purposes. Different types of stains such as Field's stain, modified Field's stain, Wright's stain, Giemsa stain, Ziehl-Neelsen stain, and trichrome stain were used to determine the best stain for the identification of this amoeba. The concentration of various stains and the duration of staining were varied to provide the best color and contrast for each stain. Acanthamoeba was also obtained from the brain of experimentally infected mice and was stained with various stains as mentioned above to determine the best stain for use in identifying the presence of this parasite in experimentally infected animals. The modified Field's stain gives a very good color contrast as compared with other stains. Furthermore, it takes only 20 s to be carried out using the least number of reagents, making it suitable for both laboratory and field use.
BACKGROUND: The larva of Toxocara spp., a common animal roundworm, may infect non-compatible hosts, causing a profound immunological reaction with marked eosinophil and IgE responses, not unlike in atopy. In this study, we determined the seroprevalence of Toxocara exposure in 66 asthmatic and 58 non-asthmatic children.
METHODS: Exposure to Toxocara was determined by examining the serum samples of the children for specific IgG antibodies to L2 Toxocara larvae, using a commercially available diagnostic kit.
RESULTS: There was no significant difference in the mean age, sex, social class, residence type and presence of domestic pets at home between the two children groups. Children with bronchial asthma were observed to have higher Toxocara seropositivity than that of the non-asthmatic controls (21.2 vs 8.6%, P=0.047).
CONCLUSION: The observed relationship between exposure to Toxocara infection and bronchial asthma in Malaysian children warrants further evaluation. An understanding of any possible contribution to the pathogenesis of childhood asthma provides a potential avenue for prevention.
Study site: Paediatric Asthma clinic, University Malaya Medical Centre (UMMC), Kuala Lumpur, Malaysia
Sera from fifty subjects with different presentations of Brugian filariasis and from common soil-transmitted helminth infections were tested for specific anti-filarial IgG and its subclasses. Anti-filarial IgG, IgG1 and IgG3 showed cross-reactivities with soil-transmitted helminthic infections and no significant differences in optical densities among the various groups of filarial patients. In comparison with other groups of subjects, IgG4-ELISA of sera from microfilaraemic patients and some previously microfilaraemic patients showed a significant increase in optical density readings, while IgG2-ELISA showed elevated optical density readings in sera of patients with chronic elephantiasis. Therefore IgG2-ELISA is potentially useful in the diagnosis of brugian chronic elephantiasis while IgG4-ELISA may be beneficial for follow-up diagnosis of treated microfilaraemic patients.
Intestinal permeability of 246 early primary schoolchildren at 2 schools (106 of whom were infected with intestinal helminths) was assessed by using the lactulose/mannitol differential absorption test. The ratio of the urinary recoveries of lactulose and mannitol was determined after oral administration of a standard solution of the 2 sugars. Assessment of intestinal permeability was repeated on 100 infected children after treatment and on a cohort of 68 uninfected children. Infected and uninfected groups were compared with respect to baseline lactulose/mannitol ratio (L/M1) and change in lactulose/mannitol ratio between assessments (delta L/M). The correlations between baseline intensity of infection and L/M1, and between fall in intensity and delta L/M, were evaluated. Based on a crude index of socioeconomic status, each child was assigned to one of 3 socioeconomic groups; all but 3 children belonged to either groups 2 or 3. Trichuris trichiura and Ascaris lumbricoides were the 2 predominant infections; the hookworm infection rate was relatively low. The results suggested that helminthiasis exerted only a marginal effect on intestinal permeability, the impact of which in children from lower socioeconomic backgrounds was negligible in comparison with the cumulative effects of other factors.
Stool examination of 249 early primary schoolchildren at 2 schools in north-eastern peninsular Malaysia revealed that 73 were infected with Ascaris lumbricoides, 103 with Trichuris trichiura, and 18 with hookworms. Infected children were treated with a single dose of 400 mg of albendazole. The school attendance records during a 60 d period before treatment and 2 consecutive 60 d periods after treatment were examined. The absenteeism rate did not improve more among infected children after treatment than it did among the uninfected control children. The correlation between worm intensity and the number of lost school-days was poor. There was no evidence that intestinal helminthiasis caused school absenteeism among this group of children.
Tropical pulmonary eosinophilia (TPE) is considered to be a variant of human filarial infection. The pulmonary manifestations of TPE have been well described. Extra-pulmonary features of the disease, although not commonly seen, have been reported previously. A 9-year-old Malay girl with a history of recurrent cough and wheezing was admitted because of cardiac failure. Physical examination revealed a very sick girl with tachypnoea, central cyanosis, finger clubbing, elevated jugular venous pulse, generalized crackles and rhonchi in the chest, a loud second heart sound and hepatosplenomegaly. A chest radiograph showed cardiomegaly and right pleural effusion. Laboratory investigations revealed hypochromic, microcytic anaemia with persistent blood eosinophilia (absolute eosinophil counts varied from 1.9 to 5.5 x 10(9)/1). The ELISA test for antifilarial IgG antibodies was strongly positive. She responded promptly to treatment with diethylcarbamazine. In summary, this is a patient with TPE who presented with cor pulmonale, probably due to late-stage interstitial pulmonary fibrosis. In order to prevent the long term morbidity of cardiorespiratory disability, the early signs of TPE should be recognized and the infection treated.
A total of 290 HIV/AIDS patients were recruited into this retrospective study, which was carried out at the National Tuberculosis Center (NTBC), Kuala Lumpur. The age range was 18 to 75 years with a mean age of 36.10 (SD +/- 7.44) years. Males outnumbered females by a ratio of 31:1. In this study, the majority of patients were male (96.9%), Malay (47.2%), single (66.9%), unemployed (81%), and smoked (61.4%). The main risk marker identified was injecting drug use (74.5%). The most common clinical manifestations were cough, fever, sputum, lymphadenopathy, and chest infiltrations. More than half of the patients (85.9%) were diagnosed with localized tuberculosis (pulmonary) and the others (14.1%) had extra-pulmonary or disseminated tuberculosis. At the time of this study, the majority of the patients (16.9%) had CD4 cell counts of less than 200 cell/mm3, with a median of 221 cell/mm3. Clinical outcomes demonstrated that among those who survived, 11.0% and 20.7% of the patients had completed treatment either > or = 6 or > or = 9 months, respectively, whereas 54.8% of patients were lost to follow-up, including 0.7% for MDR-TB. Diagnostic criteria for tuberculosis in this study were mainly clinical symptoms/signs and chest x-ray findings (31.0%).