A survey was carried out to determine the prevalence of Toxoplasma gondii antibodies among cattle farmers and cattle in the Gombak District, Selangor. A total of 79 human and 73 cattle serum samples were tested for Toxoplasma gondii antibodies by the immunofluorescent technique (IFAT). Results of the survey showed that anti-Toxoplasma gondii antibodies were found in 27.8% of the farmers, while in cattle the positive rate was only 3.8%. The prevalence rate obtained in this study did not differ much from the prevalence reported in previous studies. This suggests that the same degree of risk to this infection exists in the community. In view of the relatively low antibody prevalence in cattle, the risk of acquiring this infection from consuming undercooked beef is realtively low. Further survey on larger sample size is needed to validate the observation.
The quantitative buffy coat (QBC) technique was compared with the conventional thick blood film technique in a malaria survey carried out in a mesoendemic area of malaria in Betau, Pahang, Malaysia. The QBC technique was found to be a rapid technique but had a sensitivity of about 56% and a specificity of 95%, using the thick blood film method as the "gold standard". Malaria species identification was unsatisfactory with the QBC technique as it could identify parasites correctly in only about 60% of specimens. It was unable to detect as positive about 58% of specimens which had parasite counts < or = 500 per ul but could detect about 94% of those with counts > 500 per ul. This difference in positive detection rate was significantly different (p < 0.05). It cannot quantify parasitemia easily and the specimens cannot be stored for future reference and for quality control purposes. It is therefore concluded that the QBC technique cannot replace the classical thick blood film technique for use in malaria control programmes. Its use may be appropriate in situations like busy blood banks and outpatient clinics where rapid screening of malaria infection is needed but where experienced malaria microscopists may not be available.
Giardia duodenalis causes diarrhoea and malabsorption. The objectives of the study were to detect local isolates of G. doudenalis by polymerase chain reaction (PCR) and to determine their restriction fragment length polymorphisms (RFLP). G. doudenalis isolated from stools of patients from Hospital Orang Asli Gombak were cultured axenically using TYI-S-33 medium with 10% foetal calf serum. The commercially designed primer-pair 432/433 was used to amplify a 0.52 kb segment known to encode the homologous cysteine-rich trophozoite surface antigen (tsp11 and tsa417). Results showed that the primer-pair 432/433 could amplify the target region of the local isolates. RFLP study on the identical isolates showed that all the restriction enzymes tested ( HindIII, ClaI, PstI and Kpn) gave a banding pattern similar to that of the WB strain a reference pathogenic strain from human. The reference pathogenic strain were commercially obtained from the American Type Culture Collection (ATCC).
Giardia duodenalis is an intestinal parasite that causes diarrhoea and malabsorption in children. The parasite also infects AIDS patients with a weak immune system. A study was carried out on six local isolates of Giardia duodenalis (110, 7304, 6304, M007, 2002 and 6307) from faeces of Orang Asli patients admitted to the Gombak Hospital. WB, a reference pathogenic strain from human and G. muris from a wild mouse, were commercially obtained from the American Type Culture Collection (ATCC). All the isolates were cultured axenically in TYI-S-33 medium. Two sets of primers were used for the techniques: primers LP1 and RP1 and primers LP2 and RP2. The sets of primers amplified giardine gene of 171 bp and 218 bp in sizes respectively. The study showed that the two sets of primers could detect G. duodenalis to the genus and species level specifically.
Various previous studies have reported the implication of CYP11B2 gene polymorphism in the pathophysiology of cardiovascular diseases. In particular, the -344T/C polymorphism, which is located at a putative binding site for the steroidogenic transcription factor (SF-1) has been associated with essential hypertension, left ventricular dilation and coronary heart disease. In the present study, we aim to determine the allele and genotype frequencies of the CYP11B2 gene in patients with clinical manifestation of coronary heart disease and confirmed by angiography and blood donors and to calculate the association of the gene polymorphism with CHD. A total of 79 DNA from patients with coronary heart disease admitted to the National Heart Institute and 84 healthy blood donors have been genotyped using polymerase chain reaction technique followed by restriction enzyme digestion (RFLP). Results of the study demonstrated that out of 79 for the patients, 40 were homozygous T, 10 were homozygous C and 29 were heterozygous TC. The frequencies of genotype TT, CC and TC for patients were 0.5, 0.13 and 0.36 respectively. The frequencies of allele T and C in patients were 0.68 and 0.31 respectively. While for the blood donors, 40 subjects were of homozygous T, 7 were homozygous C and 37 were heterozygous TC. The genotype frequencies for the TT, CC and TC were 0.47, 0.08 and 0.44 respectively. The frequency of the allele T was 0.69 and allele C was 0.3. Chi-Square analysis showed that there was no significant difference in the genotype and C allele frequencies between the CHD patients and the blood donors. Our study suggests that there is lack of association between -344T/C polymorphism of CYP11B2 gene and coronary heart disease.
Three monoclonal antibodies (McAb) were produced against soluble antigens of Legionella pneumophila serogroup 1 which was cultured on BCYE agar. The McAbs were all of the IgM isotype. The McAbs were used in the McAb-based ELISA for detection of circulating L. pneumophila antigens in 186 sera collected from patients with symptoms and signs suggestive of atypical pneumonia. The normal reference optical (OD) density value of each of the McAbs was determined using 44 sera collected from healthy blood donors. The antigen positivity rates for the McAbs 1C7.2B, 2B2.10F and 2B2.11E were 11.3%, 7.7% and 22.2% respectively. Antigen positivity of the McAb 2B2.10F was significantly higher in the younger age group (p < 0.05). There is no significant association between the antigen positivity with age and sex for all the McAbs. There was no cross-reaction demonstrated between the McAbs with other bacterial antigens.
The Aborigines or Orang Asli in Peninsular Malaysia who are still seminomadic are known to have a close association with dogs. In this study, enzyme-linked immunosorbent assay (ELISA) was used to detect anti-Sarcoptes scabiei var canis antibodies in this community as a measure of exposure to the mite. Out of 312 Orang Asli tested, 24.7% were positive for polyvalent anti-Sarcoptes antibodies. No significant difference was found between the positive rates in males (26.1%) and females (23.6%). Only 1.9% were positive for IgA and none was positive for IgE anti-Sarcoptes antibodies. Since there were very few patients with clinical manifestation of scabies, there is a possibility that continuous exposure to the dogs mite confers cross-protective immunity in the community against human scabies.
An enzyme-linked immunosorbent assay using excretory-secretory antigens of the second stage larvae maintained in vitro was used to determine the seroprevalence of Toxocara antibodies in Orang Asli (aborigines) of Peninsular Malaysia. The mean + 3 SD optical density of 30 healthy subjects was used as the cut-off point. Overall prevalence was found to be 31.9%. No significant relationship was found between positive rates with sex and age groups, though children between 0 to 9 years recorded the highest positive rates. Eosinophil counts were found to be closely related to the proportion of positivity to toxocaral infection and mean optical densities. There was some degree of cross-reaction with Trichuris trichuria positive sera.
The etiology of systemic lupus erythematosus (SLE) is unknown but genetic factors seem to play a role in the disease pathogenesis. The tumor necrosis factor alpha (TNFa) gene, encoded at the TNF locus in the MHC class III region, is now known to be an important candidate gene in SLE, due to the proinflammatory activities of the TNFa. The objectives of this study were to examine the role of the TNFa polymorphism for the susceptibility of Malaysian Chinese lupus patients to SLE and to determine its association with organ involvement. The allelic frequencies of the TNFa polymorphic variant (TNF2) of seventy lupus patients were determined during follow-up at the Medical Clinic of the National University Hospital Malaysia by PCR-RFLP technique. Sixty-four females and 6 males with a mean age of 33+/-12 years were included. Clinical data were obtained from case records. Autoantibody levels were measured by ELISA. Fifty-nine ethnically-matched blood donors were used as controls. The allelic frequency of the TNF2 variant was found to be significantly increased in the patients compared to the controls (52.8% vs 33.8%). SLE patients with the polymorphic TNF2 variant were found to be at increased risk of central nervous system involvement (p = 0.004, RR = 2.59) and to have an increased frequency of anti-La antibodies (p = 0.03). In view of these findings we suggest that TNF2 variant is playing a role in conferring susceptibility to SLE and in the disease pathogenesis.
Study site: Pusat Perubatan Universiti Kebangsaan Malaysia (PPUKM), Kuala Lumpur, Malaysia
Leptospirosis is an emerging infectious disease. The differential diagnosis of leptospirosis is difficult due to the varied and often "flu like" symptoms which may result in a missed or delayed diagnosis. Leptospira is the aetiological agent of leptospirosis, a bacterial zoonosis with worldwide distribution. There are over 230 known serovars in the genus Leptospira. The true prevalence of leptospirosis in Malaysia is unknown or underestimated. Our goal was to determine the prevalence for Leptospira infection in rodents in a selected area in Beguk Dam Labis, Segamat, Johor. A study was carried out on 69 serum samples of trapped wild rodents. DNA was extracted from the sera using Leptospira PCR kit (Shanghai ZJ Bio-Tech Co., Ltd). Of 69 rodent serum samples tested by PCR, 9 (13%) showed positive results. In this study we found that (13%) of wild rodents caught in Beguk Dam Labis were infected by Leptospira.
Numerous studies have reported the prevalence of toxoplasmosis among Malaysians and various domestic animals; but there is paucity of information on its prevalence among rodents which could potentially contribute to the transmission of Toxoplasma gondii in both domestic and sylvatic fauna. Five hundred twenty-six rodents were captured from six locations in Malaysia and identified to species. Serum samples were collected from these rodents and tested for T.gondii antibodies using an immunofluorescent antibody test (IFAT). T.gondii antibodies were found in 5.9% (31/526) of the tested samples. Most of the positive antibodies were from commensal rats: Rattus exulans (9/64, 14.0%), Rattus argentiventer (2/8, 25%), Rattus rattus diardii (10/166, 6.0%) and Rattus tiomanicus (6/215, 2.7%). Only two of the forest rats were positive: Maxomys rajah (1/9, 11.1%) and Rattus bowersi (1/12, 8.3%). Eighteen point one percent of ground squirrels (Tupaia glis) tested (2/11) were positive for antibodies. The highest antibodies titer (1:1024) was found in Rattus exulans followed by T.glis (1:256). Sabak Bernam, Selangor had the highest prevalence (10.8%) followed by Baling, Kedah (5.0%) and Bagan Terap, Selangor (4.0%). None of the serum samples of rodents collected from Gua Musang, Kelantan; Jasin, Malacca; or Labis, Johor were positive. Our study reports for the first time the serologic prevalence of T.gondii antibodies among rodents in Peninsular Malaysia. Further studies are needed to confirm T.gondii infection among wild rodents, such as a bioassay, to assess their potential role in transmission of the parasite.
The frequency of the HLA class II antigens/alleles (HLA-DR, DQ and DP) were studied in 70 Malaysian Chinese patients with systemic lupus erythematosus (SLE) to examine the contribution of these genes to disease susceptibility, their clinical expression and Immunological responses. This was done using modified PCR-RFLP technique. These samples were then compared with 66 ethnically matched controls. We found a strong association of the DQA1*0102 (p corr = 0.032, rr = 3.39), DQB1*0501 (p corr = 0.003, rr = 4.55), *0601 (p corr = 0.006, rr = 4.22) and DPB1* 0901(p corr = 0.02, rr = 4.58) with SLE. Clinically, we found a strong association of DR2 and DQA1*0301 with renal involvement and DQA1*0102 with alopecia. Immunologically, statistical analysis (Chi-square test ) showed a strong association of DQA1*0102 with anti-Ro/La antibodies while DQA1*0301 was observed to be strongly associated with antibodies to ds DNA. DQA1*0102 was found more frequently in those with a later disease onset (30 years of age or above). From these data we suggest that the HLA class II genes play a role in conferring disease susceptibility and clinical and immunological expression.
Study site: SLE clinics, Pusat Perubatan Universiti Kebangsaan Malaysia (PPUKM), Kuala Lumpur, Malaysia
An analysis of the clinical and serological features of 12 male and 122 female patients with SLE was done to determine whether sex related differences exist. We found a lower incidence of mucocutaneous symptoms and arthritis but an increased incidence of discoid lesions, pleuritis and pericarditis in males at disease onset. During the disease course, there was a lower incidence of arthritis, a similar prevalence of mucocutaneous symptoms but an increased incidence of pleuritis in males with a trend towards renal involvement. These findings were however not statistically significant except for the higher incidence of thrombosis among males. Serologically, both groups showed similar frequencies of autoantibodies and hypocomplementaemia. Although the study was small, it was shown that several sex-related differences in the clinical and serological features exist in Malaysian SLE patients.
Study site: SLE Clinic, Pusat Perubatan Universiti Kebangsaan Malaysia (PPUKM), Kuala Lumpur, Malaysia
BACKGROUND: Studies have shown that certain genes within the major histocompatibility complex predispose to systemic lupus erythematosus (SLE) and may influence clinical and autoantibody expression. Thus, we studied the frequency of HLA-DR, -DQA, -DQB and -DPB alleles in ethnic Malays with SLE to determine the role of these genes in determining disease susceptibility and their association with clinical and immunological manifestations.
METHODS: Fifty-six Malay SLE patients were enrolled into the study. Demographic, clinical and immunological findings were obtained from medical records. HLA-DR, DQ and DP typing were done using modified PCR-RELP. Controls were from ethnically-matched healthy individuals.
RESULTS: We found a strongly significant association of the DR2 and DQB1 *0501 and DQB1*0601 (pcorr = 0.03, rr = 3.83, pcorr = 0.0036, rr = 4.56 and pcorr = 0.0048 and rr = 6.0, respectively). There was also a weak increase of DQB1*0.201 and DPB1*0.0901 with a weak decrease of DQA1*0601 and DQB1*0503 and *0301 which were not significant after corrections for multiple comparisons were made. There was a significant positive association of DR2 and DQB1*0501 with renal involvement and DR8 with alopecia. A nonsignificant increase of DQB1*0503 in patients with photosensitivity was noted. Significant autoantibody associations were also found: DQB1*0601 with anti-Sm/RNP, DR2 with antiSSA (Ro)/SSB (La), and DR2, DQB1*0501 and *0601 with antibodies to ds DNA. There was no specific DR, DQ or DP associations with age of disease onset (below 30 years or those at or above 30 years).
CONCLUSION: Our data suggests the role of the HLA class II genes in conferring SLE susceptibility and in clinical and autoantibody expression.
Study site: SLE Clinic, Pusat Perubatan Universiti Kebangsaan Malaysia (PPUKM), Kuala Lumpur, Malaysia