Serum samples were obtained within 3 days of capture from 106 cynomolgus monkeys (Macaca fascicularis) in peninsular Malaysia. Fifty-two monkeys were trapped on the fringes of palm oil estates and 54 in dense primary jungle. Sera were tested for antibodies to hepatitis A virus (HAV) with a commercial radioimmunoassay. Twenty-four animals had detectable serum anti-HAV activity (6 of 52 from palm oil estate sites and 18 of 54 from primary jungle sites). Among monkeys at both sites, antibody prevalence was strongly correlated with animal weight: overall only four of 69 monkeys (6%) weighing less than 2.0 kg had serum anti-HAV antibodies, while 14 of 29 (48%) weighing 2.0 to 3.9 kg, and 6 of 8 (75%) weighing 4.0 kg or more, had serum anti-HAV antibodies. These data suggest that wild cynomolgus monkeys in Malaysian jungles become infected with HAV or an HAV-like virus at a rate comparable to that of humans in the same region, and raise the possibility of a sylvatic cycle for HAV.
Using ELISA and COPT diagnostic tests, serological evidence of Malaysian schistosomiasis was discovered among Orang Asli populations from three areas in Peninsular Malaysia. Serum samples collected in 1975 indicated an ELISA-positive prevalence of 25% and a COPT prevalence of 11% from Pos Iskandar, Pahang and an ELISA prevalence of 13% and a COPT of 4% from Bukit Lanjan, Selangor. Resurveys at these site in 1982-1984 showed a continued presence of serological positive individuals but prevalence rates were markedly lower: 7% and 1% for ELISA and 4% and 2% for COPT at Pos Iskandar and Bukit Lanjan respectively. Snail hosts were not found at either site. The source of infection for persons living in these lowland areas remains unknown. In a third area, Kuala Tahan, Pahang, located in the foothills of the central mountain range, foci of transmission have been found near to Orang Asli settlements. The serological prevalence rate among Negrito Orang Asli in that study area was 9% for ELISA and 4% for COPT. Thirty-three of 36 COPT-positive sera produced vacuolated bleb precipates and in 31 these were the only reactions seen. The high percentage of positives producing only these precipates suggests that among Orang Asli schistosomiasis patients such reactions are not an indication of recently acquired infection as has been reported for schistosomiasis patients in the Philippines.
In 1977 and 1978 selected in-patients at the Tegalyoso Hospital, Klaten, Indonesia who had recent onsets of acute fever were serologically studied for evidence for alphavirus and flavivirus infections. A brief clinical history was taken and a check list of signs and symptoms was completed on admission. Acute and convalescent phase sera from 30 patients who showed evidence that a flavivirus had caused their illnesses were tested for neutralizing antibodies to several flaviviruses which occur in South-east Asia. Paired sera from seven patients demonstrated a fourfold rise in antibody titre from acute to convalescent phase. The most common clinical manifestations observed in this series of patients included high fever, malaise, stomach ache, dizziness and anorexia. None of the seven patients had headache or rash despite the fact that headache and rash had been associated with two of the three previously studied. The onsets of illness clustered toward the end of the rainy season when populations of Aedes aegypti, a probable vector in Malaysia, were most abundant.
A review of the various studies on toxoplasmosis in peninsular Malaysia is presented. The period of review spanned between 1973 and 1980 during which a number of serological surveys were carried out for the presence of Toxoplasma gondii antibody in Malaysians, using either the indirect hemagglutination (I.H.A.) or the indirect fluorescent antibody (I.F.A.) tests. The prevalence rates of Toxoplasma antibody were consistently foundhighest among Malays, followed by Indians, Orang Aslis (Aborigines) and lowest among Malays, followed by Indians, Orang Aslia (Aborigines) and lowest among Chinese, the 4 major ethnic groups living in Malaysia. Positive titres, present in all age groups, showed an increase with age but no difference due to sex. However, higher prevalence of positive cases was recorded among rural dwellers and the lower socioeconomic group than from urban dwellers. The possible routes of infection among the ethnic groups were discussed. Among animal populations, the presence of Toxoplasma antibody was detected in buffaloes, swine, goats, cattle, cats and dogs. The epidemiological importance of the findings are discussed and suggestions made for future studies.
Blood samples from 1,600 persons who sought immunisation against hepatitis B in private clinics in Singapore in 1988-1989 were screened for two viral markers. Of that total, 4.81% were positive for HBsAg and 17.31% had anti-HBs levels greater than 10 mIU/ml, indicating that about 22.12% of the general population would not benefit from immunisation. Preimmunisation screening will identify persons not requiring the hepatitis B vaccine and thus, avoid wastage. When immunisation has already been performed without screening, recall for post-immunisation screening should be considered in order to detect the infectious hepatitis B carriers. Data in this study indicates that at this point in time, it is important to immunise adolescents and adults, in addition to neonates and children.
Matched MeSH terms: Hepatitis B Antibodies/analysis
The indirect fluorescence antibody technique has been employed to study the prevalence of toxoplasma antibodies in Singapore. 42.5% of clinically suspected cases of toxoplasmosis showed antibody titres. Of these, 17.5% had titres greater than or equal to 1.64. Malays and Indians have higher positive rates compared to the main ethnic group, the Chinese. Antibody titres are found in both males and females and span through the various age groups. The possible mode of transmission is discussed and the importance of congenital toxoplasmosis is indicated.
A study of race-related distribution of hepatitis B markers was conducted in 458 children admitted consecutively to Singapore General Hospital. The positive rates for hepatitis B surface antigen (HBsAg) in Chinese, Malays and Indians were 11.2, 8.0 and 12.2% respectively and the corresponding figures for anti-HBs were 30.2, 12.0 and 14.6%. In Chinese children HBsAg prevalence was shown to be sex-related, being higher in males than females. The percentages of Chinese children positive for anti-HBs and anti-HBc were also higher than those of the Indians. This study confirmed that Singapore children were exposed to hepatitis B infection from early life. All three races were equally susceptible to this infection.
Matched MeSH terms: Hepatitis B Antibodies/analysis*
Congenital malaria from Malaysia is reported here for the first time. It occurred in a baby boy born to a 16-year-old primigravida who contracted Plasmodium falciparum infection during pregnancy. She suffered malaria during the later stages of pregnancy and at parturition. The placenta was heavily infested with various asexual stages of P. falciparum. Gametocytes were not seen. Extensive search did not show other species. Cord blood showed very light infection with young trophozoites of P. falciparum. Serological studies using IFA technique showed specific IgG and IgM antibodies to P. falciparum in maternal cord and two early neonatal sera. These serum samples showed lower levels of IgG antibodies against P. vivax and P. malariae, but there were no specific IgM antibodies against these species. The value of specific IgM antibody in the diagnosis of congenital malaria is discussed.
The indirect hemagglutination test was used to study antibody titers to Entamoeba histolytica in different Malaysian populations. Eighty-seven percent of Orang Asli (western Malaysian aborigines) adults and 79% of Orang Asli children with acute amebic dysentery were seropositive. However, significantly fewer children (39%) with amebic dysentery had high titer responses (titer greater than or equal to 1:1,280) than did adults with amebic dysentery (76%). No correlation between proctoscopic severity and amebic titer was found. Forty-four percent of asymptomatic family members were seroresponders. Satak, an Orang Asli village located near towns, had significantly more seroresponders (32%) than did the isolated, deep jungle village, Belatim (4%).
Serological surveys have been widely used in South-East Asia to determine the presence and activity of arboviruses. The haemagglutination-inhibition test has been most frequently employed but complement-fixation and neutralization tests have also been used in some investigations.Although virus isolations provide the most conclusive evidence, they can be carried out in a few specialized centres only, and serological surveys are very important for studying the distribution of arboviruses.The surveys have shown that group B arboviruses (principally all four types of dengue, Japanese encephalitis, and West Nile) are widely prevalent. Dengue and Japanese encephalitis viruses are more widespread than West Nile virus, which was not known previously to extend east of India although recent survyes have shown that its range extends to Burma. Japanese encephalitis is frequent in most of South-East Asia but in India is found mainly in eastern and south-eastern parts of the country. Kyasanur Forest disease (KFD) and Langat viruses are the only tick-borne group B arboviruses definitely known to occur in the region, the former in India, the latter in Malaysia. KFD virus has been isolated only from a small focus in Mysore, although human and animal sera containing neutralizing antibodies to this virus have been found sporadically in widely scattered areas. Among the group A arboviruses, chikungunya and Sindbis have been detected in serological surveys, but the former has not yet been found in Malaysia.
The diverse clinical syndromes characterized by asthmatic symptoms, transient pulmonary infiltrates, and eosinophilia have tended to obscure the specific association of one such entity with filarial infections. Serum IgE levels were determined before and after therapy in a group of well-characterized patients with tropical eosinophilia (TE), studied earlier in Singapore. The mean serum IgE level in 14 cases before treatment with diethylcarbamazine was 2,355 ng. per milliliter, with a trend but statistically nonsignificant decrease in levels to 600-1,000 ng. occurring 8 to 12 weeks after therapy. Leukocyte and eosinophil counts showed a rapid reduction after treatment, and although mean complement-fixing (cf) titers to Dirofilarial antigen tended to decrease, they were not significantly reduced until 5 to 6 weeks. The historical development of evidence supporting the filarial etiology of TE was reviewed. Many basic questions engendered by the clinical syndrome of tropical eosinophilia make it an excellent model for study of the immunopathology of parasitic infections.
This study determined the prevalence of glutamic acid decarboxylase antibodies (GAD Ab) in a group of 926 young Malaysian diabetics of three ethnic groups, Malay, Chinese, and Indian. Patients were clinically diagnosed to be Type 1 or Type 2 before the age of 40 years. The overall GAD Ab positivity was 17.4% (161/926), significantly higher in the Type 1 than the Type 2 diabetics (35.5%, 116/329 vs. 7.5%, 45/597, P=0.0001). Compared to GAD Ab negative patients, seropositive diabetics were diagnosed at younger age (21.2+/-0.9 vs. 27.4+/-0.3 y, P=0.0001), had lower fasting (289+/-27.4 vs. 640+/-17.6 pmol/l, P=0.0001) and post-glucagon C-peptide levels (527+/-51.8 vs. 1030+/-28.9 pmol/l, P=0.0001). There were no racial differences in the prevalence of GAD Ab; of the total Type 1, 30.8, 36.4, and 39.4% were Malay, Chinese, and Indian diabetics, respectively and of the total Type 2, 8.8, 8.2, and 4.4% were Malay, Chinese, and Indian diabetics respectively. There was a curvilinear relationship between GAD Ab and the post-glucagon C-peptide levels, suggesting that GAD Ab do play a role in the beta-cells destruction and could be an important immune marker for the LADA group. This study reconfirmed previous reports that the autoimmune mechanisms in the Type 1 Asian diabetics are indeed different from the Caucasians, and further investigations should be carried out to explain the differences.
Fifty medical students were screened for hepatitis B serological markers of whom 42 students entered the study. Those who were found to be negative for all markers were vaccinated with 1.0 ml (20 mcg HBsAg) Engerix-B vaccine intramuscularly in the deltoid region according to the 0, 1, 6 month schedule. Blood samples were taken at 1, 2, 3, 6, 9 months. One month following the first dose, 7% showed detectable AntiHBs with a GMT of 11 IU/I. By the sixth month, just before the third dose was given, 79% seroconverted with a GMT of 2952 IU/I. Three months following the third dose all had seroconverted with a GMT of 18,381 IU/I. No serious adverse reactions were noted and none of the subjects showed evidence of hepatitis B infection during the study. This study thus confirms the high immunogenicity and safety of recombinant yeast-extract hepatitis B vaccine.
Matched MeSH terms: Hepatitis B Antibodies/analysis
PURPOSE: This study was designed to find a reliable Epstein-Barr virus (EBV) immunoglobulin (Ig) G-based diagnostic/screening test for nasopharyngeal carcinoma (NPC) able to demarcate between the NPC-related seropositivity of EBV IgG antibodies and that of other head and neck cancer (HNCA) and control groups. The NPC-associated immunosuppression affects EBV IgA much more than IgG, leading to inconsistent detection of NPC using EBV IgA antibodies.
MATERIALS AND METHODS: One hundred twenty-two HNCA patients, 42 NPC, 66 laryngeal carcinoma, and 14 hypopharyngeal carcinoma and 3 groups of 100 control subjects were enrolled in this study. Enzyme-linked immunosorbent assay (ELISA) was used to find a specific cutoff value for the NPC-related seropositivity of EBV IgG antibodies.
RESULTS: NPC group showed higher serum level of EBV IgG antibodies than control and other HNCA groups (P < .05). However, the traditional cutoff value, mean + 2 SDs of control subjects, failed to demarcate the seropositives of NPC patients from those of healthy population (P > .05). The new cutoff value, mean + 2 SDs of the seropositives group of control subjects who had already been grouped by the traditional cutoff value, proved successful. It succeeded to demarcate between the NPC-related EBV IgG seropositivity and that issued from the persistent, latent, or reactivated EBV infection in the population (P < .05). The sensitivity/specificity of NPC detection by the new cutoff-based ELISA kit, 76.19% and 86%, was close or higher than that of EBV IgA antibodies.
CONCLUSION: EBV IgG-based ELISA could be used for the diagnosis of NPC using a new cutoff threshold that excludes the population baseline of EBV IgG seropositivity.
Antibodies to the ribosomal P protein are specific for SLE but their prevalence varies in different ethnic groups. In a group of Chinese SLE patients from Malaysia who have a high prevalence of this antibody, we have found an increased frequency of an uncharacterized HLA-DRB gene allele, DR16X, in patients who are positive for anti-P antibodies compared to antibody negative patients (31.3% vs 3.2%, P < 0.01, Pcorr not significant, relative risk = 13.6). DR16X has only been found in south east Asian populations and may be a genetic factor which influences the high prevalence of anti-P antibodies in Chinese.
Sera were obtained from 494 non-icteric patients admitted with illnesses other than overt hepatitis into the medical wards of the rural and urban hospitals in Malaysia. They were tested for HBsAg, HBeAg, and anti-HBs by enzyme immunoassay. The overall HBsAg carrier rate was 18.0% ranging from 9.6% in children, (10 years and under), to a maximum of 23.5% in the adolescents (11 to 20 years), the rates decreasing subsequently to 16.5% and 20.8% in the adult and middle-age groups, respectively. The Chinese (18.6%) and Malays (19.9%) had similar HBsAg carrier rates but the rate in the Indians (9.0%) was distinctly lower. Similar rates were observed in the males (16.5%) and the females (19.8%). The carrier rate was 17.1% in rural patients compared with 21.4% in the urban ones. The 'e' antigen was found in 14 of the 89 HBsAg carriers (15.7%). The overall prevalence was 14/494 (2.8%) rising sharply from childhood (2.9%) to adolescence (5.3%), subsequently declining with advancing age. The Chinese had the highest rate (6.2%) followed by the Indians (1.5%) and the Malays (1.1%). Males had a rate of 3.3% compared to the females with 2.3%. Anti-HBs was found in 33.8% of the patients, increasing steadily from childhood (18.3%) to middle-age (46.4%). The Chinese had a higher prevalence rate (41.6%) than the Indians (32.8%) and the Malays (29.3%). The rates were similar for the males (35.6%) and the females (31.5%). Rural patients (46.1%) had a higher rate than urban patients (35.7%). Both areas showed rising prevalence with increasing age.(ABSTRACT TRUNCATED AT 250 WORDS)
Matched MeSH terms: Hepatitis B Antibodies/analysis*
The antibody titres to P. falciparum and Epstein-Barr Virus-associated antigens were assayed in 22 patients with NPC and 43 controls. All, but one patient had antimalarial titres; 14 had titres greater than 80 and 4 patients greater than 640. Compared to controls the mean anti-malarial titre for most age groups were higher in the patients. Those patients with high anti-malarial titres also had high IgA anti-VCA titre, an antibody which has been demonstrated to be diagnostic for NPC. The peak anti-VCA (IgG) and anti-EA (IgG) antibody titres were associated with anti-falciparum titres of 320-640 and 80-160, respectively. The results are discussed in relation to the possible association between malarial infection and etiology of NPC.
179 heterosexuals, selected for VDRL testing on the basis of a history of involvement in promiscuous sexual activity, mainly prostitution, had their serum also tested for hepatitis B infection markers, HBsAg, HBeAg and anti-HBe. 51 samples (29%) were found to be positive for at least one of the three markers, at levels higher than the already high levels in voluntary random blood donors in Malaysia.
Matched MeSH terms: Hepatitis B Antibodies/analysis*
Introduction: Hepatitis C virus (HCV) infection is a serious health problem. It is a major contributor to end-stage liver disease. Worldwide, 1-8% of all pregnant women were infected. Women with viral hepatitis may be at an increased risk of pregnancy complications. There are several obstetrics intervention acts as risk factors, which are specific to women pertaining the HCV infection; anti-D immunoglobulin (Ig) therapy may be one of them. Our objectives were to estimate the prevalence of HCV antibodies (anti-HCV), RNA, and genotype distribution among women with anti-D Ig therapy. Materials and methods: A cross sectional study was conducted. A sample of 154 Rhesus negative (Rh - ve) pregnant women regardless of the anti-D Ig therapy was collected. Anti-HCV were tested using third generation enzyme immunoassay (EIA-3) and immunoblot assay (Lia Tek-111), subsequently. In addition, 89 serum samples were subjected to molecular analysis using RT-PCR and DNA enzyme immunoassay (DEIA) method for the detection of HCV-RNA and genotypes. Results: Anti-HCV, and HCV-RNA seroprevalence were significantly higher (17.1, 35.5%) among women with anti-D Ig than their counter group (6.4, 13.16%), p = .038, .018, respectively. Significant direct positive dose response correlation (r = 0.78, p = .005) had been seen between number of anti-D Ig therapy and anti-HCV seropositive rate. Anti-D Ig therapy act as a risk factor (odds ratio (OR) = 3.01, 95%CI: 1.01-8.9) especially from the third dose onward. Women with anti-D Ig therapy were at higher risk (3.6 times more) of positive HCV-RNA (OR =3.6, 95%CI =1.19-10.837). Genotype HCV-1b showed higher prevalent (52.9%) among the recipients of anti-D Ig therapy while genotype HCV-3a (6.6%) was the lowest. Conclusions: Our study showed that Anti-D immunoglobulin therapy acts as a risk factor for acquiring HCV infection. Screening for HCV should be recommended for all recipients of anti-D Ig. Not only HCV antibodies but HCV-RNA detection being recommended for the diagnosis of HCV infection. A brief rational: Pregnant women with HCV infection are at risk of adverse obstetric outcome. Anti-D Ig therapy may be a risk factor for HCV infection. Hence, we conducted a cross sectional study with the objectives to estimate the prevalence of HCV antibodies (anti-HCV), RNA, and genotype distribution among women with anti-D Ig therapy. We found that anti-HCV and HCV-RNA seroprevalence were significantly higher in women with anti-D Ig. In addition, women with anti-D Ig therapy were 3.6 times more at risk of positive HCV-RNA with genotype HCV-1b showed higher prevalence. Therefore, anti-D Ig therapy is a risk factor for acquiring HCV infection and we recommend screening for HCV for all recipients of anti-D Ig. In addition, the diagnosis of HCV infection, should be made with HCV antibodies and HCV-RNA detection.
Matched MeSH terms: Hepatitis C Antibodies/analysis