The present study was undertaken to investigate the antibody responses of dengue fever (DF) patients to specific dengue virus proteins. Partially purified dengue 2 New Guinea C (NGC) strain virus was used as antigen. Under the present experimental protocols, it was observed that almost all DF patients' sera had detectable presence of antibodies which recognize the dengue 2 envelope (E) protein. The convalescent-phase sera especially had significant detectable IgG, IgM and IgE against the protein. In addition, IgGs specific against the NS1 dimer and PrM were also detected. Antibody against the core (C) protein, however, was not detectable in any of the DF patients' sera. The substantial presence of IgG against the PrM in the convalescent-phase sera, and the presence of IgE specific for the E, reflect the potential importance of these antibody responses in the pathogenesis of dengue.
HIV-1 antibody patterns in two groups, those infected by the intravenous route (IV drug users) and those infected by the sexual route (prostitutes, male homosexuals and sexually transmitted disease patients) were compared using the Western blot technique. A total of 160 cases were studied. The intravenous drug user (IVDU) group appeared to respond to fewer antibody markers than the sexually infected group, the difference being significant for markers p31, p51, p55, p66, gp41 and gp120. Furthermore, a higher proportion (63%) of the sexually infected group carried antibodies to all Western blot markers as compared to the IVDU group (49%).
A 17-year-old girl was admitted to hospital with dengue fever. On the ninth day of fever she developed haemoptysis and chest X-ray changes consistent with haemorrhage in her lungs. Thrombocytopaenia and mild coagulopathy were the most likely cause of this unusual haemoptysis in this patient. Investigations excluded other causes for the haemoptysis.
The traditional methods used in the diagnosis of dengue infection do not lend themselves to field application. As such, clinical specimens have to be sent to a central laboratory for processing which invariably leads to delay. This affects patient management and disease control. The development of the dengue IgM dot enzyme immunoassay has opened up the possibility of carrying out the test in peripheral health settings.
Acquired haemophilia is a rare clinical condition arising from the spontaneous development of inhibitors to factor VIII. We describe two cases encountered in the University Hospital over the past five years. We also review the literature and discuss the therapeutic difficulties faced in dealing with patients with high levels of inhibitors. In one of these patients we also describe, for the first time in this region, a novel method in managing the acute bleeding episode in acquired haemophilia using recombinant factor VIIa.
Cerebral infarction in the young is likely to be non-atheromatous. While in previous studies no cause has been found in 40% to 50% of patients, an increasing role for haemorheological factors is becoming apparent. Among these, an association between antiphospholipid antibodies (aPLs) and ischaemic cerebrovascular disease is now well-recognised. This entity has not been previously reported in Malaysian patients. In a study of 80 patients with stroke below the age of 50 years who were seen at the University Hospital, Kuala Lumpur, between January 1982 and May 1992, 3 patients with ischaemic cerebral infarction were found to have aPLs. aPLs was detected using ELISA method for anticardiolipin antibodies (aCLs), and presence of lupus anticoagulant (LA) was established by kaolin clotting time, thromboplastin inhibition test and platelet neutralisation procedure. Only 1 patient had active systemic lupus erythematous. Cerebrovascular events were recurrent in one of the 2 non-lupus patients. aPL-related stroke should be considered in young patients who have cerebral ischaemia occurring without obvious cause. More cases are likely to emerge in Malaysia with active screening.
BACKGROUND: Dengue has been recognized as a potential hazard to tourists. A prospective, controlled study in the outpatient clinic of a German infectious disease clinic was conducted to assess the prevalence of dengue virus infection among international travelers.
METHODS: Serum samples from 130 patients with signs or recent history clinically compatible with dengue (fever, headache, muscle and joint pain, or rash), 95 matched controls with diarrhea, and 26 patients who never visited a country endemic for dengue were investigated.
RESULTS: Nine (6.9%) of the 130 patients with compatible symptoms and 1 (1%) of the 95 controls with diarrhea developed rising antibody titers against dengue virus. Of these 10 patients with probable dengue infection, 6 had been to Thailand, 2 to Malaysia, and 1 each to Indonesia and Brazil.
CONCLUSIONS: Infection with dengue virus appears to be a realistic threat to travelers to Southeast Asia. Symptoms commonly associated with dengue, such as fever, myalgia, arthralgia, and vomiting, can be helpful for diagnosis when present, but the absence of typical symptoms does not exclude infection.
We report a case of Japanese encephalitis that occurred in a woman who had spent only a few days in an area where she could have been exposed to the virus. The risks and protective efficacy of vaccination against Japanese encephalitis virus for travellers who visit endemic areas for only a short period are discussed.
This study was based on a hepatitis B screening program conducted in one of the states in Malaysia in 1989. The majority (84.6%) of the 2986 health employees were screened. One quarter (25%) was found to have serological markers for the Hepatitis B Virus (HBV); 2.1% had Hepatitis B surface Antigen (HBsAg) and 22.8% had antibody to the Hepatitis B surface Antigen (anti-HBs). The occurrence of HBsAg was higher in ethnic Chinese (6.3%) compared to Malays (1.8%) and Indians (0.9%), even when analyzed by sex, but not with age, type of institution and geographical locality. The distribution of anti-HBs was higher with ethnic Chinese (41.6%), male sex (27.2%) and age. There was a wide variation of the prevalence of serological markers among occupations and increased relative risks of HBsAg were found among medical assistants (RR3.7; 95% CI 1.4-9.1) and laboratory staff (RR 3.2; 95% CI 1-8.8), and that of anti-HBs among medical assistants (RR 2.8; 95% CI 1.8-3.7). The variations of HBsAg among occupations by type of institutions was marginal while that of anti-HBs was higher among attendants and midwives in hospitals, medical assistants in health departments, and assistant nurses and dentists in dental centers. The patterns of distribution of serological markers of HBV among health staff reflect the situation in the community with high endemicity and resemble specific occupational factors noted in previous studies in the West.
Publication year is 1992-1993
Matched MeSH terms: Hepatitis B Antibodies/analysis*
A visual, enzyme-linked immunosorbent assay using urease (ELISA-U) as the enzyme marker was adapted for rapid detection of antibody against Plasmodium falciparum. Flat-bottom, 96-well microtiter plates were coated with P. falciparum soluble antigen obtained by saponin and NP-40 treatment of parasite cultures. Antibody was detected by successive incubations with test sera, urease-conjugated rabbit-human antibody, and urease substrate. Reactive sera developed a definite and easily visualized purple color. Sera from patients with single infections of P. vivax or P. ovale were unreactive. No cross-reactivity was noted with sera from patients with rheumatoid arthritis, filariasis, amebiasis, schistosomiasis, dengue, scrub typhus, leptospirosis, or toxoplasmosis. The procedure can be performed at room temperature and completed within 1 hr. The sensitivity of the assay is comparable to that of the indirect fluorescent antibody test at all but the lowest dilutions tested.
Serum antibodies against Epstein-Barr virus (EBV)-determined antigens have traditionally been titrated by the indirect immunofluorescence (IIF) technique. The avidin-biotin complex (ABC) immunocytochemical technique was used to determine the serum levels of IgA against EBV viral capsid antigen (IgA/VCA) and IgA against EBV early antigen (IgA/EA) in sera of 106 nasopharyngeal carcinoma (NPC) patients prior to treatment and 100 normal individuals. The sensitivity of the ABC technique is enhanced by an amplification of the antigen-antibody reaction, which involves the binding of the enzyme-linked ABC to the second biotinylated antibody. There was a good correlation (r = 0.9988) between ABC and IIF-determined IgA/VCA-positive titres, with the ABC technique being more sensitive than IIF in the detection of IgA/VCA in NPC sera: 94% (99/106) and 76% (80/106), respectively. The frequency of IgA/EA reactivity in NPC sera was also markedly increased by immunodetection with the ABC technique as compared with IIF technique: 63% (69/106) and 28% (30/106) respectively. Both the immunocytochemical techniques were equally specific in discriminating between elevated serum titres of IgA/VCA and IgA/EA in NPC sera from normal human sera.
Autoantibodies to the three extractable nuclear antigens (ENA), Anti-SSA (Ro), Anti-Sm, Anti-RNP and antinuclear antibodies were determined in 150 patients with SLE. Seventy patients (46.7%) had Anti-SSA (Ro), 40 (26.7%) Anti-Sm and 25 (16.7%) Anti-RNP antibodies. Ninety four percent patients had a positive Fluorescent anti-nuclear antibody (FANA) test. The commonest FANA pattern is the speckled pattern. Subclinical keratoconjunctivitis sicca (KCS) was present in 60% patients. No correlation could be demonstrated between the presence of ENA autoantibodies and the clinical features of patients.
A serological study on dengue infection conducted in Singapore during the period 1982 to 1984 showed that 54.4% of the healthy population between 6 months and over 50 years of age surveyed possessed no haemagglutination-inhibition antibody to dengue type 2 virus. Children below 10 years of age showed the lowest antibody prevalence and were at the greatest risk, with 96.6% susceptible to infection, whereas virtually all adults over 40 showed evidence of prior dengue infection. The geometric mean titre showed a rising trend indicating continuing acquisition of infection in the older age groups. The seropositivity rate of dengue infection of males was twice that of females. Among the 3 major ethnic groups, no significant difference in seropositivity was noted between the Malays and Indians, but the differences between Malays and Chinese and between Indians and Chinese were statistically significant. The study confirmed that the successful implementation of the nation-wide Aedes control programme is reducing endemic dengue virus transmission in the country.
A seroepidemiological study was carried out on Orang Asli (Aborigines) children who lead a semi-nomadic life in the deep jungles of Ulu Kelantan, Malaysia. Out of a total of about 190 children below 14 years, 143 were studied. Blood was collected from finger pricks on standard "strip type" filter papers for indirect fluorescent antibody (IFA) tests with Plasmodium falciparum antigen. A positive reaction at 1:10 dilution in infants and young children was considered positive and the reasons are given. The P. falciparum antibody prevalence rate was 84.6% compared to 81.8% spleen and 43.4% parasite rates. Both P. Falciparum and P. vivax were present in children. The age-specific patterns of antibody, spleen and parasite rates were those of a hyperendemic community. There was a positive correlation between antibody and spleen rates up to the age of 9 years. In older children, the antibody rates increased while the spleen and the parasite rates dropped.
Serum samples from healthy adults in four geographic/ethnic groups (Ghanaian Blacks, Malaysian Chinese, Malaysian Indians and United States Caucasians) were tested under code for antibodies to human herpesvirus-6 (HHV-6). The prevalence and titer of HHV-6 antibody in the healthy Ghanaians were significantly higher than in the Malaysian Chinese; United States Caucasians and Malaysian Indians had intermediate prevalence and titer of antibodies. Thus far, no specific differences in HHV-6-associated diseases have been noted between geographic/ethnic groups with these marked variations in antibody patterns.
Specific antibody to Pseudomonas pseudomallei exotoxin was detected in sheep sera exposed to natural infection. An enzyme-linked immunosorbent assay (ELISA) was used. Serum antitoxin was present in 49.3% of sera obtained from a flock of sheep naturally exposed to P. pseudomallei infection. Among these sera, 17.0% gave titers of 10,000. In contrast, serum antitoxin was present in only 6.0% of sera collected from sheep kept on a melioidosis-free farm. The ELISA reactivity of all positive sera could be completely absorbed with purified P. pseudomallei exotoxin. Similarly, preincubation of the exotoxin-coated wells with specific antiserum inhibited the ELISA reactivity of sheep sera. The results indicate that exotoxin is produced in vivo during infection by P. pseudomallei.
A study was carried out at the University Hospital, Kuala Lumpur, Malaysia to determine the age-specific prevalence of measles infection by serology and the age specific - seroconversion rates following measles vaccination. The results show that the percentage of children with passively acquired measles antibodies decreased with increasing age fill three to five months of age. From 12 months of age, the percentage of positivity increased sharply due probably to natural infection. The geometric mean antibody titre was low at birth, but from six months it started to increase. These results indicate that measles infection is common in Malaysia and a small number of children began to acquire natural measles infection from six to eight months of age; however the peak age for the acquisition of measles infection was from 12 months to five years of age. Seroconversion rates following vaccination from nine months of age, ranged from 94-99%. However, the rates and the geometric mean titre were higher among those vaccinated at 11 months of age or older compared with those vaccinated at nine or ten months of age. Based on the above results, it is concluded that the optimum age for measles immunization in Malaysia should be 11 months.