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Biomedical subjects

A Hossain

Publications and source records attributed to A Hossain.

At least 91 records · Page 5Linked to original sources
PubMed1989

Seroepidemiology of rubella in Saudi Arabia.

The seroepidemiology of infection due to rubella virus in Saudi Arabia was investigated in various age groups including unvaccinated children (newborn to 15 years of age) using a newer rubella antibody test system, the ELISA with maximum sensitivity and reliability. The assessment of the immune status indicated the lowest level of naturally acquired rubella IgG antibodies in children aged 13-18 months and thereafter a pattern of progressive age-specific increase in seropositivity. About 90 per cent of the women of childbearing age were seroimmune. The target population for rubella immunization is identified.

Adolescent↗
PubMed1989

Herpes simplex virus type 1 (HSV-1) and varicella-zoster virus (VZV) infections in Saudi Arabia.

The seroepidemiology of infection due to herpes simplex type 1 (HSV-1) and varicella-zoster (VZV) viruses was investigated in 224 Saudi children aged from under 1 year to 15 years and 452 adults (healthy male blood donors and pregnant women) using a presently available sensitive indirect immunofluorescence technique to detect antibodies to these viruses in order to determine the age of primary infection. Age-specific prevalence of IgG antibodies to HSV-1 and VZV showed a progressive increase with age in both males and females with no obvious sex-related variation in the level. The overall prevalence of antibodies was 60 per cent for HSV-1 and 68 per cent for VZV in children whereas about 90 per cent of the adults showed the presence of antibodies to both viruses. Virological and serological confirmation of two cases in children of herpes simplex encephalitis (HSE) due to HSV-1 and VZV reactivation in two adults is described.

Adolescent↗
PubMed1989

Rubella and cytomegalovirus (CMV) infections: laboratory aspects of investigation of antenatal, congenital, persistent, and subclinical infections.

Rubella specific IgM tests carried out on pregnant women with history of rubella contact or rubella-like rash indicated the presence of rubella-IgM by the second week after contact, persistence to 3-4 weeks followed by a decline and non-detectability around 8-9 weeks and at delivery. Laboratory investigation of cases of rubella infection in infants and children, including clinically proven and suspected congenital rubella revealed distinct patterns of combinations of positivity and negativity of IgM and IgG antibodies. Three cases of persistence of rubella specific IgM antibodies with one even up to 3 years in congenital rubella and a case of CMV-IgM persistence in congenital CMV are described. Rubella-IgM and CMV-IgM were detected in the serum of two patients aged 12 years and 24 years with CMV mononucleosis. Utilization of rubella-IgM/CMV-IgM tests enabled the identification of four cases of subclinical rubella and one of subclinical CMV in a pediatric population.

Adolescent↗
PubMed1989

Indirect haemagglutination (IHA) test in the serodiagnosis of amoebiasis.

Among 72 patients clinically suspected of Entamoeba histolytica (E. histolytica) infections, 39 positive cases (54%) were detected serologically by the indirect hemagglutination (IHA) test. Parasitologically, microscopic examination of three consecutive stool specimens from all these patients indicated positivity for E. histolytica cysts and or trophozoites in 10 of the patients with IHA antibody titers greater than or equal to 1:128, which is of clinical significance. Another 2 patients were parasitologically positive but showed low IHA antibody titres (1:32-1:64); follow up indicated response to treatment with metronidazole. The highest serological positivity (100%) were detected in patients with liver abscess, all were clinically proven cases of extra-intestinal amoebiasis. IHA antibody levels of clinical significance were seen in all four patients with chronic dysentery with parasitological evidence of E. histolytica in their stools. In a group of patients with abdominal pain nine positives were detected serologically, four of which were positively diagnosed concurrently by parasitology; the remaining five patient's sera showed high IHA antibody titres with absence of cysts or trophozoites in stools, indicative possibly of persistence of antibodies from past infection. The serologic determination of E. histolytica IHA antibodies in a control group consisting of normal healthy school children and adults of both sexes without any clinical evidence of amoebiasis showed the absence of any positive titres of clinical significance; low titres (1:32-1:64) were detected in 5.2% of 232 sera tested. Parasitological examination of three consecutive stool specimens from all individuals in the control group showed the presence of cysts of E. histolytica in just two among 232 tested (0.9%).

Adolescent↗
PubMed1989

Enzyme immunoassay in the diagnosis of Chlamydia trachomatis infections in diverse patient groups.

An enzyme immunoassay (EIA) in parallel with cell culture was used to investigate the extent of infections due to Chlamydia trachomatis. EIA reactive confirmed in cell culture was taken as positive. C. trachomatis was found in 6 (26.0%) of 23 men with symptomatic non-gonococcal urethritis (NGU), ten (17.2%) of 58 symptom-free males and in three of 4 with postgonococcal urethritis. Among 106 asymptomatic pregnant women studied the incidence of C. trachomatis was 8.5% while a higher incidence (16.7%) was found in those with symptoms. C. trachomatis positivity in asymptomatic and symptomatic post-natal screening were 11.4% and 7.7%. Of 43 symptomatic non-pregnant females investigated, 7 (16.3%) were found to be positive for C. trachomatis. Of 3 women with PID, 2 (66.7%) harboured C. trachomatis in their cervix while in another 29 infertile women, C. trachomatis was positive in 3 (8.1%). Contraceptives appeared to have an effect on the chlamydial positivity. Comparative testing of EIA with the standard cell culture method in this study indicate EIA as a suitable alternative for the definitive diagnosis of chlamydial infection in high prevalence settings and with caution in low prevalence settings.

Antigens, Bacterial↗
PubMed1988

Serologic diagnosis of Chlamydia trachomatis infections.

The serology of various infections often caused by Chlamydia trachomatis including complications such as pelvic inflammatory disease (PID) and infertility was investigated comprehensively among diverse patient groups in a developing country using initially an indirect immunofluorescent antibody test (IFA). Any positives detected were further examined by a micro-immunofluorescence (MIF) method for the presence of type specific anti-chlamydial IgG/IgM antibodies. Conventional cell culture was carried out concurrently to compare culture results with serologic results. Among 416 patients (107 males and 309 females) C. trachomatis D-K antibodies to IgG were identified in 87 (20.9%) and to type specific IgM were identified in 11(2.6%) patients. Cell culture identified C. trachomatis in 60 patients (14.4%). C. trachomatis IgG antibodies were detectable in 6.4% of chlamydia culture negative patients.

Antibodies, Bacterial↗
PubMed1988

Studies on the factors affecting the haemolysin production of Vibrio mimicus isolated from clinical and environmental sources.

The in vitro production of haemolysin by Vibrio mimicus, a newly described aetiological agent for human diarrhoea, was determined using sheep erythrocytes. The effects of medium composition and sodium chloride concentration on haemolysin production and its heat stability were investigated. The haemolysin was produced optimally in brain-heart infusion broth and was unaffected by salt concentration up to 1.5%. However, haemolysin production decreased gradually with increasing concentrations of salt above 1.5%, with no production at 5% NaCl. Haemolytic activity was completely lost when culture supernatants were heated at 56 degrees C for 30 min. In general, clinical strains were more haemolytic than environmental strains. The assay system described is simple and rapid, and can be used to study the pathogenic potential of V. mimicus and other noncholera vibrio strains.

DNA↗
PubMed1988

Tonsillitis and respiratory infections of viral aetiology in a developing country.

Among 75 clinically diagnosed cases of tonsillitis, 55 (73.3%) were found to be of viral aetiology. Serological and virological investigations identified adenovirus as the main causative agent in children as well as in adults. In only two instances, both in children, was an association with respiratory syncytial virus (RSV) in tonsillitis detected, an extremely rare finding. A cross-sectional sero-epidemiological study of respiratory infections caused by adenovirus, RSV, influenza (A,B) and para-influenza (types 1,2,3) viruses was carried out in 289 Saudi children (newborn to 15 years of age) and 86 adults (healthy male blood donors and pregnant women) using a single serological technique. In children as well as in adults, adenoviruses were the most predominant respiratory pathogens, with no marked variation in age-specific antibody prevalence rates.

Adenovirus Infections, Human↗
PubMed1988

Comparison of haemagglutination test, enzyme-linked immunosorbent assay and indirect immunofluorescence antibody test for determination of rubella immune status.

Comparative evaluations of immune status for rubella are described for the enzyme-linked immunosorbent assay (ELISA), indirect immunofluorescence (IFA) and two standard haemagglutination inhibition tests (HAI kaolin; HAI heparin-MnCl2). In general, a reasonably good correlation was obtained between the level of rubella antibodies measured by the HAI (kaolin) test and by ELISA, but an appreciable proportion (15%) of ELISA positive specimens were encountered among HAI (kaolin) negative sera. All of these HAI negative, ELISA positive sera, except one were found to be positive for rubella antibodies by IFA. Neutralization test performed on this serum positive by ELISA only, confirmed the presence of protective rubella antibodies. Of all the tests evaluated ELISA appeared unequivocally to be the most sensitive test followed closely by IFA. The standard HAI (heparin-MnCl2) was more suitable than the HAI (kaolin), for the determination of immune status. Further, no linear relationship between single rubella virus HAI and ELISA values was observed.

Antibodies, Viral↗
PubMed1988

Enzyme immunoassay (EIA) in the rapid diagnosis of gonorrhoea.

The diagnostic value of a new, modified enzyme immunoassay (EIA) (Gonozyme; Abbott Laboratories, North Chicago III) was evaluated for the rapid antigenic detection of Neisseria gonorrhoeae in endocervical and urethral specimens. EIA results were compared with those of Gram stain (GS) and conventional culture tests. EIA sensitivity and specificity for male patients attending dermatovenerological clinic were 100% and 96.8% respectively in comparison to 86.7% and 96.8% obtained by Gram staining. For female Obstetrics-Gynaecology patients EIA sensitivity of 100% was highly significant compared to 50% sensitivity by the Gram stain. In culture, 30 strains of N. gonorrhoeae were isolated from 125 male specimens and 2 from 105 specimens from females; this suggests a prevalence of N. gonorrhoeae of 24% in males and 1.9% in females. In vitro antibiotic sensitivity testing indicated 55% resistance to penicillin and 43% to ampicillin in these isolated strains; all were sensitive to erythromycin/tetracycline. 12% of the strains were beta-lactamase producers.

Evaluation Studies as Topic↗
PubMed1987

Routine screening of gynaecological and obstetric patients for Chlamydia trachomatis.

Chlamydia trachomatis infection of the cervix uteri was diagnosed in 9% of 221 gynaecological and obstetric patients. Infection occurred more commonly among obstetric (12.6%) than gynaecological patients (5.5%). In obstetric patients chlamydial infection was commoner in those complaining of excessive vaginal discharge or spontaneous premature rupture of the membranes. Chlamydial infection in gynaecological patients occurred in those with previous pelvic infection, menstrual disorders or excessive vaginal discharge. No cases of chlamydial infection were detected among intrauterine device users. The enzyme immunoassay we used is an easy and relatively quick method of diagnosis for genital chlamydial infection.

Cervix Uteri↗
PubMed1987

Rapid diagnosis of cholera by coagglutination test using 4-h fecal enrichment cultures.

A simple, rapid, and reliable method to detect Vibrio cholerae in fecal specimens would assist in the management of cases of severe diarrhea, especially since most such cases occur in areas with minimal laboratory facilities. A coagglutination test was used to detect V. cholerae antigen in bile-peptone broth incubated with feces. In the technique, Staphylococcus aureus Cowan 1 coated with anti-V. cholerae O1 antiserum was tested with cultures incubated for 4 h. When 165 specimens were tested, the sensitivity, specificity, and accuracy of the test, compared with standard culture methods, were 97, 99, and 98%, respectively. These promising results were better than those of dark-field microscopy using the same specimens, and the test was logistically easy to perform. The coagglutination test using enrichment broth culture of feces is a simple and rapid method which may be used to confirm a diagnosis of cholera.

Agglutination Tests↗