A solid-phase reverse immunosorbent test for the detection of enterovirus IgM.

IgM antibodies against enterovirus antigen were determined by solid-phase reverse immunosorbent test (SPRIST). The 145 sera studied were sampled from cases of enterovirus infections diagnosed by virus isolation and/or complement fixation. In 91 sera from enterovirus infections diagnosed by virus isolation 11/40, 16/28 and 9/23 were positive in SPRIST against ECHO 3 and/or Coxsackie B3 antigen during the first, during the second and third, and after 3 weeks of illness, respectively. The corresponding figures for 85 sera from enterovirus infections diagnosed by a greater than or equal to 4-fold rise in complement fixing (CF) antibody titre against antigen from ECHO 18 and/or Coxsackie B5 antigen were 10/39, 12/20 and 9/26. None out of 22 sera with rheumatoid factor reacted in SPRIST, but 1/92 and 1/154 sera from blood donors was positive in SPRIST with Coxsackie B3 and ECHO 3 antigen, respectively. IgM antibodies against ECHO 3 antigen as determined by SPRIST were found to be cross-reactive over a broad range of enterovirus types and positive results were recorded with sera from infections with Coxsackie A9, B3, B4, B5, ECHO 3, 9, 17, 18, 25 and 30. Heterotypic titres in SPRIST were of the same magnitude (up to 25,600) as recorded against the homotypic virus, 12,800 and 1,600, in two sera from one patient with an ECHO 3 infection. SPRIST was found to be a rapid convenient, cross-reactive and a cheap mu-capture assay for enteroviruses with more than 50% sensitivity during the second and third weeks after onset of illness.

The use of saliva for the detection of IgG and anti-bodies against rubella virus: comparison of indirect ELISA and antibody capture immunoassay.

Serum and saliva specimens, collected simultaneously from 26 normal adult females, were tested for IgG and IgA antibodies to rubella virus by indirect ELISA and antibody capture assays. Antibody capture assays were found to be more sensitive than indirect ELISA for the detection of IgG and IgA antibodies in saliva samples whereas both assays were similar in sensitivity for the detection of IgG and IgA antibodies in serum samples. Comparison of the results obtained from serum and saliva samples showed that by an indirect ELISA test 13 out of the 22 seropositive subjects were also positive for antibodies in their saliva. So this test had 9 false negative results, whereas by an antibody capture assay 18 out of 22 seropositive subjects were also positive for antibody in saliva. Thus there were only 4 false negative results. Further comparison of results derived from testing serum and saliva are needed before recommending the use of saliva alone for detection of antibodies to rubella virus.

Asymptomatic bacteriuria in school children in a rural area, Egypt.

Forty hundred and fifty urine samples collected from school children in a rural area were screened for the presence of significant bacteriuria. The incidence of asymptomatic bacteriuria was found to be 7% with Predominance in females (11%) than in males (3.6%). From the total bacterial isolates E. coli were isolated in 18% of cases, Co-agulase positive staphylococci in 30%, co-agulase negative staphylococci in 15%, streptococcus pyogenes in 6%, Klebsiella species in 9% and enterococci in 21% of cases. There was no difference between the incidence of asymptomatic bacteriuria (ABU) in younger children than in older ones. We recommended a routine screening for ABU among school children for the early diagnosis and management of such cases.

Diagnosis of tuberculous meningitis by immunofluorescence and enzyme immunoassay.

Cerebrospinal fluid was collected from 29 patients with tuberculous meningitis, 21 and 7 patients with bacterial and viral meningitis and 5 normal subjects. Pressure, aspect, glucose, protein and cellular content of CSF were studied. Detection of acid fast bacilli in direct film stained by Zeil Neilsen (Z.N.) and fluorochrom (Fl.Ch.) and Culture on Lowenstein Jensen media were done. Then specific immunoglobulin G & M to Mycobacteria were assayed by Immunofluorescence (IF using BCG) and by Enzyme Linked Immunosorbant assay (ELISA) using protein-A of M. Tuberculosis. It was found that diagnosis of M. Tuberculosis by CSF culture was more sensitive than by direct CSF film stained with Z.N. or Fl.Ch. stain (positive in 44.8%, 10.3% and 17.2% of cases respectively). It was noticed that the detection of CSF IgG antibodies was more sensitive than IgM antibodies either by IF or ELISA. By comparing ELISA and IF tests for detection of specific anti-mycobacterial immunoglobulin in CSF, it was clear that the sensitivity and specificity of ELISA was more than IF test. A positive result for antimycobacteria IgG antibodies was obtained in 79.3% and 58.6% of cases respectively (p less than 0.05). None of the CSF of normal controls, bacterial and viral meningitis cases gave positive antimycobacteria IgG by ELISA while 9.5% of the CSF of bacterial and 14.3% of aseptic meningitis cases gave positive results with IF. The sensitivity, specificity and predictive value of the described ELISA test, make it useful for early diagnosis of tuberculous meningitis.

An outbreak of acute haemorrhagic conjunctivitis caused by enterovirus 70 in Jeddah during 1985.

Seventy-five cases of acute haemorrhagic conjunctivitis (A.H.C.) were subjected to full ophthalmic, bacteriological, virological, serological as well as cytological examinations. The majority of cases presented with bilateral conjunctivitis (70 out of 75). Although follicular reaction was the earliest sign, yet subconjunctival haemorrhages were the most constant findings in all the cases. Enterovirus 70 was isolated in 57 cases from conjunctival swabs and in 43 cases from serum samples. Complement flaxation test was positive for enterovirus 70 in 42 cases but negative for coxsackie and adenoviruses. No primary role has been found for bacteria in the pathogenesis of A.H.C. in this outbreak. Cytological examination of conjunctival scrappings showed the characteristics cytopathic effect (CPE) of enteroviruses.

Immunomodulatory effects of secondary hyperparathyroidism on circulating CD4+ and CD8+ T-lymphocytes in chronic renal failure patients.

The immunomodulatory effects of parathyroid hormone (PTH) in patients with end stage renal disease (ESRD) is controversial. This study was carried out to investigate the effect of PTH levels on the circulating CD4+, CD8+ T cell counts (%) in patients with chronic renal failure (CRF) on regular hemodialysis ((HD). The study included 22 patients with serum levels of PTH < 300 pg/ml (group 1), 18 patients with PTH > 300 pg/ml (group II) and 10 age and sex matched normal controls (group III). Chemiluminescence and flowcytometry assays were performed for determination of serum PTH levels and T cell subset counts respectively. The mean (%) of total lymphocyte, CD4+, CD8+ and CD4\CD8 ratio of group I were (81.68+/- 9.38), (52.00+/-6.24), (27.13+/- 6.31) and (1.99+/-0.42) respectively, as compared to (73.83+/-13.30), (46.05+/-8.59), (23.05+/-4.63) and (2.03+/-0.41) respectively in group II. Values of group I and II were significantly (P<0.001) lower than controls (88.50 +/- 6.02), (63.30 +/- 6.44), (36.80 +/- 6.44) and (1.76+/-0.36) respectively. In group II, the reduction was significantly (P<0.001) prominent in patients with high PTH levels, with significant inverse correlations (P<0.001) between PTH and % of total lymphocyte (r= -0.93), CD4+ (r= -0.74) and CD8+ % (r=-0.69). In conclusion, increased level of PTH in CRF patients on hemodialysis is associated with lymphopenia and reduction in CD4+ & CD8+ subsets of T cells. Monitoring circulating PTH levels in such patients can restore their immune competence.

Experimental immunosuppression and infection of chickens with Quaranfil virus.

In ovo hormonal bursectomy of chick embryos was carried out by chorioallantoic membrane inoculation with testosterone propionate at the 18th day of embryonation. At hatching immunosuppression was complemented with sublethal X-irradiation. At 40 days of age the immunomanipulated and control chickens were inoculated subcutaneously with a single dose of Quaranfil virus. It was observed that bursectomy and bursectomy with sublethal X-irradiation prolonged viraemia up to the 20th day following virus infection with a significant reduction of natural haemagglutinins and of virus induced specific antibody response.