Indirect immunofluorescence test: role in seroepidemiology and serodiagnosis of herpes simplex viral infections.
A study was carried out to find out a) the seroprevalence of herpes simplex viral infections (HSV) in and around Chandigarh city, North India and the probable age of acquisition of infection; b) the usefulness of salivary antibody detection in seroprevalence studies; c) role of HSV immunofluorescence antibodies in the sero-diagnosis of herpes simplex encephalitis (HSE) patients. Single blood samples from 306 and paired blood and saliva samples from 48 apparently healthy individuals as well as paired blood and C.S.F. samples from 50 clinically suspected patients of HSE were included in the study proper. The subjects belonged to <6 months to > 30 years age group. Serum, saliva and C.S.F. samples were subjected to in house standardized indirect immunofluorescence test for the detection of HSV antibody. The overall seropositivity was 59.3%, which increased from 37.5% in children less than 10-years of age to 88.9% in individuals above 30 years of age (p<0.001). The maximum titer in less than 10 years children and above 10 years subjects were found to be 40 and 160 respectively. The difference in percentage positivity of HSV antibody in these groups was statistically significant (p<0.001). No difference in the seroprevalence rate was observed between different socio-economic groups and sex. Saliva in comparison to serum showed a sensitivity of 44% and specificity of 100% for the detection of HSV antibodies. Among the suspected HSE patients 4 (8%) could be serologically confirmed. This study indicated the endemicity of HSV infection in this locality. Indirect immunofluorescence test could detect intrathecal HSV antibodies in 8% of suspected HSE patients proving it to be a very useful rapid serodiagnostic tool. However, saliva testing showed limited sensitivity in HSV sero surveys.
Ratho
R K
RK
Department of Virology, Postgraduate Institute of Medical Education and Research, Chandigarh. medinst@pgi.chd.nic.in
Mishra
B
B
Hassan
S
S
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D006561:Herpes Simplex / Q000150:complications / Q000175:diagnosis* / Q000453:epidemiology*; D006801:Humans; D007194:India / Q000453:epidemiology; D007223:Infant; D008297:Male; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000175:diagnosis / Q000453:epidemiology; D016036:Seroepidemiologic Studies; D012698:Serologic Tests