Detection of 5 Latent Herpes Viruses and Pneumocystis Jirovecii in Saliva of Healthy Children by PCR

Herpes virus group can persist in the latent form in the body, Pneumocystis jerovecii, on the other hand, is a fungus which is ubiquitous in the respiratory tract of mammals, with 90% of adult human beings possessing antibodies to this organism. Concomitant presence of different microorganisms, may result in one microorganism altering the activity of another. To determine the frequency of 5 latent Herpes viruses and Pneumocystis jirovecii and to ascertain the rate of concomitant presence of these microorganisms in saliva of healthy children. This cross-sectional study was performed on 150 immune-competent children 1 to 15 years old visited in the outpatient clinics at a university-affiliated children’s hospital from 22nd May to 21st August 2011. Samples of saliva obtained from the children were subjected to DNA extraction by polymerase chain reaction. At least one microorganism was isolated from saliva of 148 children, (98.6%). In 13 cases only 1 microbe was detected, (8.6%), 2 pathogens were isolated from 24 children, (16%), 3 from 20 cases, (13.3%), 4 from 54 individuals (36%), and 5 from 37 subjects (54.4). HSV was the most frequent organism detected in 80.7%, and P. jirovecii the least frequent, (32.7%). Other viruses were HHV6, 66.7%, CMV 66.0%, HHV7 64.7%, and EBV 37.3% in order. No significant difference was found in the frequency of microorganisms in the two sexes or in different age groups, except for CMV which was significantly less frequent in age group of 6-10 years (P value = 0.001). Regression analysis revealed an association between HHV6 and HHV7 (OR = 1599.4; P value < 0.001); a correlation was also found between EBV and CMV (OR = 3.1; P value = 0.012). In contrast, a negative correlation was found between P. jirovecii and three viruses of the Herpes virus group including EBV (OR = 0.27; P value = 0.006), HSV1 (OR = 0.36; P value = 0.028), and CMV (OR = 0.48; P value = 0.075). Shedding of latent Herpes viruses and concomitant presence of multiple inactive micro-organisms is common in saliva of immune-competent children.