detection of 5 latent herpes viruses and pneumocystis jirovecii in saliva of healthy children by pcr

background: 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. objectives: 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. patients and methods: 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. results: 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). conclusions: shedding of latent herpes viruses and concomitant presence of multiple inactive micro-organisms is common in saliva of immune-competent children.