Supervisors info:
Χρυσομάλη Ευανθία (Επίκουρη Καθηγήτρια), Σκλαβούνου Ανδρικοπούλου Αλεξάνδρα (Καθηγήτρια), Δρακούλης Νικόλαος (Επίκουρος Καθηγητής)
Summary:
Introduction: Human Papillomavirus is a small, epitheliotropic, double-stranded
DNA virus that infects mucosal and cutaneous epithelia of the skin, the upper
aerodigestive tract and the genital area. HPV infection may induce clinically
visible alterations, either bening or malignant, but it may also develop into a
subclinical disease.
Aim: The aim of the present study was to estimate the prevalence of HPV DNA in
normal oral mucosa among Greek young adults and to study the natural history of
HPV infections on 12-month follow up after initial examination.
Material and method: To estimate incidence and clearance of oral HPV
infections, undergraduate students attending Faculty of Medicine, Dentistry,
Nursing and Pharmacology, who were above 18 years of age with clinically
healthy oral mucosa, were recruited into the present study. Each participant
was kindly asked to fullfill a questionnaire and then provide one rinse-
and-gargle sample, using 10ml of Scope mouthwash (Procter and Gamble). DNA was
extracted from oral rinse samples and was quantified using PCR technique, while
DNA microaaray techonology was used for detection and genotyping of HPV. The
participants, who proved to be HPV positive, provided second rinse-and-gargle
sample on a 12-month follow-up visit.
Results: 106 postgraduate students aged 18-25 years old were included in the
study. At initial examination, 5,7% of students proved to be HPV positive. HPV
DNA was detected in 3 of 39 male participants (7,7%) and in 3 of 67 female
students (4,5%). All infected individuals were non-smokers, while none of them
reffered HPV-related medical history. HPV infection from high risk types was
observed in 6 of 106 samples (5,7%) while 1,9% (2/106) was infected by a low
risk type. The most commonly detected HPV type was HPV 53, followed by HPV 16
and HPV 66, while infections from multiple HPV types were recognised in 5 of 6
positive samples. At 12-month follow-up examination, HPV DNA was detected in
all individuals who were proved to be HPV-positive at the initial examination.
Persistent infection, which has been defined as detection of the same HPV type
at 2 consecutive tests, was detected in 6 of 6 positive samples (100%).
Clearance of at least one HPV type-specific infection was observed in 4 of 6
participants (66,7%). For oncogenic HPV types, clearance rate was 35,2%, while
for non-oncogenic types clearance rate was 100%. All HPV-53 infections that
were detected at baseline examination proved to be persistent. In total,
clearance rate of HPV infection at 12-month follow-up interval was 45%, since
20 HPV type-specific infections were detected at initial examination and 11 of
them still were detectable after 1 year.
Conclusions: Low proportion of young Greek adults with normal oral mucosa is
HPV DNA positive. However, infections from multiple and high risk HPV types are
common among infected individuals. In addition to these, persistent high risk
infections, that last more than a year, are not uncommon.
Keywords:
Human Papilloma Virus (HPV), Healthy oral mucosa, Greek, Persistence, Clearance
