SEASONAL FLUCTUATIONS IN THE CERVICAL SMEAR DETECTION RATES FOR (PRE)MALIGNANT CHANGES AND FOR INFECTIONS

The detection of diseases can exhibit seasonal fluctuations. This can be studied in cervical smears. Over a 9-year observation span (January 1983-January 1992) a ser ies of 504,093 cervical smears obtained from a routine cytology laboratory in The Netherlands were examined for in fections (monilia, trichomonas, actinomyces, human papilloma virus [HP V], chlamydia, and herpes) as well as for mild, moderate, and severe d ysplasias, carcinoma in situ, and squamous carcinoma. Statistical anal ysis (principal component analysis) demonstrates clear seasonal rhythm s in the detection of infections as weil as in precursor lesions. Thes e findings suggest that we are dealing with ''true'' detection rhythms . For the detection of (pre)malignancy and HPV, yearly fluctuations in women being screened might be the explanation for our observations. ( C) 1997 Wiley-Liss, Inc.