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Human papillomavirus (HPV) infection is the most common sexually transmitted disease in the world and accounts for an estimated 11% of the global cancer incidence in women. HPV-16 is the most prevalent type detected in cervical cancer and along with types 18, 31, 33 and 45 has been classified as a class I carcinogen. In addition to cervical cancer, HPVs are also associated with the malignant transformation of other mucosal and skin cancers. Thus, the combination of the malignant potential of HPV and its high prevalence of infection confers to it an importance of generalized clinical and virological significance. The natural history of HPV infection with or without treatment varies from spontaneous regression to persistence. The most important mechanism for wart regression appears to be cell-mediated immunity. Cytokines released by keratinocytes or cells of the immune system may play a part in the induction of an effective immune response against HPV infection and the subsequent regression of lesions. This review discusses the molecular biology, pathogenesis and immunology of HPV infections.

Enzyme-linked immunosorbent assay (ELISA) and a reversed passive hemagglutination (RPHA) test were evaluated for rapid detection of Crimean-Congo hemorrhagic fever (CCHF) virus antigens. Both RPHA and ELISA detected CCHF antigen in the brains of infant mice 2 to 3 days after infection, several days before the animals sickened and died. Antigen was also detected after 1 to 2 days in infected cell culture extracts and after 2 to 4 days in culture supernatant fluids. Both tests detected CCHF antigen at threshold values of approximately 2.5 log1, tissue culture infective doses per ml and were more sensitive than complement fixation, immunodiffusion, or immunofluorescence. In a comparative study on specimens from CCHF patients, virus was isolated from 38 of 49 sera and 23 of 28 patients. Antigen was detected in 20 of 49 sera (15 of 28 patients) by RPHA and in 29 of 49 sera (18 of 28 patients) by ELISA. Antigenemia was detected more frequently in fatal cases (9 of 11) than in nonfatal cases (9 of 17). Although the antigen detection assays offered a more rapid approach than infectivity assays for diagnosing CCHF, the latter test was more sensitive. The results suggest that RPHA and ELISA may be of use in rapid diagnosis of CCHF infection, particularly in severe cases, in which the danger of nosocomial spread is greatest.

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