[Molecular epidemiological study of molluscum contagiosum]

The agarose gel electrophoretic analysis of molluscum contagiosum virus (MCV) DNA obtained from 92 Japanese patients revealed the presence of four different BamHI cleavage patterns of MCV DNAs, classified as MCV-1,2,3 and 4. MCV-1 was found in 69% of the patients, MCV-2 in 4%, MCV-3 in 25%, and MCV-4 in 2%. Almost all the isolates from children and all female adult cases were infected with either MCV-1 or 3. No obvious clinical differences were seen between these two types. MCV-4 was found in only two adult male cases. The sizes of the lesions induced by MCV-4 appeared to be larger than those of other types. Six sets of siblings were shown to be infected with the same types, whereas two sets were infected with the different types. Some different MCV types were found in the cases attending the same swimming pools.