Intrafamilial transmission and family-specific spectra of cutaneous betapapillomaviruses

Abstract

Cutaneous human betapapillomaviruses (beta-HPVs) are widespread in the general population and have been associated with skin cancer. To evaluate the impact of continuous person-to-person contact within families on an individual's beta-HPV type spectrum, we collected serial skin swab samples from parents and children from 10 families. All participants were found to be beta-HPV DNA positive, with 1 to 13 types at study entry (median, 4.0 types). Initial and cumulative (2 to 16 types) HPV type multiplicities varied widely between different families but only a little between family members. The high intrafamilial correlation of HPV multiplicity is already obvious for babies aged 10 days to 10 months. Family members typically displayed similar spectra of HPV types. More than 75% of the HPV types in babies were also detected in their parents. This indicates that HPV transmission mainly results from close contact between family members. Type-specific persistence for at least 9 months was more prevalent in parents (92%) than in children (66%). Of the types detected throughout the study, 24% turned out to persist in the parents and only 11% in the children. Interestingly, about one-half of the HPV types found to persist in one of the parents occurred less frequently or even only sporadically in the spouse. Similarly, only one-third of the persisting parental types also persisted in their children. This indicates that even regular exposure to cutaneous HPV does not necessarily lead to the establishment of a persistent infection, which may point to type-specific susceptibilities of different individuals.

FIG. 1.

Persistent and nonpersistent HPV infections and family-specific type spectra. Black circles, persistently found types (for definition of persistence see text); gray circles, types detected in >20% of the samples but not persistent according to the definition; open circles, types detected in <20% of the samples; gray diamonds, types in participants tested only once. F, father; M, mother; fC, female child; mC, male child; MM, mother of the mother; FM, father of the mother; MF, mother of the father; FF father of the father. Footnotes: 1, number of sampling episodes (SE); 2, observation period (OP) in months; 3, age in months of children at study entry.

FIG. 2.

Persistent HPV types and types detected at different sampling dates in parents and the child of family 2. Footnotes: 1, age of child in months; 2, HPV type 49 was detected once in the mother, and HPV types 21 and 80 were detected in the child and are not included in the figure; 3, sample sites were forehead (1), buttock (2), and back of the hand (3).

FIG. 3.

Persistent HPV types and types detected at different sampling dates in parents and the child of family 4. Footnotes: 1, age of child in months; 2, HPV types 24 and 92 and an unspecified HPV type were detected once in the mother and are not included in the figure; 3, sample sites were forehead (1), buttock (2), and back of the hand (3).