Human papillomavirus type 16 in infants: use of DNA sequence analyses to determine the source of infection

Seroprevalence of mucosal and cutaneous human papillomavirus (HPV) types among children and adolescents in the general population in Germany

Background

In Germany, HPV vaccination of adolescent girls was introduced in 2007. Nationally representative data on the distribution of vaccine-relevant HPV types in the pre-vaccination era are, however, only available for the adult population. To obtain data in children and adolescents, we assessed the prevalence and determinants of serological response to 16 different HPV types in a representative sample of 12,257 boys and girls aged 1–17 years living in Germany in 2003–2005.

Methods

Serum samples were tested for antibodies to nine mucosal and seven cutaneous HPV types. The samples had been collected during the nationally representative German Health Interview and Examination Survey for Children and Adolescents in 2003–2006. We calculated age- and gender-specific HPV seroprevalence. We used multivariable regression models to identify associations between demographic and behavioral characteristics and HPV seropositivity.

Results

We found low but non-zero seroprevalence for the majority of tested HPV types among children and adolescents in Germany. The overall seroprevalence of HPV-16 was 2.6%, with slightly higher values in adolescents. Seroprevalence of all mucosal types but HPV-6 ranged from 0.6% for HPV-33, to 6.4% for HPV-31 and did not differ by gender. We found high overall seroprevalence for HPV-6 with 24.8%. Cutaneous HPV type seroprevalence ranged from 4.0% for HPV-38 to 31.7% for HPV-1. In the majority of cutaneous types, seroprevalence did not differ between boys and girls, but increased sharply with age, (e.g., HPV-1 from 1.5% in 1–3-years-old to 45.1% in 10–11-years-old). Associations between behavioral factors and type-specific HPV prevalence were determined to be heterogeneous.

Conclusions

We report the first nationally representative data of naturally acquired HPV antibody reactivity in the pre-HPV-vaccination era among children and adolescents living in Germany. These data can be used as baseline estimates for evaluating the impact of the current HPV vaccination strategy targeting 9–14-years-old boys and girls.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07028-8.

Contributory role of viral infection in congenital tumour development

Congenital tumours are a group of distinct infrequent disorders whose exact aetiologies have not clearly been understood so far. Viral infection seems to be one of the key factors involved in the carcinogenesis of certain tumours. This study was performed to assess whether viral DNAs are present in the congenital tumours or not. Nucleic acid from 31 congenital tumours was extracted. Detection of Epstein–Barr virus, Cytomegalovirus (CMV), adenovirus, Herpes simplex virus 1 (HSV1) and 2, Human herpes virus 6 (HHV6), and BK virus was performed using polymerase chain reaction. Viral nucleic acid was detected in eight subjects (25.8%), mostly adenovirus, CMV, and HHV6. Despite their low frequencies, a possible role could be identified for viral infections in tumour development or progression.

Rate of vertical transmission of human papillomavirus from mothers to infants: relationship between infection rate and mode of delivery

Background

In contrast to consistent epidemiologic evidence of the role of sexual transmission of human papillomavirus (HPV) in adults, various routes may be related to HPV infection in infants. We have assessed the extent of HPV infection during the perinatal period, and the relationship between mode of delivery and vertical transmission.

Results

A total of 291 pregnant women over 36 weeks of gestation were enrolled with informed consent. Exfoliative cells were collected from maternal cervix and neonatal buccal mucosa. HPV infection and genotypes were determined with an HPV DNA chip, which can recognise 24 types. The HPV-positive neonates were re-evaluated 6 months after birth to identify the presence of persistent infection. HPV DNA was detected in 18.9 % (55/291) of pregnant women and 3.4 % (10/291) of neonates. Maternal infection was associated with abnormal cytology (p = 0.007) and primiparity (p = 0.015). The infected neonates were all born to HPV-positive mothers. The rate of vertical transmission was estimated at 18.2 % (10/55) which was positively correlated with maternal multiple HPV infection (p = 0.003) and vaginal delivery (p = 0.050), but not with labour duration and premature rupture of membranes. The rate of concordance of genotype was 100 % in mother-neonate pairs with vertical transmission. The neonatal HPV DNAs found at birth were all cleared at 6 months after delivery.

Conclusions

Vertical transmission of HPV DNA from HPV infected mother to the neonate increased when the infant was delivered through an infected cervix. However, the absence of persistent infection in infants at 6 months after delivery may suggest temporary inoculation rather than true vertical infection.

High prevalence of high-risk human papillomavirus in palatine tonsils from healthy children and adults

OBJECTIVE

The aim of this study was to determine the prevalence of human papillomavirus (HPV) in 80 tumor-free tonsils from healthy children and adults using a sensitive E6/E7 type-specific polymerase chain reaction (PCR).

STUDY DESIGN

Cross-sectional study.

SETTING

Ear, nose, and throat department, university hospital.

SUBJECTS AND METHODS

Paraffin-embedded tissues from tumor-free tonsils (TFTs) were evaluated for HPV DNA using GP5+/6+ consensus PCR and subsequent genotyping using E6/E7 type-specific PCR for HPV types 6, 11, 16, 18, 31, 33, 35, 39, 45, 51, 52, 53, 56, 58, 59, 66, and 68. The immunohistochemical expression of p16 and p53 was also assessed.

RESULTS

In 80 TFTs, the authors identified 10 (12.5%) that tested positive for the following high-risk HPV types: HPV 16 (8 cases), 18 (1 case), and 31 (1 case). Twelve patients (15%) tested positive for HPV infection using the GP5+/GP6+ consensus primers but were negative using quantitative PCR. These patients were considered infected with low-risk HPV types. Fifty-eight TFTs (72.5%) tested negative for both GP5+/GP6+ and type-specific HPV PCR analysis (HPV negative). Among patients infected with HPV, the authors observed a slight increase in frequency with age.

CONCLUSION

In TFTs, oncogenic and nononcogenic HPVs were present at a relatively high frequency in children and adults. The presence of high-risk HPV DNA in young children supports the horizontal transmission hypothesis and argues in favor of HPV vaccination at birth.

High-risk human papillomavirus in the oral cavity of women with cervical cancer, and their children

BACKGROUND

Association of High-risk Human Papillomavirus (HR-HPV) with oral cancer has been established recently. Detecting these viruses in oral cavity is important to prevent oral lesions related to them. The purpose of this study was to evaluate the prevalence of HR-HPV in the oral cavity of women with cervical cancer, and their children. A total of 70 women, previously diagnosed with cervical cancer, and 46 children of these women, born by vaginal delivery only, were selected for this study. Buccal swabs were collected from their oral cavity and HPV detection was carried out using Hybrid Capture 2 high-risk HPV (HC2 HR-HPV) detection system.

RESULTS

Out of 70 women with cervical cancer, four (5.71%) were found to be positive for HR-HPV in their oral cavity. No association of HR-HPV was found with sociodemographic profile, marital status, reproductive history, tobacco and alcohol usage, contraceptive pills usage, and presence of oral lesions (p>0.05). Among children, HR-HPV in the oral cavity was detected in only 1 of the 46 subjects examined (2.17%). Clinically healthy oral mucosa, without any oral lesions, was observed in all the HR-HPV positive subjects.

CONCLUSION

The result of this study showed that there is low, if any, risk of HR-HPV infection in the oral cavity of women with cervical cancer. Further, our study suggests that there is very low risk for children of women with cervical cancer, to acquire and sustain HR-HPV in their oral cavity until childhood or adolescence.

Evidence for vertical transmission of HPV from mothers to infants

Few large studies have evaluated concordance based on a broad spectrum of human papillomavirus (HPV) types in oral and genital specimens of mothers and their recently born infants. This information is important in determining whether HPV vaccines administered prior to pregnancy may be useful for preventing vertical transmission. HPV DNA was positive in 30% of mothers and 1.5% of newborns. Maternal/newborn concordance (HPV+/+ or HPV−/−) was 71%. Among HPV DNA+ mothers, only 3% of their infants were DNA+ and only 1 pair had the same HPV type. Among HPV− women, 0.8% of infants were HPV+. HPV DNA detected in hospitalized newborns reflects current infection transmitted to infants during pregnancy or delivery. None of the mother/baby HPV DNA+ concordance pairs detected viral types found in HPV vaccines suggesting that vaccination prior to pregnancy is unlikely to be efficacious in preventing vertical transmission.

[How did I contract human Papillomavirus (HPV)?]

More than 120 genotypes have been identified among the Papillomavirus (HPV) family. These viruses are ubiquitary with skin or mucous membrane tropism and cause various pathologies from wart to neoplasia. HPV family is classified according to their tropism. Genital HPV infection is considered as the most frequent sexually transmitted disease in the world. Seventy-five percent of women will be in contact with HPV at least one time in their life. HPV is usually transmitted through direct skin-to-skin contact, more often during penetrative genital contact. Other types of genital contact in the absence of penetration can lead to HPV infection, but those routes of transmission are much less common than sexual intercourse. However, virgins (<2 % of cases) and young children can present HPV infection, suggesting other routes of transmission than sexual intercourse. HPV infection could occur during delivery; vaginal deliveries appear to promote this transmission in comparison with cesarean section. But cesarean section do not completely protect against contamination risk. In utero, vertical transmission has been suggested by different studies but with lack of evidence. HPV infection can be detected on inanimate objects, such as clothing or environmental surfaces. However, transmission is not known to occur by this route. More detailed knowledges of the transmission route of HPV infection will enable to get prevention more effective.

Perinatal transmission of human papilomavirus DNA

The purpose was to study the perinatal transmission of human papillomavirus DNA (HPV-DNA) in 63 mother-newborn pairs, besides looking at the epidemiological factors involved in the viral DNA transmission. The following sampling methods were used: (1) in the pregnant woman, when was recruited, in cervix and clinical lesions of the vagina, vulva and perineal region; (2) in the newborn, (a) buccal, axillary and inguinal regions; (b) nasopharyngeal aspirate, and (c) cord blood; (3) in the children, buccal was repeated in the 4th week and 6th and 12th month of life. HPV-DNA was identified using two methodologies: multiplex PCR (PGMY09 and MY11 primers) and nested-PCR (genotypes 6/11, 16, 18, 31, 33, 42, 52 and 58). Perinatal transmission was considered when concordance was found in type-specific HPV between mother/newborn or mother/child. HPV-DNA genital was detected in 49 pregnant women submitted to delivery. Eleven newborns (22.4%, n = 11/49) were HPV-DNA positive. In 8 cases (16.3%, n = 8/49) there was type specific HPV concordance between mother/newborn samples. At the end of the first month of life three children (6.1%, n = 3/49) became HPV-DNA positive, while two remained positive from birth. In 3 cases (100%, n = 3/3) there was type specific HPV concordance between mother/newborn samples. In the 6th month, a child (2%, n = 1/49) had become HPV-DNA positive between the 1st and 6th month of life, and there was type specific HPV concordance of mother/newborn samples. All the HPV-DNA positive children (22.4%, n = 11/49) at birth and at the end first month of life (6.1%, n = 3/49) became HPV-DNA negative at the age of 6 months. The HPV-DNA positive child (2%, n = 1/49) from 1st to the 6th month of life became HPV-DNA negative between the 6th and 12th month of life and one child had anogenital warts. In the twelfth month all (100%, n = 49/49) the children studied were HPV-DNA negative. A positive and significant correlation was observed between perinatal transmission of HPV-DNA and the immunodepression of maternal variables (HIV, p = 0.007). Finally, the study suggests that perinatal transmission of HPV-DNA occurred in 24.5% (n = 12/49) of the cases studied.

Vulval intraepithelial neoplasia and periungual Bowen's disease concordant for mucosal (HPV-34) and epidermodysplasia verruciformis (HPV-21) human papillomavirus types

Human papillomavirus (HPV) infection is associated with genital malignancy and specific cutaneous malignancies. We report a case of an HPV-associated concurrent vulval intraepithelial neoplasia and periungual Bowen's disease in a young immunocompetent Afro-Caribbean woman with no known risk factors for either disease. HPV genotyping studies detected multiple alpha and beta papillomaviruses with concordance for HPV-34 [a high-risk (HR) mucosal type], and HPV-21 [an epidermodyslasia verruciformis (EV) type] in both vulval and finger tissue. Although the HR-mucosal viruses detected are likely to have a pathogenic role in vulval intraepithelial neoplasia, this is the first report of concordance for EV HPV types in both genital and nongenital skin premalignancies. This case, in the context of accumulating epidemiological and experimental data in cutaneous SCC, raises the question of whether EV HPV may contribute to vulval malignancy, and further study is merited.

Human Papillomaviruses and Genital Disease

Human papillomavirus (HPV) infection is causally related to several benign and malignant diseases of the anogenital tract. In this article the authors detail the epidemiology, methods of transmission and risk factors, pathogenesis, and oncogenesis of HPV, and describe clinical manifestations and current treatments. Special attention is given to condyloma acuminatum and non-cervical anogenital intraepithelial neoplasia. The authors conclude with the latest information on prophylactic vaccine development and prospects for future control of HPV-related disease.

High-risk mucosal human papillomavirus infections during infancy & childhood

Human papillomaviruses (HPVs) are small DNA tumour viruses associated with a variety of proliferative diseases. More than 100 types have been identified and can broadly be grouped into cutaneous and mucosal types according to their site of infection, and can be further subdivided into low-risk (LR) and high-risk (HR) types depending upon their association with malignancy. The main route of transmission of HR mucosal HPVs is through sexual contact, although the acquisition of virus cannot be entirely explained by this mode alone. Evidence also exists for horizontal transmission by other routes and vertical transmission. HR HPVs, particularly HPV-16, have been detected in oral swabs from newborns, infants and children. Such alternative modes of transmission and acquisition may have an important impact in several areas, including vaccination strategies, epidemiological studies, and the clinical management of children with HPV-associated diseases. This article reviews the literature describing the detection of HPV infections during infancy and childhood and provides evidence for a role of vertical transmission in the spread of HPV infection.

Vertical transmission of the human papillomavirus: a systematic quantitative review

In order to better understand the exact mode and risk of vertical transmission in asymptomatic pregnant women, as well as the relationship between HPV transmission and mode of delivery, we have proposed this systematic quantitative review of prospective cohort studies. A comprehensive search was performed in the Cochrane Library, MEDLINE, LILACS, CANCERLIT, and EMBASE, as well as in the reference lists from the identified studies. Nine primary studies, which included 2,111 pregnant women and 2,113 newborns, met our selection criteria and were analyzed. A positive HPV test in the mother increased the risk of vertical HPV transmission (RR: 4.8; 95%CI: 2.2-10.4). We also observed a higher risk of HPV infection after vaginal delivery than after cesarean section (RR: 1.8; 95%CI: 1.3-2.4). The results of this meta-analysis showed the HPV DNA-positive rate only after birth, but an HPV DNA-positive neonatal sample does not necessarily indicate infection; it could merely indicate contamination (perinatal HPV contamination may have occurred). Infants born through vaginal delivery were at higher risk of exposure to HPV.

The Effect of Paralogous Lineages on the Application of Reconciliation Analysis by Cophylogeny Mapping

Paralogy defines similarity caused by duplication rather than common descent and is well known in the case of paralogous gene copies within a single genome. The term is here extended to paralogous lineages of associates within a single host. The phylogenies of four genera within the Herpesviridae were reconciled with host phylogenies using cophylogenetic mapping. The observed correspondence for each pair of phylogenies was evaluated through randomization of the viral phylogeny and demonstrated to be greater than expected by chance. A simulation study was then carried out to assess the influence of paralogous lineages on the efficacy of reconciliation analysis. Combining viral taxa from different genera that infected common hosts introduced incongruence into the cophylogenies and reduced both the minimum and maximum observed number of codivergence events relative to the initial analysis of orthologous clades. However, at an average sample size this did not alter the fundamental significance of observed correspondence. With smaller sample sizes, the number of orthologous taxa selected at random from the pool of taxa was reduced. False-negative results then increased in proportion from 0.02 to 0.33. These results demonstrated that reconciliation analysis is robust under conditions of paralogy at "normal" sample sizes but is adversely affected by a combination of paralogy and low sample size. Consideration of phylogenies for Papillomavirus, Atadenovirus, and Mastadenovirus suggest that paralogous lineages may be a widespread phenomenon among DNA viruses and that duplication irrespective of host speciation is an important cause of viral diversification.

Human papillomaviruses in the normal oral cavity of children in Japan

The purpose of this study was to determine the frequency of human papillomavirus (HPV) infections in the normal oral cavity of children in Japan. Oral squamous cell specimens were collected from 77 children (44 boys and 33 girls), aged 3 and 5 years. Extracted DNA was evaluated for HPV infections by polymerase chain reaction (PCR) methods, using consensus primers for the L1 region, specific primers, and direct DNA sequencing analysis. Thirty-seven of 77 specimens (48.1%) were positive for HPV DNA. Positive rates of boys and girls in all specimens were 28.3 (22/77) and 19.5 (15/77)%, respectively. The positive rate in 3-year-old children was 45.2 (14/31)%, and positive rates in boys and girls were 52.6 (10/19) and 33.3 (4/12)%, respectively. The positive rate in 5-year-old children was 50.0 (23/46)%, and positive rates in boys and girls were 48.0 (12/25) and 52.4 (11/21)%, respectively. HPV types were determined by specific PCR and direct DNA sequencing analysis. Frequent HPV types in the specimens of all children were HPV-16 (11/37; 29.7%),-1 (6/37; 16.2%),-2 (6/37; 16.2%),-75 (6/37; 16.2%). The results of the present investigation indicate that many HPVs, including HPV-16 (a high-risk type for cancer), are present in the oral cavity of 3- and 5-year-old children. It is suggested, therefore, that the oral cavity is already a reservoir of HPVs in childhood where later HPV-associated diseases, such as oral cancer and other oral lesions, may develop.

Buccal exposure to human papillomavirus type 16 is a common yet transitory event of childhood

High-risk human papillomaviruses, such as type 16 (HPV-16), are established etiological agents for cervical carcinoma. In most cases, this virus is transmitted sexually, though can also be spread from mother to infant at delivery. We have demonstrated previously a high prevalence ( approximately 52%) of HPV-16 DNA in the mouths of prepubertal children, albeit with low levels of transcription [Rice et al., 2000]. We investigated whether childhood buccal infections with HPV-16 are persistent or transient and whether children became infected through contact with their immediate family members. Two groups of children were selected: one group were all initially HPV-16 E5 DNA-positive in sensitive polymerase chain reaction tests of swabs from their buccal mucosa (n = 20), and the other group consisted of children who were all HPV-16 E5-negative (n = 19). Thirty months later, a second oral swab was collected from each child and tested for HPV DNA. At this second visit, 40% of the HPV-16-positive group had no detectable HPV-16 DNA; conversely, 63% of children who were originally HPV-16-negative had now acquired the virus. Three months later, a third sample was collected from eight children and their immediate families (seven were HPV-16 E5 DNA-positive at the second visit). Amongst the family samples tested, in two families a single previously untested child was HPV-16 DNA-positive. It is concluded that HPV-16 DNA in the oral cavities of children is a transient event and is most probably acquired from their peers.

Papillomavirus vaccines in clinical trials

Cervical cancer remains a leading cause of death for women in the developing world, and the treatment of preneoplastic cervical lesions is a considerable public-health burden in the developed world. There is unambiguous evidence that human papillomaviruses (HPVs) trigger the development of cervical and other anogenital malignancies, and that continued expression of HPV antigens in the tumours drives the neoplastic progression. The viral cause of cervical cancer is also its Achilles heel. Prophylactic vaccines to prevent HPV infection and therapeutic vaccines targeted at the HPV tumour antigens are in clinical trials. A firm grasp of the molecular pathogenesis of HPVs and the natural history of genital HPV infections, combined with greater understanding of how to trigger effective immune responses, offers hope for the elimination of HPV-associated diseases.

External genital warts: diagnosis, treatment, and prevention

External genital warts (EGWs) are visible warts that occur in the perigenital and perianal regions. They are due primarily to non-oncogenic human papillomavirus (HPV) types, usually types 6 and 11. Physical examination assisted by bright light and magnification is the recommended approach for primary diagnosis. Biopsy is indicated when EGWs are fixed to underlying structures or discolored or when standard therapies are not effective. Recurrences are common, and there is no single treatment that is superior to others. Among women with atypical squamous cells, molecular HPV testing may be useful in determining who should be referred for colposcopy. Condoms may provide some protection against HPV-related diseases and thus are recommended in new sexual relationships and when partnerships are not mutually monogamous. Because the efficacy of cesarean section in preventing vertical transmission of HPV infection from women with EGWs to their progeny has not been proved, it is not recommended.

Human papillomavirus infections in children: the potential role of maternal transmission

To date, more than 100 types of human papillomavirus (HPV) have been identified. In the past 20 years, there has been an increasing interest in HPVs because of their potential role in the pathogenesis of malignant tumors. HPV infections are known to affect predominantly adult, sexually active age groups, whereas skin warts, at various anatomic sites, are usually associated with younger individuals. The modes of viral transmission in children remain controversial, including perinatal transmission, auto- and hetero-inoculation, sexual abuse, and, possibly, indirect transmission via fomites. Recent studies on perinatal infection with HPV have been inconclusive. It is still unclear how frequently perinatal infection progresses to clinical lesions, whether genital, laryngeal, or oral. Conflicting reports have been published on the prevalence of HPV infections in children. The current consensus is, however, that newborn babies can be exposed to cervical HPV infection of the mother. The detection rate of HPV DNA in oral swabs of newborn babies varies from 4% to 87%. The concordance of HPV types detected in newborn babies and their mothers is in the range of 57% to 69%, indicating that the infants might acquire the HPV infection post-natally from a variety of sources. HPV antibodies have been detected in 10% to 57% of the children, and there is usually no correlation between seropositivity and the detection of HPV DNA in either the oral or the genital mucosa. There is also evidence that transmission in utero or post-natal acquisition is possible. The mode of in utero transmission remains unknown, but theoretically the virus could be acquired hematogenously, by semen at fertilization, or as an ascending infection in the mother. The understanding of viral transmission routes is important, particularly because several vaccination programs are being planned worldwide. The serologic response to HPV detected in different populations of young women or women at risk of cervical cancer might be due to genital infections, but the possibility that HPV infection has been acquired earlier in life through the oral mucosa or respiratory tract cannot be ruled out.

Human papillomavirus in the oral cavities of children and adolescents

OBJECTIVE

The purpose of this pilot study was to determine the frequency of human papillomavirus (HPV) in the oral cavities of children and adolescents and to identify potential risk factors for HPV infection.

STUDY DESIGN

Sociodemographic information was obtained on 268 healthy infants, children, and adolescents who were < or = 20 years old. Oral squamous cells were collected from swabs with young children and from oral saline solution rinses with older children and adolescents. Extracted DNA was evaluated for HPV by polymerase chain reaction, dot blot hybridization, and DNA sequencing. Factors associated with the presence of HPV were tested by using chi(2), Fisher's exact test, and logistic regression tests.

RESULTS

HPV was detected in 6.0% of the participants. HPV frequency among young children (<7 years old) was 8.7% (11/127), and among adolescents (13-20 years old) it was 5.2% (5/97). HPV was not detected in children aged 7 to 12 years old (0/44). Fifty-four percent (6/11) of HPV-positive children were 1 year of age or less; 3 of the HPV-positive children (<7 years old) were delivered by cesarean section. No statistically significant association was found between the detection of HPV in the oral cavity and method of delivery or gender; parent's race, education, HPV-related conditions, smoking history, or number of sex partners; or adolescent's smoking history or history of sexual activity.

CONCLUSIONS

This study suggests that HPV is present in the oral cavity primarily in children 2 years old and younger and in adolescents 13 years and older. Cesarean delivery was not protective against oral HPV infection; in fact, half of the HPV-positive infants were born by cesarean delivery.

High prevalence of human papillomavirus type 16 infection among children

Infection with high-risk human papillomaviruses (HPV), is the most significant risk factor for cervical cancer and it may be possible to prevent this malignancy by immunisation. Before immunisation programmes can be designed, however, it is necessary to know the age of acquisition and all routes of infection for these viruses. Sexual transmission is well documented and vertical transmission has also been demonstrated, although the frequency of transmission remains controversial. We previously showed that vertical transmission frequently results in persistent infection, and now present data on the prevalence of HPV-16 DNA (the most prevalent high-risk HPV type) in healthy children. Buccal samples from 267 healthy children aged 3-11 years were tested for HPV DNA by generic PCR (MY09/MY11), and a HPV-16 specific nested PCR. Reverse transcriptase (RT)-PCR was used to determine the prevalence of transcriptionally active HPV-16 infection in a subset of children. HPV-16 DNA was detected by nested PCR in 138 of 267 (51.7%) samples, whereas HPV DNA was detected in only 45 (16.8%) specimens by generic PCR, that has a lower analytical sensitivity. There were no significant differences in prevalence according to age or sex. Early region mRNA was detected by RT-PCR in six (11.3%) of 53 HPV-16 E5 DNA positive samples. HPV-16 E5 DNA sequences from 10 children confirmed the identity of the sequences detected and identified 13 HPV-16 variants.

High risk genital papillomavirus infections are spread vertically

It is well recognised that high-risk human papillomaviruses (HPVs) are spread by sexual activity, but the possibility of non-sexual transmission remains controversial. We present evidence for vertical transmission from at least 30% HPV positive mothers to their infants, resulting in persistent infection in children. That the mother is the source of infant infection has been confirmed by DNA sequencing. We also discuss the evidence for oral HPV-16 infection in children. In our own studies, HPV-16 DNA was detected in buccal cells from 48% children, aged 3-11 and transcriptionally active infection was confirmed in some children. Other studies have reported prevalences of 19%-27% among children less than 11 years of age. Studies that have failed to detect high-risk HPVs in children have used techniques which were insufficiently sensitive to detect the low levels of virus present. Serological studies also suggest that < or = 45% prepubertal children have acquired HPV-16. Thus, convincing evidence is now available for vertical transmission of high risk HPVs, which probably results in widespread infection among children. The consequences of such infections remain to be elucidated.

Detection and typing of human papillomaviruses by polymerase chain reaction in cervical scrapes of Croatian women with abnormal cytology

The association between certain human papillomaviruses (HPV) and cervical intraepithelial neoplasia (CIN) is well documented, but still unknown among Croatian women. In 1995, women between the age of 17 and 64 with cytomorphologically abnormal smears (CIN I-IV) were tested for the presence of HPV. Consensus and specific primers were used in the polymerase chain reaction (PCR) to detect the most common types: 6, 11, 16, 18, 31 and 33, as well as the unknown-risk HPV types (HPV X). Out of 379 specimens, 163 (43%) contained one or more HPV types. Coinfection with different HPV types in the same sample was observed in 16 cases. Beside low-risk HPV 6/11 (25.8%) the most frequently observed types were high-risk HPV types 16 (20.2%) and 31 (17.8%). Globally, the HPV positivity rate declines with age. The presence of HPV DNA significantly increased from 35.5 to 61.1% along with the severity of the cervical intraepithelial neoplasia (CIN I-IV). HPV type 6/11 was strongly associated with CIN I (33.8%), HPV type 31 with CIN II (22.9%), and HPV type 16 with CIN III (50%).

Human papillomavirus-associated tumors of the skin and mucosa

This review discusses diseases of the lower genital tract in which the presence of human papillomavirus (HPV) DNA is well documented. We discuss epidemiologic, clinical, and experimental data supporting a causative role for HPV in mucosal malignancies, with emphasis on the role of viral and host factors in their pathogenesis. Of special interest is the recently discovered association of cutaneous tumors with HPVs, previously known only for tumors in epidermodysplasia verruciformis (EV). The frequent detection of EV-specific or EV-related HPVs in immunosuppressed persons and in cutaneous tumors in the general population supports the importance of EV as a model of cutaneous oncogenesis. We also discuss recent serologic findings based on enzyme-linked immunosorbent assay results with the use of viruslike particles. This is important both for detection of present or past HPV infection and for epidemiologic and immunologic studies. Novel therapeutic modalities for HPV tumors and prospects for prophylactic and therapeutic vaccination are presented.