Seropositivity to multiple sexually transmitted infections is not common

Maternal Antibodies to Chlamydia trachomatis and Risk of Gastroschisis

BACKGROUND

Gastroschisis, a birth defect of the abdominal wall, is increasing in prevalence. The largest increase in prevalence has been observed among young mothers (<20 years). The prevalence of Chlamydia trachomatis (CT) infection is highest among young women and has also been increasing over time. The objective was to investigate the association between immunoglobulin G antibodies to Chlamydia trachomatis (CT) (anti-CT) and Chlamydial heat shock protein 60 (anti-CHP60) during pregnancy, and risk of gastroschisis among offspring.

METHODS

We conducted a nested case-control study of 292 gastroschisis cases identified from the Congenital Malformations Register and 826 live born controls matched on age and birth year within the Finnish Maternity Cohort. Early pregnancy serum samples were used to categorize women by seropositivity to anti-CT and anti-CHP60. Women seronegative for anti-CT and anti-CHP60 served as the reference. We used conditional logistic regression to calculate odds ratios (ORs) and 95% confidence intervals (CIs). Effect measure modification by maternal age (<25 years, ≥25 years) was also assessed.

RESULTS

Seropositivity to anti-CT (17.8% of cases vs. 16.0% of controls) or anti-CHP60 (23.6% of cases vs. 22.0% of controls) was not associated with gastroschisis. Although, the OR for seropositivity to anti-CT alone was slightly elevated (OR, 1.19; 95% CI, 0.73-1.94), specifically among young mothers (<25 years) (OR, 1.65; 95% CI, 0.81-3.37), the results were imprecise.

CONCLUSION

Chlamydia infection, as measured by immunoglobulin G antibodies to CT and CHP60, is not associated with gastroschisis, however, our assays were not able to distinguish recent infection.Birth Defects Research 109:543-549, 2017.© 2017 Wiley Periodicals, Inc.

Prevalence and Clinical Significance of Herpesvirus Infection in Populations of Australian Marsupials

Herpesviruses have been reported in several marsupial species, but molecular classification has been limited to four herpesviruses in macropodids, a gammaherpesvirus in two antechinus species (Antechinus flavipes and Antechinus agilis), a gammaherpesvirus in a potoroid, the eastern bettong (Bettongia gaimardi) and two gammaherpesviruses in koalas (Phascolarctos cinereus). In this study we examined a range of Australian marsupials for the presence of herpesviruses using molecular and serological techniques, and also assessed risk factors associated with herpesvirus infection. Our study population included 99 koalas (Phascolarctos cinereus), 96 eastern grey kangaroos (Macropus giganteus), 50 Tasmanian devils (Sarcophilus harrisii) and 33 common wombats (Vombatus ursinius). In total, six novel herpesviruses (one alphaherpesvirus and five gammaherpesviruses) were identified in various host species. The overall prevalence of detection of herpesvirus DNA in our study population was 27.2% (95% confidence interval (CI) of 22.6-32.2%), but this varied between species and reached as high as 45.4% (95% CI 28.1-63.7%) in common wombats. Serum antibodies to two closely related macropodid herpesviruses (macropodid herpesvirus 1 and 2) were detected in 44.3% (95% CI 33.1-55.9%) of animals tested. This also varied between species and was as high as 92% (95% CI 74.0-99.0%) in eastern grey kangaroos. A number of epidemiological variables were identified as positive predictors for the presence of herpesvirus DNA in the marsupial samples evaluated. The most striking association was observed in koalas, where the presence of Chlamydia pecorum DNA was strongly associated with the presence of herpesvirus DNA (Odds Ratio = 60, 95% CI 12.1-297.8). Our results demonstrate the common presence of herpesviruses in Australian marsupials and provide directions for future research.

Risk of seropositivity to multiple oncogenic human papillomavirus types among human immunodeficiency virus-positive and -negative Ugandan women

To understand the prospects for human papillomavirus (HPV) mass vaccination in the setting of a developing country, we studied the co-occurrence of seropositivity to multiple high-risk (hr) HPV types among HIV-positive and HIV-negative Ugandan women. Our seroepidemiological study was conducted among 2053 women attending antenatal clinics. Sera were analysed for antibodies to eight hrHPV types of the α-7 (18/45) and α-9 (16/31/33/35/52/58) species of HPV by using a multiplex serology assay. Our results show that seropositivity for greater than one hrHPV type was as common (18 %) as for a single type (18 %). HIV-positive women had higher HPV16, HPV18 and HPV45 seroprevalences than HIV-negative women. In multivariate logistic regression analysis, age (>30 years) and level of education (secondary school and above) reduced the risk, whereas parity (>5) and HIV-positivity increased the risk for multiple hrHPV seropositivity. However, in stepwise logistic regression analyses, HIV-status remained the only independent, stand-alone risk factor [odds ratio (OR) 1.7, 95 % confidence interval (CI) 1.0–2.8). On the other hand, the risk of HPV16 or HPV18 seropositive women, as compared to HPV16 or HPV18 seronegative women, for being seropositive to other hrHPV types was not significantly different when they were grouped by HIV-status (ORHPV16/HIV+ 12, 95 % CI 4.5–32 versus ORHPV16/HIV− 22, 95 % CI 15–31 and ORHPV18/HIV+ 58, 95 % CI 14–242 versus ORHPV18/HIV− 45, 95 % CI 31–65). In conclusion, seropositivity to HPV16, HPV18 and to non-vaccine hrHPV types is common in Ugandan women, suggesting that there is little natural cross-protective immunity between the types. HIV-positivity was an independent, stand-alone, albeit moderate risk factor for multiple hrHPV seropositivity. HPV mass vaccination may be the most appropriate method in the fight against cervical cancer in the Ugandan population.

Aspects of prophylactic vaccination against cervical cancer and other human papillomavirus-related cancers in developing countries

Cervical cancer and other human papillomavirus- (HPV-) related cancers are preventable, but preventive measures implemented in developing countries and especially in low-income rural regions have not been effective. Cervical cancer burden derived from sexually transmitted HPV infections is the heaviest in developing countries, and a dramatic increase in the number of cervical cancer cases is predicted, if no intervention is implemented in the near future. HPV vaccines offer an efficient way to prevent related cancers. Recently implemented school-based HPV vaccination demonstration programmes can help tackle the challenges linked with vaccine coverage, and access to vaccination and health services, but prevention strategies need to be modified according to regional characteristics. In urban regions WHO-recommended vaccination strategies might be enough to significantly reduce HPV-related disease burden, but in the rural regions additional vaccination strategies, vaccinating both sexes rather than only females when school attendance is the highest and applying a two-dose regime, need to be considered. From the point of view of both public health and ethics identification of the most effective prevention strategies is pivotal, especially when access to health services is limited. Considering cost-effectiveness versus justice further research on optional vaccination strategies is warranted.

Self-Reported and Serum Cotinine-Validated Smoking in Pregnant Women in Estonia

OBJECTIVES

Although widely used in epidemiological studies, self-report has been shown to underestimate the prevalence of smoking among pregnant women. Objectives of this study were to examine the discrepancy between self-reported and cotinine-validated smoking status, and the sociodemographic characteristics associated with the misclassification of real smoking status among pregnant women in Tallinn, the capital of Estonia.

METHODS

Serum cotinine assays were performed on a subsample (n = 1360) of the pregnant women, who had participated in a recent study of human papillomavirus type 16 (HPV-16) seroprevalence in Estonia. In the present study, serum concentrations > or = 15 ng/ml were used to distinguish current smokers from nonsmokers. The serum-validated smoking level was compared with the self-reported level in the records of the Estonian Medical Birth Registry. For the group of self-reported non-smokers, the differences between the cotinine-validated smokers and the cotinine-validated nonsmokers, with respect to their sociodemographic characteristics (age, ethnicity, educational level, employment status, marital status, parity), were estimated by logistic regression.

RESULTS

Of 1239 women who reported being nonsmokers, 259 (20.9%) had serum cotinine levels > or = 15 ng/ml, and can be regarded as current smokers. Among self-reported nonsmokers, nondisclosure of current smoking was significantly more frequent in non-Estonian, less educated, socially inactive, cohabiting and multiparous women.

CONCLUSIONS

Self-reported data on smoking in pregnant women underestimates the real smoking prevalence in Estonia. Maternal unwillingness to declare smoking during pregnancy needs to be taken into account in the practice of maternal and child health to better target prenatal smoking cessation interventions.

Time trends in incidence and prevalence of human papillomavirus type 6, 11 and 16 infections in Finland

Human papillomavirus (HPV) type 16 is the major cause of cervical carcinoma, the incidence of which is decreasing in western countries. In Finland the incidence is, however, increasing in women aged <40 years, but possible underlying changes in HPV-16 epidemiology are unknown. To assess incidence trends of HPV infections, paired sera from a random sample of 8000 women with two pregnancies/sera within 5 years, taken from the serum bank of the Finnish Maternity Cohort (1983-98), were analysed for HPV-6, -11 and -16 antibodies. For 23-31-year-old women, HPV-16 incidence increased over the period 1983-97. HPV-16 seroprevalence increased from 17% in 1983-85 to 24% in 1995-97, but HPV-6 and HPV-11 prevalence was stable at 9-12% throughout the study period. Epidemic spread of the oncogenic HPV-16, but not the non-oncogenic HPV-types, throughout the 1980s and 1990s preceded an increase in the incidence of cervical carcinoma in fertile-aged Finnish women.

Clustering of seropositivities for sexually transmitted infections

BACKGROUND

Serology for different sexually transmitted infections (STIs) is useful for epidemiologic studies on the spread of STIs in different populations. Studying whether seropositivities for different STIs cluster could be useful, both for development of improved serologic markers of sexual behavior in populations and for understanding how STIs may differ in terms of the dynamics of their spread.

GOAL

To evaluate the degree of clustering of different STIs in relation to sexual history.

STUDY DESIGN

An age- and sexual history-stratified subsample of 275 women from a survey of healthy Swedish women seeking contraceptive advice was tested for human papillomavirus (HPV) types 6, 11, 16, 18, and 33; Chlamydia trachomatis; herpes simplex virus 2 (HSV-2); and human herpesvirus 8.

RESULTS

Significant clustering was observed only for HPV types 6 and 11; for HPV types 16, 18, and 33; and for C trachomatis and HSV-2. The serologic marker that correlated best with lifetime number of sex partners was HPV type 16 (odds ratio [OR], 10.2; 95% CI, 3.8-27.6). The combined serologic marker that correlated most highly with sexual history was joint positivity for HPV types 16 and 33 (OR, 25.5; 95% CI, 5.4-120.4).

CONCLUSIONS

The degree of clustering between different STIs varies from nonexistent to strong, implying that different STIs commonly have very different transmission dynamics. Certain combinations of STI serologic tests may be useful in epidemiologic studies for predicting sexual behavior in groups.

Prospects for phase III-IV HPV vaccination trials in the Nordic countries and in Estonia

BACKGROUND

oncogenic, i.e. high risk human papillomavirus (hrHPV) types are the major cause of invasive cervical cancer (ICC). Putatively licensable vaccines against the hrHPVs have been developed and are approaching clinical phase III trials that use persistent HPV infection as end point. Direct extension of the phase III trials towards long-term end points (ICC and its immediate precursors: carcinoma in situ and severe dysplasia, i.e. cervical intraepithelial neoplasia grade III, CINIII) is important, to avoid early contamination of the target population by opportunistic use of licensed HPV vaccines. Country-wide registration on population and health events in a stable population of 25 million make Estonia and the Nordic countries a unique venue for long-term evaluation of cervical cancer control measures. Mass-screening programmes exist in all Nordic countries, but not in Estonia.

AIM

design of phase III-IV trials for evaluation of protection against ICC and CINIII by preventive HPV vaccines based on cancer registry follow-up.

RESULTS

in the Nordic countries, population based randomisation of all 15-year-old women to the vaccination (vaccine and placebo) and reference cohorts entering conventional Pap-smear screening after a clinical phase III trial would assure comparability of the cohorts. Enrollment of 10094 vaccinees +10094 placebo vaccinees +30282 other hrHPV negative women without vaccination at the age of 16 would give 80% power for the demonstration of 70% vaccine efficacy (VE) against ICC in 20 years by cancer registry follow-up. On the other hand, vaccination of 8303 Estonian hrHPV negative women among the entire 15-year-old female birth cohort (about 10000 women) with an already licensed HPV vaccine would enable demonstration of 70% VE against ICC by 20 years of registry follow-up of these and comparable 16606 women identified among the 16-19-year-old birth cohorts.

CONCLUSIONS

evaluation of the protective effect of an HPV vaccine against ICC is possible both in countries with or without mass-screening. The effects of vaccination on spread of different HPVs in the population would need to be monitored, especially in Estonia. Ethical aspects, cost-benefit evaluation and comparisons with other new means of cervical cancer control warrant further investigation.