Factors associated with syphilis seroprevalence in women with and at-risk for HIV infection in the Women's Interagency HIV Study (1994-2015)

OBJECTIVE

Syphilis rates among women in the USA more than doubled between 2014 and 2018. We sought to identify correlates of syphilis among women enrolled in the Women's Interagency HIV Study (WIHS) to inform targeted interventions.

METHODS

The retrospective cross-sectional analysis of secondary data included women with HIV or at-risk of HIV who enrolled in the multisite US WIHS cohort between 1994 and 2015. Syphilis screening was performed at baseline. Infection was defined serologically by a positive rapid plasma reagin test with confirmatory treponemal antibodies. Sociodemographic and behavioural characteristics stratified by baseline syphilis status were compared for women enrolled during early (1994-2002) and recent (2011-2015) years. Multivariable binomial modelling with backward selection (p>0.2 for removal) was used to model correlates of syphilis.

RESULTS

The study included 3692 women in the early cohort and 1182 women in the recent cohort. Syphilis prevalence at enrolment was 7.5% and 3.7% in each cohort, respectively (p<0.01). In adjusted models for the early cohort, factors associated with syphilis included age, black race, low income, hepatitis C seropositivity, drug use, HIV infection and >100 lifetime sex partners (all p<0.05). In the recent cohort, age (adjusted prevalence OR (aPOR) 0.2, 95% CI 0.1 to 0.6 for 30-39 years; aPOR 0.5, 95% CI 0.2 to 1.0 for 40-49 years vs ≥50 years), hepatitis C seropositivity (aPOR 2.1, 95% CI 1.0 to 4.1) and problem alcohol use (aPOR 2.2, 95% CI 1.1 to 4.4) were associated with infection.

CONCLUSIONS

Syphilis screening is critical for women with HIV and at-risk of HIV. Targeted prevention efforts should focus on women with hepatitis C and problem alcohol use.

1,3-Butadiene, styrene and lymphohaematopoietic cancers among North American synthetic rubber polymer workers: exposure-response analyses

OBJECTIVE

To evaluate exposure-response between 1,3-butadiene, styrene and lymphohaematopoietic cancers in an updated cohort of workers at six North American plants that made synthetic rubber polymers.

METHODS

Employees were followed from 1943 through 2009 to determine mortality outcomes. Cox regression analyses estimated rate ratios (RRs) and 95% CIs by quartile of cumulative exposure to butadiene or styrene, measured in parts per million-years (ppm-years), and exposure-response trends for all leukaemia, lymphoid leukaemia, myeloid leukaemia, acute myeloid leukaemia, non-Hodgkin's lymphoma (NHL), multiple myeloma and all B-cell malignancies.

RESULTS

Among 21 087 workers, adjusted RRs for butadiene and all leukaemia (132 deaths) rose with increasing exposure, with an RR of 2.53 (95% CI 1.37 to 4.67) in the highest exposure quartile (≥363.64 ppm-years), and the exposure-response trend was statistically significant for all leukaemia (p=0.014) and for lymphoid leukaemia (52 deaths, p=0.007). Styrene exposure-response trends for all leukaemia and lymphoid leukaemia were less consistent than those for butadiene. Cumulative exposures to butadiene and styrene were not associated consistently with myeloid leukaemias or the B-cell malignancies, NHL and multiple myeloma.

CONCLUSIONS

We confirmed a positive exposure-response relationship between butadiene and all leukaemia among workers, most of whom had coexposure to styrene. Results supported an association between butadiene and lymphoid leukaemia, but not myeloid leukaemia, and provided little evidence of any association of butadiene or styrene exposures with major subtypes of B-cell malignancies other than lymphoid leukaemia, including NHL and multiple myeloma.

Genital Abnormalities, Hormonal Contraception, and Human Immunodeficiency Virus Transmission Risk in Rwandan Serodifferent Couples

BACKGROUND

We explored the role of genital abnormalities and hormonal contraception in human immunodeficiency virus (HIV) transmission among heterosexual serodifferent couples in Rwanda.

METHODS

From 2002 to 2011, HIV-serodifferent couples who were not using antiretroviral treatment were followed up, and sociodemographic and clinical data were collected, family planning provided, and HIV-negative partners retested. Couples were assessed for genital ulcers; nonulcerative genital sexually transmitted infection (STIs), including gonorrhea, chlamydia, and trichomoniasis; and non-STI vaginal infections, including bacterial vaginosis and candida. Multivariable models evaluated associations between covariates and HIV transmission genetically linked to the index partner.

RESULTS

Among 877 couples in which the man was HIV positive, 37 linked transmissions occurred. Factors associated with women's HIV acquisition included genital ulceration in the female partner (adjusted hazard ratio, 14.1) and nonulcerative STI in the male partner (8.6). Among 955 couples in which the woman was HIV positive, 46 linked transmissions occurred. Factors associated with HIV acquisition in men included nonulcerative STI in the female partner (adjusted hazard ratio, 4.4), non-STI vaginal dysbiosis (7.1), and genital ulceration in the male partner (2.6). Hormonal contraception use was not associated with HIV transmission or acquisition.

CONCLUSIONS

Our findings underscore the need for integrating HIV services with care for genital abnormalities. Barriers (eg, cost of training, demand creation, advocacy, and client education; provider time; and clinic space) to joint HIV/STI testing need to be considered and addressed.

Schistosomiasis is associated with incident HIV transmission and death in Zambia

Background

We examined relationships between schistosome infection, HIV transmission or acquisition, and all-cause death.

Methods

We retrospectively tested baseline sera from a heterosexual HIV-discordant couple cohort in Lusaka, Zambia with follow-up from 1994–2012 in a nested case-control design. Schistosome-specific antibody levels were measured by ELISA. Associations between baseline antibody response to schistosome antigens and incident HIV transmission, acquisition, and all-cause death stratified by gender and HIV status were assessed. In a subset of HIV- women and HIV+ men, we performed immunoblots to evaluate associations between Schistosoma haematobium or Schistosoma mansoni infection history and HIV incidence.

Results

Of 2,145 individuals, 59% had positive baseline schistosome-specific antibody responses. In HIV+ women and men, baseline schistosome-specific antibodies were associated with HIV transmission to partners (adjusted hazard ratio [aHR] = 1.8, p<0.005 and aHR = 1.4, p<0.05, respectively) and death in HIV+ women (aHR = 2.2, p<0.001). In 250 HIV- women, presence of S. haematobium-specific antibodies was associated with increased risk of HIV acquisition (aHR = 1.4, p<0.05).

Conclusion

Schistosome infections were associated with increased transmission of HIV from both sexes, acquisition of HIV in women, and increased progression to death in HIV+ women. Establishing effective prevention and treatment strategies for schistosomiasis, including in urban adults, may reduce HIV incidence and death in HIV+ persons living in endemic areas.

This study explored the association between schistosome infections (a disease caused by parasitic flatworms, also known as ‘snail fever’, which is very common throughout sub-Saharan Africa) and human immunodeficiency virus (HIV). We found in Lusaka, the capital of Zambia, that schistosome infections were associated with transmission of HIV from adult men and women, and schistosome infections were also associated with increased HIV acquisition in adult women. We additionally found that schistosome infections were associated with death in HIV+ adult women. Since treatment of schistosome infections with praziquantel is inexpensive, effective, and safe, schistosomiasis prevention and treatment strategies may be a cost-effective way to reduce not only the symptoms associated with the infection, but also new cases of HIV and death among HIV+ persons. Though often viewed as an infection of predominantly rural areas and children, this study highlights that schistosomiasis prevention and treatment efforts are also needed in urban areas and among adults.

Erratum to: Risky Sex and HIV Acquisition Among HIV Serodiscordant Couples in Zambia, 2002-2012: What Does Alcohol Have To Do With It?

The article Risky Sex and HIV Acquisition Among HIV Serodiscordant Couples in Zambia, 2002-2012: What Does Alcohol Have To Do With It?, written by Dvora Joseph Davey, William Kilembe, Kristin M. Wall, Naw Htee Khu, Ilene Brill, Bellington Vwalika, Elwyn Chomba, Joseph Mulenga, Amanda Tichacek, Marjan Javanbakht, W. Scott Comulada, Susan Allen, Pamina M. Gorbach, was originally published Online First without open access. After publication in volume 21, issue 7, pages 1892-1903, the author decided to opt for Open Choice and to make the article an open access publication. Therefore, the copyright of the article has been changed to

Risk of heterosexual HIV transmission attributable to sexually transmitted infections and non-specific genital inflammation in Zambian discordant couples, 1994-2012

Background

Studies have demonstrated the role of ulcerative and non-ulcerative sexually transmitted infections (STI) in HIV transmission/acquisition risk; less is understood about the role of non-specific inflammatory genital abnormalities.

Methods

HIV-discordant heterosexual Zambian couples were enrolled into longitudinal follow-up (1994-2012). Multivariable models estimated the effect of genital ulcers and inflammation in both partners on time-to-HIV transmission within the couple. Population-attributable fractions (PAFs) were calculated.

Results

A total of 207 linked infections in women occurred over 2756 couple-years (7.5/100 CY) and 171 in men over 3216 CY (5.3/100 CY). Incident HIV among women was associated with a woman's non-STI genital inflammation (adjusted hazard ratio (aHR) = 1.55; PAF = 8%), bilateral inguinal adenopathy (BIA; aHR = 2.33; PAF = 8%), genital ulceration (aHR = 2.08; PAF = 7%) and the man's STI genital inflammation (aHR = 3.33; PAF = 5%), BIA (aHR = 3.35; PAF = 33%) and genital ulceration (aHR = 1.49; PAF = 9%). Infection among men was associated with a man's BIA (aHR = 4.11; PAF = 22%) and genital ulceration (aHR = 3.44; PAF = 15%) as well as with the woman's non-STI genital inflammation (aHR = 1.92; PAF = 13%) and BIA (aHR = 2.76; PAF = 14%). In HIV-M+F- couples, the man being uncircumcised. with foreskin smegma. was associated with the woman's seroconversion (aHR = 3.16) relative to being circumcised. In F+M- couples, uncircumcised men with BIA had an increased hazard of seroconversion (aHR = 13.03 with smegma and 4.95 without) relative to being circumcised. Self-reporting of symptoms was low for ulcerative and non-ulcerative STIs.

Conclusions

Our findings confirm the role of STIs and highlight the contribution of non-specific genital inflammation to both male-to-female and female-to-male HIV transmission/acquisition risk. Studies are needed to characterize pathogenesis of non-specific inflammation including inguinal adenopathy. A better understanding of genital practices could inform interventions.

Optimizing Prevention of HIV and Unplanned Pregnancy in Discordant African Couples

BACKGROUND

Dual method use, which combines condoms with a more effective modern contraceptive to optimize prevention of HIV and unplanned pregnancy, is underutilized in high-risk heterosexual couples.

MATERIALS AND METHODS

Heterosexual HIV-discordant Zambian couples were enrolled from couples' voluntary HIV counseling and testing services into an open cohort with 3-monthly follow-up (1994-2012). Relative to dual method use, defined as consistent condom use plus modern contraception, we examine predictors of (1) condom-only use (suboptimal pregnancy prevention) or (2) modern contraceptive use with inconsistent condom use (effective pregnancy prevention and suboptimal HIV prevention).

RESULTS

Among 3,049 couples, dual method use occurred in 28% of intervals in M+F- and 23% in M-F+, p < 0.01; condom-only use in 56% in M+F- and 61% in M-F+, p < 0.01; and modern contraceptive use with inconsistent condom use in 16% regardless of serostatus. Predictors (p < 0.05) of condom-only use included the man being HIV+ (adjusted hazard ratio, aHR = 1.15); baseline oral contraceptive pill (aHR = 0.76), injectable (aHR = 0.48), or implant (aHR = 0.60) use; woman's age (aHR = 1.04 per 5 years) and lifetime number of sex partners (aHR = 1.01); postpartum periods (aHR = 1.25); and HIV stage of the index partner III/IV versus I (aHR = 1.10). Predictors (p < 0.05) of modern contraceptive use with inconsistent condom use included woman's age (aHR = 0.94 per 5 years) and HIV+ male circumcision (aHR = 1.51), while time-varying implant use was associated with more consistent condom use (aHR = 0.80).

CONCLUSIONS

Three-quarters of follow-up intervals did not include dual method use. This highlights the need for counseling to reduce unintended pregnancy and HIV transmission and enable safer conception.

Prostate-specific antigen concentration in vaginal fluid after exposure to semen

OBJECTIVE

Prostate-specific antigen (PSA) is the best established biomarker of semen exposure. PSA in vaginal fluid returns to pre-exposure concentrations within 24-48 h, but the speed of decay during the first 10 h is unknown. We sought to determine how fast PSA concentrations decline during the first 10 h after exposure to semen.

STUDY DESIGN

Women in the 50 enrolled couples were intravaginally inoculated with 10, 20, 100 and 200 μl of their partner's semen and then collected vaginal swabs immediately after, 30 min, 4 h and 10 h after exposure. Forty-seven sets of samples were tested for PSA. Mixed linear models for repeated measures examined the association between log-transformed PSA values and sampling time and semen exposure volume. Sensitivity analyses excluded data from nonabstainers. Fixed-effect estimates from the statistical models were graphed.

RESULTS

PSA values were highest at 200 μl inoculation volumes and at earlier post-exposure time points, then decline steadily. The lowest inoculation volume (10 μl) corresponded to the smallest concentration of PSA throughout the post-inoculation time points. Average PSA levels return to clinically non-detectable levels within 10 h only at the lowest semen exposures. The PSA decay curve assumes a very similar profile across all time points and semen amounts.

CONCLUSIONS

The PSA decay curve is similar for varying semen exposure volumes, with average PSA concentrations remaining above clinical thresholds 10 h after exposure at all except the very smallest semen exposure levels. PSA is an objective marker of recent exposure to semen, permitting such detection with high accuracy.

IMPLICATIONS

This study clarifies how PSA values vary at different semen exposure levels and time points during the first 10 h post-exposure. Future contraceptive studies that use PSA as a semen biomarker will be better informed about PSA concentrations at different sampling times and exposure amounts.

Risky Sex and HIV Acquisition Among HIV Serodiscordant Couples in Zambia, 2002-2012: What Does Alcohol Have To Do With It?

In this paper we evaluate the effects of heavy alcohol consumption on sexual behavior, HIV acquisition, and antiretroviral treatment (ART) initiation in a longitudinal open cohort of 1929 serodiscordant couples in Lusaka, Zambia from 2002 to 2012. We evaluated factors associated with baseline heavy alcohol consumption and its association with condomless sex with the study partner, sex outside of the partnership, and ART initiation using multivariable logistic regression. We estimated the effect of alcohol consumption on HIV acquisition using multivariable Cox models. Baseline factors significantly associated with women’s heavy drinking (drunk weekly or more in 12-months before enrollment) included woman’s older age (adjusted prevalence odds ratio [aPOR] = 1.04), partner heavy drinking (aPOR = 3.93), and being HIV-infected (aPOR = 2.03). Heavy drinking among men was associated with less age disparity with partner (aPOR per year disparity = 0.97) and partner heavy drinking (aPOR = 1.63). Men’s being drunk daily (aOR = 1.18), women’s being drunk less than monthly (aOR = 1.39) vs. never drunk and being in a male HIV-negative and female HIV-positive union (aOR = 1.45) were associated with condomless sex. Heavy alcohol use was associated with having 1 or more outside sex partners among men (aOR drunk daily = 1.91, drunk weekly = 1.32, drunk monthly = 2.03 vs. never), and women (aOR drunk monthly = 2.75 vs. never). Being drunk weekly or more increased men’s risk of HIV acquisition (adjusted hazard ratio [aHR] = 1.72). Men and women being drunk weekly or more was associated (p < 0.1) with women’s seroconversion (aHR = 1.42 and aHR = 3.71 respectively). HIV-positive women who were drunk monthly or more had lower odds of initiating ART (aOR = 0.83; 95% CI = 0.70–0.99) adjusting for age, months since baseline and previous pregnancies. Individuals in HIV-serodiscordant couples who reported heavy drinking had more outside sex partnerships and condomless sex with their study partner and were more likely to acquire HIV. HIV-positive women had lower odds of initiating ART if they were heavy drinkers.

Sustained effect of couples' HIV counselling and testing on risk reduction among Zambian HIV serodiscordant couples

Background

We present temporal trends in self-reported and biological markers of unprotected sex and sex with concurrent partners in discordant couples receiving couples' voluntary HIV counselling and testing (CVCT).

Methods

Heterosexual Zambian HIV-serodiscordant couples were enrolled into longitudinal follow-up in an open cohort (1994–2012). Multivariable Anderson-Gill models explored predictors of self-report and biological indicators of unprotected sex within (including sperm on a vaginal swab, incident pregnancy or incident linked HIV infection) and outside (including self-report, STI and unlinked HIV infection) the union. Measures of secular trends in baseline measures were also examined.

Results

At enrolment of 3049 couples, men were 35 years old on average, women were 29 years, and couples had been together for an average of 7 years. M+F− couples reported an average of 16.6 unprotected sex acts in the 3 months prior to enrolment (pre-CVCT), dropping to 5.3 in the >0–3 month interval, and 2.0 in >6 month intervals (p-trend <0.001). Corresponding values for M−F+ couples were 22.4 unprotected sex acts in the 3 months prior enrolment, dropping to 5.2 in the >0–3 month interval, and 3.1 in >6 month intervals (p-trend <0.001). Significant reductions in self-report and biological markers of outside partners were also noted. Predictors of unprotected sex between study partners after CVCT included prevalent pregnancy (adjusted HR, aHR=1.6–1.9); HIV+ men being circumcised (aHR=1.2); and HIV− women reporting sex with outside partners (aHR=1.3), alcohol (aHR=1.2), injectable (aHR=1.4) or oral (aHR=1.4) contraception use. Fertility intentions were also predictive of unprotected sex (aHR=1.2–1.4). Secular trends indicated steady declines in reported outside partners and STIs.

Conclusion

Reductions in self-reported unprotected sex after CVCT were substantial and sustained. Reinforced risk-reduction counselling in pregnant couples, couples desiring children and couples with HIV− women having outside partners or using alcohol or injectable or oral contraception are indicated.

Hormonal Contraceptive Use Among HIV-Positive Women and HIV Transmission Risk to Male Partners, Zambia, 1994-2012

BACKGROUND

Evidence on the association between female-to-male human immunodeficiency virus (HIV) transmission risk and hormonal contraception is sparse and conflicting.

METHODS

Heterosexual HIV-discordant couples from Lusaka, Zambia, were followed longitudinally at 3 month-intervals from 1994 to 2012. The impact of hormonal contraception on time to HIV transmission from HIV-positive women to their HIV-negative male partners (M-F+) was evaluated.

RESULTS

Among 1601 M-F+ couples, 171 genetically linked HIV transmissions occurred in men over 3216 couple-years (5.3 transmissions/100 couple-years; 95% confidence interval [CI], 4.5-6.2). In multivariable Cox models, neither injectable (adjusted hazard ratio [aHR], 0.6; 95% CI, .4-1.2), oral contraceptive pill (aHR, 0.8; 95% CI, .3-2.1), nor implant (aHR, 0.8; 95% CI, .5-1.4) use was associated with HIV transmission, relative to nonhormonal methods, after controlling for the man's age at baseline and time-varying measures of pregnancy, self-reported unprotected sex with the study partner, sperm present on a vaginal swab wet mount, genital inflammation of either partner, genital ulceration of the man, and first follow-up interval. Sensitivity analyses, including marginal structural modeling and controlling for viral load and fertility intentions available in a subset of couples, led to similar conclusions.

CONCLUSIONS

Our findings suggest null associations between hormonal contraception and risk of female-to-male HIV transmission. We support efforts to increase the contraceptive method mix for all women, regardless of HIV serostatus, along with reinforced condom counseling for HIV-serodiscordant couples.

Hormonal contraception does not increase women's HIV acquisition risk in Zambian discordant couples, 1994-2012

OBJECTIVE

To determine the impact of hormonal contraceptive methods on risk of HIV acquisition among HIV-negative women cohabiting with HIV-positive male partners.

STUDY DESIGN

From 1994-2012, HIV discordant couples recruited from a couples' voluntary HIV counseling and testing center in Lusaka, Zambia were followed longitudinally. HIV-negative partners were tested quarterly. This analysis is restricted to couples in which the man was HIV-positive and the woman was HIV-negative at enrollment and the man was not on antiretroviral treatment. Multivariate Cox models evaluated associations between time-varying contraceptive methods and HIV acquisition among women. Sensitivity analyses explored exposure misclassification and time-varying confounder mediation.

RESULTS

Among 1393 couples, 252 incident infections occurred in women over 2842 couple-years (8.9 infections per 100 couple-years; 95% CI, 7.8-10.0). Multivariate Cox models indicated that neither injectable [adjusted hazard ratio (aHR)=1.2; 95% CI, 0.8-1.7], oral contraceptive pill (OCP, aHR=1.3; 95% CI, 0.9-1.8), or implant (aHR=1.1; 95% CI, 0.5-2.2) use was significantly associated with HIV acquisition relative to non-hormonal contraception controlling for woman's age, literacy and time-varying measures of genital ulceration/inflammation. This remained true when only looking at the subset of infections acquired from the spouse (82% of infections) and additionally controlling for baseline HIV viral load of the male partner, pregnancy status, and time-varying measures of sperm on a vaginal swab wet prep and self-reported unprotected sex. OCP and injectable users reported more unprotected sex (p<.001), and OCP users were more likely to have sperm on vaginal swab (p=.1) than nonhormonal method users.

CONCLUSIONS

We found no association between hormonal contraception and HIV acquisition risk in women. Condom use and reinforced condom counseling should always be recommended for HIV discordant couples. HIV testing of sex partners together is critical to establish HIV risk, ascertain couple fertility intentions and counsel appropriately.

IMPLICATIONS

These findings add to a controversial literature and uniquely address several common design and analytic challenges faced by previous studies. After controlling for confounders, we found no association between hormonal contraception and HIV acquisition risk in women. We support promoting condoms for HIV prevention and increasing the contraceptive method mix to decrease unintended pregnancy.

Contraceptive discontinuation and switching among couples receiving integrated HIV and family planning services in Lusaka, Zambia

OBJECTIVE

To describe predictors of contraceptive method discontinuation and switching behaviours among HIV-positive couples receiving couples' voluntary HIV counselling and testing services in Lusaka, Zambia.

DESIGN

Couples were randomized in a factorial design to two-family planning educational intervention videos, received comprehensive family planning services and were assessed every 3 months for contraceptive initiation, discontinuation and switching.

METHODS

We modelled factors associated with contraceptive method upgrading and downgrading via multivariate Andersen-Gill models.

RESULTS

Most women continued the initial method selected after randomization. The highest rates of discontinuation/switching were observed for injectable contraceptive and intrauterine device users. Time to discontinuing the more effective contraceptive methods or downgrading to oral contraceptives or condoms was associated with the women's younger age, desire for more children within the next year, heavy menstrual bleeding, bleeding between periods and cystitis/dysuria. Health concerns among women about contraceptive implants and male partners not wanting more children were associated with upgrading from oral contraceptives or condoms. HIV status of the woman or the couple was not predictive of switching or stopping.

CONCLUSION

We found complicated patterns of contraceptive use. The predictors of contraception switching indicate that interventions targeted to younger couples that address common contraception-related misconceptions could improve effective family planning utilization. We recommend these findings be used to increase the uptake and continuation of contraception, especially long-acting reversible contraceptive (LARC) methods, and that fertility goal based, LARC-focused family planning be offered as an integral part of HIV prevention services.

Unintended pregnancy among HIV positive couples receiving integrated HIV counseling, testing, and family planning services in Zambia

Objective

We describe rates of unintended pregnancy among HIV positive couples in Lusaka, Zambia. We also identify factors associated with unintended pregnancy among oral contraceptive pill (OCP) using couples in this cohort.

Design

Data were analyzed from couples randomized in a factorial design to two family planning intervention videos.

Methods

Rates of unintended pregnancy were stratified by contraceptive method used at time of pregnancy. Predictors of time to unintended pregnancy among OCP users were determined via multivariate Cox modeling.

Results

The highest rates of unintended pregnancy were observed among couples requesting condoms only (26.4/100CY) or OCPs (20.7/100CY); these rates were not significantly different. OCP users accounted for 37% of the couple-years (CY) observed and 87% of unintended pregnancies. Rates of unintended pregnancy for injectable (0.7/100CY) and intrauterine device (1.6/100CY) users were significantly lower relative to condom only users. No pregnancies occurred among contraceptive implant users or after tubal ligation. Factors associated (p<0.05) with time to unintended pregnancy among OCP users in multivariate analysis included the man wanting more children, the woman being HIV negative versus having stage IV HIV disease, and the woman reporting: younger age, no previous OCP use, missed OCPs, or sex without a condom.

Conclusions

Long-acting reversible contraceptive methods were effective in the context of integrated couples HIV prevention and contraceptive services. Injectable methods were also effective in this context. Given the high user failure rate of OCPs, family planning efforts should promote longer-acting methods among OCP users wishing to avoid pregnancy. Where other methods are not available or acceptable, OCP adherence counseling is needed, especially among younger and new OCP users.

Trial registration

ClinicalTrials.gov NCT00067522

Impact of long-term contraceptive promotion on incident pregnancy: a randomized controlled trial among HIV-positive couples in Lusaka, Zambia

OBJECTIVES

To evaluate the impact of family planning promotion on incident pregnancy in a combined effort to address Prongs 1 and 2 of prevention of mother-to-child transmission of HIV.

DESIGN

We conducted a factorial randomized controlled trial of 2 video-based interventions.

METHODS

"Methods" and "Motivational" messages promoted long-term contraceptive use among 1060 couples with HIV in Lusaka, Zambia.

RESULTS

Among couples not using contraception before randomization (n = 782), the video interventions had no impact on incident pregnancy. Among baseline contraceptive users, viewing the "Methods video" which focused on the intrauterine device and contraceptive implant was associated with a significantly lower pregnancy incidence [hazard ratio (HR) = 0.38; 95% confidence interval (CI): 0.19 to 0.75] relative to those viewing control and/or motivational videos. The effect was strongest in concordant positive couples (HR = 0.22; 95% CI: 0.08 to 0.58) and couples with HIV-positive women (HR = 0.23; 95% CI: 0.09 to 0.55).

CONCLUSIONS

The "Methods video" intervention was previously shown to increase uptake of long-acting contraception and to prompt a shift from daily oral contraceptives to quarterly injectables and long-acting methods such as the intrauterine device and implant. Follow-up confirms sustained intervention impact on pregnancy incidence among baseline contraceptive users, in particular couples with HIV-positive women. Further work is needed to identify effective interventions to promote long-acting contraception among couples who have not yet adopted modern methods.

Genetic variations and heterosexual HIV-1 infection: analysis of clustered genes encoding CC-motif chemokine ligands

Several CC-motif chemokine ligands (CCLs) can block HIV-1-binding sites on CC-motif chemokine receptor 5 (CCR5) and inhibit viral entry. We studied single-nucleotide polymorphisms (SNPs) in genes encoding three CCR5 ligands (CCL3 (MIP-1a), CCL4 (MIP-1b)and CCL5 (RANTES)) along with an adjacent gene encoding a CCR2ligand (CCL2 (MCP-1)) to identify candidate markers for HIV-1 infection and pathogenesis. Analyses of 567 HIV-1 serodiscordant Zambian couples revealed that rs5029410C (in CCL3 intron 2) was associated with lower viral load (VL) in seroconverters, adjusted for gender and age (regression β=-0.57 log(10), P=4x10(-6)). Inaddition, rs34171309A in CCL3 exon 3 was associated with increased risk of HIV-1 acquisition in exposed seronegatives(hazard ratio=1.52, P=0.006 when adjusted for VL of the initially seropositive partner and genital ulcer/inflammation). SNPrs34171309 encodes a conservative Glu-to-Asp substitution. Fiven eighboring SNPs in tight linkage disequilibrium with rs34171309all showed similar associations with HIV-1 acquisition. How these multiple CCL3 SNPs may alter the occurrence or course of HIV-1 infection remains to be determined [corrected].

Cigarette smoking and risk of histological subtypes of epithelial ovarian cancer in the EPIC cohort study

New data regarding a positive association between smoking and risk of epithelial ovarian cancer (EOC), especially the mucinous tumor type, has started to emerge. The purpose of this study was to examine the association between different measures of smoking exposures and subtypes of EOC in a large cohort of women from 10 European countries. The European Prospective Investigation into Cancer and Nutrition (EPIC) cohort is a multicenter prospective study initiated in 1992. The questionnaires included data about dietary, lifestyle, and health factors. Information about cigarette smoking was collected from individuals in all participating countries. We used Cox proportional hazard regression models to estimate hazard ratio (HR) of EOC overall and serous, mucinous, and endometroid histological subtypes, with 95% confidence intervals (CIs) associated with different measures of smoking exposures adjusting for confounding variables. Altogether 836 incident EOC cases were identified among 326,831 women. The tumors were classified as 400 serous, 83 mucinous, 80 endometroid, 35 clear cell, and 238 unspecified. Compared with never smokers, current smokers had a significantly increased risk for mucinous tumors [HR = 1.85 (95% CI 1.08-3.16)] and those smoking more than 10 cigarettes per day had a doubling in risk [HR = 2.25(95% CI 1.26-4.03)] as did those who had smoked less than 15 pack-years of cigarettes [HR = 2.18 (95% CI 1.07-4.43)]. The results from the EPIC study add further evidence that smoking increases risk of mucinous ovarian cancer and support the notion that the effect of smoking varies according to histological subtype.

Disparate associations of HLA class I markers with HIV-1 acquisition and control of viremia in an African population

BACKGROUND

Acquisition of human immunodeficiency virus type 1 (HIV-1) infection is mediated by a combination of characteristics of the infectious and the susceptible member of a transmission pair, including human behavioral and genetic factors, as well as viral fitness and tropism. Here we report on the impact of established and potential new HLA class I determinants of heterosexual HIV-1 acquisition in the HIV-1-exposed seronegative (HESN) partners of serodiscordant Zambian couples.

METHODOLOGY/PRINCIPAL FINDINGS

We assessed the relationships of behavioral and clinically documented risk factors, index partner viral load, and host genetic markers to HIV-1 transmission among 568 cohabiting couples followed for at least nine months. We genotyped subjects for three classical HLA class I genes known to influence immune control of HIV-1 infection. From 1995 to December 2006, 240 HESNs seroconverted and 328 remained seronegative. In Cox proportional hazards models, HLA-A*68:02 and the B*42-C*17 haplotype in HESN partners were significantly and independently associated with faster HIV-1 acquisition (relative hazards = 1.57 and 1.55; p = 0.007 and 0.013, respectively) after controlling for other previously established contributing factors in the index partner (viral load and specific class I alleles), in the HESN partner (age, gender), or in the couple (behavioral and clinical risk score). Few if any previously implicated class I markers were associated here with the rate of acquiring infection.

CONCLUSIONS/SIGNIFICANCE

A few HLA class I markers showed modest effects on acquisition of HIV-1 subtype C infection in HESN partners of discordant Zambian couples. However, the striking disparity between those few markers and the more numerous, different markers found to determine HIV-1 disease course makes it highly unlikely that, whatever the influence of class I variation on the rate of infection, the mechanism mediating that phenomenon is identical to that involved in disease control.

Abstract 1831: Cigarette smoking and risk of epithelial ovarian cancer according to histological subtypes: results from the EPIC study

Objective: Studies regarding the association between smoking and risk of epithelial ovarian cancer (EOC) are few and inconsistent. The purpose of this study was to examine the association between smoking and subtypes of EOC in the EPIC cohort.

Material and methods : The EPIC cohort is a large, multi-centre prospective study to investigate the relations of nutritional, lifestyle, metabolic and genetic risk factors and cancer incidence. It was initiated in 1992 in ten European countries (Sweden, Denmark, Norway, the Netherlands, United Kingdom, France, Germany, Spain, Italy and Greece). The questionnaires included data about dietary, lifestyle and health factors. Information about tobacco smoking was collected from individuals in all participating countries. Subjects were asked if they smoked cigarettes currently and whether they had smoked in the past. Information was available on current and life-time number of cigarettes per day, duration of smoking, age started smoking and age of smoking cessation (for former smokers). Incident cancer cases were identified through several methods, including record linkage with regional cancer registries, health insurance records, cancer and pathology registries and active follow-up of study subjects. We used Cox proportional hazard regression models to estimate hazard ratio (RR) of EOC with 95% confidence intervals (CIs) associated with different measures of smoking exposures adjusting for confounding variables and stratifying by center.

Results: Altogether 836 [731 (87%) invasive, 67(8%) borderline and 38(5%) unclassified] incident EOC cases were identified among the 326,788 women during an average of 6 years of follow-up. The tumours were classified as 400 serous, 83 mucinous, 80 endometroid and 35 clear cell and 238 unspecified. Altogether, 11% of the serous and 28% of the mucinous tumors was classified as borderline tumors. Twenty-three percent of the women reported to be former and 20% current smokers. The multivariate models showed that current smokers had a 10 % increased risk for EOC overall [RR=1.1(95 % CI 0.9 − 1.4)], a 70% increased risk of borderline tumors [RR=1.7(95 % CI 0.9 − 3.0) and an 80 % [RR=1.8(95 % CI 1.1 − 3.0)] increased risk of mucinous tumors. Only the latter association achieved statistical significance. A positive trend test for age started smoking (&lt;17,17-19,20+, never) and risk of EOC overall (P=0.03) was found among ever smokers who had smoked at least 20 years.

Conclusion: Our results support the notion that smoking increases the risk of mucinous EOC.

Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1831.

Genotypes and haplotypes in the insulin-like growth factors, their receptors and binding proteins in relation to plasma metabolic levels and mammographic density

BACKGROUND

Increased mammographic density is one of the strongest independent risk factors for breast cancer. It is believed that one third of breast cancers are derived from breasts with more than 50% density. Mammographic density is affected by age, BMI, parity, and genetic predisposition. It is also greatly influenced by hormonal and growth factor changes in a woman's life cycle, spanning from puberty through adult to menopause. Genetic variations in genes coding for hormones and growth factors involved in development of the breast are therefore of great interest. The associations between genetic polymorphisms in genes from the IGF pathway on mammographic density and circulating levels of IGF1, its binding protein IGFBP3, and their ratio in postmenopausal women are reported here.

METHODS

Samples from 964 postmenopausal Norwegian women aged 55-71 years were collected as a part of the Tromsø Mammography and Breast Cancer Study. All samples were genotyped for 25 SNPs in IGF1, IGF2, IGF1R, IGF2R, IGFALS and IGFBP3 using Taqman (ABI). The main statistical analyses were conducted with the PROC HAPLOTYPE procedure within SAS/GENETICS (SAS 9.1.3).

RESULTS

The haplotype analysis revealed six haploblocks within the studied genes. Of those, four had significant associations with circulating levels of IGF1 or IGFBP3 and/or mammographic density. One haplotype variant in the IGF1 gene was found to be associated with mammographic density. Within the IGF2 gene one haplotype variant was associated with levels of both IGF1 and IGFBP3. Two haplotype variants in the IGF2R were associated with the level of IGF1. Both variants of the IGFBP3 haplotype were associated with the IGFBP3 level and indicate regulation in cis.

CONCLUSION

Polymorphisms within the IGF1 gene and related genes were associated with plasma levels of IGF1, IGFBP3 and mammographic density in this study of postmenopausal women.

Human leukocyte antigens and HIV type 1 viral load in early and chronic infection: predominance of evolving relationships

Background

During untreated, chronic HIV-1 infection, plasma viral load (VL) is a relatively stable quantitative trait that has clinical and epidemiological implications. Immunogenetic research has established various human genetic factors, especially human leukocyte antigen (HLA) variants, as independent determinants of VL set-point.

Methodology/Principal Findings

To identify and clarify HLA alleles that are associated with either transient or durable immune control of HIV-1 infection, we evaluated the relationships of HLA class I and class II alleles with VL among 563 seroprevalent Zambians (SPs) who were seropositive at enrollment and 221 seroconverters (SCs) who became seropositive during quarterly follow-up visits. After statistical adjustments for non-genetic factors (sex and age), two unfavorable alleles (A*3601 and DRB1*0102) were independently associated with high VL in SPs (p<0.01) but not in SCs. In contrast, favorable HLA variants, mainly A*74, B*13, B*57 (or Cw*18), and one HLA-A and HLA-C combination (A*30+Cw*03), dominated in SCs; their independent associations with low VL were reflected in regression beta estimates that ranged from −0.47±0.23 to −0.92±0.32 log₁₀ in SCs (p<0.05). Except for Cw*18, all favorable variants had diminishing or vanishing association with VL in SPs (p≤0.86).

Conclusions/Significance

Overall, each of the three HLA class I genes had at least one allele that might contribute to effective immune control, especially during the early course of HIV-1 infection. These observations can provide a useful framework for ongoing analyses of viral mutations induced by protective immune responses.

The impact of project closure on HIV incidence and mortality in a cohort of couples in Lusaka, Zambia

The objective of this study was to assess the impact of temporary closure of an HIV research clinic on the health of study participants. Primary data were collected quarterly from couples enrolled in research studies at an established HIV study site. There were 632 participating couples enrolled when the project closed, 475 of whom returned when it re-opened six months later. HIV sero-incidence, mortality rates and risk-taking behaviours were compared before and during the closure. Perceived impact of the closure was measured in returning participants. Demographic data collected at the last pre-closure study visit were used to look at the differences between returning and non-returning study participants. Serologic data from those who returned were compared pre- and post-closure to examine changes in HIV incidence. Mortality rates were estimated from reported deaths, and were compared pre- and during project closure. Perceptions of the impact of the closure among returning participants were examined through an interviewer administered questionnaire. It was found that couples who returned were not demographically different from couples who did not return. Most participants reported no problems with finding alternate sources of condoms and the incidence of HIV did not change significantly during the closure. Eighty-four percent respondents reported that the closure had a negative impact on them, 87% of whom rated loss of medical care as the main impact. The mortality rate among HIV-positive participants doubled from 6.7/100 person years to 12.4/100 person years during the closure (p=0.01). Results indicate that couples voluntary counselling and testing (CVCT) established durable risk-reduction behaviours that persisted during project closure. ThIn ae loss of healthcare was perceived as the most negative impact on participants, reflected in increased mortality rates. Research projects should make transition plans and budget for mechanisms to reduce the negative impact on participants of project closures.

Human leukocyte antigen class I genotypes in relation to heterosexual HIV type 1 transmission within discordant couples

Differences in immune control of HIV-1 infection are often attributable to the highly variable HLA class I molecules that present viral epitopes to CTL. In our immunogenetic analyses of 429 HIV-1 discordant Zambian couples (infected index partners paired with cohabiting seronegative partners), several HLA class I variants in index partners were associated with contrasting rates and incidence of HIV-1 transmission within a 12-year study period. In particular, A*3601 on the A*36-Cw*04-B*53 haplotype was the most unfavorable marker of HIV-1 transmission by index partners, while Cw*1801 (primarily on the A*30-Cw*18-B*57 haplotype) was the most favorable, irrespective of the direction of transmission (male to female or female to male) and other commonly recognized cofactors of infection, including age and GUI. The same HLA markers were further associated with contrasting viral load levels in index partners, but they had no clear impact on HIV-1 acquisition by the seronegative partners. Thus, HLA class I gene products not only mediate HIV-1 pathogenesis and evolution but also influence heterosexual HIV-1 transmission.

Modified Kigali combined staging predicts risk of mortality in HIV-infected adults in Lusaka, Zambia

We assessed the utility of the modified Kigali combined (MKC) staging system for predicting survival in HIV-infected Zambian adults in a prospective, longitudinal, open cohort. From 1995 to 2004, HIV-discordant couples (one HIV-infected partner and one HIV-negative partner) were recruited from couples' voluntary counseling and testing centers in Lusaka, Zambia and followed at 3-month intervals. MKC stage, which incorporates clinical stage with erythrocyte sedimentation rate (ESR), hematocrit, and body mass index (BMI), was determined at enrollment. Kaplan-Meier survival and Cox proportional hazard methods were used to calculate median survival and relative hazards. We enrolled 1479 HIV-discordant couples with a combined 7305 person-years of follow-up. Among HIV-infected participants over the 9-year study period, there were 333 confirmed deaths. The time to 50% mortality was 8.5 years with MKC stage 1 and 2 disease compared to 3.7 years with MKC stage 4 disease at enrollment. Survival rates at 3 years were 85% with MKC stage 1 and 2 disease, 74% with MKC stage 3 disease, and 51% with MKC stage 4 disease. A total of 275 HIV-negative partners seroconverted during follow-up. In comparison, survival rates at 3 years were 94% for HIV-negative participants and 92% for participants who seroconverted during follow-up. In multivariate analysis, MKC stage 4 disease (HR = 3.7, 95% CI = 2.7-5.0) remained a strong predictor of mortality. Incorporating ESR, hematocrit, and BMI with clinical staging is a powerful, low-cost tool to identify HIV-infected adults at high risk for mortality.

Mandatory fortification with folic acid in the United States is not associated with changes in the degree or the pattern of global DNA methylation in cells involved in cervical carcinogenesis

The purpose of this study was to evaluate whether mandatory fortification of grain products with folic acid in the USA is associated with changes in global DNA methylation in cells involved in cervical carcinogenesis. Archived specimens of cervical intraepithelial neoplasia (CIN) diagnosed before (1990-92) and after mandatory folic acid fortification (2000-02) were used to examine for global DNA methylation in specific lesions involved in cervical carcinogenesis by using a monoclonal antibody specific for 5 methyl cytosine (5-mc). The total number of lesions examined was 152 in the pre-fortification period and 172 in the post-fortification period. Immunohistochemical staining for 5-mc, the assessment of methylation status and data entry were blinded with regard to the fortification status. Age- and race-adjusted mean percentage of cells positive for 5-mc or the 5-mc score was not significantly different (P>0.05) between the pre- and post fortification periods in any of the individual lesions evaluated (i.e., normal cervical epithelium, reactive cervical epithelium, metaplastic cervical epithelium, CIN or carcinoma in situ). The degree of global DNA methylation was significantly higher (P<0.0001) in >or= CIN 2 lesions compared to <or= CIN 1 lesions, regardless of the fortification group. These results suggest that mandatory fortification with folic acid in the United States has not resulted in a change in the degree or the pattern of global DNA methylation in cells involved in cervical carcinogenesis.

Lower red blood cell folate enhances the HPV-16-associated risk of cervical intraepithelial neoplasia

OBJECTIVE

We previously reported that higher circulating concentrations of folate are independently associated with a lower likelihood of becoming positive for high-risk human papillomaviruses (HR-HPVs) and of having a persistent HR-HPV infection and a greater likelihood of becoming HR-HPV negative (Cancer Res 2004;64:8788-93). In the present study conducted in the same study population, we tested whether circulating folate concentrations modify the risk of cervical intraepithelial neoplasia (CIN) > or =2 associated with specific types of HR-HPV.

METHODS

Multiple logistic regression models were used to assess associations (odds ratio with 95% confidence intervals) across HR-HPV, folate, and rigorously reviewed cervical histology of each subject.

RESULTS

HPV-16-positive women with low red blood cell folate were significantly more likely to be diagnosed with CIN > or =2 than were HPV-16-negative women with higher red blood cell folate (odds ratio 9, 95% confidence interval 3.3-24.8).

CONCLUSION

To our knowledge, this is the first study reporting an independent association of folate with risk of having CIN > or =2 in a population tested extensively for HR-HPV and CIN that also adequately controlled for several other micronutrients and known risk factors for CIN. Our findings suggest that improving the folate status in HR-HPV-infected women may reduce the risk of CIN and thus the risk of cervical cancer. Folate supplementation should be tested as a means of reducing the risk of developing CIN > or =2 in women exposed to HR-HPV, especially HPV-16.

A randomized trial of clinician-delivered interventions promoting barrier contraception for sexually transmitted disease prevention

OBJECTIVE

The objective of this study was to compare 2 interventions promoting condoms and vaginal microbicides to prevent sexually transmitted disease (STD).

STUDY

Women (N = 427) attending an STD clinic were randomly assigned to 2 clinician-delivered interventions and followed up monthly to assess condom/microbicide use and incidence of gonorrhea, chlamydia, and syphilis.

RESULTS

During follow up, condom use rates were 69% (enhanced) and 49% (basic) and microbicide use rates were 44% and 29%, respectively. STD rates did not significantly differ between intervention groups. Perfect condom use (regardless of intervention arm) was associated with a 3-fold decrease in STD rates (relative risk [RR], 0.3; 95% confidence interval [CI], 0.1-0.8). Using a vaginal microbicide during > or =50% of the acts of intercourse was associated with reduced STD rates (RR, 0.5; 95% CI, 0.3-1.0) across intervention groups and condom use categories.

CONCLUSIONS

The enhanced intervention increased use of condoms and vaginal microbicide; however, STD rates did not decrease because a protective effect was seen only among perfect barrier users, and the enhanced intervention only modestly increased perfect use.

Do participant characteristics influence the effectiveness of behavioral interventions? Promoting condom use to women

OBJECTIVES

This study assessed whether participant baseline characteristics modified the effects of a skill-based intervention promoting condom use.

STUDY

The randomized, controlled trial enrolled 427 women from a sexually transmitted disease clinic in Birmingham, Alabama. The main outcome measures: consistent (100%) and problem-free (correct, no breakage or slippage) condom use were verified by sexual diary self-report and contraceptive product counts.

RESULTS

The enhanced intervention group had a 60% higher consistent condom use rate compared to the basic group (risk ratio [RR], 1.6; 95% confidence interval [CI], 1.4-1.8). There was no statistically significant difference between groups in relationship to problem-free, consistent use (RR, 1.0; 95% CI, 0.9-1.1). A binomial regression analysis identified the following factors as significant modifiers of intervention effectiveness on consistent condom use: intention to use condoms next time, early-age sexual debut, marital status combined with place of intercourse, and substance use before sex.

CONCLUSIONS

The results suggest that participant baseline characteristics can be modifiers of intervention effectiveness.

Participation and retention in a study of female condom use among women at high STD risk

PURPOSE

Differential participation and retention can bias the findings of a follow-up study. This problem was evaluated in a study of barrier contraception among women at high STD risk. The goal of this study was to identify predictors of participation and retention and determine whether they could influence study results.

METHODS

Six-month follow-up study of women attending STD clinics. Determinants of participation and retention were evaluated using logistic and proportional hazards models.

RESULTS

Agreement to participate was associated with young age, black race, low education and income, older age at first intercourse, the number of lifetime partners, and STD history. Early attrition was associated with young age, non-black race, higher income, lack of interest/commitment to using the female condom, high coital frequency, no STD history, not using a birth control method at baseline, and with inconsistent condom use, high coital frequency, and pregnancy during follow up.

CONCLUSIONS

There was little evidence that differential participation influenced the validity of the study. Differential attrition may have biased behavioral measures of intervention effectiveness, but not necessarily measures of condom use effectiveness.

An intervention to promote the female condom to sexually transmitted disease clinic patients

This article describes a 1-hour behavioral intervention designed to promote female condoms and safer sex to women at a high risk for sexually transmitted diseases (STDs). The intervention includes a promotional videotape; a skills-oriented counseling session with a nurse clinician; assorted take-home items, including a videotape for men; and free supplies of female and male condoms. Designed for women ages 18 to 34 attending public STD clinics, the intervention is developed using a systematic process of formative evaluation influenced by principles of social marketing and drawing on the social cognitive theory. The effect of the intervention on female and male condom use is evaluated using a pretest-posttest design with 1,159 women. Most elements of the intervention could be replicated in settings other than STD clinics and delivered by persons other than nurse clinicians.

Application of the case-crossover design to reduce unmeasured confounding in studies of condom effectiveness

This analysis examined how unmeasured confounding affects estimates of the effectiveness of condoms in preventing sexually transmitted infections. Data were analyzed from a prospective cohort study of 1,122 female sexually transmitted disease clinic patients in Alabama (1992-1995), wherein participants were evaluated for sexually transmitted infections at six 1-month intervals. Associations between condom use and incident gonorrhea and chlamydia infection were compared between case-crossover and cohort analyses. In a case-crossover analysis of 228 follow-up visits ending in gonorrhea/chlamydia ("case intervals") and 743 self-matched follow-up visits not ending in gonorrhea/chlamydia ("noncase intervals") (183 women), consistent condom use without breakage or slippage was associated with significantly reduced risk of infection relative to nonuse (adjusted risk odds ratio = 0.49, 95% confidence interval: 0.26, 0.92). Conversely, a cohort analysis of 245 case intervals and 3,896 noncase intervals (919 women) revealed no significant reduction in infection risk from consistent use of condoms (adjusted risk odds ratio = 0.79, 95% confidence interval: 0.53, 1.17). Dose-response relations between the number of unprotected sex acts and infection were stronger in the case-crossover analysis (p for trend = 0.009) than in the cohort analysis (p for trend = 0.18). These findings suggest that epidemiologic studies confounded by unmeasured differences between condom users and nonusers underestimate condom effectiveness against these infections. The case-crossover method provides an additional technique for reducing unmeasured confounding in studies of condom effectiveness.

Mortality among workers at a talc mining and milling facility

BACKGROUND

This study evaluated mortality among workers at a talc mining and milling facility.

METHODS

Subjects were white men actively employed between 1948 and 1989 and known to have been alive in or after 1950. Analyses assessed cancer mortality during the period 1950-89 (809 subjects) and non-cancer mortality during 1960-89 (782 subjects).

RESULTS

Comparisons with regional general population death rates for 1960-89 indicated that the workers had more than expected deaths from all causes combined [209 observed/160 expected, standardized mortality ratio (SMR) = 131, 95% confidence interval (CI) = 114-150], due mainly to increased mortality from lung cancer (31/13, SMR = 232, CI = 157-329) and non-malignant respiratory disease (NMRD) (28/13, SMR = 221, CI = 147-320). The lung cancer excess was concentrated in miners (18/4.6, SMR = 394, CI = 233-622); millers had only a small increase (7/5.5, SMR = 128, CI = 51-263). An excess of NMRD occurred both in miners (10/4.2, SMR = 241, CI = 116-444) and in millers (11/4.8, SMR = 227, CI = 113-407). The median estimated exposure to respirable dust was 511 mg/m(3)-days for all exposed employees, 739 mg/m(3)-days for mine workers and 683 mg/m(3)-days for mill workers. Employees with high, compared with low, estimated exposure to dust had a rate ratio of 0.5 (CI = 0.2-1.3) for lung cancer and of 11.8 (CI = 3.1-44.9) for pulmonary fibrosis.

CONCLUSIONS

Exposure to talc ore dust may not have been responsible for the lung cancer excess among these workers but probably contributed to the elevated rate of NMRD, particularly pulmonary fibrosis.

Assessment of Historical Exposures to Talc at a Mining and Milling Facility

The purpose of this study was to develop an estimate of exposure to respirable dust for all job categories and all years in a retrospective follow-up study of worker mortality in a talc mining and milling facility. All jobs were assigned to work areas that were considered to have similar exposure profiles. Uniform exposure time periods during which non-random, deterministic variables were thought to be constant were identified and an experienced rater assigned categorical exposure scores to each work area/time period. These scores and measured baseline respirable dust concentrations were used to calculate the estimated job area/year concentrations for each work area/time period. Estimates were compared to available historical measurements. The estimated exposures ranged from 1.7 to 0.1 mg/m(3) and displayed a decreasing trend over time. When compared with measured exposures, the estimated exposures had a correlation coefficient of 0.55 with an average difference of 0.01 mg/m(3) and a range of 0.60 to -0.48 mg/m(3). The estimates were considered to be acceptable for determining relative ranking of subjects according to cumulative exposure.

Effectiveness of an intervention promoting the female condom to patients at sexually transmitted disease clinics

OBJECTIVES

This study evaluated a behavioral intervention designed to promote female condoms and reduce unprotected sex among women at high risk for acquiring sexually transmitted diseases (STDs).

METHODS

The effect of the intervention on barrier use was evaluated with a pretest-posttest design with 1159 female STD clinic patients.

RESULTS

Among participants with follow-up data, 79% used the female condom at least once and often multiple times. More than one third of those who completed the study used female condoms throughout follow-up. Use of barrier protection increased significantly after the intervention, and high use was maintained during a 6-month follow-up. To account for attrition, the use of protection by all subjects was projected under 3 conservative assumptions. The initial visit and termination visit projections suggest that use increased sharply after the intervention and declined during follow-up but remained elevated compared with the baseline.

CONCLUSIONS

Many clients of public STD clinics will try, and some will continue, to use female condoms when they are promoted positively and when women are trained to use them correctly and to promote them to their partners. A behavioral intervention that promotes both female and male condoms can increase barrier use.

Brain tumors among electronics industry workers

We evaluated the relation between work experience in the United States operations of an electronics company and brain tumor mortality, focusing on video display terminal (VDT) development jobs. Subjects were 149 brain tumor cases and 591 matched controls selected from a company registry of all employees dying between 1975 and 1989. Company databases and interviews with company personnel constituted the basis for work histories, including information on whether subjects had held VDT development jobs. Subjects who worked at plants with hardware or VDT development operations had slightly but imprecisely elevated odds ratios (OR). The study found no meaningful association between VDT development work and brain tumor mortality. Other results included an elevated OR for 10 or more years of employment in engineering/technical jobs [OR = 1.7; 95% confidence interval (CI) = 1.0-3.0] or in programming jobs (OR = 2.8; 95% CI = 1.1-7.0). The OR for glioma for all subjects who had accrued 5 years of programming work 10 years before the case's death was 3.9 (95% CI = 1.2-12.4). These associations were limited in large part to one of four division groups. Also, only male programmers experienced an elevated OR. These patterns indicate that the associations may be due to chance, although unidentified causal exposures present in a subset of engineering/technical and programming jobs cannot be ruled out.

A case-control study of leukemia among petroleum workers

This case-control study evaluates the relationship between leukemia and the work histories of active and retired employees of a large petroleum company. The study includes 69 cases with leukemia and 284 matched controls. Employment in production-related work in the oil and gas division was associated with myelogenous leukemia (odds ratio [OR] = 2.0, 95% confidence interval [CI] = .97 to 4.2) and particularly with acute myelogenous leukemia (OR = 2.8, 95% CI = 1.1 to 7.3). The association with acute myelogenous leukemia was strongest for subjects in the highest tertile (32+ years) of duration of employment in oil- and gas production-related work (OR = 8.7, 95% CI = 2.0 to 37), and there was a consistent trend of increasing ORs with increasing duration of employment (P = .01). No clear association was observed for refining division work and leukemia. This is the first epidemiologic study reporting a positive association between oil and gas field work and acute myelogenous leukemia.

The development of encapsulated filtering blebs

The development of an encapsulated filtering bleb (Tenon's cyst) complicated 56 of 409 consecutive filtering operations (13.7%) performed during a 40-month period after January 1983. Fifteen eyes (27.8% of encapsulated blebs) required surgical revision. The recognition of bleb encapsulation occurred 20.4 +/- 12.7 days (mean +/- standard deviation) postoperatively. Prolonged duration of beta-adrenergic antagonist therapy was associated with an increased frequency of bleb encapsulation (180.6 +/- 128.5 weeks without encapsulation, 229.0 +/- 129.3 weeks with encapsulation, P less than 0.009). Bleb encapsulation occurred in 42 of 272 eyes with previous argon laser trabeculoplasty, but in only 4 of 85 eyes without any previous anterior segment laser (P less than 0.01). Encapsulated filtering blebs developed in 4 of 12 (33.3%) eyes with congenital glaucoma and 4 of 9 (44.4%) eyes with juvenile glaucoma (P less than 0.0002). The intraocular pressures (IOPs) in the eyes with encapsulated filtering blebs were significantly elevated at 1, 2, and 3 postoperative weeks, and at final follow-up compared with eyes without bleb encapsulation.