Risk factors for transmission of tuberculosis among United States-born African Americans and Whites.

SETTING: Tuberculosis (TB) patients and their contacts enrolled in nine states and the District of Columbia from 16 December 2009 to 31 March 2011. OBJECTIVE: To evaluate characteristics of TB patients that are predictive of tuberculous infection in their close contacts. DESIGN: The study population was enrolled from a list of eligible African-American and White TB patients from the TB registry at each site. Information about close contacts was abstracted from the standard reports of each site. RESULTS: Close contacts of African-American TB patients had twice the risk of infection of contacts of White patients (adjusted risk ratio [aRR] 2.1, 95%CI 1.3-3.4). Close contacts of patients whose sputum was positive for acid-fast bacilli on sputum smear microscopy had 1.6 times the risk of tuberculous infection compared to contacts of smear-negative patients (95%CI 1.1-2.3). TB patients with longer (>3 months) estimated times to diagnosis did not have higher proportions of infected contacts (aRR 1.2, 95%CI 0.9-1.6). CONCLUSION: African-American race and sputum smear positivity were predictive of tuberculous infection in close contacts. This study did not support previous findings that longer estimated time to diagnosis predicted tuberculous infection in contacts.

Barriers to universal prenatal HIV testing in 4 US locations in 1997.

OBJECTIVES: We determined rates of prenatal HIV testing and investigated barriers to testing. METHODS: We surveyed 1362 representative parturient women from 7 hospitals in 4 locations of the United States. RESULTS: Overall, 89.9% of women reported being offered HIV testing and 69.6% reported being tested. Proportions of women not offered testing differed by location (range = 5.2%-16.3%), as did proportions not tested (range = 12.2%-54.4%). Among women who perceived that their clinicians had not recommended testing, 41.7% were tested, compared with 92.8% of women who perceived a strong recommendation (P < .05). Private insurance for prenatal care was also associated with not being tested. Women gave multiple reasons for not being tested, most commonly not being at risk, having been tested recently, and the test's not being offered or recommended, cited by 55.3%, 39.1% and 11.1% of women, respectively. CONCLUSIONS: Although most parturient women were offered a prenatal HIV test and got tested, testing proportions did not reach national goals and differed significantly by location and payment status. Concern about testing consequences was not a major barrier. Perception of clinicians' recommendations strongly influenced testing. Changing provider practices will be essential to implementing universal prenatal HIV testing.

New mothers' knowledge and attitudes about perinatal human immunodeficiency virus infection.

OBJECTIVES: To assess new mothers' attitudes toward perinatal human immunodeficiency virus (HIV) testing, their knowledge about perinatal HIV, and their trust of government and scientists. METHODS: In a cross-sectional survey of 1362 postpartum women at four United States locations in 1997, a standardized interview was administered to new mothers 24-48 hours postpartum to determine their HIV test acceptance, attitudes, and knowledge. RESULTS: Seventy-five percent of women who were offered HIV tests reported being tested. Although 95% of women were aware of perinatal HIV transmission, only 60% knew that HIV can be transmitted through breast-feeding, and only 51% knew of medication to prevent perinatal transmission. Eighty-four percent of women thought that all pregnant women should be tested for HIV, and 60% thought that prenatal HIV testing should be legally mandated. Twenty percent of women indicated mistrust of government and scientists regarding origins of HIV and potential cures for AIDS. Knowledge about perinatal transmission was unrelated to receipt of prenatal HIV tests. When other factors were controlled for, mistrust was not significantly associated with getting tested. CONCLUSION: Incomplete knowledge of prevention of perinatal HIV transmission and mistrust were prevalent among new mothers. Knowledge deficits or mistrust did not appear to reduce reported prenatal test rates, but our data suggest that future public health efforts need to educate women about methods of preventing perinatal HIV transmission and at enhancing their trust in the public health system.

Bacterial vaginosis and cervical dilation and effacement at 24-29 weeks' gestation.

The purpose of this study was to investigate the association between bacterial vaginosis (BV) and cervical dilation and effacement, as measures of impending preterm delivery. The Pregnancy, Infection, and Nutrition Study collected genital tract specimens and documented cervical change from 807 eligible women between 24 and 29 weeks' gestation. BV was assessed with Nugent-scored vaginal smears, and analyzed in relation to cervical measurements. At 24-29 weeks' gestation, <7% of women had a dilated cervix, 31% had a cervix < or =2 cm, and 17.3% had BV. Unadjusted analyses found no associations between BV and cervical measurements. Adjusted logistic regression suggested an association between BV and cervical effacement among women with a sexually transmitted disease (STD) earlier in pregnancy (odds ratio = 1.9, 95% CI 0.8-4.3). Stratified analyses for BV/dilation also suggested interaction with STDs. Overall, BV was not association with cervical dilation or effacement at 24-29 weeks' gestation.

Effects of short interpregnancy intervals on small-for-gestational age and preterm births.

We examined the effects of short interpregnancy intervals on small-for-gestational age and preterm births in a biracial population using North Carolina birth certificate data from 1988 to 1994. We defined small-for-gestational age birth as being below the 10th percentile on a race-, sex-, and parity-specific growth curve after a gestation of 37-42 weeks. We defined preterm birth as a gestation of less than 37 weeks. We analyzed birth records from all eligible singleton births to black or white women ages 15-45 years after an interpregnancy interval of 0-3 months (N = 11,451) and a random sample of singleton births after an interval of 4-24 months (N = 23,118). We defined interpregnancy interval exposure categories as 0-3, 4-12, and 13-24 months. The multivariate adjusted odds ratio for small-for-gestational age births after interpregnancy intervals of 0-3 months compared with 13-24-month intervals was 1.6 (95% confidence interval = 1.4-1.8). The odds ratio for preterm birth after interpregnancy intervals of 0-3 months was 1.2 (95% confidence interval = 1.1-1.3). Odds ratios did not vary substantially by race for either outcome.

What's driving an epidemic? The spread of syphilis along an interstate highway in rural North Carolina.

OBJECTIVES: The purpose of this study was to determine whether county syphilis rates were increased along Interstate Highway 95 (I-95) in North Carolina during a recent epidemic. METHODS: Ecological data on syphilis cases demographic data, highway data, and drug activity data were used to conduct a cross-sectional and longitudinal study of North Carolina countries from 1985 to 1994. Crude and adjusted incidence rate ratios (IRRs) were determined by means of standard and longitudinal Poisson regression models adjusted for sociodemographic factors and drug use. RESULTS: Ten-year syphilis rates in I-95 counties greatly exceeded rates in non-I-95 counties (38 vs 16 cases per 100,000 persons) and remained higher after adjustment for race, age, sex, poverty, large cities, and drug activity (adjusted IRR = 2.05, 95% confidence interval [CI] = 1.84, 2.28). Syphilis rates were stable until 1989, when rates increased sharply in I-95 counties but remained stable in non-I-95 counties. Increased drug activity in I-95 counties preceded the rise in syphilis cases. CONCLUSIONS: A better understanding of the relationship between high-ways and the spread of sexually transmitted diseases may guide future prevention interventions.

Bacterial vaginosis associated with HIV infection in pregnant women from North Carolina.

BACKGROUND: We investigated whether bacterial vaginosis is associated with HIV infection in pregnant women in North Carolina, U.S.A. METHODS: At 24 to 29 weeks' gestation, we recruited 724 women receiving prenatal care to provide interview information and vaginal swabs for Gram's stain scoring of vaginal flora. FINDINGS: As vaginal flora score increased, prevalence of HIV increased (trend p = .03). HIV prevalence was 0.8% (4 of 489 patients), 1.2% (1 of 84 patients), and 3.3% (5 of 151 patients) among women with normal, intermediate, and abnormal vaginal flora, respectively. All HIV-infected women were free from AIDS and were taking antiretroviral medication. Compared with women with normal vaginal flora, the relative risk for prevalence of HIV infection with intermediate flora was 1.5 (95% confidence interval [CI], 0.2, 12.9) and with abnormal flora was 4.0 (95% CI, 1.1, 14.9). The association between abnormal vaginal flora and HIV infection could not be explained by age, ethnicity, number of sexual partners in the past 6 months, sexually transmitted diseases (STDs), or douching during pregnancy. INTERPRETATION: In a population with a relatively low HIV prevalence, vaginal flora abnormalities were associated with prevalent HIV infection. We cannot determine whether vaginal flora abnormalities increase women's susceptibility to HIV infection or become more common after infection. The increased prevalence of bacterial vaginosis among HIV-infected pregnant women increases risk for preterm delivery. Incidence studies are required to discern whether control of bacterial vaginosis might reduce HIV infectivity.

Race/ethnicity, vaginal flora patterns, and pH during pregnancy.

OBJECTIVES: To investigate the relationship between bacterial vaginosis during pregnancy and black race/ethnicity. STUDY DESIGN: Gram staining was used to evaluate vaginal flora in 842 women at 24 to 29 weeks' gestation. RESULTS: Overall, 22.3% of blacks and 8.5% of whites had bacterial vaginosis. Vaginal pH and flora differed significantly by race/ethnicity; blacks were more likely to have pH > or = 4.5, no lactobacilli, small gram-variable and -negative rods, and Mobiluncus compared with whites (odds ratios 1.6, 1.5, 1.4, and 10.6, respectively). Quantity of morphotypes also differed, especially for Mobiluncus. Among women with Mobiluncus present (12.0% of blacks and 1.3% of whites), 73.3% of blacks compared with 40.0% of whites had the highest level. Adjustment for sociodemographics, sexual activity, sexually transmitted diseases, health behavior, and sexual hygiene did not explain these differences. CONCLUSION: We observed race/ethnicity differences in vaginal flora ecology. These differences may ultimately play a role in the larger proportion of preterm deliveries among black women compared with white women.

Association between bacterial vaginosis and fetal fibronectin at 24-29 weeks' gestation.

OBJECTIVE: To investigate the relationship between fetal fibronectin and bacterial vaginosis, which are associated with an increased risk for preterm delivery. METHODS: Researchers for the Pregnancy, Infection and Nutrition Study, a cohort study of pregnant women at three central North Carolina sites, collected genital tract specimens from all enrolled women between 24 and 29 weeks' gestation. Among women with last menstrual periods between March 10, 1995, and August 15, 1996, 868 pregnancies were eligible for this analysis. Fetal fibronectin was assessed by a dipstick immunoassay kit. Bacterial vaginosis was evaluated by Nugent-scored, Gram-stained vaginal smears (scores of 7-10 considered positive). RESULTS: Overall, 6.3% of women had positive fetal fibronectin test results, and 18.8% had bacterial vaginosis. The unadjusted relative risk (RR) of fetal fibronectin-positivity comparing women with bacterial vaginosis to those without bacterial vaginosis was 1.6 (95% confidence interval [CI] 1.1, 2.5). Using multiple logistic regression to adjust for race, maternal age, parity, and location of care, women who had bacterial vaginosis and smoked at the time of recruitment were at substantially increased risk of fetal fibronectin-positivity (RR 7.8, 95% CI 2.2, 27.8) compared with smokers without bacterial vaginosis. Among nonsmokers, bacterial vaginosis was not associated with fetal fibronectin-positivity (RR 1.0, 95% CI 0.4, 2.4). These results were essentially unchanged after adding the requirement of vaginal pH exceeding 4.5 to the bacterial vaginosis definition. CONCLUSION: Fetal fibronectin was associated positively with bacterial vaginosis, but only among women who smoked. These results might provide clues as to the biologic relationship between smoking, infection, and preterm delivery.

High levels of human immunodeficiency virus type 1 in blood and semen of seropositive men in sub-Saharan Africa.

High levels of human immunodeficiency virus type 1 (HIV-1) replication, as reflected in HIV-1 RNA concentrations in blood and semen, probably contribute to both rapid disease progression and enhanced sexual transmission. Semen and blood were collected from 49 Malawian and 61 US and Swiss (US/Swiss) HIV-1-seropositive men with similar CD4 cell counts and no urethritis or exposure to antiretroviral drugs. Median seminal plasma and blood plasma HIV-1 RNA concentrations were >3-fold (P = .034) and 5-fold (P = .0003) higher, respectively, in the Malawian men. Similar differences were observed in subsets of the Malawian and US/Swiss study groups matched individually for CD4 cell count (P = .035 and P < .002, respectively). These observations may help explain the high rates of HIV-1 sexual transmission and accelerated HIV-1 disease progression in sub-Saharan Africa.

Risk factors for horizontal transmission of hepatitis B virus in a rural district in Ghana.

Most hepatitis B virus (HBV) infections in sub-Saharan African infants and children are acquired through horizontal transmission, but the exact mechanisms of spread have not been documented. The authors conducted a study in rural Ghana which determined seroprevalence in a probability sample of 1,385 individuals of all ages, and evaluated risk factors for horizontal transmission of HBV in a subsample of 547 children aged 1-16 years who were not hepatitis B surface antigen (HBsAg) carriers. Most residents in this district live in compounds which typically contain 2-4 households each. Overall prevalence of HBV seropositives (any HBV marker) was 74.7% (95% confidence interval (CI) 72.5%-76.9%). Prevalence of HBsAg was 20.9% (95% CI 18.8%-23.1%). The data suggest a continuous nonuniform acquisition of HBV infection with advancing age predominantly through horizontal transmission in childhood, with the household, rather than the domestic compound, being the primary place for transmission. The behaviors most strongly associated with prevalence of HBV were sharing of bath towels (OR = 3.1, 95% CI 2.1-4.5), sharing of chewing gum or partially eaten candies (OR = 3.4, 95% CI 2.3-5.0), sharing of dental cleaning materials (OR = 2.5, 95% CI 1.3-4.6), and biting of fingernails in conjunction with scratching the backs of carriers (OR = 2.5, 95% CI 1.6-4.3).

PIP: Most hepatitis B virus (HBV) infections in sub-Saharan African infants and children are acquired through horizontal transmission. Findings are reported from a study conducted in rural Ghana to measure seroprevalence in a probability sample of 1385 people of all ages, and evaluate risk factors for the horizontal transmission of HBV in a subsample of 547 children aged 1-16 years who were not hepatitis B surface antigen (HBsAg) carriers. Most residents in the sample area live in compounds which typically contain 2-4 households each. The overall prevalence of HBV seropositives was 74.7% and the prevalence of HBsAg was 20.9%. These data suggest a continuous nonuniform acquisition of HBV infection with advancing age mainly through horizontal transmission in childhood, with the household, rather than the domestic compound, being the main place for transmission. The sharing of bath towels, sharing of chewing gum or partially eaten candies, sharing of dental cleaning materials, and biting of fingernails together with scratching the backs of carriers are the behaviors found to be most strongly associated with HBV prevalence.

Previous cesarean birth. A risk factor for placenta previa?

OBJECTIVE: To study the risk of placenta previa following a previous cesarean birth. STUDY DESIGN: We conducted a population-based, case-control study using 1990 North Carolina state birth certificate data. The study population included 342 women with a pregnancy complicated by placenta previa and 1,082 randomly selected controls. Analysis was restricted to women who reported one or more previous live births and delivered a singleton, live neonate. Adjusted odds ratios (ORs) with 95% confidence intervals (95% CIs) were calculated using logistic regression, controlling for maternal age, race, prior spontaneous or induced abortions and cigarette use. RESULTS: When the data were adjusted for maternal age, race, prior spontaneous or induced abortions, and cigarette use, women who had a previous cesarean birth and had a parity of 3 were 1.7 times more likely (OR 1.7, 95% CI 0.7, 4.2) and women of parity > or = 4 were 5.5 times more likely (OR 5.5, 95% CI 1.0, 30.1) to have placenta previa than women of parity 1 who had a previous cesarean birth. CONCLUSION: Women with a history of a previous cesarean birth and parity > or = 3 were at increased risk of having a pregnancy complicated by placenta previa.

Reduction of concentration of HIV-1 in semen after treatment of urethritis: implications for prevention of sexual transmission of HIV-1. AIDSCAP Malawi Research Group.

BACKGROUND: Transmission of HIV-1 is predominantly by heterosexual contact in sub-Saharan Africa, where sexually transmitted diseases (STDs) are also common. Epidemiological studies suggest that STDs facilitate transmission of HIV-1, but the biological mechanism remains unclear. We investigated the hypothesis that STDs increase the likelihood of transmission of HIV-1 through increased concentration of the virus in semen. METHODS: HIV-1 RNA concentrations were measured in seminal and blood plasma from 135 HIV-1-seropositive men in Malawi; 86 had urethritis and 49 controls did not have urethritis. Men with urethritis received antibiotic treatment according to the guidelines of the Malawian STD Advisory Committee. Samples were analysed at baseline and at week 1 and week 2 after antibiotic therapy in urethritis patients, and at baseline and week 2 in the control group. FINDINGS: HIV-1-seropositive men with urethritis had HIV-1 RNA concentrations in seminal plasma eight times higher than those in seropositive men without urethritis (12.4 vs 1.51 x 10(4) copies/mL, p = 0.035), despite similar CD4 counts and concentrations of blood plasma viral RNA. Gonorrhoea was associated with the greatest concentration of HIV-1 in semen (15.8 x 10(4) copies/mL). After the urethritis patients received antimicrobial therapy directed against STDs, the concentration of HIV-1 RNA in semen decreased significantly (from 12.4 x 10(4) copies/mL to 8.91 x 10(4) copies/mL at 1 week [p = 0.03] and 4.12 x 10(4) copies/mL at 2 weeks [p = 0.0001]). Blood plasma viral RNA concentrations did not change. There was no significant change in seminal plasma HIV-1 RNA concentrations during the 2-week period in the control group (p = 0.421). INTERPRETATION: These results suggest that urethritis increases the infectiousness of men with HIV-1 infection. HIV-1-control programmes, which include detection and treatment of STDs in patients already infected with HIV-1, may help to curb the epidemic. Targeting of gonococcal urethritis may be a particularly effective strategy.

The natural history of HIV-1 infection: staging classifications of disease.

We evaluated and compared four staging classification systems for HIV infection in a population-based cohort: (1) a staging based on prodromal clinical criteria; (2) the Walter Reed Staging Classification (WRSC); (3) the immunologic staging system (ISS), and (4) a simple staging based on oral disease and CD4+ T-cell depletion. The staging systems were applied to 386 HIV-infected men in the San Francisco Men's Health Study cohort who did not have AIDS at the baseline examination. After 48-56 months of follow-up the cumulative incidence of AIDS and the cumulative mortality by stage was determined for each staging. Unlike the other systems, the WRSC could not classify a substantial proportion of HIV-infected men (51.9%). The WRSC and ISS include one or more stages which did not appear to be associated with a prognosis substantially different from that of adjacent stages. The simplified staging system based on CD4+ T-cell depletion and oral disease may be the most effective of the systems studied. A more complete understanding of the pathophysiology during the evolution of HIV infection will be required to define a more detailed staging of this disease.

HIV infection, cigarette smoking and CD4+ T-lymphocyte counts: preliminary results from the San Francisco Men's Health Study.

The effect of cigarette smoking on CD4+ T lymphocytes was investigated in the San Francisco Men's Health Study cohort. The cohort was established by probability sampling in 1984 to study infection with HIV. Smoking showed an association with increased CD4+ cell counts in all men but the effect was attenuated in HIV-seropositive men (85 cells/microliter difference in median counts, non-smokers compared with smokers) compared with HIV-seronegative men (230 cells/microliter difference in median counts). The positive dose response between packs smoked per day and CD4+ counts observed in uninfected men was substantially reduced in infected men (slope 87 versus 27 cells/microliter). Analysis of data from HIV seroconverters suggest that smokers' counts fall faster than non-smokers' following infection, and that response to smoking becomes less pronounced soon after infection. This report demonstrates that those who monitor CD4+ cell counts in HIV-infected individuals for clinical and/or research purposes should also consider smoking status.