Public Health Impact
Women and infants are at significant risk for long-term consequences of STDs. A woman’s relationship status with her male partner, such as the concurrency of the relationship, has been identified as an important predictor of her sexual health. In addition to social factors such as poverty and lack of access to quality STD services, homelessness or unstable housing may increase a woman’s risk for acquiring a sexually transmitted infection.4 For some women maintaining the relationship with her partner may take a higher priority than STD risk reduction5, thereby affecting her sexual and reproductive health, as well as the health of her unborn baby.
Because it may be her male partner’s risk, rather than the woman’s that increases a woman’s risk for STDs, even a woman who has only one partner may be obliged to practice safer sex, such as using condoms. A number of studies have found significant associations between condom use and socio-demographic characteristics, including age, income, education, and acculturation.
Women infected with Chlamydia trachomatis or Neisseria gonorrhoeae can develop pelvic inflammatory disease (PID), which, in turn, can lead to reproductive morbidity such as ectopic pregnancy and tubal factor infertility. An estimated 10–20% of women with chlamydial and gonococcal infections may develop PID if they do not receive adequate treatment. Among women with PID, tubal scarring can cause infertility in 8% of women, ectopic pregnancy in 9%, and chronic pelvic pain in 18%.
The majority of chlamydial and gonococcal infections in women are asymptomatic, and hence are detected primarily through screening. Because the symptoms associated with PID can be nonspecific, up to 85% of women with PID delay seeking medical care, thereby increasing the risk for infertility and ectopic pregnancy.Data from two randomized controlled trials of chlamydia screening suggest that such screening programs reduce PID incidence.
Human papillomavirus (HPV) infections are highly prevalent in the United States, especially among young sexually active adults. Although most HPV infections in women are cleared within several years, high-risk HPV type infections can be accompanied by abnormal changes in the uterine cervical epithelium, which are detected by cytological examination of Papanicolaou (Pap) smears. Persistent high-risk HPV-type infections may lead to cervical cancer precursors, which if undetected can result in cancer. Other low-risk HPV types cause genital warts, low-grade Pap smear abnormalities, and, rarely, recurrent respiratory papillomatosis in infants born to infected mothers.
As with non-pregnant women, a high proportion of pregnant women with chlamydial and gonococcal infections are asymptomatic. Documented sequelae of untreated infections in pregnancy include stillbirth, premature delivery, premature rupture of the membranes, and low birth weight. Maternal infection can also affect the neonate, leading to neonatal ophthalmia, and, in the case of C. trachomatis, neonatal pneumonia. Although topical prophylaxis of infants at delivery is effective for prevention of gonococcal ophthalmia neonatorum, prevention of neonatal pneumonia requires prenatal detection and treatment.
Genital infections with herpes simplex virus (HSV) are extremely common, can cause painful outbreaks, and can have serious consequences for pregnant women and their infants.Neonatal herpes can be a severe illness presenting with pulmonary disease, seizures, fever, and a high case fatality rate following contact with infected genital secretions during delivery. Risk of transmission to the infant is greatest when the mother has primary genital lesions during delivery, especially if she acquires infection towards the end of her pregnancy.
Syphilis has long been known to be an important risk factor for adverse pregnancy outcomes. The consequences of untreated maternal infection include fetal death, preterm birth, and also congenital infection in a proportion of surviving infants resulting in both physical and mental developmental disabilities. Most cases of congenital syphilis are easily preventable if women are screened for syphilis and treated early during prenatal care.
Chlamydial infections in women are usually asymptomatic and screening is necessary to identify most infections.Routine chlamydia screening of sexually-active young women has been recommended by the CDC since 1993.Rates of reported cases of chlamydia among women increased steadily from the early 1990s, likely reflecting expanded screening coverage and use of more sensitive diagnostic tests . During 2011–2013, rates decreased from 643.4 to 619.0 cases per 100,000 females and then increased a total of 4.3% over the next 2 years, resulting in a rate of 645.5 cases per 100,000 females in 2015 .
Chlamydia rates are highest among young women, the population targeted for screening. During 2014–2015, rates of reported chlamydia cases increased 1.5% and 2.7% among females aged 15–19 and 20–24 years, respectively. Regionally, chlamydia case rates were highest among women in the South, with a rate of 720.2 cases per 100,000 females in 2015 . Rates of reported chlamydia cases exceeded gonorrhea rates among women in all regions (Figures and , Tables and).
Like chlamydia, gonorrhea is often asymptomatic in women. Thus, gonorrhea screening is an important strategy for the identification of gonorrhea among women. Large scale screening programs for gonorrhea in women began in the 1970s. After an initial increase in cases detected through screening, rates of reported gonorrhea cases for both women and men declined steadily throughout the 1980s and early 1990s, and then declined more gradually in the late 1990s and the 2000s. However, more recently, there have been increases in cases since 2009.
After reaching a 40-year low in 2009 (104.5 cases per 100,000 females), the rate of reported cases of gonorrhea for women increased slightly each year during 2009–2011, and then decreased each year during 2012–2014 . In 2015, the gonorrhea rate among women increased 6.8% to 107.2 cases per 100,000 females .
The gonorrhea rate among women was slightly higher than the rate among men during 2006–2012; however, the rate among men was higher than the rate among women during 2013–2015 . During 2011–2015, gonorrhea rates were highest among young women and adolescents aged 15–24 years. For women in this age group, rates were highest among 19-year olds in 2015 (666.0 cases per 100,000 females) .
Trends in congenital syphilis usually follow trends in primary and secondary (P&S) syphilis among women, with a lag of 1–2 years. After plateauing at a relatively low rate (0.9 cases per 100,000 females) during 2011–2013, the rate of reported P&S syphilis cases among women increased to 1.1 cases per 100,000 females in 2014, and then increased 27.3%, to 1.4 cases per 100,000 females during 2014–2015.
Similarly, the rate of reported congenital syphilis cases has increased each year since 2012. In 2015, there were 487 reported cases of congenital syphilis and the national congenital syphilis rate was 12.4 cases per 100,000 live births. This increase in 2015 represents a 6.0% increase relative to 2014 and a 36.3% increase relative to 2011.
In 2015, the highest rates of P&S syphilis among women and the highest rates of congenital syphilis were observed in the South and in the West (FiguresC and D, Tables 28 and 41). The P&S syphilis rates among women increased in every region during 2014–2015. However, only the West experienced an increase in the congenital syphilis rate during this time period. During 2014–2015, the largest increases in the P&S syphilis rates among women were seen in the West (41.7%), followed by the Northeast (40.0%), South (20.0%), and Midwest (11.1%). The congenital syphilis rate increased 42.3% in the West and decreased 17.4% in the Northeast, 7.7% in the South, and 3.5% in the Midwest .
Although most cases of congenital syphilis occur among infants whose mothers have had some prenatal care, late or limited prenatal care has been associated with congenital syphilis. Failure of health care providers to adhere to maternal syphilis screening recommendations also contributes to the occurrence of congenital syphilis.
Neonatal herpes simplex virus (HSV) infections, although relatively rare, cause significant morbidity and mortality. Most neonatal HSV infections result from perinatal transmission from mother to neonate, but postnatal infection can occur. Although reporting of neonatal HSV infection is required in a few jurisdictions,it is not a nationally reportable disease.
An examination of inpatient records of infants aged 60 days or younger at admission using the Healthcare Cost and Utilization Project Kid’s Inpatient Database showed an overall incidence of 9.6 cases per 100,000 live births in 2006. Rates did not vary significantly by region or race/ethnicity; however prevalence was significantly higher among cases for which the expected primary payer was Medicaid (15.1 cases per 100,000) compared with private insurance or managed health care (5.4 cases per 100,000).
In New York City, 76 cases of neonatal HSV infection were identified through population-based surveillance during a 4.5 year period (April 2006–September 2010), for an average annual incidence of 13.3 cases per 100,000 live births. Forty-one percent of the confirmed cases were infected with HSV type 1. A review of certificates of death or stillbirth issued in New York City during 1981–2013 identified 34 deaths due to neonatal HSV infection, or 0.82 deaths per 100,000 live births.
For information on adolescent and adult HSV infections, see Other STDs.
Accurate estimates of PID and tubal factor infertility resulting from chlamydial and gonococcal infections are difficult to obtain, in part because definitive diagnoses of these conditions can be complex. Published data suggest overall declining U.S. rates of women diagnosed with PID in both hospital and ambulatory settings.The National Disease and Therapeutic Index provides estimates of initial visits to office-based, private physicians for PID. NDTI estimated that from 2005–2014 the number of initial visits to such physicians for PID among women aged 15–44 years have decreased by 71.0% from 176,000 to 51,000 visits . The 2015 NDTI data were not obtained in time to include them in this report.
Differences in PID diagnoses or treatment by race/ethnicity have been observed in earlier research Data from the National Survey of Family Growth indicates that the overall proportion of sexually experienced women who have been treated for PID declined from 8.6% in 1995 to 4.1% during 2011–2013 While this pattern was observed across all racial/ethnic groups, the proportion who had received PID treatment was higher in non-Hispanic Blacks than in Hispanics or non-Hispanic Whites. These disparities are consistent with the marked racial disparities observed for chlamydia and gonorrhea. However, because of the subjective methods by which PID is diagnosed, racial disparity data should be interpreted with caution.
Several factors may be contributing to declining PID rates, including increases in chlamydia and gonorrhea screening coverage, more sensitive diagnostic technologies, and availability of single-dose therapies that increase adherence to treatment. While PID is declining nationally, it still causes an enormous amount of unnecessary and expensive morbidity.
Ectopic pregnancy (EP) is a potentially life-threatening condition that requires prompt evaluation and treatment. In 1992, CDC estimated the U.S. ectopic rate at 2% of all pregnancies. Since then, reliable estimates using national healthcare surveys has been challenging because medical and surgical treatment of EP is currently provided in both inpatient and outpatient settings. More recent attempts to estimate EP incidence use data from administrative databases of public and private insurance and managed care systems. Using data from a large administrative claims database of U.S. commercial health plans, trends in the rate of ectopic pregnancy among pregnancies in females aged 15–44 years during the period of 2003–2014 have remained relatively stable across all 5 year age groups . Rates of ectopic pregnancy increased with age, with the greatest rate concentrated in the 35–39 and 40–44 year age groups.