STDs in Women and Infants
Women and their infants are uniquely vulnerable to the consequences of sexually transmitted infections (STI). While individual-level determinants, including high-risk behaviors, contribute to disease transmission and acquisition risk, it is widely accepted that social barriers to STD prevention and control efforts also contribute to infectious disease prevalence. A woman’s relationship status with her male partner, including concurrency of the relationship, may be an important predictor of her sexual health.1–3 In addition to poverty and lack of access to quality STD services, homelessness or unstable housing may influence a woman’s sexual risk.4 For some women, maintaining the relationship with a partner may take a higher priority than STD risk reduction,5 affecting her sexual and reproductive health, as well as the health of her unborn baby.6,7 A woman can also be placed at risk for STIs through her partner’s sexual encounter with an infected partner. Consequently, even a woman who has only one partner may be obliged to practice safer sex, such as using condoms.8
Chlamydia and gonorrhea disproportionately affect women because early infection may be asymptomatic and, if untreated, infection may ascend to the upper reproductive tract resulting in pelvic inflammatory disease (PID). Data from studies suggest that as much as 10% of untreated chlamydial infections progress to clinically diagnosed PID and the risk with untreated gonococcal infection may be even higher.9–11 PID is a major concern because it can result in inflammation and damage to the fallopian tubes, elevating the risk of infertility and ectopic pregnancy. Tubal factor infertility ranks among the most common causes of infertility, accounting for 30% of female infertility in the United States,12 and much of this damage results from previous episodes of PID.13
An important public health measure for preventing PID, and ultimately tubal factor infertility, is through the prevention and control of Chlamydia trachomatis and Neisseria gonorrhoeae. Strategies to improve the early detection and treatment of chlamydia and gonorrhea, as demonstrated in randomized controlled trials,10,14 has been shown to reduce a woman’s risk for PID and ultimately protect the fertility of women.
Human papillomavirus (HPV) infections are highly prevalent in the United States.15–16 Although most HPV infections in women appear to be transient and may not result in clinically significant sequelae,17 high-risk HPV-type infections can cause abnormal changes in the uterine cervical epithelium,17–18 which are detected by cytological examination of Papanicolaou (Pap) smears.19 Persistent high-risk HPV-type infections may lead to cervical cancer precursors, which, if undetected can result in cancer.18 Other low-risk HPV-type infections can cause genital warts,18,20 low-grade Pap smear abnormalities,18,21 laryngeal papillomas,22 and, rarely, recurrent respiratory papillomatosis in children born to infected mothers.23–24 For more information on adolescent and adult HPV infections, see Other STDs.
Impact on Maternal and Fetal Outcomes
Similar to non-pregnant women, a high proportion of pregnant women with chlamydial and gonococcal infections are asymptomatic. Documented sequelae of untreated infections in pregnancy include premature delivery, premature rupture of the membranes, low birth weight, and stillbirth. Maternal infection can also affect the infant, leading to conjunctivitis infections (termed ophthalmia neonatorum in the first four weeks of life), and, in the case of C. trachomatis, 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. The clinical presentation of conjunctivitis can be variable and these infections are especially important to treat promptly, as they can lead to visual impairment.25
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 preventable if women are screened for syphilis and treated early during prenatal care.26
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.27 Neonatal herpes can be a severe illness presenting with vesicular lesions on the skin, eye, or mouth, seizures, respiratory collapse, and/or liver failure, following contact with infected cervical or vaginal secretions during delivery.27–28 Risk of transmission to the infant is greatest when the mother has a first-episode primary genital infection during pregnancy, especially if she acquires infection towards the end of her pregnancy.28–29 For more information on genital HSV infections among pregnant women, see Other STDs.
Pelvic Inflammatory Disease
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 rates of women diagnosed with PID in both hospital and ambulatory settings in the United States.30–32 The National Disease and Therapeutic Index (NDTI; see Section A2.5 in the Appendix) provides estimates of initial visits to office-based, private physicians for PID. NDTI estimated that from 2007–2016 the number of initial visits to such physicians for PID among women aged 15–44 years decreased by 38.3% from 146,000 to 90,000 visits (Figure A). The 2017 NDTI data was not obtained in time to include in this report. Similar declines have been observed in nationally representative data of emergency department (ED) visits from the Healthcare Cost and Utilization Project (HCUP), the largest all-payer publicly available database of ED visits across the US. The percentage of ED visits with a PID diagnosis decreased during 2006–2013 among females aged 15–44 years, with the largest decreases among females aged 15–19 years (Figure B).33 It is not entirely clear what may be driving these declines, though several factors have been suggested including earlier identification and treatment of chlamydia and gonorrhea infection, and availability of single-dose therapies that increase adherence to treatment.31-32,34 While PID is declining nationally, it is still a major cause of morbidity in women.
Differences in self-reported lifetime diagnosis of PID by race/Hispanic ethnicity in reproductive age women have been observed in earlier research.35 Data from the 2013–2014 cycle of the National Health and Nutrition Examination Survey (NHANES) indicates that non-Hispanic Black and non-Hispanic White women reporting a previous STI diagnosis had nearly equal self-reported lifetime PID prevalence (10.3% vs. 10.0%) (Figure C).36 However, the lifetime prevalence of PID among non-Hispanic Black women was 2.2 times that among non-Hispanic White women if no previous STI was diagnosed (6.0% vs. 2.7%). These findings suggest that PID is associated with previous STI diagnoses and it is therefore important for physicians to screen female patients for chlamydia and gonorrhea to reduce the incidence of PID. The racial disparities observed in PID diagnoses 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.
Ectopic pregnancy is a potentially life-threatening condition that requires prompt evaluation and treatment. Up until the early 1990’s, a primary data source used to estimate the incidence of ectopic pregnancy was the National Hospital Discharge Survey, a sample of inpatient discharge records from select hospitals. However, the ability to ascertain the number of ectopic pregnancies occurring in the United States has been affected by a shift in clinical management from an inpatient to an outpatient event, making inpatient hospital surveillance data sources unreliable. As a result, alternative surveillance methods, including data from large administrative claims,36–37 have been used to evaluate trends and assess the continued public health burden of this condition. Data from MarketScan Commercial Claims and Encounters Database, a large administrative claims database of United States commercial health plans, indicate that the ratio of ectopic pregnancy diagnoses to all live births among women with live births aged 15–44 years during the period of 2005–2016 have marginally increased across all age groups (Figure D). As in previous years, in 2016, rates of ectopic pregnancy were highest among women in the 35–44 year age groups.
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 1993.38 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 (Table 1). During 2011–2013, chlamydia case rates decreased from 643.4 to 619.0 cases per 100,000 females and then increased 11.1% over the next 4 years, resulting in a rate of 687.4 cases per 100,000 females in 2017 (Table 4).
Chlamydia rates are highest among young women, the population targeted for screening (Figure 5, Table 10). During 2016–2017, rates of reported chlamydia cases increased 6.5% and 3.7% among females aged 15–19 and 20–24 years, respectively (Figure 6). Regionally, chlamydia case rates were highest among women in the South, with a rate of 748.8 cases per 100,000 females in 2017 (Table 4). Rates of reported chlamydia cases exceeded gonorrhea case rates among women in all regions (Figures E and F, Tables 4 and 15).
Chlamydia Positivity in Selected Populations
The STD Surveillance Network (SSuN) is an ongoing collaboration of state, county, and city health departments from 10 participating jurisdictions where demographic, clinical, and laboratory data are collected from women aged 15–44 years attending facilities that provide family planning and reproductive health services (See Section A2.2 of the Appendix). Figure G shows chlamydia testing and positivity reported only among facilities that tested more than 100 women and more than 60% of young women aged 14–24 years. In 2017, the overall positivity of chlamydia among women aged 14–24 years was 9.6%, but for women 14–19 years of age, chlamydia positivity was 10.8%. For women between the ages of 14–24 years, chlamydia positivity among non-Hispanic Blacks was about 1.5 times those of non-Hispanic Whites or Hispanics.
Like chlamydia, gonorrhea is often asymptomatic in women. Therefore, 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 overall cases (Figure 14, Table 1).
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 during 2012–2014 (Figure 18). During 2015–2017, the gonorrhea rate among women increased 33.4% to 141.8 cases per 100,000 females (Figure 18, Table 15).
The gonorrhea case rate among women was slightly higher than the rate among men during 2008–2012; however, the rate among men was higher than the rate among women during 2013–2017 (Figure 18, Tables 15 and 16). During 2013–2017, gonorrhea rates among women were highest among those aged 15–24 years (Figure 20, Table 21). For women in this age group, rates were highest among 19-year olds in 2017 (872.2 cases per 100,000 females) (Table 23).
During 2013–2017, 461 chlamydia or gonorrhea cases among infants aged <1 year with a specimen source of either ‘eye’ or ‘conjunctiva’ (conjunctivitis infections) were reported to CDC. The overall reported rate of chlamydial conjunctivitis in infants was relatively stable during 2013–2017, ranging from 1.6 to 2.3 cases per 100,000 live births (Figure H). Similarly, the rate of gonococcal conjunctivitis in infants remained relatively constant and low during 2013–2017, at 0.4 cases or less per 100,000 live births each year. The rate of reported cases is heavily influenced by the completeness of reported data on specimen source. Of all cases reported to CDC of chlamydia or gonorrhea in infants aged <1 year during 2013–2017 (n=2,567), nearly 82% did not have a specimen source of either ‘eye’ or ‘conjunctiva’; of those, 56.2% had a specimen source of ‘unknown’ (42.1%), ‘other-not specified’ (9.7%), or was missing (4.4%). When evaluating rates including these cases, the rate of chlamydia and gonorrhea infections follows similar trends but is higher in all years, indicating potential missed cases for surveillance (Figure H).
Trends in congenital syphilis usually follow trends in primary and secondary (P&S) syphilis among reproductive-aged women (Figure 49). 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 all women increased each year since then. During 2013–2017, the rate among women increased 155.6%, from 0.9 to 2.3 cases per 100,000 females (Table 28). During this same time, the rate among reproductive-aged women (women aged 15–44 years) increased 142.8%, from 2.1 to 5.1 cases per 100,000 females aged 15–44 years (Figure 49).
Similarly, the rate of reported congenital syphilis cases has increased each year since 2012 (Figure 49, Table 1). In 2017, there were 918 reported cases of congenital syphilis and the national congenital syphilis rate was 23.3 cases per 100,000 live births, the highest rate reported since 1997. This increase in 2017 represents a 43.8% increase relative to 2016 and a 153.3% increase relative to 2013 (Table 41).
In 2017, the highest rates of P&S syphilis among women and the highest rates of congenital syphilis were observed in the West and in the South (Figures I and J, Tables 28 and 41). The P&S syphilis rates among women increased in every region during 2016–2017. During 2016–2017, the largest increases in the P&S syphilis rates among women were seen in the West (29.6%), followed by the South (22.7%), Northeast (11.1%), and Midwest (8.3%) (Table 28). The congenital syphilis rate increased 60.3% in the South, 40.7% in the West, 5.7% in the Northeast, and 5.7% in the Midwest during 2016–2017 (Table 41).
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 prenatal syphilis screening recommendations, as well as acquisition of infection during pregnancy after the initial screening test, also contribute to the occurrence of congenital syphilis.26
Neonatal Herpes Simplex Virus
Neonatal HSV infections, although relatively rare, cause significant morbidity and mortality.27 Most neonatal HSV infections result from perinatal transmission from mother to neonate,28 but postnatal infection can occur.39 Although reporting of neonatal HSV infection is required in a few jurisdictions,40–41 it is not a nationally reportable disease.
An examination of inpatient records of infants aged 60 days or younger at admission using the HCUP Kid’s Inpatient Database showed an overall incidence of 9.6 cases per 100,000 live births in 2006.42 Rates did not vary significantly by region or by race and Hispanic ethnicity; however prevalence was significantly higher among cases for which the expected primary payer was Medicaid (15.1 cases per 100,000 live births) compared with private insurance or managed health care (5.4 cases per 100,000 live births).
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.43 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.42
For information on adolescent and adult HSV infections, see Other STDs.
STDs are an important health priority and what may often be overlooked is the substantial morbidity and mortality related to sequelae of STDs. This is particularly true for women and their infants. The overall rate of reported female chlamydia cases has increased 11.1% over the last four years, much of that attributed to increased screening and more complete national reporting. Gonorrhea infections have also increased 33.4% to 141.8 cases per 100,000 females in recent years. Surveillance data continues to show that numbers and rates of chlamydia and gonorrhea cases are highest in females between the ages of 15 and 24 and certain races are disproportionately impacted. Despite increases in chlamydia and gonorrhea, available data suggest an overall decline in the incidence of PID, largely attributed to an increase in effective screening and treatment of chlamydial and gonococcal infections in adolescents and young women. In contrast to declining PID rates, surveillance data suggests rates of ectopic pregnancy have marginally increased over time.
Mother to child transmission of STDs can result in serious adverse consequences. Potential adverse neonatal outcomes include neonatal ophthalmia, neonatal pneumonia, and prematurity. The rate of congenital syphilis in the United States has increased every year since 2013. In 2017, there were 918 reported cases of congenital syphilis and the national congenital syphilis rate was 23.3 cases per 100,000 live births, the highest rate in two decades. Despite current recommended STD testing during pregnancy, women remain underscreened for STDs during pregnancy, either because of a lack of or limited prenatal care, or infection outside of the testing window.
2. Dolwick Grieb SM, Davey-Rothwell M, Latkin CA. Concurrent sexual partnerships among urban African American high risk women with main sex partners. AIDS Behav 2012; 16(2):323–333. DOI: 10.1007/s10461-011-9954-6.
4. Kelly J, Cohen J, Grimes B, et al. High rates of herpes simplex virus type 2 infection in homeless women: Informing public health strategies. J Women’s Health (Larchmt) 2016; 25(8):840–845. DOI: 10.1089/jwh.2015.5579.
7. McCree DH, Rompalo A. Biological and behavioral risk factors associated with STDs/HIV in women: Implications for behavioral interventions. In: Aral SO, Douglas JM, Lipshutz JA, eds. Behavioral Interventions for Prevention and Control of Sexually Transmitted Diseases. New York, NY: Springer; 2007:310–324.
10. Oakeschott, P, Kerry S, Aghaizu A, et al. Randomised controlled trial of screening for Chlamydia trachomatis to prevent pelvic inflammatory disease: The POPI (prevention of pelvic infection) trial. BMJ 2010; 340:c1642.
11. Price MJ, Ades AE, De Angelis D, et al. Risk of pelvic inflammatory following Chlamydia trachomatis infection: Analysis of prospective studies with a multistate model. Am J Epidemiol 2013; 178(3):484–492.
16. McQuillan G, Kruszon-Moran D, Markowitz LE, et al. Prevalence of HPV in adults aged 18–69: United States, 2011–2014. NCHS Data Brief, No. 280. Hyattsville, MD: National Center for Health Statistics; 2017.
17. Insinga RP, Perez G, Wheeler CM, et al. Incident cervical HPV infections in young women: Transition probabilities for CIN and infection clearance. Cancer Epidemiol Biomarkers Prev 2011; 20(2):287–296.
19. Saslow D, Solomon D, Lawson HW, et al. American Cancer Society, American Society for Colposcopy and Cervical Pathology, and American Society for Clinical Pathology screening guidelines for the prevention and early detection of cervical cancer. J Low Genit Tract Dis 2012; 16(3):175–204.
20. Garland SM, Steben M, Sings HL, et al. Natural history of genital warts: Analysis of the placebo arm of 2 randomized phase III trials of a quadrivalent human papillomavirus (Types 6, 11, 16, and 18) vaccine. J Infect Dis 2009; 199(6):805–814.
21. Clifford GM, Rana RK, Franceschi S, et al. Human papillomavirus genotype distribution in low-grade cervical lesions: Comparison by geographic region and with cervical cancer. Cancer Epidemiol Biomarkers Prev 2005; 14(5):1157–1164.
22. Gissmann L, Wolnik L, Ikenberg H, et al. Human papillomavirus types 6 and 11 DNA sequences in genital and laryngeal papillomas and in some cervical cancers. Proc Natl Acad Sci USA 1983; 80(2): 560–563.
26. Kidd SE, Bowen VB, Torrone EA, et al. Use of national syphilis surveillance data to develop a congenital syphilis prevention cascade and estimate the number of potential congenital syphilis cases averted. Sex Transm Dis 2018; DOI: 10.1097/OLQ.0000000000000838. [Epub ahead of print].
35. Leichliter JS., Chandra A., Aral SO. Correlates of self-reported pelvic inflammatory disease treatment in sexually experienced reproductive aged women in the United States, 1995 and 2006–2010. Sex Transm Dis 2013; 40(5):413–418.
39. Centers for Disease Control and Prevention. Neonatal herpes simplex virus infection following Jewish ritual circumcisions that included direct orogenital suction — New York City, 2000–2011. MMWR Morb Mortal Wkly Rep 2012; 61(22):405–409.