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CASE Pregnant woman with symptoms of genital infection
A 23-year-old primigravid woman at 15 weeks and 2 days’ gestation reported having a 2-week history of increased urinary frequency and vaginal discharge. She said she experienced similar symptoms 6 weeks previously that resolved within a week. The patient has had 3 sexual partners in the past year. Her current partner was experiencing a yellow urethral discharge and dysuria. On the patient’s speculum examination, the clinician noted a yellow-green discharge emanating from the cervix as well as cervical motion tenderness.
What is the most likely diagnosis, and how would you treat this patient?
The culprit was chlamydia
Chlamydia trachomatis is an obligate intracellular bacterium that does not stain with Gram staining. A rigid cell wall encloses its intracellular component. C trachomatis infection begins when the chlamydial elementary body enters a susceptible host cell.
Once ingested, the organism’s surface antigens (major outer membrane protein and lipopolysaccharide antigens) provide intracellular sanctuary for the bacterium by inhibiting phagolysosomal fusion. Subsequently, the elementary body morphs into a reticular body, which replicates through adenosine triphosphate (ATP)–dependent binary fission. After approximately 48 hours of replication, the organism again morphs into an elementary body and is released to infect additional cells and acquire new ATP stores for further replication.
Chlamydia can be transmitted horizontally during oral, vaginal, or anal intercourse or vertically to the infant during vaginal delivery.
The US’s most common notifiable disease
According to the Centers for Disease Control and Prevention (CDC), the incidence of chlamydia infection in the United States increased considerably in recent years: from 976,455 cases in 2005 to 1,758,668 cases in 2018.1 In 2018, rates of chlamydia infection in women were nearly double the rates in men, with an incidence of 688.2 versus 377.5 per 100,000 cases, and a prevalence of 1,150,672 versus 612,020.1
Young adults have a higher frequency of chlamydia infection than any other age group. From 2017 to 2018, reported cases in women aged 15–19 years increased by 1.3%, to 3,306.8 per 100,000; in women aged 20–24 years, cases increased by 0.8%, to 4,064.6 per 100,000. In young men in the same age ranges, reported cases increased by 3.7%, to 959.0 cases per 100,000, and by 3.3%, to 1,784.5 per 100,000 cases, respectively.1
Both the incidence and prevalence of chlamydia infection are higher in African Americans than in whites, while Asians have the lowest rates.1 The prevalence of infection also is increased with incarceration, lower socioeconomic status, and residence in the southern United States.
The prevalence of chlamydia infection in pregnant women is approximately 2% to 3%, but it may be as high as 30% in high-risk populations, such as women who are unmarried, have multiple sex partners, are coinfected with another sexually transmitted disease (STD), have partners with nongonococcal urethritis, have mucopurulent discharge, have acute urethral syndrome, and have late or no prenatal care.2 Since chlamydia infection often is asymptomatic and some infections resolve spontaneously, the true prevalence of infection probably is underreported.
Continue to: Chlamydia infection can cause serious clinical manifestations...
Chlamydia infection can cause serious clinical manifestations
The 15 serotypes of C trachomatis are grouped into 3 categories according to clinical manifestations:
- Serotypes A, B, Ba, and C cause endemic trachoma, characterized by bilateral irritation of the eyelids that progresses to eyelid thickening and scarring, eventually leading to corneal abrasion and blindness.
- Serotypes D–K manifest as conjunctivitis and pneumonia in newborns, proctitis in men (especially in men who have sex with men), and genitourinary infections in women. Reactive arthritis and inclusion conjunctivitis also can occur with D–K serotypes.
- Serotypes L1–L3 cause lymphogranuloma venereum.
About 70% of women with chlamydia infection are asymptomatic. Those who have symptoms often present with endocervicitis or acute urethral syndrome (acute urethritis). Manifestations of these 2 conditions include a frothy yellow-green vaginal and/or urethral discharge, dysuria, and frequency. Women who engage in rectal intercourse also may notice a purulent discharge from the anus. Untreated, C trachomatis organisms may ascend the reproductive tract, causing both endometritis and pelvic inflammatory disease (PID).
While a single episode of PID increases tubal infertility risk by 10%, a second episode increases the risk by 40%.3 Over time, recurrent and/or chronic PID causes scarring and adhesion formation, which may result in chronic pelvic pain. In addition, chronic infection is the single most important risk factor for ectopic pregnancy. Finally, chlamydia infection is a risk factor for Fitz-Hugh-Cutis syndrome (perihepatitis). In this condition, organisms ascend from the site of pelvic infection along the pericolic gutter to ultimately infect the liver capsule.
Specific complications in pregnancy
Chlamydia infection in pregnant women is associated with preterm delivery and preterm premature rupture of membranes. Infants born to mothers with untreated chlamydia infection are at risk for pneumonia, conjunctivitis, and even perinatal death.2 Acquisition of infection occurs at the time of delivery rather than in the antepartum period.
The significant morbidity associated with chlamydia infection underscores the importance of regular screening, especially in pregnant women. The current United States Preventive Service Task Force guidelines recommend annual screening of all sexually active women who are 24 years of age or younger, as well as of older, high-risk women.
The CDC recommends routine screening of all pregnant women for chlamydia at the first prenatal visit. Repeat screening is recommended in the third trimester for all pregnant women younger than 25 years, those at increased risk, and those infected within the past 3 to 6 months or during the first trimester. Those who test positive should be retested 3 weeks after completion of treatment.1
Chlamydia screening strategies
Historically, a chlamydia diagnosis was made by isolating the organisms in tissue culture. In the 1990s, however, that extremely time-consuming and resource-intensive procedure was replaced by nucleic acid amplification testing (NAAT).
NAAT methodology. NAAT is the gold standard for diagnosing C trachomatis infection; this methodology utilizes various assays, including polymerase chain reaction, ligase chain reaction, and transcription-mediated amplification.
Continue to: Compared with previous culture and antigen detection techniques...
Compared with previous culture and antigen detection techniques, NAAT’s advantages include excellent sensitivity and specificity (>90% and ≥99%, respectively), enabling detection of a low inoculum of organisms in a sample obtained by noninvasive methods, such as first-void urine collection or vaginal swab.2,4,5 Furthermore, NAAT does not impose any specific storage regulations on collected specimens, is cost effective, and can jointly test for Neisseria gonorrhoeae, which commonly co-infects with C trachomatis.6
Screening in pregnancy. In 2012, Blatt and colleagues examined testing patterns in nearly 1.3 million obstetric patients and found that only 59% (761,315) of women were tested for chlamydia at least once in pregnancy.7 Only 1 in 3 women were tested during the first prenatal visit, as CDC guidelines recommend. Testing rates declined with increasing age. Of women screened, 3.5% tested positive for chlamydia.7 Of these, 3 of 4 were retested at least once, with almost 20% having at least 1 subsequent positive result.7
Of note, in a study of women who reported receptive anal intercourse (n = 2,818), 292 women tested positive for chlamydia; 10.4% tested positive in genital-only sites, 58.6% in genital and rectal sites, and 20.5% at the rectal site only.8
It is alarming that only 59% of pregnant women are screened for chlamydia given the significant perinatal complications associated with this infection. Barriers to screening pregnant women may include clinician discomfort in discussing STDs and patient refusal of screening. Furthermore, clinicians should routinely ask women about receptive anal sex. Women who report this risk factor should be tested for chlamydia in both the endocervix and rectum.
Retesting and follow-up. After the initial diagnosis of chlamydia, a test of cure 3 weeks after treatment is an important aspect of care. Thus, identifying and overcoming barriers to retesting is important. Clinicians should educate patients about the importance of follow-up. Also consider incorporating the use of home-based, self-obtained vaginal swabs for retesting. Results from 2 randomized trials showed that eliminating a patient’s transportation barriers and providing a home-based alternative to a follow-up visit significantly increased rescreening rates by 33% in STD clinic patients and by 59.2% in family planning clinic patients.9
Reinfection risk. The rate of venereal chlamydia transmission in heterosexual partners is 70%. Since sexually active chlamydia-positive patients are at risk for reinfection by their partner after treatment completion, clinicians should refer the sex partners for evaluation. If the sex partners are reluctant to have testing, it is reasonable to provide empiric antibiotic treatment to decrease the risk of re-infection in the patient.7 Before doing so, however, make certain that state law permits this practice, and be sure to document the prescribed treatment in the patient’s record.
Treatment options
Prompt treatment of C trachomatis infection is essential to decrease the risk of disease sequelae. Nonpregnant adults can be treated with oral doxycycline 100 mg twice daily for 7 days.
In a head-to-head study performed in a controlled environment that ensured treatment adherence, 97% efficacy was achieved with one oral dose of azithromycin (1 g) compared with 100% efficacy with doxycycline.10 However, in the real-world setting, imperfect adherence to the multi-day doxycycline regimen is associated with treatment failures. Thus, a single dose of azithromycin is preferable for patients with questionable compliance.11
In obstetric patients, azithromycin and amoxicillin are preferred as first-line agents for treatment of C trachomatis due to their improved safety profile in this demographic. Amoxicillin 500 mg orally 3 times daily for 7 days has 95% efficacy.2
Women allergic to these agents may be treated with an alternative regimen of erythromycin base, 500 mg orally 4 times daily for 7 days, or erythromycin ethylsuccinate, 800 mg orally 4 times daily for 7 days. Erythromycin should be reserved for second-line therapy because of its lower efficacy (64%) and frequent gastrointestinal adverse effects.2 Doxycycline is contraindicated in pregnancy because of possible teratogenic effects on the teeth and bone of the fetus.
- Centers for Disease Control and Prevention Division of STD Prevention. Sexually transmitted disease surveillance 2018. October 2019. https://www.cdc.gov/std/stats18/default.htm. 2019. Accessed January 4, 2020.
- Duff P. Maternal and fetal infections. In: Creasy RK, Resnik R, Iams JD, et al, eds. Creasy and Resnik’s Maternal-Fetal Medicine: Principles and Practice. 8th ed. Philadelphia, PA: Elsevier Saunders; 2019:869.
- Ljubin-Sternak S, Meštrović T. Chlamydia trachomatis and genital mycoplasmas: pathogens with an impact on human reproductive health. J Pathog. 2014. doi: 10.1155/2014/183167.
- Meyer T. Diagnostic procedures to detect Chlamydia trachomatis infections. Microorganisms. 2016:4(3).
- Centers for Disease Control and Prevention.. Recommendations for the laboratory-based detection of Chlamydia trachomatis and Neisseria gonorrhoeae. MMWR Recomm Rep. 2014;63:1-19.
- Wiesenfeld HC. Screening for Chlamydia trachomatis infections in women. N Engl J Med. 2017;376:765-773.
- Blatt AJ, Lieberman JM, Hoover DR, et al. Chlamydial and gonococcal testing during pregnancy in the United States. Am J Obstet Gynecol. 2012;207:55.e1-8.
- Llata E, Braxton J, Asbel L, et al. Rectal Chlamydia trachomatis and Neisseria gonorrhoeae infections among women reporting anal intercourse. Obstet Gynecol. 2018;132:692-697.
- Xu F, Stoner BP, Taylor SN, et al. Use of home-obtained vaginal swabs to facilitate rescreening for Chlamydia trachomatis infections: two randomized controlled trials. Obstet Gynecol. 2011;118(2 pt 1):231-239.
- Geisler WM, Uniyal A, Lee JY, et al. Azithromycin versus doxycycline for urogenital Chlamydia trachomatis infection. N Engl J Med. 2015;373:2512-2521.
- Quinn TC, Gaydos CA. Treatment for chlamydia infection—doxycycline versus azithromycin. N Engl J Med. 2015;373:2573-2575.
CASE Pregnant woman with symptoms of genital infection
A 23-year-old primigravid woman at 15 weeks and 2 days’ gestation reported having a 2-week history of increased urinary frequency and vaginal discharge. She said she experienced similar symptoms 6 weeks previously that resolved within a week. The patient has had 3 sexual partners in the past year. Her current partner was experiencing a yellow urethral discharge and dysuria. On the patient’s speculum examination, the clinician noted a yellow-green discharge emanating from the cervix as well as cervical motion tenderness.
What is the most likely diagnosis, and how would you treat this patient?
The culprit was chlamydia
Chlamydia trachomatis is an obligate intracellular bacterium that does not stain with Gram staining. A rigid cell wall encloses its intracellular component. C trachomatis infection begins when the chlamydial elementary body enters a susceptible host cell.
Once ingested, the organism’s surface antigens (major outer membrane protein and lipopolysaccharide antigens) provide intracellular sanctuary for the bacterium by inhibiting phagolysosomal fusion. Subsequently, the elementary body morphs into a reticular body, which replicates through adenosine triphosphate (ATP)–dependent binary fission. After approximately 48 hours of replication, the organism again morphs into an elementary body and is released to infect additional cells and acquire new ATP stores for further replication.
Chlamydia can be transmitted horizontally during oral, vaginal, or anal intercourse or vertically to the infant during vaginal delivery.
The US’s most common notifiable disease
According to the Centers for Disease Control and Prevention (CDC), the incidence of chlamydia infection in the United States increased considerably in recent years: from 976,455 cases in 2005 to 1,758,668 cases in 2018.1 In 2018, rates of chlamydia infection in women were nearly double the rates in men, with an incidence of 688.2 versus 377.5 per 100,000 cases, and a prevalence of 1,150,672 versus 612,020.1
Young adults have a higher frequency of chlamydia infection than any other age group. From 2017 to 2018, reported cases in women aged 15–19 years increased by 1.3%, to 3,306.8 per 100,000; in women aged 20–24 years, cases increased by 0.8%, to 4,064.6 per 100,000. In young men in the same age ranges, reported cases increased by 3.7%, to 959.0 cases per 100,000, and by 3.3%, to 1,784.5 per 100,000 cases, respectively.1
Both the incidence and prevalence of chlamydia infection are higher in African Americans than in whites, while Asians have the lowest rates.1 The prevalence of infection also is increased with incarceration, lower socioeconomic status, and residence in the southern United States.
The prevalence of chlamydia infection in pregnant women is approximately 2% to 3%, but it may be as high as 30% in high-risk populations, such as women who are unmarried, have multiple sex partners, are coinfected with another sexually transmitted disease (STD), have partners with nongonococcal urethritis, have mucopurulent discharge, have acute urethral syndrome, and have late or no prenatal care.2 Since chlamydia infection often is asymptomatic and some infections resolve spontaneously, the true prevalence of infection probably is underreported.
Continue to: Chlamydia infection can cause serious clinical manifestations...
Chlamydia infection can cause serious clinical manifestations
The 15 serotypes of C trachomatis are grouped into 3 categories according to clinical manifestations:
- Serotypes A, B, Ba, and C cause endemic trachoma, characterized by bilateral irritation of the eyelids that progresses to eyelid thickening and scarring, eventually leading to corneal abrasion and blindness.
- Serotypes D–K manifest as conjunctivitis and pneumonia in newborns, proctitis in men (especially in men who have sex with men), and genitourinary infections in women. Reactive arthritis and inclusion conjunctivitis also can occur with D–K serotypes.
- Serotypes L1–L3 cause lymphogranuloma venereum.
About 70% of women with chlamydia infection are asymptomatic. Those who have symptoms often present with endocervicitis or acute urethral syndrome (acute urethritis). Manifestations of these 2 conditions include a frothy yellow-green vaginal and/or urethral discharge, dysuria, and frequency. Women who engage in rectal intercourse also may notice a purulent discharge from the anus. Untreated, C trachomatis organisms may ascend the reproductive tract, causing both endometritis and pelvic inflammatory disease (PID).
While a single episode of PID increases tubal infertility risk by 10%, a second episode increases the risk by 40%.3 Over time, recurrent and/or chronic PID causes scarring and adhesion formation, which may result in chronic pelvic pain. In addition, chronic infection is the single most important risk factor for ectopic pregnancy. Finally, chlamydia infection is a risk factor for Fitz-Hugh-Cutis syndrome (perihepatitis). In this condition, organisms ascend from the site of pelvic infection along the pericolic gutter to ultimately infect the liver capsule.
Specific complications in pregnancy
Chlamydia infection in pregnant women is associated with preterm delivery and preterm premature rupture of membranes. Infants born to mothers with untreated chlamydia infection are at risk for pneumonia, conjunctivitis, and even perinatal death.2 Acquisition of infection occurs at the time of delivery rather than in the antepartum period.
The significant morbidity associated with chlamydia infection underscores the importance of regular screening, especially in pregnant women. The current United States Preventive Service Task Force guidelines recommend annual screening of all sexually active women who are 24 years of age or younger, as well as of older, high-risk women.
The CDC recommends routine screening of all pregnant women for chlamydia at the first prenatal visit. Repeat screening is recommended in the third trimester for all pregnant women younger than 25 years, those at increased risk, and those infected within the past 3 to 6 months or during the first trimester. Those who test positive should be retested 3 weeks after completion of treatment.1
Chlamydia screening strategies
Historically, a chlamydia diagnosis was made by isolating the organisms in tissue culture. In the 1990s, however, that extremely time-consuming and resource-intensive procedure was replaced by nucleic acid amplification testing (NAAT).
NAAT methodology. NAAT is the gold standard for diagnosing C trachomatis infection; this methodology utilizes various assays, including polymerase chain reaction, ligase chain reaction, and transcription-mediated amplification.
Continue to: Compared with previous culture and antigen detection techniques...
Compared with previous culture and antigen detection techniques, NAAT’s advantages include excellent sensitivity and specificity (>90% and ≥99%, respectively), enabling detection of a low inoculum of organisms in a sample obtained by noninvasive methods, such as first-void urine collection or vaginal swab.2,4,5 Furthermore, NAAT does not impose any specific storage regulations on collected specimens, is cost effective, and can jointly test for Neisseria gonorrhoeae, which commonly co-infects with C trachomatis.6
Screening in pregnancy. In 2012, Blatt and colleagues examined testing patterns in nearly 1.3 million obstetric patients and found that only 59% (761,315) of women were tested for chlamydia at least once in pregnancy.7 Only 1 in 3 women were tested during the first prenatal visit, as CDC guidelines recommend. Testing rates declined with increasing age. Of women screened, 3.5% tested positive for chlamydia.7 Of these, 3 of 4 were retested at least once, with almost 20% having at least 1 subsequent positive result.7
Of note, in a study of women who reported receptive anal intercourse (n = 2,818), 292 women tested positive for chlamydia; 10.4% tested positive in genital-only sites, 58.6% in genital and rectal sites, and 20.5% at the rectal site only.8
It is alarming that only 59% of pregnant women are screened for chlamydia given the significant perinatal complications associated with this infection. Barriers to screening pregnant women may include clinician discomfort in discussing STDs and patient refusal of screening. Furthermore, clinicians should routinely ask women about receptive anal sex. Women who report this risk factor should be tested for chlamydia in both the endocervix and rectum.
Retesting and follow-up. After the initial diagnosis of chlamydia, a test of cure 3 weeks after treatment is an important aspect of care. Thus, identifying and overcoming barriers to retesting is important. Clinicians should educate patients about the importance of follow-up. Also consider incorporating the use of home-based, self-obtained vaginal swabs for retesting. Results from 2 randomized trials showed that eliminating a patient’s transportation barriers and providing a home-based alternative to a follow-up visit significantly increased rescreening rates by 33% in STD clinic patients and by 59.2% in family planning clinic patients.9
Reinfection risk. The rate of venereal chlamydia transmission in heterosexual partners is 70%. Since sexually active chlamydia-positive patients are at risk for reinfection by their partner after treatment completion, clinicians should refer the sex partners for evaluation. If the sex partners are reluctant to have testing, it is reasonable to provide empiric antibiotic treatment to decrease the risk of re-infection in the patient.7 Before doing so, however, make certain that state law permits this practice, and be sure to document the prescribed treatment in the patient’s record.
Treatment options
Prompt treatment of C trachomatis infection is essential to decrease the risk of disease sequelae. Nonpregnant adults can be treated with oral doxycycline 100 mg twice daily for 7 days.
In a head-to-head study performed in a controlled environment that ensured treatment adherence, 97% efficacy was achieved with one oral dose of azithromycin (1 g) compared with 100% efficacy with doxycycline.10 However, in the real-world setting, imperfect adherence to the multi-day doxycycline regimen is associated with treatment failures. Thus, a single dose of azithromycin is preferable for patients with questionable compliance.11
In obstetric patients, azithromycin and amoxicillin are preferred as first-line agents for treatment of C trachomatis due to their improved safety profile in this demographic. Amoxicillin 500 mg orally 3 times daily for 7 days has 95% efficacy.2
Women allergic to these agents may be treated with an alternative regimen of erythromycin base, 500 mg orally 4 times daily for 7 days, or erythromycin ethylsuccinate, 800 mg orally 4 times daily for 7 days. Erythromycin should be reserved for second-line therapy because of its lower efficacy (64%) and frequent gastrointestinal adverse effects.2 Doxycycline is contraindicated in pregnancy because of possible teratogenic effects on the teeth and bone of the fetus.
CASE Pregnant woman with symptoms of genital infection
A 23-year-old primigravid woman at 15 weeks and 2 days’ gestation reported having a 2-week history of increased urinary frequency and vaginal discharge. She said she experienced similar symptoms 6 weeks previously that resolved within a week. The patient has had 3 sexual partners in the past year. Her current partner was experiencing a yellow urethral discharge and dysuria. On the patient’s speculum examination, the clinician noted a yellow-green discharge emanating from the cervix as well as cervical motion tenderness.
What is the most likely diagnosis, and how would you treat this patient?
The culprit was chlamydia
Chlamydia trachomatis is an obligate intracellular bacterium that does not stain with Gram staining. A rigid cell wall encloses its intracellular component. C trachomatis infection begins when the chlamydial elementary body enters a susceptible host cell.
Once ingested, the organism’s surface antigens (major outer membrane protein and lipopolysaccharide antigens) provide intracellular sanctuary for the bacterium by inhibiting phagolysosomal fusion. Subsequently, the elementary body morphs into a reticular body, which replicates through adenosine triphosphate (ATP)–dependent binary fission. After approximately 48 hours of replication, the organism again morphs into an elementary body and is released to infect additional cells and acquire new ATP stores for further replication.
Chlamydia can be transmitted horizontally during oral, vaginal, or anal intercourse or vertically to the infant during vaginal delivery.
The US’s most common notifiable disease
According to the Centers for Disease Control and Prevention (CDC), the incidence of chlamydia infection in the United States increased considerably in recent years: from 976,455 cases in 2005 to 1,758,668 cases in 2018.1 In 2018, rates of chlamydia infection in women were nearly double the rates in men, with an incidence of 688.2 versus 377.5 per 100,000 cases, and a prevalence of 1,150,672 versus 612,020.1
Young adults have a higher frequency of chlamydia infection than any other age group. From 2017 to 2018, reported cases in women aged 15–19 years increased by 1.3%, to 3,306.8 per 100,000; in women aged 20–24 years, cases increased by 0.8%, to 4,064.6 per 100,000. In young men in the same age ranges, reported cases increased by 3.7%, to 959.0 cases per 100,000, and by 3.3%, to 1,784.5 per 100,000 cases, respectively.1
Both the incidence and prevalence of chlamydia infection are higher in African Americans than in whites, while Asians have the lowest rates.1 The prevalence of infection also is increased with incarceration, lower socioeconomic status, and residence in the southern United States.
The prevalence of chlamydia infection in pregnant women is approximately 2% to 3%, but it may be as high as 30% in high-risk populations, such as women who are unmarried, have multiple sex partners, are coinfected with another sexually transmitted disease (STD), have partners with nongonococcal urethritis, have mucopurulent discharge, have acute urethral syndrome, and have late or no prenatal care.2 Since chlamydia infection often is asymptomatic and some infections resolve spontaneously, the true prevalence of infection probably is underreported.
Continue to: Chlamydia infection can cause serious clinical manifestations...
Chlamydia infection can cause serious clinical manifestations
The 15 serotypes of C trachomatis are grouped into 3 categories according to clinical manifestations:
- Serotypes A, B, Ba, and C cause endemic trachoma, characterized by bilateral irritation of the eyelids that progresses to eyelid thickening and scarring, eventually leading to corneal abrasion and blindness.
- Serotypes D–K manifest as conjunctivitis and pneumonia in newborns, proctitis in men (especially in men who have sex with men), and genitourinary infections in women. Reactive arthritis and inclusion conjunctivitis also can occur with D–K serotypes.
- Serotypes L1–L3 cause lymphogranuloma venereum.
About 70% of women with chlamydia infection are asymptomatic. Those who have symptoms often present with endocervicitis or acute urethral syndrome (acute urethritis). Manifestations of these 2 conditions include a frothy yellow-green vaginal and/or urethral discharge, dysuria, and frequency. Women who engage in rectal intercourse also may notice a purulent discharge from the anus. Untreated, C trachomatis organisms may ascend the reproductive tract, causing both endometritis and pelvic inflammatory disease (PID).
While a single episode of PID increases tubal infertility risk by 10%, a second episode increases the risk by 40%.3 Over time, recurrent and/or chronic PID causes scarring and adhesion formation, which may result in chronic pelvic pain. In addition, chronic infection is the single most important risk factor for ectopic pregnancy. Finally, chlamydia infection is a risk factor for Fitz-Hugh-Cutis syndrome (perihepatitis). In this condition, organisms ascend from the site of pelvic infection along the pericolic gutter to ultimately infect the liver capsule.
Specific complications in pregnancy
Chlamydia infection in pregnant women is associated with preterm delivery and preterm premature rupture of membranes. Infants born to mothers with untreated chlamydia infection are at risk for pneumonia, conjunctivitis, and even perinatal death.2 Acquisition of infection occurs at the time of delivery rather than in the antepartum period.
The significant morbidity associated with chlamydia infection underscores the importance of regular screening, especially in pregnant women. The current United States Preventive Service Task Force guidelines recommend annual screening of all sexually active women who are 24 years of age or younger, as well as of older, high-risk women.
The CDC recommends routine screening of all pregnant women for chlamydia at the first prenatal visit. Repeat screening is recommended in the third trimester for all pregnant women younger than 25 years, those at increased risk, and those infected within the past 3 to 6 months or during the first trimester. Those who test positive should be retested 3 weeks after completion of treatment.1
Chlamydia screening strategies
Historically, a chlamydia diagnosis was made by isolating the organisms in tissue culture. In the 1990s, however, that extremely time-consuming and resource-intensive procedure was replaced by nucleic acid amplification testing (NAAT).
NAAT methodology. NAAT is the gold standard for diagnosing C trachomatis infection; this methodology utilizes various assays, including polymerase chain reaction, ligase chain reaction, and transcription-mediated amplification.
Continue to: Compared with previous culture and antigen detection techniques...
Compared with previous culture and antigen detection techniques, NAAT’s advantages include excellent sensitivity and specificity (>90% and ≥99%, respectively), enabling detection of a low inoculum of organisms in a sample obtained by noninvasive methods, such as first-void urine collection or vaginal swab.2,4,5 Furthermore, NAAT does not impose any specific storage regulations on collected specimens, is cost effective, and can jointly test for Neisseria gonorrhoeae, which commonly co-infects with C trachomatis.6
Screening in pregnancy. In 2012, Blatt and colleagues examined testing patterns in nearly 1.3 million obstetric patients and found that only 59% (761,315) of women were tested for chlamydia at least once in pregnancy.7 Only 1 in 3 women were tested during the first prenatal visit, as CDC guidelines recommend. Testing rates declined with increasing age. Of women screened, 3.5% tested positive for chlamydia.7 Of these, 3 of 4 were retested at least once, with almost 20% having at least 1 subsequent positive result.7
Of note, in a study of women who reported receptive anal intercourse (n = 2,818), 292 women tested positive for chlamydia; 10.4% tested positive in genital-only sites, 58.6% in genital and rectal sites, and 20.5% at the rectal site only.8
It is alarming that only 59% of pregnant women are screened for chlamydia given the significant perinatal complications associated with this infection. Barriers to screening pregnant women may include clinician discomfort in discussing STDs and patient refusal of screening. Furthermore, clinicians should routinely ask women about receptive anal sex. Women who report this risk factor should be tested for chlamydia in both the endocervix and rectum.
Retesting and follow-up. After the initial diagnosis of chlamydia, a test of cure 3 weeks after treatment is an important aspect of care. Thus, identifying and overcoming barriers to retesting is important. Clinicians should educate patients about the importance of follow-up. Also consider incorporating the use of home-based, self-obtained vaginal swabs for retesting. Results from 2 randomized trials showed that eliminating a patient’s transportation barriers and providing a home-based alternative to a follow-up visit significantly increased rescreening rates by 33% in STD clinic patients and by 59.2% in family planning clinic patients.9
Reinfection risk. The rate of venereal chlamydia transmission in heterosexual partners is 70%. Since sexually active chlamydia-positive patients are at risk for reinfection by their partner after treatment completion, clinicians should refer the sex partners for evaluation. If the sex partners are reluctant to have testing, it is reasonable to provide empiric antibiotic treatment to decrease the risk of re-infection in the patient.7 Before doing so, however, make certain that state law permits this practice, and be sure to document the prescribed treatment in the patient’s record.
Treatment options
Prompt treatment of C trachomatis infection is essential to decrease the risk of disease sequelae. Nonpregnant adults can be treated with oral doxycycline 100 mg twice daily for 7 days.
In a head-to-head study performed in a controlled environment that ensured treatment adherence, 97% efficacy was achieved with one oral dose of azithromycin (1 g) compared with 100% efficacy with doxycycline.10 However, in the real-world setting, imperfect adherence to the multi-day doxycycline regimen is associated with treatment failures. Thus, a single dose of azithromycin is preferable for patients with questionable compliance.11
In obstetric patients, azithromycin and amoxicillin are preferred as first-line agents for treatment of C trachomatis due to their improved safety profile in this demographic. Amoxicillin 500 mg orally 3 times daily for 7 days has 95% efficacy.2
Women allergic to these agents may be treated with an alternative regimen of erythromycin base, 500 mg orally 4 times daily for 7 days, or erythromycin ethylsuccinate, 800 mg orally 4 times daily for 7 days. Erythromycin should be reserved for second-line therapy because of its lower efficacy (64%) and frequent gastrointestinal adverse effects.2 Doxycycline is contraindicated in pregnancy because of possible teratogenic effects on the teeth and bone of the fetus.
- Centers for Disease Control and Prevention Division of STD Prevention. Sexually transmitted disease surveillance 2018. October 2019. https://www.cdc.gov/std/stats18/default.htm. 2019. Accessed January 4, 2020.
- Duff P. Maternal and fetal infections. In: Creasy RK, Resnik R, Iams JD, et al, eds. Creasy and Resnik’s Maternal-Fetal Medicine: Principles and Practice. 8th ed. Philadelphia, PA: Elsevier Saunders; 2019:869.
- Ljubin-Sternak S, Meštrović T. Chlamydia trachomatis and genital mycoplasmas: pathogens with an impact on human reproductive health. J Pathog. 2014. doi: 10.1155/2014/183167.
- Meyer T. Diagnostic procedures to detect Chlamydia trachomatis infections. Microorganisms. 2016:4(3).
- Centers for Disease Control and Prevention.. Recommendations for the laboratory-based detection of Chlamydia trachomatis and Neisseria gonorrhoeae. MMWR Recomm Rep. 2014;63:1-19.
- Wiesenfeld HC. Screening for Chlamydia trachomatis infections in women. N Engl J Med. 2017;376:765-773.
- Blatt AJ, Lieberman JM, Hoover DR, et al. Chlamydial and gonococcal testing during pregnancy in the United States. Am J Obstet Gynecol. 2012;207:55.e1-8.
- Llata E, Braxton J, Asbel L, et al. Rectal Chlamydia trachomatis and Neisseria gonorrhoeae infections among women reporting anal intercourse. Obstet Gynecol. 2018;132:692-697.
- Xu F, Stoner BP, Taylor SN, et al. Use of home-obtained vaginal swabs to facilitate rescreening for Chlamydia trachomatis infections: two randomized controlled trials. Obstet Gynecol. 2011;118(2 pt 1):231-239.
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- Xu F, Stoner BP, Taylor SN, et al. Use of home-obtained vaginal swabs to facilitate rescreening for Chlamydia trachomatis infections: two randomized controlled trials. Obstet Gynecol. 2011;118(2 pt 1):231-239.
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