Category Archives: Sexual Health

Syphilis

Facts about congenital syphilis

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Syphilis a sexually transmitted disease caused by the bacterium Treponema pallidum subspecies pallidum. It has been called “The Great Pretender”, as symptoms can resemble other diseases.

Syphilis during pregnancy is associated with miscarriage, stillbirth, or infant death shortly after delivery in up to 40% of cases (1). Congenital syphilis occurs when an infected pregnant woman passes syphilis to her fetus during pregnancy. The transmission of syphilis to the infant is more likely to occur in situations where the mother has been infected during the pregnancy, but many cases still occur where the mother was infected prior to the pregnancy (2). There is about a 70% chance of an untreated woman passing syphilis to her fetus (3).

Early congenital syphilis
The signs of early congenital syphilis are usually apparent at 3-14 weeks of age, but in rare cases, there may be no obvious symptoms until 2-5 years of age. A wide range of symptoms are associated with early congenital syphilis including:

  • Inflammation of the umbilical cord, iris of the eye, and bone joints
  • Fever
  • Skin rash and shedding of the skin on the palms and soles
  • Low birth weight
  • Anemia
  • High cholesterol levels at birth
  • Meningitis
  • Jaundice
  • Mental retardation
  • Hair loss
  • Pneumonia
  • Enlarged liver and spleen

Late congenital syphilis
The signs of late congenital syphilis appear after five years of age, but may not be diagnosed until adulthood. A wide range of symptoms are associated with late congenital syphilis including:

  • Bone pain
  • Retinitis pigmentosa (serious eye disease)
  • Peg-shaped upper central incisors
  • Interstitial keratitis (blurred vision, eye pain, light sensitivity)
  • Bone abnormalities (prominent forehead, saddle nose, short upper jaw)
  • Fissuring around the mouth and anus

Diagnosis
Congenital syphilis should be suspected in any child of a mother with syphilis, as there is a 70% chance of transmission in untreated pregnant women (3). However, the wide range of symptoms associated with congenital syphilis often leads to a delayed diagnosis. Furthermore, maternal antibodies to syphilis transferred through the placenta to the fetus can complicate the interpretation of diagnostic tests (4).

Factors that influence newborn treatment decisions include:

  • Diagnosis of syphilis in the mother
  • Syphilis treatment of the mother
  • Presence of clinical, laboratory, or radiographic evidence of syphilis in the newborn
  • Comparisons of maternal and newborn antibody titres

Prevention and treatment
The prevention of congenital syphilis is by far the best option. This is by routine syphilis testing in pregnant women and prompt treatment to prevent the transmission to the fetus. If an infected pregnant woman is untreated there is a 70% risk of passing syphilis to her fetus.

For infected infants, treatment must begin immediately to prevent developmental delays, seizures, and other fatal complications (5). Penicillin is the most effective treatment for infants with congenital syphilis. Additional treatments may include corticosteroids and atropine drops (2).

References
1. Syphilis – CDC Fact Sheet (Detailed). (2017, January). 
2. Congenital Syphilis. (2009). Rare Disease Database. 
3. Sheffield JS, et al. (2002). Congenital syphilis after maternal treatment for syphilis during pregnancy. Am J Obstet Gynecol, 186 (3), 569-573.
4. 2015 STD Treatment Guidelines – Congenital Syphilis. (2015, June 4). CDC. 
5. Sexually Transmitted Diseases Treatment Guidelines, 2015. (2015). MMWR, 64 (RR-3).

Chlamydia and Gonorrhea

Causes and symptoms of chlamydial conjunctivitis

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Chlamydia is a common sexually transmitted disease (STD) caused by infection with the obligate intracellular bacterium Chlamydia trachomatis. Chlamydia is transmitted through sexual contact with the penis, vagina, mouth, or anus of an infected individual. It can also be transmitted from a mother with an untreated chlamydial cervical infection to her newborn during childbirth (1). 

Chlamydial infections most commonly occur in the genital area. However, chlamydia can also affect the eyes, resulting in chlamydial conjunctivitis (2). Chlamydial conjunctivitis is also known as adult inclusion conjunctivitis or swimming pool conjunctivitis (3).

How do people get chlamydial conjunctivitis?
Chlamydial conjunctivitis usually occurs through sexual contact with a person that has a genital chlamydia infection. In rare cases, an infection may be acquired from contaminated and incompletely chlorinated swimming pool water (3). Often the infection arises due to the spread of semen or vaginal fluids from an infected person to the eye (1).

Conjunctivitis can also occur due to other bacterial infections, as well as viral infections that tend to be more common than bacterial causes (4).

What are the symptoms of chlamydial conjunctivitis?
The incubation period (time from exposure to symptom appearance) is between two and 19 days. The severity of symptoms varies, but generally people present with mild symptoms that have lasted for several weeks or months. Often only one eye is affected, but symptoms can occur in both eyes for some people. The symptoms of conjunctivitis are due to inflammation of the conjunctiva (mucous membrane of the eye). Symptoms can include:

  • Bloodshot eyes
  • Watery eyes, due to overactive tear glands
  • Mucus production that sticks to and coats the eyelashes
  • Eye pain and grittiness feeling
  • Swelling and redness of the eyes
  • Eye irritation and itchiness

Severe infections may scar the conjunctiva, causing abnormalities in the tear film, or spread to the cornea of the eye (4).

Many people affected by chlamydial conjunctivitis also have symptoms of a genital infection, such as painful urination and abnormal discharge from the penis/vagina (4).

How is chlamydial conjunctivitis diagnosed?
Chlamydial conjunctivitis symptoms tend to last for several weeks and fail to clear up from topical antibiotics that are effective against other bacterial conjunctivitides (3). A clinical evaluation of symptoms, as well as laboratory testing (e.g. bacterial cultures, immunofluorescent staining, and nucleic acid detection), is generally undertaken for an accurate diagnosis (3).

How is chlamydial conjunctivitis treated?
Chlamydial conjunctivitis usually resolves spontaneously, but symptoms can last for 6-18 months before recovery (5). Oral antibiotics are required to treat chlamydial conjunctivitis, as topical antibiotics are often ineffective. Options include azithromycin, doxycycline, or erythromycin. These antibiotics also cure any concomitant genital infections (3). Sexual partners should be evaluated and treated at the same time as an infected individual.

References
1. Sexually Transmitted Disease Surveillance, 2018. CDC. October 2019. 
2. Kalayoglu MV. (2002) Ocular chlamydial infections: pathogenesis and emerging treatment strategies. Curr Drug Targets Infect Disord, 2 (1), 85-91.
3. Adult Inclusion Conjunctivitis. MERCK MANUAL Professional Version. October 2019. 
4. Infectious Conjunctivitis. MERCK MANUAL Consumer Version. December 2019. 
5. Yang EB, Oetting TA. (2007). Adult Chlamydial Conjunctivitis: 23-year-old male with 6-week duration of red eyes. EyeRounds.org. 

Hepatitis

Important things to note if you test positive for hepatitis C

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What does a positive hepatitis C antibody test mean?
A positive result on a hepatitis C antibody test indicates that hepatitis C antibodies were detected in the specimen tested. This result is consistent with a current infection, or a past infection that has resolved, or a biologic false positivity for hepatitis C antibody (1).

What are the next steps?
Consult with a health care professional for follow up testing for hepatitis C nucleic acid (RNA). The detection of hepatitis C RNA utilizes a different lab technique compared to the detection of hepatitis C antibodies.

If hepatitis C RNA is not detected, it indicates a past hepatitis C infection that has resolved, and generally no further action or treatment is required. It is estimated that up to half of all infected individuals are able to spontaneously clear hepatitis C after an acute infection (2).

If hepatitis C RNA is detected, it indicates a current hepatitis C infection. Generally an additional test for hepatitis C RNA is recommended to confirm a current infection before any treatment protocols begin (3).

Management and treatment of an active hepatitis C infection
Appropriate counseling, care and treatment will be organized by the health professional who requested the hepatitis C RNA test (4). Management and treatment options may include:

  • Medical evaluation for chronic liver disease
  • Vaccinations for hepatitis A and hepatitis B (no vaccines are available for hepatitis C)
  • Screening for and control of alcohol consumption
  • HIV testing
  • Direct acting antivirals to limit the replication of the hepatitis C virus and slow the progression of the disease
  • Following a healthy diet and staying physically active
  • Consultations before taking any new prescriptions, medications or supplements (to prevent further potential liver damage)
  • Avoid donating blood, tissue, or semen
  • Covering of cuts and sores to prevent transmission of hepatitis C

References
1. Ghany MG, Strader DB, Thomas DL, & Seeff LB. (2009). Diagnosis, management, and treatment of hepatitis C: An update. Hepatology, 49 (4),1335-1374.
2. Seo S, et al. (2020). Prevalence of Spontaneous Clearance of Hepatitis C Virus Infection Doubled From 1998 to 2017. Clin Gastroenterol Hepatol, 18 (2), 511-513.
3. Hepatitis C. (2020, July). World Health Organization. 
4. Viral Hepatitis – Hepatitis C Questions and Answers for Health Professionals. (2020, August). CDC. 

Hepatitis

What are the differences between hepatitis A, B, and C?

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What is hepatitis?
Hepatitis refers to inflammation and damage to the liver. The most common cause of hepatitis is a viral infection, particularly from the hepatitis A, B, and C viruses, but also including the less common hepatitis D and E viruses (1). Autoimmune hepatitis and excessive alcohol and drug intake are also causes of hepatitis. This article focuses on the similarities and differences between hepatitis A, B, and C, which account for the majority of hepatitis cases.

Functions of the liver
The liver damage associated with hepatitis results in multiple different symptoms, because the liver performs many critical functions, including:

  • Bile production for digestion
  • Filtering of toxins
  • Metabolism of carbohydrates, fats, and proteins
  • Activation of enzymes
  • Storage of various mineral and vitamins
  • Synthesis of blood proteins and clotting factors. 

Hepatitis transmission
Hepatitis A is generally transmitted by the consumption of food or water contaminated with faeces from an infected individual, or through close direct contact with an infectious individual (e.g. oral-anal sex) (2).

Hepatitis B is transmitted through contact with infectious body fluids, including blood, vaginal secretions, and semen. The most common source of transmission is from an infected mother to her child during childbirth. Risk factors for hepatitis B include using injectable drugs, sexual intercourse with an infected partner, and sharing razors (or other products that may have come into contact with blood) from an infected individual (3).

Hepatitis C is usually transmitted through exposure to blood from an infected individual, most commonly through sharing needles. Other potential sources of infection include at birth, sexual intercourse, healthcare exposures, blood transfusions and organ transplants, unregulated tattoos or body piercings, and sharing personal items that have been contact with infected blood (4). 

What are the symptoms of hepatitis?
Many individuals with hepatitis do not show any symptoms or only mild symptoms. Symptoms can include:

  • Fever
  • Loss of appetite
  • Diarrhea
  • Nausea
  • Abdominal pain
  • Dark urine
  • Jaundice

Hepatitis A is an acute (short-term) illness, which does not cause chronic liver disease, and is rarely fatal. However, it can still cause debilitating symptoms resulting in significant economic and social consequences, as it is one of the most frequent causes of foodborne infection. Infected children under six years of age often don’t experience any noticeable symptoms, while older children and adults are more likely to suffer from severe symptoms. The incubation period (time from exposure to onset of symptoms) is usually 14-28 days (2).

Hepatitis B can result in a chronic infection that can develop into cirrhosis or liver cancer. The most at-risk individuals for a chronic infection are infants and young children, with 80-90% of infected infants and 30-50% of infected children under 6 years of age developing a chronic infection. Less than 5% of infected adults will develop a chronic infection, assuming they have no other health complications. The incubation period of the hepatitis B virus is 75 days on average, but can vary from 30 to 180 days (3).  

Hepatitis C can develop into a chronic infection (>50% of infected individuals) (5). Most individuals with chronic hepatitis C also remain asymptomatic or only show general symptoms such as fatigue or depression. Over several decades mild to severe liver disease develops in most affected individuals, including cirrhosis (5-25% of cases) and liver cancer (6). Several factors increase the risk of the development of cirrhosis in infected individuals, including being male, >50 years, increased alcohol consumption, hepatitis B or HIV coinfection, and immunosuppressive therapy (6). Chronic hepatitis C is a common reason for a liver transplant in the United States (7).

Treatment and prevention options for hepatitis
Hepatitis A treatment options aim to maintain comfort and adequate nutrition, particularly the replacement of fluids. Although most infections are mild, the recovery can take several weeks to months in some individuals. The majority of infected people develop immunity to further hepatitis A infection. The transmission of hepatitis A can be reduced by provisions of safe drinking water, proper sewage disposal, and following proper hygiene practices. There are also several effective hepatitis A vaccines available (2).

Hepatitis B treatment focuses on maintaining comfort and adequate nutrition for acute infections. Chronic hepatitis B infections can be treated with various medications, including antivirals, to reduce progression of cirrhosis and incidence of liver cancer. However, these treatments do not generally eliminate the hepatitis C virus, so treatment is life-long. Vaccination is the most effective prevention tool for hepatitis B and is included in routine childhood vaccination schedules worldwide (3).

Hepatitis C affected individuals should be provided with a medical evaluation for liver disease, vaccinations for hepatitis A and B, HIV testing, and advice regarding reduced alcohol consumption and weight management for overweight and obese individuals. Affected individuals should not donate blood, tissue, or semen, and refrain from sharing items that may come into contact with blood (e.g. razors, glucose meters, toothbrushes). Any cuts or sores on the skin should be covered to reduce the risk of transmission. There is currently no available vaccine for hepatitis C. It is treated with antiviral medications to eliminate the virus from the body. Newly developed “direct-acting” antivirals have improved treatment considerably with fewer side effects and shorter treatment periods. Nowadays, over 90% of individuals infected with hepatitis C can be cured with 8-12 weeks of oral therapy (8).

References
1. Hepatitis. from World Health Organization. 
2. Hepatitis A. (2020, July). World Health Organization. 
3. Hepatitis B. (2020, July). World Health Organization. 
4. Viral Hepatitis – Q&As from the Public. (2020, July). CDC. 
5. Liang TJ, Rehermann B, Seef LB, & Hoofnagle JH (2000). Pathogenesis, natural history, treatment, and prevention of hepatitis C. Ann Intern Med, 132 (4), 296-305.
6. Thomas DL, & Seef LB. (2005). Natural history of hepatitis C. Clin Liver Dis, 9 (3), 383-398.
7. Definition & Facts of Liver Transplant. (2017, March). National Institute of Diabetes and Digestive and Kidney Diseases. 
8. Initial Treatment of Adults with HCV Infection. (2020, August). AASLD. 

Chlamydia and Gonorrhea

What are the symptoms of chlamydia?

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What are the symptoms of chlamydia?
Chlamydia is a common sexually transmitted disease (STD) caused by infection with the obligate intracellular bacterium Chlamydia trachomatis. Chlamydia is transmitted through sexual contact with the penis, vagina, mouth, or anus of an infected individual. It can also be transmitted from a mother with an untreated chlamydial cervical infection to her newborn during childbirth (1). 

Most individuals infected with chlamydia remain asymptomatic, with only an estimated 10% of infected males showing symptoms and 5-30% of infected females (2).

Symptoms in females
C. trachomatis initially infects the cervix of females and sometimes the urethra, but at least 70% of infected females don’t notice any symptoms. For those that do experience symptoms, the most common signs are:

  • Dysuria – burning, tingling, or stinging when urinating
  • Mucopurulent endocervical discharge – abnormal vaginal discharge
  • Easily induced endocervical bleeding – bleeding between periods and/or after sexual intercourse
  • Increased urinary frequency
  • Pain during sexual intercourse
  • Abdominal and/or pelvic pain

Untreated chlamydial infections in females can lead to pelvic inflammatory disease (PID), and PID-associated infertility, ectopic pregnancy, and chronic pelvic pain. Untreated chlamydia during pregnancy has been associated with preterm delivery (3). Chlamydial infections can be passed to newborns during delivery, increasing the risk of conjunctivitis (18-44% of cases) and pneumonia (3-16% of cases) (4). 

Symptoms in males
In males, C. trachomatis can infect the urethra (tube through the penis) and, less commonly, the epididymis (tube at the back of the testicles). The majority of infected males do not show any symptoms. For those that do experience symptoms, the most common signs are:

  • Dysuria – burning, tingling, or stinging when urinating
  • Mucoid or watery urethral discharge from the penis
  • Burning or itching in the urethra
  • Irritation at the tip of the penis
  • Testicular pain, which may spread to the groin
  • Swollen, red, or warm scrotum
  • Abdominal and/or pelvic pain

Complications in untreated males are rare, but can include infertility.

Infections in the rectum
C. trachomatis can also affect the rectum in both males and females. This can occur through receptive anal sex or spread from the cervix and vagina in a female with a cervical chlamydial infection. The symptoms of an infection in rectum can include rectal pain, discharge, and bleeding (5).

Chlamydial conjunctivitis
Sexually acquired chlamydial conjunctivitis can occur in both males and females (6). Inflammation of the conjunctiva leads to:

  • Bloodshot eyes
  • Watery eyes, due to overactive tear glands
  • Mucus production that sticks to and coats the eyelashes
  • Eye pain and grittiness feeling
  • Swelling and redness of the eyes
  • Eye irritation and itchiness

References
1. Sexually Transmitted Disease Surveillance, 2018. CDC. October 2019. 
2. Farley TA, Cohen DA, Elkins W. (2003). Asymptomatic sexually transmitted diseases: the case for screening. Prev Med, 36 (4), 502-509.
3. Rours GI, et al. (2011). Chlamydia trachomatis infection during pregnancy associated with preterm delivery: a population-based prospective cohort study. Eur J Epidemiol, 26 (6), 493-502.
4. Frommell GT, et al. (1979). Chlamydial infection of mothers and their infants. J Pediatrics, 95 (1), 28-32.
5. Quinn TC, et al. (1981). Chlamydia trachomatis Proctitis. N Engl J Med, 305, 195-200.
6. Kalayoglu MV. (2002), Ocular chlamydial infections: pathogenesis and emerging treatment strategies. Curr Drug Targets Infect Disord, 2 (1), 85-91.

Chlamydia and Gonorrhea

What are the long-term complications of chlamydia?

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Chlamydia is a common sexually transmitted disease (STD) caused by infection with the obligate intracellular bacterium Chlamydia trachomatis. Chlamydia is transmitted through sexual contact with the penis, vagina, mouth, or anus of an infected individual. It can also be transmitted from a mother with an untreated chlamydial cervical infection to her newborn during childbirth (1).

Chlamydia can cause abnormal vaginal discharge, endocervical bleeding, increased urinary frequency, and dysuria in females, and urethral discharge, dysuria, and testicular pain in males. Chlamydia infections of the rectum may lead to proctitis, rectal pain, discharge and/or bleeding (2). Sexually acquired chlamydial conjunctivitis can also occur in both males and females (3). However, most individuals infected with chlamydia remain asymptomatic, with only an estimated 10% of infected males showing symptoms and 5-30% of infected females (4; 5).

Despite the absence of disease symptoms in many individuals, long-term health complications can still occur. Complications in females include pelvic inflammatory disease (PID), infertility, ectopic pregnancy, preterm delivery, and increased risk of disease in newborns. Complications in untreated males are rare, but can include epididymitis and infertility. Chlamydial infections can also facilitate the transmission of HIV infection (6), and in rare cases can cause reactive arthritis (7).

Pelvic Inflammatory Disease (PID)
PID is an infection of a female’s reproductive organs. It is often caused by an untreated STD infection, such as chlamydia, which moves upwards from the vagina/cervix into the reproductive organs. The proportion of females with untreated chlamydia that develop PID varies significantly between studies, but is estimated to be around 16% (8; 9). Other microorganisms have also been implicated in the pathogenesis of PID (10).

Some individuals do not experience any symptoms or only show mild symptoms. Symptoms can include lower abdomen pain, fever, abnormal vaginal discharge with an unpleasant odor, pain and/or bleeding during sexual intercourse, painful and frequent urination, and bleeding between periods (11).

PID is usually diagnosed based on medical history, physical exams, and other test results. Pelvic examinations are used to detect cervical motion, uterine, and/or adnexal tenderness. Inflammation in the lower genital tract can be detected by a predominance of leukocytes (white blood cells) in vaginal secretions, elevated C-reactive protein, and cervical friability (sensitive and irritated cervix tissue). Additional diagnostic tools include endometrial biopsy, transvaginal sonography and MRI (12).

Treatment of PID is with broad-spectrum antibiotics to cover likely pathogens. However, antibiotics do not heal any tissue damage already caused by PID. It is important for any prescribed medications to be taken properly and completely, and any sexual partners should be treated concurrently (12).

Infertility in Females
Untreated PID is associated with an increased risk of infertility, particularly in females with recurrent episodes of PID and severe tubal inflammation (11). However, infertility can also occur in individuals with subclinical PID (13); hence why prompt diagnosis and treatment of chlamydia is very important.

Ectopic Pregnancy
Inflammation associated with chlamydia increases the risk of ectopic pregnancy, which is when the fertilized egg implants and grows outside the main cavity of the uterus (14). An ectopic pregnancy cannot proceed as normal and may cause life-threatening bleeding if untreated. Early symptoms can include light vaginal bleeding, pelvic pain, and an urge to have a bowel movement. If the fallopian tube ruptures, heavy internal bleeding occurs causing fainting and shock (14).

Preterm Delivery
Chlamydial infections during pregnancy are associated with preterm delivery with studies reporting a 4-fold increased risk for delivery before 32 weeks gestation (15), and 2- to 3-fold increased risk for delivery before 35 weeks (15; 16). Premature births increase the risk of several complications, including problems associated with breathing, the heart and brain, temperature control, digestion and metabolism. Long-term complications of a premature birth can include cerebral palsy, impaired learning, vision and hearing problems and chronic health issues.    

Disease in Newborns
Untreated chlamydia during pregnancy is associated with a 50-70% risk of passing the infection to the newborn during childbirth. This increases the risk of conjunctivitis (18-44% of cases) and pneumonia (3-16% of cases) (17; 18; 19). Untreated conjunctivitis may last for months and cause corneal and conjunctival scarring (19). Pneumonia is the leading cause of death in the neonatal period (20).

Epididymitis
Epididymitis is a clinical syndrome most frequently caused by chlamydial or gonorrheal infections. It is characterized by pain, swelling, and inflammation of the epididymis, and sometimes the testis (known as epididymo-orchitis). Treatment is by antibiotic therapy to cure the underlying infection. Sexual partners should also undergo treatment to prevent reinfection after the treatment course (21).

Infertility in Males
Chlamydial infections in males are associated with dramatic genetic changes in sperm, which reduce male fertility. However, standard antibiotic treatment for chlamydia significantly improves fertility again in affected males (22).

HIV
Chlamydial infections increase the risk of getting HIV, due to the presence of chlamydial-associated inflammation and sores (6). Chlamydia in HIV-positive individuals also increases the risk of passing HIV to any sexual partners, although effective HIV-treatment prevents this risk.

Reactive Arthritis
Reactive arthritis (aka Reiter’s syndrome) is joint inflammation that develops as a reaction to an infection in another area of the body. Chlamydia is the most common cause of reactive arthritis in the United States (23).

References:
1. Sexually Transmitted Disease Surveillance, 2018. CDC. October 2019.
2. Thompson CI, MacAulay AJ, Smith IW. (1989). Chlamydia trachomatis infections in the female rectums. Genitourin Med, 65 (4), 269-273.
3. Kalayoglu MV. (2002). Ocular chlamydial infections: pathogenesis and emerging treatment strategies. Curr Drug Targets Infect Disord, 2 (1), 85-91.
4. Farley TA, Cohen DA, Elkins W. (2003). Asymptomatic sexually transmitted diseases: the case for screening. Prev Med, 36 (4), 502-509.
5. Korenromp EL, et al. (2002). What proportion of episodes of gonorrhoea and chlamydia becomes symptomatic? Int J STD AIDS, 13 (2), 91-101.
6. Fleming DT and Wasserheit JN. (1999). From epidemiological synergy to public health policy and practice: the contribution of other sexually transmitted diseases to sexual transmission of HIV infection. Sex Transm Infect, 75 (1), 3-17.
7. Cheeti A, Chakraborty RK, Ramphul K. (2020) Reactive Arthritis (Reiter Syndrome). StatPearls (Internet). Treasure Island : StatPearls Publishing, 2020, Vol. January.
8. Price MJ, et al. (2013). Risk of Pelvic Inflammatory Disease Following Chlamydia trachomatis Infection: Analysis of Prospective Studies With a Multistate Model. Am J Epidemiol, 178 (3), 484-492.
9. Reekie J, et al. (2018). Risk of Pelvic Inflammatory Disease in Relation to Chlamydia and Gonorrhea Testing, Repeat Testing, and Positivity: A Population-Based Cohort Study. Clin Infect Dis, 66 (3), 437-443.
10. Hillier SL, et al. (1996). Role of bacterial vaginosis-associated microorganisms in endometritis. Am J Obstet Gynecol, 175 (2), 435-441.
11. Pelvic Inflammatory Disease (PID) Detailed Fact Sheet. CDC. January 2017.
12. Workowski KA and Bolan GA. (2015). Sexually Transmitted Diseases Treatment Guidelines, 2015. MMWR. 64 (RR3), 1-137.
13. Wiesenfeld HC, et al. (2012). Subclinical pelvic inflammatory disease and infertility. Obstet Gynecol, 120 (1), 37-43.
14. Murray H, et al. (2005). Diagnosis and treatment of ectopic pregnancy. CMAJ, 173 (8), 905-912.
15. Rours GI, et al. (2011). Chlamydia trachomatis infection during pregnancy associated with preterm delivery: a population-based prospective cohort study. Eur J Epidemiol, 26 (6), 493-502.
16. Andrews WW, et al. (2000). The Preterm Prediction Study: association of second-trimester genitourinary chlamydia infection with subsequent spontaneous preterm birth. Am J Obstet Gynecol, 183 (3), 662-668.
17. Hammerschlag MR, et al. (1982). Longitudinal studies of chlamydial infection in the first year of life. Pediatr Infect Dis, 1 (6), 395-401.
18. Heggie AD, et al. (1981). Chlamydia trachomatis infection in mothers and infants: A prospective study. Am J Dis Child, 135 (6), 507-511.
19. Chlamydia of the Newborn. Pediatrics Clerkship, The University of Chicago.
20. Mishra KN, et al. (2011), Acute Chlamydia trachomatis Respiratory Infection in Infants. J Glob Infect Dis, 3 (3), 216-220.
21. 2015 Sexually Transmitted Diseases Treatment Guidelines, Epididymitis. CDC. June 2015. 
22. Gallegos G, et al. (2008). Sperm DNA fragmentation in infertile men with genitourinary infection by Chlamydia trachomatis and Mycoplasma. Fertility and Sterility. 90 (2), 328-334.
23. Carter. Reactive Arthritis. Rare Disease Database.