For sexually active women who are not pregnant, screening is recommended in those under 25 and others at risk of infection. Risk factors include a history of chlamydial or other sexually transmitted infection, new or multiple sexual partners, and inconsistent condom use. For pregnant women, guidelines vary: screening women with age or other risk factors is recommended by the U.S. Preventive Services Task Force (USPSTF) (which recommends screening women under 25) and the American Academy of Family Physicians (which recommends screening women aged 25 or younger). The American College of Obstetricians and Gynecologists recommends screening all at risk, while the Centers for Disease Control and Prevention recommend universal screening of pregnant women. The USPSTF acknowledges that in some communities there may be other risk factors for infection, such as ethnicity. Evidence-based recommendations for screening initiation, intervals and termination are currently not possible. For men, the USPSTF concludes evidence is currently insufficient to determine if regular screening of men for chlamydia is beneficial. They recommend regular screening of men who are at increased risk for HIV or syphilis infection.

In the United Kingdom the National Health Service (NHS) aims to:

1. Prevent and control chlamydia infection through early detection and treatment of asymptomatic infection;

2. Reduce onward transmission to sexual partners;

3. Prevent the consequences of untreated infection;

4. Test at least 25 percent of the sexually active under 25 population annually.

5. Retest after treatment.

Chlamydia can be transmitted during vaginal, anal, or oral sex or direct contact with infected tissue such as conjunctiva. Chlamydia can also be passed from an infected mother to her baby during vaginal childbirth.

The infection is usually spread from one person to another through vaginal, oral, or anal sex. Men have a 20% risk of getting the infection from a single act of vaginal intercourse with an infected woman. The risk for men that have sex with men (MSM) is higher. Active MSM may get a penile infection, while passive MSM may get anorectal gonorrhea. Women have a 60–80% risk of getting the infection from a single act of vaginal intercourse with an infected man. A pregnant women can pass on the infection to her unborn infant.

A mother may transmit gonorrhea to her newborn during childbirth; when affecting the infant's eyes, it is referred to as ophthalmia neonatorum. It may be able to spread through the objects contaminated with body fluid from an infected person. The bacteria typically does not survive long outside the body, typically dying within minutes to hours.

Gonorrhea if left untreated may last for weeks or months with higher risks of complications. One of the complications of gonorrhea is systemic dissemination resulting in skin pustules or petechia, septic arthritis, meningitis, or endocarditis. This occurs in between 0.6 and 3% of infected women and 0.4 and 0.7% of infected men.

In men, inflammation of the epididymis, prostate gland, and urethra can result from untreated gonorrhea. In women, the most common result of untreated gonorrhea is pelvic inflammatory disease. Other complications include inflammation of the tissue surrounding the liver, a rare complication associated with Fitz-Hugh–Curtis syndrome; septic arthritis in the fingers, wrists, toes, and ankles; septic abortion; chorioamnionitis during pregnancy; neonatal or adult blindness from conjunctivitis; and infertility. Men who have had a gonorrhea infection have an increased risk of getting prostate cancer.

Newborn babies coming through the birth canal are given erythromycin ointment in the eyes to prevent blindness from infection. The underlying gonorrhea should be treated; if this is done then usually a good prognosis will follow. Adults may also have eyes infected with gonorrhoea and require proper personal hygiene and medications.

Among persons in the United States between 14 and 39 years of age, 46% of people with gonorrheal infection also have chlamydial infection.

Over one million cases of acute salpingitis are reported every year in the US, but the number of incidents is probably larger, due to incomplete and untimely reporting methods and that many cases are reported first when the illness has gone so far that it has developed chronic complications. For women age 16–25, salpingitis is the most common serious infection. It affects approximately 11% of females of reproductive age.

Salpingitis has a higher incidence among members of lower socioeconomic classes. However, this is thought of being an effect of earlier sex debut, multiple partners, and decreased ability to receive proper health care rather than any independent risk factor for salpingitis.

As an effect of an increased risk due to multiple partners, the prevalence of salpingitis is highest for people age 15–24 years. Decreased awareness of symptoms and less will to use contraceptives are also common in this group, raising the occurrence of salpingitis.

Although previously considered a mere nuisance infection, untreated bacterial vaginosis may cause complications, such as increased susceptibility to sexually transmitted infections including HIV and pregnancy complications.

It has been shown that HIV-infected women with bacterial vaginosis (BV) are more likely to transmit HIV to their sexual partners than those without BV. Diagnostic criteria for BV have also been associated with a female genital tract factor that induces expression of HIV.

There is evidence of an association between BV and increased rates of sexually transmitted infections such as HIV/AIDS. BV is associated with up to a six-fold increase in HIV shedding. There is also a correlation between the absence of vaginal lactobacilli and infection by Neisseria gonorrhea and Chlamydia trachomatis. BV is a risk factor for viral shedding and herpes simplex virus type 2 infection. BV may increase the risk of infection with or reactivation of human papillomavirus (HPV).

In addition, bacterial vaginosis an intercurrent disease in pregnancy may increase the risk of pregnancy complications, most notably premature birth or miscarriage.

Pregnant women with BV have a higher risk of chorioamnionitis, miscarriage, preterm birth, premature rupture of membranes, and postpartum endometritis. BV is associated with gynecological and obstetric complications. Data suggest an association between BV, tubal factor infertility, and pelvic inflammatory disease. Women with BV who are treated with in vitro fertilization have a lower implantation rate and higher rates of early pregnancy loss.

The bacteria most associated with salpingitis are:

- N. gonorrhoeae

- Chlamydia trachomatis

- Mycoplasma

- Staphylococcus

- Streptococcus

However, salpingitis is usually polymicrobial, involving many kinds of organisms. Other examples of organisms involved are:

- Ureaplasma urealyticum

- Anaerobic and aerobic bacteria

Healthy vaginal microbiota consists of species which neither cause symptoms or infections, nor negatively affect pregnancy. It is dominated mainly by Lactobacillus species. BV is defined by the disequilibrium in the vaginal microbiota, with decline in the number of lactobacilli. While the infection involves a number of bacteria, it is believed that most infections start with Gardnerella vaginalis creating a biofilm, which allows other opportunistic bacteria to thrive.

One of the main risks for developing BV is douching, which alters the vaginal flora and predisposes women to developing BV. Douching is strongly discouraged by the U.S. Department of Health and Human Services and various medical authorities, for this and other reasons.

BV is a risk factor for pelvic inflammatory disease, HIV, sexually transmitted infections (STIs), and reproductive and obstetric disorders or negative outcomes. It is possible for sexually inactive persons to develop bacterial vaginosis.

Bacterial vaginosis may sometimes affect women after menopause. Also, subclinical iron deficiency may correlate with bacterial vaginosis in early pregnancy. A longitudinal study published in February 2006, in the "American Journal of Obstetrics and Gynecology", showed a link between psychosocial stress and bacterial vaginosis persisted even when other risk factors were taken into account. Exposure to the spermicide nonoxynol-9 does not affect the risk of developing bacterial vaginosis.

Having a female partner increases the risk of BV by 60%. The bacteria associated with BV have been isolated from male genitalia. BV microbiota has been found in the penis, coronal sulcus, and male urethra, in the male partners of infected females. Partners who have not been circumcised may act as a ‘reservoir’ increasing the likelihood of acquiring an infection after sexual intercourse. Another mode of transmission of the BV-associated microbiota is to a female sexual partner via skin-to-skin transfer. BV may be transmitted via the perineal enteric bacteria from the microbiota of the female and male genitalia.

Specific age groups, persons who participate in risky sexual behavior, or those have certain health conditions may require screening. The CDC recommends that sexually active women under the age of 25 and those over 25 at risk should be screened for chlamydia and gonorrhea yearly. Appropriate times for screening are during regular pelvic examinations and preconception evaluations. Nucleic acid amplification tests are the recommended method of diagnosis for gonorrhea and chlamydia. This can be done on either urine in both men and women, vaginal or cervical swabs in women, or urethral swabs in men. Screening can be performed:

- to assess the presence of infection and prevent tubal infertility in women

- during the initial evaluation before infertility treatment

- to identify HIV infection

- for men who have sex with men

- for those who may have been exposed to hepatitis C

- for HCV

Cervicitis can be caused by any of a number of infections, of which the most common are chlamydia and gonorrhea, with chlamydia accounting for approximately 40% of cases. As many half of pregnant women are asymptomatic with a gonorrhea infection of the cervix. "Trichomonas vaginalis" and herpes simplex are less common causes of cervicitis. There is a consistent association of M. genitalium infection and female reproductive tract syndromes. M. genitalium infection is significantly associated with increased risk of cervicitis.

Researchers had hoped that nonoxynol-9, a vaginal microbicide would help decrease STI risk. Trials, however, have found it ineffective and it may put women at a higher risk of HIV infection.

Prognosis is highly variable. Spontaneous remission is common. Complete cure can be obtained with proper antibiotic treatments to kill the causative bacteria, such as tetracycline, doxycycline, or erythromycin. Prognosis is more favorable with early treatment. Bacterial superinfections may complicate course. Death can occur from bowel obstruction or perforation, and follicular conjunctivitis due to autoinoculation of infectious discharge can occur.

The most common bacterial cause of NGU is "Chlamydia trachomatis", but it can also be caused by "Ureaplasma urealyticum", "Haemophilus vaginalis", "Mycoplasma genitalium", Mycoplasma hominis, Gardnerella vaginalis, Acinetobacter lwoffi, Ac.calcoclaceticus and "E.coli".

Vulvovaginitis in children may be "nonspecific", or caused by irritation with no known infectious cause, or infectious, caused by a pathogenic organism. Nonspecific vulvovaginitis may be triggered by fecal contamination, sexual abuse, chronic diseases, foreign bodies, nonestrogenized epithelium, chemical irritants, eczema, seborrhea, or immunodeficiency. It is treated with topical steroids; antibiotics may be given in cases where itching has resulted in a secondary infection.

Infectious vulvovaginitis can be caused by group A beta-hemolytic "Streptococcus" (7-20% of cases), "Haemophilus influenzae, Streptococcus pneumoniae, Staphylococcus aureus, Shigella, Yersinia", or common STI organisms ("Neisseria gonorrhoeae, Chlamydia trachomatis, Trichomonas vaginalis", herpes simplex virus, and human papillomavirus)"." Symptoms and treatment of infectious vulvovaginitis vary depending on the organism causing it. "Shigella" infections of the reproductive tract usually coexist with infectious of the gastrointestinal tract and cause mucous, purulent discharge. They are treated with trimethoprim-sulfamethoxazole. "Streptococcus" infections cause similar symptoms to nonspecific vulvovaginitis and are treated with amoxicillin. STI-associated vulvovaginitis may be caused by sexual abuse or vertical transmission, and are treated and diagnosed like adult infections.

Vaginitis is the disruption of the healthy vaginal microbiota. The vaginal microbiota consists of those organisms which generally do not cause symptoms, infections, and results in good pregnancy outcomes, and is dominated mainly by Lactobacillus species. The disruption of the normal microbiota can cause a vaginal yeast infection. Vaginal yeast infection can affect women of all ages and is very common. The yeast "Candida albicans" is the most common cause of vaginitis. Specific forms of vaginal inflammation include the following types:

Infectious vaginitis accounts for 90% of all cases in reproductive age women:

- Candidiasis: vaginitis caused by proliferation of "Candida albicans", "Candida tropicalis", "Candida krusei"

- Bacterial vaginosis: vaginitis caused by increased growth of "Gardnerella" (a bacterium).

- Aerobic vaginitis

Other less common infections are caused by gonorrhea, chlamydia, "Mycoplasma", herpes, "Campylobacter", improper hygiene, and some parasites, notably "Trichomonas vaginalis". Women who have diabetes develop infectious vaginitis more often than women who do not.

Vaginal infections often have multiple causes (varies between countries between 20 and 40% of vaginal infections), which present challenging cases for treatment. Indeed, when only one cause is treated, the other pathogens can become resistant to treatment and induce relapses and recurrences. Therefore, the key factor is to get a precise diagnosis and treat with broad spectrum anti-infective agents (often also inducing adverse effects).

Further, either a change in pH balance or introduction of foreign bacteria in the vagina can lead to infectious vaginitis. Physical factors that have been claimed to contribute to the development of infections include the following: constantly wet vulva due to tight clothing, chemicals coming in contact with the vagina via scented tampons, antibiotics, birth control pills, or a diet favoring refined sugar and yeast.

There are many causes of NGU. This is in part due to the large variety of organisms living in the urinary tract. "Ureaplasma urealyticum" and "Mycoplasma genitalium" are some of the culprits.

NGU is also associated with Reiter's syndrome,in which triad of Arthritis,Conjunctivitis & Urethritis is there.

Genital elephantiasis or esthiomene, which is the dramatic end-result of lymphatic obstruction, which may occur because of the strictures themselves, or fistulas. This is usually seen in females, may ulcerate and often occurs 1–20 years after primary infection.

Fistulas of, but not limited to, the penis, urethra, vagina, uterus, or rectum. Also, surrounding edema often occurs. Rectal or other strictures and scarring. Systemic spread may occur, possible results are arthritis, pneumonitis, hepatitis, or perihepatitis.

The disease is classified as either gonococcal urethritis, caused by "Neisseria gonorrhoeae", or non-gonococcal urethritis (NGU), most commonly caused by "Chlamydia trachomatis". NGU, sometimes called nonspecific urethritis (NSU), has both infectious and noninfectious causes.

Urethritis is part of triad of Reiter's Syndrome.

Other causes include:

- Adenoviridae

- Uropathogenic "Escherichia coli" (UPEC)

- Herpes simplex

- Cytomegalovirus

- "Mycoplasma genitalium"

- Reactive arthritis

- "Trichomonas vaginalis"

- "Ureaplasma urealyticum"

- "Methicillin-resistant Staphylococcus aureus"

- "Group B streptococcus"

Cervices is inflammation of the uterine cervix. Cervicitis in women has many features in common with urethritis in men and many cases are caused by sexually transmitted infections. Death may occur. Non-infectious causes of cervicitis can include intrauterine devices, contraceptive diaphragms, and allergic reactions to spermicides or latex condoms.

The condition is often confused with vaginismus which is a much simpler condition and easily rectified with simple exercises.

Regular testing for sexually transmitted infections is encouraged for prevention. The risk of contracting pelvic inflammatory disease can be reduced by the following:

- Using barrier methods such as condoms; see human sexual behavior for other listings.

- Seeking medical attention if you are experiencing symptoms of PID.

- Using hormonal combined contraceptive pills also helps in reducing the chances of PID by thickening the cervical mucosal plug & hence preventing the ascent of causative organisms from the lower genital tract.

- Seeking medical attention after learning that a current or former sex partner has, or might have had a sexually transmitted infection.

- Getting a STI history from your current partner and strongly encouraging they be tested and treated before intercourse.

- Diligence in avoiding vaginal activity, particularly intercourse, after the end of a pregnancy (delivery, miscarriage, or abortion) or certain gynecological procedures, to ensure that the cervix closes.

- Reducing the number of sexual partners.

- Sexual monogamy.

- Abstinence

The epidemiology of TOA is closely related to that of pelvic inflammatory disease which is estimated to one million people yearly.

Sexually transmitted disease that affect the vagina include:

- Herpes genitalis. The herpes simplex virus (HSV) can infect the vulva, vagina, and cervix, and this may result in small, painful, recurring blisters and ulcers. It is also common for there to be an absence of any noticeable symptoms.

- Gonorrhea

- Chlamydia

- Trichomoniasis

- Human papillomavirus (HPV), which may cause genital warts.

HIV/AIDS can be contracted through the vagina during vaginal intercourse, but it is not associated with any local vaginal or vulval disease.

Because of STIs, health authorities and other health outlets recommend safe sex practices when engaging in sexual activity.

Complications of TOA are related to the possible removal of one or both ovaries and fallopian tubes. Without these reproductive structures, fertility can be affected. Surgical complications can develop and include:

- Allergic shock due to anesthetics

- A paradoxical reaction to a drug

- Infection

PID can cause scarring inside the reproductive system, which can later cause serious complications, including chronic pelvic pain, infertility, ectopic pregnancy (the leading cause of pregnancy-related deaths in adult females), and other complications of pregnancy. Occasionally, the infection can spread to in the peritoneum causing inflammation and the formation of scar tissue on the external surface of the liver (Fitz-Hugh–Curtis syndrome).

Babies can also become infected by their mothers during birth. Some infectious agents may be transmitted to the embryo or fetus in the uterus, while passing through the birth canal, or even shortly after birth. The distinction is important because when transmission is primarily during or after birth, medical intervention can help prevent infections in the infant.

During birth, babies are exposed to maternal blood, body fluids, and to the maternal genital tract without the placental barrier intervening. Because of this, blood-borne microorganisms (hepatitis B, HIV), organisms associated with sexually transmitted disease (e.g., "Neisseria gonorrhoeae" and "Chlamydia trachomatis"), and normal fauna of the genitourinary tract (e.g., "Candida albicans") are among those commonly seen in infection of newborns.