Pelvic
Inflammatory Disease
Article courtesy of the NIAID:
Aside from AIDS, the most common and serious complication of
sexually transmitted diseases (STDs) among women is pelvic
inflammatory disease (PID), an infection of the upper genital
tract. PID can affect the uterus, ovaries, fallopian tubes, or
other related structures. Untreated, PID causes scarring and can
lead to infertility, tubal pregnancy, chronic pelvic pain, and
other serious consequences.
Each year in the United States, more than 1
million women experience an episode of acute PID, with the rate
of infection highest among teenagers. More than 100,000 women
become infertile each year as a result of PID, and a large
proportion of the 70,000 ectopic (tubal) pregnancies occurring
every year are due to the consequences of PID. In 1997 alone, an
estimated $7 billion was spent on PID and its complications.
Cause
PID occurs when disease-causing organisms
migrate upward from the urethra and cervix into the upper genital
tract. Many different organisms can cause PID, but most cases are
associated with gonorrhea and genital chlamydial infections, two
very common STDs. Scientists have found that bacteria normally
present in small numbers in the vagina and cervix also may play a
role.
Investigators are learning more about how
these organisms cause PID. The gonococcus, Neisseria gonorrhea,
probably travels to the fallopian tubes, where it causes
sloughing (casting out) of some cells and invades others.
Researchers think it multiplies within and beneath these cells.
The infection then may spread to other organs, resulting in more
inflammation and scarring.
Chlamydia trachomatis and other
bacteria may behave in a similar manner. Researchers do not know
how other bacteria that normally inhabit the vagina (e.g.,
organisms such as Gardnerella vaginalis and Bacteroides)
gain entrance into the upper genital tract. The cervical mucus
plug and secretions may help prevent the spread of microorganisms
to the upper genital tract, but it may be less effective during
ovulation and menses. In addition, the gonococcus may gain access
more easily during menses, if menstrual blood flows backward from
the uterus into the fallopian tubes, carrying the organisms with
it. This may explain why symptoms of PID caused by gonorrhea
often begin immediately after menstruation as opposed to any
other time during the menstrual cycle. It is noteworthy that the
co-incidence of menses and chlamydial infection is not a
prominent feature of chlamydial PID.
Symptoms
The major symptoms of PID are lower
abdominal pain and abnormal vaginal discharge. Other symptoms
such as fever, pain in the right upper abdomen, painful
intercourse, and irregular menstrual bleeding can occur as well.
PID, particularly when caused by chlamydial infection, may
produce only minor symptoms or no symptoms at all, even though it
can seriously damage the reproductive organs.
Risk Factors for PID
- Women with STDs episode of –
especially gonorrhea and chlamydial infection – are
at greater risk of developing PID; a prior PID increases
the risk of another episode because the body’s
defenses are often damaged during the initial bout of
upper genital tract infection.
- Sexually active teenagers are more
likely to develop PID than are older women.
- The more sexual partners a woman has,
the greater her risk of developing PID.
Recent data indicate that women who douche
once or twice a month may be more likely to have PID than those
who douche less than once a month. Douching may push bacteria
into the upper genital tract. Douching also may ease discharge
caused by an infection, so the woman delays seeking health care.
Diagnosis
PID can be difficult to diagnose. If
symptoms such as lower abdominal pain are present, the doctor
will perform a physical exam to determine the nature and location
of the pain. The doctor also should check the patient for fever,
abnormal vaginal or cervical discharge, and evidence of cervical
chlamydial infection or gonorrhea. If the findings of this exam
suggest that PID is likely, current guidelines advise doctors to
begin treatment.
If more information is necessary, the
doctor may order other tests, such as a sonogram, endometrial
biopsy, or laparoscopy to distinguish between PID and other
serious problems that may mimic PID. Laparoscopy is a surgical
procedure in which a tiny, flexible tube with a lighted end is
inserted through a small incision just below the navel. This
procedure allows the doctor to view the internal abdominal and
pelvic organs, as well as take specimens for cultures or
microscopic studies, if necessary.
Treatment
Because culture of specimens from the upper
genital tract are difficult to obtain and because multiple
organisms may be responsible for an episode of PID, especially if
it is not the first one, the doctor will prescribe at least two
antibiotics that are effective against a wide range of infectious
agents. The symptoms may go away before the infection is cured.
Even if symptoms do go away, patients should finish taking all of
the medicine. Patients should be re-evaluated by their physicians
two to three days after treatment is begun to be sure the
antibiotics are working to cure the infection.
About one-fourth of women with suspected
PID must be hospitalized. The doctor may recommend this if the
patient is severely ill; if she cannot take oral medication and
needs intravenous antibiotics; if she is pregnant or is an
adolescent; if the diagnosis is uncertain and may include an
abdominal emergency such as appendicitis; or if she is infected
with HIV (human immunodeficiency virus, the virus that causes
AIDS).
Many women with PID have sex partners who
have no symptoms, although their sex partners may be infected
with organisms that can cause PID. Because of the risk of
reinfection, however, sex partners should be treated even if they
do not have symptoms.
Consequences of PID
Women with recurrent episodes of PID are
more likely than women with a single episode to suffer scarring
of the tubes that leads to infertility, tubal pregnancy, or
chronic pelvic pain. Infertility occurs in approximately 20
percent of women who have had PID.
Most women with tubal infertility, however,
never have had symptoms of PID. Organisms such as C.
trachomatis can silently invade the fallopian tubes and cause
scarring, which blocks the normal passage of eggs into the
uterus.
A women who has had PID has a
six-to-tenfold increased risk of tubal pregnancy, in which the
egg can become fertilized but cannot pass into the uterus to
grow. Instead, the egg usually attaches in the fallopian tube,
which connects the ovary to the uterus. The fertilized egg cannot
grow normally in the fallopian tube. This type of pregnancy is
life-threatening to the mother, and almost always fatal to her
fetus. It is the leading cause of pregnancy-related death in
African-American women.
In addition, untreated PID can cause
chronic pelvic pain and scarring in about 20 percent of patients.
These conditions are difficult to treat but are sometimes
improved with surgery.
Another complication of PID is the risk of
repeated attacks of PID. As many as one-third of women who have
had PID will have the disease at least one more time. With each
episode of reinfection, the risk of infertility is increased.
Prevention
Women can play an active role in protecting
themselves from PID by taking the following steps:
- Signs of discharge with odor or
bleeding between cycles could mean infection. Early
treatment may prevent the development of PID.
- If used correctly and
consistently, male latex condoms will prevent
transmission of gonorrhea and partially protect
against chlamydial infection.
Research
Although much has been learned about the
biology of the microbes that cause PID and the ways in which they
damage the body, there is still much to learn. Scientists
supported by the National Institute of Allergy and Infectious
Diseases (NIAID) are studying the effects of antibiotics,
hormones, and substances that boost the immune system. These
studies may lead to insights about how to prevent infertility or
other complications of PID. Topical microbicides and vaccines to
prevent gonorrhea and chlamydial infection also are being
developed. Clinical trials are in progress to test a suppository
containing lactobacilli – the normal bacteria found in the
vaginas of healthy women. These bacteria colonize the vagina and
may be associated with reduced risk of gonorrhea and bacterial
vaginosis, both of which can cause PID.
Rapid, inexpensive, easy-to-use diagnostic
tests are being developed to detect chlamydial infection and
gonorrhea. A recent study conducted by NIAID-funded researchers
demonstrated that screening and treating women who unknowingly
had chlamydial infection reduced cases of PID by more than 60
percent. Meanwhile, researchers continue to search for better
ways to detect PID itself, particularly in women with
"silent" or asymptomatic PID.
