Pelvic Inflammatory Disease (PID)

By Dr Joe Kabyemela, MD

Pelvic infection or pelvic inflammatory disease (PID) is a fairly common problem among sexually active women. The commonest causative organisms are Chlamydia and Neisseria gonorrhoeae causing well known infections which go by the same names. However Chlamydia and gonorrhoea are by no means the only pelvic infections. Other types of bacteria in the lower genital tract can ascend through the cervix to cause pelvic inflammatory disease (PID).

Signs and symptoms of PID

What is frustrating about pelvic infection or PID is that, it is not always symptomatic. Chlamydia, the commonest sexually transmitted bacterial infection is particularly notorious for being silent. Even gonorrhoea pelvic infection could remain silent for a while after it has occurred.

When clinical features are present the symptoms could include some or all of the following:

v Lower abdominal or pelvic pain: This tends to affect both sides but can sometimes affect one side more than the other.

v Vaginal discharge: This can be watery, creamy, yellowish or gray. It is not always offensive. It can also be completely absent.

v Feeling feverish, sometimes with a raised temperature

v Pain in the pelvis during sexual intercourse

v Contact bleeding: Light bleeding usually provoked by sexual intercourse. This is seen only occasionally and is not common..

When a woman with acute pelvic inflammatory disease is examined, there is likely to be:

v Tenderness over the lower abdomen

v Pain provoked by moving the cervix from side to side, the so-called ‘cervical excitation tenderness’

Confirming diagnosis of PID

Once a diagnosis of pelvic infection is suspected, vaginal and cervical swabs need to be taken for microbiology studies. In addition, a swab may be taken from the urethra. This is the only way the diagnosis can be conclusively established and the causative organism (bacteria) identified. A sensitivity test is also done to see which antibiotics will be effective in treating the condition. If Chlamydia is the suspected infection, an early morning sample of urine can also be used. Crucially, however, treatment does and should not wait for these microbiology results. Once there is clinical suspicion of pelvic infection, treatment should be started straight away to eliminate the infection and, more importantly, minimise the possibility of long-term complications from the infection. The infection needs to remain untreated for only a handful of days (two or three) for the possibility of long-term irreversible damage to occur in the pelvis. We shall discuss this shortly.

Imaging (ultrasound or CT scans) for diagnosing PID

Imaging investigations such as ultrasound and CT scans have very limited role in the diagnosis of pelvic infection. If the woman is presenting late where there may already be damage to pelvic organs, a scan may help to identify something like a tubo-ovarian abscess or a blocked tube which is fluid-filled (hydrosalpinx). For those with newly acquired infection, scanning has little or no role to play. It could be employed, however, in a bid to rule out other causes of pelvic pain if the diagnosis is in doubt.

Pus Cells

Many women tested for pelvic infection will have seen their reports indicating that there are ‘Pus cells’ identified. Whilst this is non-specific, it is a very useful guide for the doctor trying to establish a diagnosis. If a swab taken from the cervix shows no pus cells, this is almost confirmatory that there cannot be a pelvic infection. It means, this simple test is very useful in ruling out PID. However, the opposite is not true. The positive predictive value of cervical pus cells is quite poor. Less than 1 in 5 of those found to have pus cells will actually have pelvic infection. So, whilst absence of pus cells helps in ruling out PID, presence of pus cells is of little diagnostic value.

Antibiotics for Pelvic Inflammatory Disease (PID)

In each country, there is an accepted treatment protocol for suspected pelvic infection. This is based on local antibiotic sensitivities. The variant that is prevalent in one part of the world may respond to a particular antibiotic but a variant found in another part may be resistant to that antibiotic. It is therefore important for health authorities to keep track of the behaviour of the organisms causing infection in their part of the world.

In the UK, recommended antibiotic regimes are (use one or the other):

v Ofloxacin 400mg twice daily and Metronidazole 400mg twice daily both taken orally for two weeks. Metronidazole can also be taken rectally in the form of suppositories if the patient so prefers.

v Ceftriaxone 250mg single intramuscular injection followed by a two week course of both Doxycycline 100mg once daily and Metronidazole 400mg twice daily.

These regimes consisting of strong and broad spectrum antibiotics are meant to cover most of the potential causes of pelvic infection including gonorrhoea, Chlamydia and anaerobic bacteria. These regimens remain effective even for those women with concurrent HIV infection.

When the disease is clinically severe, the patient should be admitted and treatment given on an inpatient basis. This may also be necessary if surgical intervention is likely to be required such as in a case of a pelvic abscess.

If it becomes necessary to treat as an inpatient, the antibiotic regimen will normally be adjusted slightly like this:

v Ceftriaxone 2 grams administered intravenously once daily plus the 14 day course of Doxycycline and Metronidazole described above. The intravenous Ceftriaxone course is stopped once there is clinical improvement.

v Clindamycin 900mg administered intravenously three times daily plus intravenous Gentamicin (dose calculated on the basis of the patient’s body weight). Once the clinical picture improves, these are substituted with oral Clindamycin 450 mg four times daily to complete a 14 day course

v A 14 day course of intravenous Ofloxacin (400mg twice daily) and Metronidazole (500 mg three times daily). This is usually adopted for those patients unable to tolerate oral medication.

It is important to have a repeat test 4 – 6 weeks after completing the course of treatment to ensure the infection has cleared.

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