Managing urinary tract infections.

THE diagnosis of urinary tract infections (UTI) is made from the history presented by the patient, a physical examination, and laboratory investigations. The clinical features of UTI may differ depending on whether the lower, i.e. bladder or urethra, or upper urinary tract, i.e. kidney, is involved.

The clinical features suggestive of UTI involving the bladder (cystitis) include pain or a burning sensation when passing urine, frequent passing of urine, feeling the urge to pass urine, lower abdominal discomfort or pain, urine that smells or appears cloudy or red, and tenderness in the lower abdomen.

The clinical features suggestive of UTI involving the kidneys (pyelonephritis) include frequent passing of urine, pain when passing urine, feeling the urge to pass urine, aches in the back, groin and side of the body, fever, blood and/or pus in the urine, nausea, vomiting, and tenderness in the back.

Clinical features of the factors that increase the risk of UTI may also be present. These factors have been discussed in the article a fortnight ago.

Drink up: It is common practice to advise a patient with UTI to drink plenty of fluids. This leads to the body producing more urine, which results in the flushing out of bacteria from the urinary tract.

Sometimes, symptoms are less specific and they include tiredness and confusion. The latter is more common in senior citizens. It is advisable for anyone with these symptoms to seek medical attention.

Many people who are suffering from UTI have no symptoms at all. This is particularly so in the case of people who are at increased risk of UTI, e.g. pregnancy, diabetis.

Other conditions which may have symptoms similar to that of a UTI include common infections of the genital tract, e.g. sexually transmitted infections and fungal infections of the vulva and vagina, urethral syndrome (a condition in which the symptoms indicate a UTI but there is no underlying infection), non-infective cystitis due to nonsteroidal anti-inflammatory and other drugs, and an enlarged or infected prostate in men.

The distinction between an uncomplicated and a complicated UTI is important as it has an impact on the type and choice of antibiotics, and the extent to which the urinary tract will be evaluated. Certain factors suggestive of a potential complicated UTI include male gender, senior citizens, pregnancy, diabetes, abnormalities of the urinary tract, recent antibiotic use, immunosuppression, symptoms present for a week or more, indwelling urinary catheter, and hospital acquired infection.

Investigations

An examination of a midstream specimen of urine will provide a rapid idea of whether UTI is present. The midstream specimen of urine is used because of the need to avoid contamination of the sample. Indirect evidence of infection can be found in the urine sample. They include blood, protein, white blood cells, and nitrites.

Most bacteria that commonly cause UTI convert nitrate, which is a compound that is normally present in the urine, into nitrites. The latter is usually not present in urine.

A urine sample is also collected at the same time for laboratory investigation. The presence of 100,000 bacteria per millilitre of urine is indicative of an infection. Pus and white blood cells are also present on microscopic examination of the urine. It is the usual practice to culture the urine sample to determine the type of bacteria present and its sensitivity to various antibiotics commonly used to treat UTI.

If risk factors of UTI are present or suspected, other investigations may be carried out, e.g. ultrasound and X-ray studies.

General treatment measures

It is common practice to advise a patient with UTI to drink plenty of fluids, e.g. water, juice. This leads to the body producing more urine, which results in the flushing out of bacteria from the urinary tract. It also reduces the collection of urine (stasis) which is a factor that increases the risk of UTI.

Doctors also advise patients with UTI to consume substances like citrate, which help in alleviating symptoms and provide an environment in the urinary tract that is more hostile to bacterial growth, and as such, improves the effectiveness of the antibiotics prescribed.

Oestrogens may also be prescribed in post-menopausal women with UTI.

Antibiotics

Antibiotics are the primary measures used to treat UTI. The choice of antibiotic is influenced by its effectiveness, side effects, resistance levels, costs and whether the UTI is simple or complicated. Different antibiotics are used for cystitis and pyelonephritis.

The common antibiotics used in the treatment of UTI include trimethoprim, nitrofurantoin, cephalosporins, penicillins, fluoroquinolones, and fosfomycin. The doctor may prescribe another antibiotic after receiving the results of the culture of the urine.

The widespread and indiscriminate usage of certain antibiotics has resulted in the development of high bacterial resistance levels. This means that the more powerful and recent antibiotics may not be of use or are of limited use when a serious infection occurs. That is why concerns have been raised about the possible overuse of the more powerful antibiotics as first line treatment for UTI in the community setting.

When prescribed an antibiotic for UTI, it would be advisable to raise these issues with the attending doctor. It is important to complete the course of antibiotics in the manner prescribed by the doctor.

Recurrent UTI

Recurrent UTI is defined as the occurrence of three or more episodes of UTI in the preceding 12 months, or two episodes in the preceding six months. The causes of recurrent UTI are genetic or behavioural. Women who are non-secretors of blood group substances are at increased risk of recurrent UTI. A secretor is a person who secretes his or her blood type antigens into the body fluids and secretions like saliva.

The risk factors associated with recurrent UTI in sexually active premenopausal women include frequency of sexual intercourse, use of spermicides, the age of first UTI (the risk is greater if it is less than 15 years), and history of UTI in the mother, suggesting that genetic factors may be involved. The risk factors after the menopause include bladder prolapse, incontinence, and residual urine in the bladder after passing urine.

If there are recurrent UTIs, the doctor will refer the patient to a specialist, who will recommend the necessary measures for the identification and treatment of the underlying cause.

Prophylactic antibiotics may be prescribed. Other prophylactic measures like the vaginal application of lactobacilli, and consumption of cranberry juice, have been reported to have produced variable effects.

The doctor may prescribe “bladder toilet”, i.e. drinking at least two to three litres of fluid daily and always passing urine before going to bed and after sexual intercourse.

Those who have urinary tract conditions that require surgical intervention will be advised accordingly by the urologist.

Source: Dr Milton Lum