Urinary infections
The urinary tract is made up of the kidneys, ureters, bladder and urethra; infection of any of these organs may spread to the others.
The symptoms of urinary tract infections may differ widely. Some women have no symptoms at all, and the infection remains hidden until it causes kidney failure. Other women are crippled with pain and ‘cystitis’, and may pass blood in their urine. Women experiencing more than three infections per year are defined as having recurrent infections.
What causes infections?
Bacteria are small organisms that are found everywhere. Normally they do not cause an infection when they are in their normal habitat. If the balance of bacteria changes, this may allow an overgrowth of one type and, in these circumstances, it can cause damage that shows as an infection.
It is not unusual to find bacteria in a normal woman’s bladder. Cystitis is an inflammation of the bladder and can be the result of infection. The female urethra (the passage between the bladder and the outside) is relatively short, which allows easy access to bacteria found around the vagina and perineum (the area between the vagina and the anus). Quite often these are the same as the bacteria found in the bowel. When the bladder empties it washes them out of the bladder, and as the urine leaves the body it cleans the area just outside the urethra.
If the bladder does not empty fully these bacteria stay in the bladder and can start to multiply or colonise it. If the bacteria increase in number they can then start to damage the lining of the bladder, producing inflammation. This, in turn, causes the symptoms of burning and frequency characteristic of cystitis. Thus, difficulties in emptying the bladder are a major cause of infections.
Another factor in infection is sexual intercourse. During intercourse, the bacteria normally present outside the urethra can be pushed into it and so spread up into the bladder. This is called auto- or self-infection. New types of bacteria can also be introduced from the man. Sex can also cause small abrasions, which can give the bacteria a stronger foothold from which to colonise the bladder.
There are simple measures that can be used to avoid infections associated with sexual intercourse. Emptying the bladder completely soon after sex may help to wash out the bacteria in the bladder. In order to gain the full protective effect, however, the bladder must be at least comfortably full. Just emptying a small drop out of the bladder will not wash all the bacteria away.
You should also consider the type of contraception that you use. Urinary infections can occur as a result of using the diaphragm and spermicide in around 10 per cent of women, and in some cases using condoms stops infections occurring. Some women are allergic to the most common spermicide, nonoxinol ‘9’. Non-allergic condoms can be used in these cases.
Simple hygienic measures may also help lessen the growth of bacteria on the outside of the vagina, for example, always wiping from the vagina towards the anus after using the toilet. Douching is unwise, because it will normally remove the natural, helpful bacteria, allowing more harmful bowel bacteria to colonise, and may actually increase the risk of infection. The vagina is a self-cleaning organ and does not require detergents or perfumes.
Kidney stones are another rare cause of infections. If bacteria infect a stone it is almost impossible to clear the infection. In these cases the stone needs to be removed. Infections are also more common in pregnancy.
Investigation
When you see your doctor he or she will first confirm that you have an infection rather than some other condition such as interstitial cystitis (see below). To do this a urine sample will be sent off for testing before you are treated with antibiotics.
The urine sample needs to be a mid-stream specimen. This is collected by starting to empty your bladder into a toilet and, when the stream is established, catching a sample in a sterile container. The reason for discarding the first part of the stream is that this can be contaminated by bacteria on the skin and in the urethra. The mid-stream sample should give a representative specimen from inside the bladder. The results from the sample will be used to ensure that the correct antibiotic is being used.
If you get recurrent infections, repeated samples will be taken to build up a picture of the types of infection that you get. This will suggest whether you are developing different infections, or whether the problem is the same infection that is not being adequately treated.
Women with proven recurrent infections require further investigation to exclude other causes of infection, such as chronic kidney infection. A frequency volume chart (see Urodynamics) may give important information on your bladder behaviour.
Urodynamics is routinely used to check, along with a cystoscopy, inside the bladder.
Treatment
In mild cases the infection will settle on its own, just requiring the treatment described below for the symptoms. Many women say that drinking a lot of water clears infections. It is more likely that it reduces the symptoms by keeping the urine dilute while the bladder is sore, allowing the body’s natural defences to clear the infection. Bicarbonate of soda, barley water and cranberry juice are also commonly suggested as cures for cystitis: they may help to reduce the acidity of urine which may make it less painful to void.
Established infections will need adequate treatment with an appropriate antibiotic. Often doctors will treat empirically, which means that they prescribe an antibiotic likely to treat the infection. This is because they wish to treat immediately rather than wait three days for confirmation of the type of infection and the correct antibiotic. Remember that because an antibiotic does not work on one occasion does not mean that it will not work in subsequent infections.
After exclusion of any underlying cause for the recurrent infections there are two treatment options:
- Low-dose antibiotics can be used at night in an attempt to keep the bladder sterile and treat any infection before it gets a hold.
- The second approach is to treat only when necessary.
If symptoms occur only after intercourse, an antibiotic can be taken either before or immediately afterwards. Alternatively, most women who have recurrent cystitis know when symptoms are going to develop up to 12 hours beforehand. In these cases taking a single dose of an antibiotic often cures the symptoms. If they persist, further antibiotics can be taken. Symptoms lasting longer than 24 hours normally mean that the infection is resistant to the antibiotic.
Very occasionally the infections are caused by bacteria such as Ureaplasma or Mycoplasma. These infections are not usually checked for and, if symptoms persist, a special sample of urine should be sent to the laboratory to look for them specifically. They may require long-term treatment with antibiotics for around three months.
Some patients occasionally have relief of their symptoms using mannose preparations (mannose is a type of sugar). This has been reported anecdotally and, although there may be little scientific evidence to support the use the mannose, it certainly does help some patients with symptoms.
Interstitial cystitis
Interstitial cystitis is a relatively rarely diagnosed inflammatory condition of the bladder, the cause of which is far from clear. It causes bladder pain and mimics cystitis resulting from an infection. It often causes frequency and urgency and can cause the bladder lining to bleed, leading to blood in the urine.
Diagnosis is based on several symptoms and signs, including changes to the bladder’s capacity and increased bladder sensitivity, plus a biopsy or sample of the bladder wall, which will show an increase in inflammatory cells, particularly mast cells (a type of immune cell).
Interstitial cystitis occurs almost exclusively in women, raising the question of whether there is a hormonal influence. Most women with the condition (up to 95 per cent) are white, and symptoms start after the age of 20. This is around the age when many women become sexually active, which makes it more difficult to distinguish from recurrent infections.
Even though the cause of interstitial cystitis is unknown, the effects are now beginning to be understood. The bladder wall becomes inflamed and thickened. This may be as a direct result of an infection or because the body’s defence mechanism acts against the cells of the bladder. It is these two ideas that have led to most approaches to treatment.
Treatment
Common treatments include long-term antibiotic treatment (for at least three months). This is to keep the bladder free of any infection while giving the bladder wall a chance to heal and recover. Alternatively, bladder antiseptics taken by mouth can be used to try to create an environment for healing.
Drugs known to reduce inflammation can be used and simple medications such as aspirin or aspirin-like medications may help. A greater anti-inflammatory effect is achieved using steroids such as prednisolone.
Another anti-inflammatory treatment involves using antihistamines, better known as a treatment for hay fever and stomach ulcers. The mast cells in the bladder wall release histamine, which is involved in producing inflammation. Antihistamines reduce the effects of this and, consequently, may improve symptoms.
Many other medications, such as antidepressants, anticholinergics and calcium antagonists, have been suggested for interstitial cystitis, as well as some operations. Many doctors will employ bladder instillations using preparations such as heparin, Cystistat and DMSO, which may be effective in certain patients.
Unfortunately, the causes that trigger interstitial cystitis have not been identified and therefore medication can currently treat only the symptoms.
There are some lifestyle changes that appear to help. These are based on trying to identify trigger factors for the condition, such as caffeine. Avoidance of these substances can often be as effective as medication. There are a number of diets available to help patients with interstitial cystitis, often based around reducing acids or spices.
KEY POINTS
- Recurrent urinary tract infections are often related to sex or difficulties in emptying the bladder
- Simple hygiene measures can help
- Treatment is with antibiotics
- Recurrent infections may be confused with interstitial cystitis or vice versa
- Interstitial cystitis is a rare type of cystitis
