The majority of women who have burning on urination, frequency and urgency have urinary tract infections, even if their cultures do not grow any germs (Clinical Microbiology and Infection, published online April 28, 2017).
In addition to a standard urine culture, researchers in this study used a sophisticated technique called quantitative polymerase chain reaction (qPCR) to look for E. coli and Staphylococcus saprophyticus DNA. The authors report that “almost all women with typical urinary complaints and a negative culture still have an infection with E. coli.” More than 90 percent of the symptomatic women with a negative urine culture tested positive using the more sensitive qPCR approach for the intestinal bacteria, E. Coli, while only five percent of women without symptoms tested positive using qPCR. This sensitive test also found sexually-transmitted bacteria such as mycoplasma and trichomonas in some of the women who had negative results on their standard urine culture.
The authors recommend that all women with these symptoms be treated with antibiotics without getting a conventional culture. The reason for the false negative cultures is that the laboratories do not report urine cultures as being positive for infection when the germs grow in low numbers. As a result, many women with active urinary tract infections and low amounts of bacteria in their urine cultures are told that they don’t have an infection and are sent home without treatment. Many other previous research papers have found that negative urine cultures do not rule out a urinary tract infection.
If You Have Frequent Urinary Infections
Go to your doctor to see if he or she agrees with these researchers and will allow you to treat yourself without further testing. Most bladder infections in women are caused by the intestinal bacteria E. coli (N Engl J Med, Nov 14, 2013;369(20):1883-91).
Diagnosis and Treatment of Urinary Symptoms
If this is your first episode of urinary symptoms, your doctor should order a urine culture and take a look at your urine under a microscope for white blood cells. If white blood cells are present or if the dipstick into the urine shows that you have a positive leukocyte esterase test, you have a proven infection and should be treated with an immediate course of antibiotics. If no white blood cells are seen and the dipstick leukocyte esterase test is negative, your doctor may want to wait a few days for the lab results. However this study shows that statistically you will benefit from an immediate short course of antibiotics. This is still controversial.
Your doctor will also ask you if you think that you may have a venereal disease, and if that is a possibility, he or she will order cultures for chlamydia, mycoplasma and ureaplasma and tests for syphilis, gonorrhea and perhaps HIV. If any of these lab tests are positive, both you and your partner and all contacts must be treated at the same time with the appropriate antibiotics. Realize that some cases of mycoplasma or chlamydia may require long-term treatment with antibiotics. Also realize that any repeat future sexual contact with an untreated individual will cause another infection since you do not get immunity from having previously had most venereal diseases. Realize that people who are infected with mycoplasma can have false negative cultures and lab tests as these germs are very difficult to culture in the laboratory and therefore may need more sophisticated tests.
You also may have an infection with one or more of the more than 150 different HPV viruses that are very difficult to culture and for which there is no effective treatment or cure. Most people get rid of most types of HPV by themselves in six to nine months. However, some HPVs do not go away and put you at increased risk for genital and oral cancers. See Cancer-Causing HPV Found in 20 Percent of U.S. Adults and Teens
If your symptoms continue, you need further evaluation of your bladder, kidneys and genitals by a gynecologist or urologist.