Prevalence, Risk Factors and Antimicrobial Resistance of Asymptomatic Bacteriuria Among Antenatal Women
Urinary tract infection (UTI) during pregnancy is classified as either symptomatic or asymptomatic. Symptomatic UTI are divided into lower tract(acute cystitis) and upper tract(acute pyelonephritis) infection. Asymptomatic bacteriuria (ABU), generally defined as true bacteriuria in the absence of specific symptoms of acute UTI. The prevalence of ABU among antenatal women varies between 2% and 10%. The anatomical and physiological changes imposed on urinary tract by pregnancy, as well as pressure on ureters by the gravid uterus and the muscle relaxant effect of progesterone, predisposes women with ABU to UTI. Women identified with ABU in early pregnancy have 20-30 fold increased risk of developing pyelonephritis during pregnancy, compared with women without bacteriuria. These women also are more likely to experience premature delivery and to have infants with low-birth weight.
SUBJECTS AND METHODS:
Study area The present prospective study was carried out in the clinical Microbiology laboratory of a tertiary care hospital, which is located in southern Odisha, India. The duration of the study was 6 months period from July 2012 to December 2012.
A total of 287 women in their first, second and third trimester of pregnancy, in the age group of 20-40 years who attended the antenatal clinic for the first time of our hospital were assessed for ABU. For asymptomatic pregnant women, bacteriuria is defined as two consecutive voided urine specimens with isolation of the same bacterial strain in quantitative counts ≥105 colony forming units per milliliter (cfu/mL).Inclusion criteria included those pregnant women who consented to give two consecutive urine samples on the first antenatal visit.
The data were analyzed using GraphPad Quick Calcs Statistical Software Inc., USA. Inferential statistics was done by Chi-square (χ2 ) test and a P < 0.05 was considered significant.
The mean age of antenatal women who attended antenatal clinic and participated the study was 25.87 (5.2) years (median 24, minimum 20 and maximum 40 years). Out of total 287 antenatal women examined for ABU, 33 were positive for significant bacteriuria; thus showed a prevalence of 11.5% (33/287). Table1 shows the socio-economic characteristics of the study subjects by age, level of education, socio-economic status, estimated gestational age and parity. Majority (241/287,84%) of subjects were between the age group of 20 and 30 years, showed a prevalence of 11.2%(27/241). Similarly, majority (54.4%, 156/287) of the subjects were multipara and presented in 2nd and 3rd trimester of pregnancy (61%).
Our study showed prevalence rate of ABU among antenatal women was 11.5%. Nitrofurantoin was the most effective antibiotic for both Gram-negative and Gram-positive bacteria with resistance rate of <10%. Therefore, it is important to screen all antenatal women with gold standard urine culture for significant bacteriuria during their 1st antenatal visit preferably at the end of 1st trimester. This should be followed with antibiotic susceptibility for determining therapy as inappropriate or no therapy has been responsible for recurrences of ABU and subsequent development of acute pyelonephritis. Thus empirical treatment of ABU may not apply for specific geographical regions, where decreased susceptibility rates to commonly used antibiotics have been documented for uropathogens.
Journal of Basic and Clinical Reproductive Sciences