|
|
||||
|
Published by : PROFESSIONAL MEDICAL PUBLICATIONS |
||||
|
ISSN 1681-715X |
||||
|
||||
|
- |
||||
|
ORIGINAL ARTICLE |
||||
|
- |
||||
|
Volume 22 |
April - June 2006 |
Number 2 |
||
|
|
||||
|
|
||||
|
|
||||
|
Published by : PROFESSIONAL MEDICAL PUBLICATIONS |
||||
|
ISSN 1681-715X |
||||
|
||||
|
- |
||||
|
ORIGINAL ARTICLE |
||||
|
- |
||||
|
Volume 22 |
April - June 2006 |
Number 2 |
||
|
|
||||
|
|
||||
Prevalence of Asymptomatic
Bacteriuria in Pregnant womenAziz Marjan Khattak1, Salim Khattak2, Habibullah Khan3,
Bushra Ashiq4, Dur Mohammad5, Mohammad Rafiq6ABSTRACT
Objective: To study the prevalence of asymptomatic bacteriuria (ASB) in pregnant women of local population in Karachi.
Design: Prospective, hospital based conducted during September 2001–March 2002.
Setting: Basic Medical Sciences Institute, Jinnah Postgraduate Medical Center Karachi.
Subjects and Methods: Group A (study group) consisted of 290 pregnant women attending the OPD of Gynaecology and Obstetrics units for antenatal check up and Group B (control) consisted of 70 nonpregnant women of fertile age. Midstream urine was collected and aerobically incubated at 37oC on CLED agar. Growth of >1x105 CFU/mL was taken as significant bacteriuria. Gram-negative bacteria were identified by API 20-E and gram-positive by standard routine methods.
Results: The two groups were age matched (P value>0.05). Prevalence of asymptomatic bacteriuria was 6.2% (18/290) in the study group and 2.85%( 2/70) in control group. E. coli was the common uropathogen in both groups and Staph. saprophyticus the second common only in-group A. Prevalence of ASB remained statistically the same in pregnant and nonpregnant women (P value >0.05) by x2 application.
Conclusion: Prevalence of ASB before pregnancy continues during pregnancy, if not treated. Uropathogens remain the same. All pregnant women should be screened for ASB by culture.
KEY WORDS: Asymptomatic bacteriuria, Pregnant women, Urine culture.
Pak J Med Sci April - June 2006 Vol. 22 No. 2 162 - 166
1. Aziz Marjan Khattak, M.Phil Microbiology
Assistant Professor Pathology.2. Salim Khattak FCPS Surgery,
Associate Professor3. Habibullah Khan MRCP Medicine,
Associate Professor1-3: Gomal Medical College,
Dera Ismail Khan, N.W.F.P.
4. Bushra Ashiq,
Professor, Microbiology
JPMC, Karachi5. Dur Mohammad M.Phil, Microbiology,
Demonstator,
Sindh Medical College, Karachi6. Mohammad Rafiq M.Phil, Microbiology,
M.O. Lawari Hospital, KarachiCorrespondences:
Dr. Aziz Marjan Khattak,
Assistant Professor of Pathology,
Gomal Medical College,
Dera Ismail Khan, N.W.F.P.* Received for Publication: April 11, 2005
Revision Received: November 23, 2005
Accepted: December 26, 2005
INTRODUCTION
Urine in bladder is normally sterile.
1 The presence of bacteria in urine is called bacteriuria.2 Asymptomatic bacteriuria (ASB) is bacteriuria3 without apparent symptoms of urinary tract infections (UTIs). The importance of ASB lies in the insight it provides into symptomatic infections.4Asymptomatic bacteriuria may exist for short term in non-pregnant women but rarely resolves spontaneously during pregnancy.
5 The prevalence of ASB does not change during pregnancy but there is change in pathogenesis, which keeps mother and baby at risk of complications due to bacteriuria.6 Symptomatic UTIs mostly occur later in pregnancy.7 ASB during pregnancy is an established risk for symptomatic UTI, premature delivery, intrauterine growth retardation, endometritis and even fatality for mother and baby.6,8,9 ASB may persist throughout pregnancy and cause complications even at the perinatal and postnatal period.9,10Screening for ASB has little apparent value in adults with exceptions before urologic surgery and during pregnancy.
11 A high co-relation has been found between a negative urine culture at early pregnancy and no bacteriuric complications later in pregnancy.7,8 By identification and appropriate treatment of patients at this stage of ASB, the complications in future can be prevented.12 The present study was designed to screen pregnant women for ASB, to ascertain its prevalence, and to observe the spectrum of urine isolates.SUBJECTS AND METHODS
Setting: This study was conducted in the Microbiology Department, Basic Medical Sciences Institute (BMSI), Jinnah Postgraduate Medical Centre (JPMC), Karachi, during September 2001 - March 2002. JPMC is a tertiary level major hospital in public sector, located in the center of Karachi. BMSI works as referral laboratory as well as a training institute for postgraduate students. The safe Motherhood and Neonatal Care Department is the Gynecological and Obstetrics wing of JPMC. It has two units providing free health services in the respective field round the clock. BMSI is closely situated to it.
Methods: Group A – study group subjects were 290 pregnant women with confirmed diagnosis of pregnancy of 12-26 weeks
8 attending the Gynecology/Obstetrics Outpatient Department. All women were of indigent population. They were interviewed and data recorded in proforma. Only those women were registered who fulfilled the criteria of apparently normal health without any signs of UTI except frequency.Group B – control group subjects were 70 females (married and unmarried) of fertile age 18-45 years in apparently normal health without signs and symptoms of UTI. They were either companion of pregnant women or else contacted via staff members and colleagues. Exclusion criteria were strictly observed.
Exclusion Criteria Women with:
1. Known congenital anomalies of urinary tract.
2. Signs and symptoms of UTI.
3. Pyrexia.
4. History of antibiotics during the previous two weeks.
5. Catheterization during past two weeks.Method of Specimen Collection: One sample of urine was collected in sterile wide mouth 100 ml capacity container with a cover.
13 Midstream voided urine 30-50 ml was requested.2 At least 4 hours stay of urine in bladder was ensured before collection.14 Instructions to women were explained for collection of the specimen. After collection and labeling the specimen, it was immediately transported and processed on the same day. In case of delay, specimen was refrigerated at 4°C.Processing of Specimen: Specimen was processed in the laboratory for (i) Physical and chemical examination. (ii) Microscopy for cells. (iii) Culture was done on CLED Agar, blood agar and MacConkey agar with the help of standardized platinum (2mm) loop. Half of plate was used for specimen inoculation. Incubation was done at 37°C aerobically for 18-24 hours. Inoculation from well-mixed specimen was performed first, followed by other procedures.
Definitions:
5 colony forming unit (CFU) per millilitre of one organism in a culture of clean voided midstream urine from a patient without fever or symptoms of UTI.6 * Asymptomatic bacteriuria was defined as the presence of >1x10
* Pure growth between >1x10
3 and <1x105CFU/ml was taken as doubtful significance and culture was repeated. Pure growth <1x103 CFU/ml was taken as growth of no significance.* Mixed growth of two or more organisms especially with gram positive bacilli Lactobacilli, Gardnerella vaginalis, Diphtherias, were considered to be urinary contamination.
14Identification of gram-positive organisms was done according to standard methods.
14 Gram-negative organisms were confirmed by system of API-20E.Statistical Applications: P values were read out from standard statistical tables with the help of t-values and degree of freedom. T-value was calculated by student "t" test formula for means ± standard deviations of ages. Chi-square (x
2) applied for t-value derivation for comparison of findings of two groups.RESULTS
The mean ages of pregnant women (Group A) and non-pregnant women (Group B) were 25.33±5.81 and 27.82±6.18 years respectively (Table-I), with the minimum age 18 years and maximum 44 years of group A. The two extremes of ages in group B were 19 and 42 years.
Table-II represents age-wise distribution of subjects in group A and group B. There were 199 subjects from group A in the age range of 18-25 years whereas 32 from group B, with means of ages 22±2.35 and 22.33±2.52 years respectively. In age range of 26-35 years and 36-45 years, the number of subjects with means of ages separately given. There is no statistical difference in the mean of ages of subjects in both groups (P>0.05).
Out of 290 pregnant women there were 18 samples of urine (6.20%) and only 2 cases out of 70 (2.85%) were positive for significant bacteriuria in group B. The number of positive cases in pregnant women and non-pregnant women did not show any statistical difference (P>0.05). Results are shown in Table-III and in Figure-1.
Among the significant positive cases of urine samples of pregnant women, the most frequent isolate was E. coli (38.89%), followed by S. saprophyticus and Enterobacter spp. each 16.68% (3 out of 18 isolates), while Staph. aureus, Strep. agalactiae, Proteus mirabilis, Serratia marcescens and C. albicans, each were 5.55% (one out of 18 isolates). Results are given in Table-IV and Figure-2. The two positive samples of urine were bacteriuric with E. coli in the control group.
DISCUSSION
The majority of infections in pregnancy are asymptomatic. Hence asymptomatic bacteriuria is also difficult to diagnose and it may persist throughout the pregnancy. The relative high prevalence of asymptomatic bacteriuria during pregnancy, its adverse consequences in women and for the pregnancy plus the ability to avoid sequelae with proper treatment justify screening pregnant women for bacteriuria.
6,8We screened pregnant as study and non-pregnant women as control for prevalence of asymptomatic bacteriuria. Both the groups were age-matched. The mean ± Standard Deviation (S.D.) of ages in study group was 25.33±5.81 which coincide with the study done by Bachman,
15 who showed mean ages of pregnant women as 28.2±4.5 years.In our study the prevalence of asymptomatic bacteriuria was found 6.2% in pregnant women. This finding is similar to 6% prevalence by Abyad (1991).
16 Findings of other authors were 5.6%,17 5.9%.7 Our results are lower than 10%,18 but higher than 2.3%.15 The prevalence 2.3% was found among the well educated and well status women but we, like Little,19 did not find difference in bacteriuria according to socio-economic status of subjects.The finding of ASB in non-pregnant healthy women (18-40 years) was 5%
20 but in our study it was 2.85%. The prevalence of bacteriuria in females varies from less than 1% in infants to 10% and more in older women.5 Our study represents no significant difference of ASB in pregnant and non-pregnant women. Our results are in agreement with Weissenbacher and Reisenberger5 who described that during pregnancy the prevalence of infection does not change, but there are some variations in the pathogenesis.In this study the etiologic agent E. coli (38.89%) in young women, was the most frequent uropathogen but it is different from other studies which have reported as 72%,
9 80%,11 and 60%.21 Nathaniel22 found E. coli to be 30% in non-pregnant fertile age, symptomatic women, of Karachi. The second most common urine isolate found by us was Staph. saprophyticus (16.68%), which is according to findings by Stamm and Hooton11 as 5-15% and by Nathenial22 as 17%. Bailey23 isolated 16.7% Staph. saprophyticus from urine of women of child-bearing age as 1st and Staph. epidermidis (9%) being the second most common uropathogen.Our study findings of Staph. saprophyticus being the second common urine isolate are similar to the findings of Masteron et al.
21 who reported K. pneumoniae as second common urine isolate (12.28%). There was great variation in distribution and frequency of the third common pathogen of urine isolates reported.9,21CONCLUSIONS
Our study showed 6.20% asymptomatic significant bacteriuria in pregnant women on screening by culture. There was no statistical difference in prevalence of asymptomatic bacteriuria in pregnant and non-pregnant women. Other studies with similar prevalence of asymptomatic bacteriuria suggest that screening of pregnant women should be done by culture. Organisms recovered in order of frequency were E. coli, Staph. saprophyticus and Enterobacter spp.
REFERENCES
1. Kass EH, Pyelonephritis and bacteriuria. A major problem in preventive medicine. Ann Intern Med 1962; 65(1): 46-53.
2. Whalley P. Bacteriuria of pregnancy. Am J Obstet Gynecol 1967; 97(5): 723-38.
3. Barr JG, Ritchie JWK, Henry O, Sheikh MEL, Deeb KEL Microaerophilic/anaerobic bacteria as a cause of urinary tract infection in pregnancy. Br J Obstet Gynecol 1985; 92:506-10.
4. Nicolle LE. Asymptomatic bacteriuria in the elderly. Infect Dis Clin N Amer 1997; 11(3): 647-62.
5. Weissenbacher ER, Reisenberger K. Uncomplicated urinary tract infections in pregnant and non- pregnant women. Curr Opin Obstet Gynecol 1993; 5(4): 513-6.
6. Delzell JE, Lefevre ML. Urinary tract infections during pregnancy. Am Fam Physician 2000; 61:713-21.
7. Golan A, Wexler S, Amit A, Gordon D, David MP. Asymptomatic bacteriuria in normal and high-risk pregnancy. Eur J Obstet Gynecol Rep Biol 1989; 33: 202-8.
8. U.S. Preventive Services Task Force. Guide to clinical preventive services. 2d ed. Washington, DC. Office of Disease Prevention and Health Promotion, 1996.
9. Bailey RR. Single dose antibacterial treatment for bacteriuria in pregnancy. Drugs 1984; 27:183-6.
10. Monif GR. Intrapartum bacteriuria and postpartum endometritis. Obstet Gynecol 1991; 78:245-8.
11. Stamm WE, Hooton TM. Management of urinary tract infections in adults. N Engl J Med 1993; 329(18): 1328-34.
12. Hohnson K. Unchecked bacteriuria can cause preterm labor, organ failure. Obstet Gynecol News. Int Med News Group 2000.
13. Avorn J, Monane M, Gurwitz JH, Glynn RJ, Choodnovskly I, Lipsitz LA. Reduction of bacteriuria and pyuria after ingestion of cranberry juice. JAMA 1994; 271(10): 751-4.
14. Cheesbrough M. Microbiological Tests In: District Laboratory Practice in Tropical Countries. 3rd Edition. Great Britain, Cambridge University Press 2000; 266.
15. Bachman JW, Heise RH, Naessens JM, Timmerman MG. A study of various tests to detect asymptomatic urinary tract infections in an obstetric population. JAMA1993; 270(16): 1971-4.
16. Abyad A Screening for asymptomatic bacteriuria in pregnancy: urinalysis versus urine culture. J Fam Pract 1991; 33:471-4.
17. Harris RE. The significance of eradication of Bacteriuria during pregnancy. Gynecol 1979; 53(1): 71-3.
18. McDowall DRM, Buchanan JD, Fairley KF, Gilbert GL. Anaerobic and other fastidious micro-organisms in asymptomatic bacteriuria in pregnant women. J Infect Dis 1981; 144(2): 114-22.
19. Little PJ. The incidence of urinary infection in 5000 pregnant women. Lancet 1966:925-8.
20. Hooton TM, Scholes D, Stapleton AE, Roberts PL, Winter MSC, et al. A prospective study of asymptomatic bacteriuria in sexually active young women. N Engl J Med 2000; 343(14): 992-7.
21. Masterton RG, Evans DC, Strike PW. Single dose amoxicillin in the treatment of bacteriuria in pregnancy and the puerperium: a controlled clinical trial. Br J Obstet Gynecol 1985; 92: 498-505.
22. Nathaniel E. Urinary tract infection in females of child-bearing age group, caused by Staphylococcus saprophyticus. Thesis Karachi University 1985; pp 20-22.
23. Bailey RR. Significance of coagulase negative Staphylococcus in urine. J Infect Dis 1973; 127:179-82.
HOME | SEARCH | CURRENT ISSUE | PAST ISSUES
Professional
Medical Publications
Room No. 522, 5th Floor, Panorama Centre
Building No. 2, P.O. Box 8766, Saddar, Karachi - Pakistan.
Phones : 5688791, 5689285 Fax : 5689860
pjms@pjms.com.pk
