Investigation of Uti in Pregnancy
Chapter One
OBJECTIVES OF THE RESEARCH
These objectives of this research are to;
- Investigate the Urinary tract infections in pregnancy.
- Investigate Urinary tract infections in relation to age distributions of pregnant women.
- Determine percentage of occurrence and distribution of bacterial pathogens in Urinary tract infections among pregnant women
CHAPTER TWO
LITERATURE REVIEW
CONCEPT OF URINARY TRACT INFECTION (UTI)
The urinary tract is a passage from the urethra to the kidneys. Any form of infection along this tract is referred to as urinary tract infection. It could be upper (pyelonephritis) or lower (cystitis) tract infection. In the kidney is called pyelonephritis; in the bladder, cystitis; and in the urethra, urethritis. Urinary tract infections may result from direct or indirect infection; direct infection involves introduction of microorganisms via the use of indwelling catheters, unhygienic practices or from sexual partners. Indirect infection may be from hematogenous spread of pathogenic organisms from other infected organs or tissues (Jawetz et al., 1982).
Blood, lymph and urethra are the three major routes by which bacteria can gain access to urinary tract. The heamatogenous and lymphatic routes are relatively uncommon. The primary route by which bacteria gain access to the urinary tract is the intraluminal ascent of the urethra. This ascent from the urethra to the bladder can be the result of bacteria migration, urinary uretho-vesical reflux or mechanical trauma. Poor micturition habits such as incomplete voiding or delayed urination can result in reflux or migration of bacterial to the bladder. Mechanical trauma such as insertion of the catheters or urethral milking which occurs during sexual intercourse, can also force bacteria into the bladder (Nicolle, 2005; Newman, 2010). With the exception of urethra, the urinary tract is sterile, the distal one third of the urethra, and in women, the vaginal vestibule is contaminated with enteric bacteria.
ETIOLOGY OF URINARY TRACT INFECTION
Urinary tract infection is usually caused by bacteria, particularly E.coli, which accounts for at least 80-90% of all urinary tract infections (McDowall, et al., 1981; Barr, et al., 1985; Patterson and Andriole, 1987), but also may be caused by other bacteria, viral, and fungal organisms. Klebsiella, Proteus, and Pseudomonas are commonly associated with urinary tract infection, particularly in recurrent cases (Aviva et al., 2010). Additionally pregnant women develop glycosuria, which encourages bacterial growth in the urine. These multiple factors contribute to the development of UTIs during pregnancy. The organisms that cause UTIs during pregnancy are the same as those found in non-pregnant patients. Urine itself is normally sterile, but the moist environment of the periurethral area, the proximity of the urethral orifice to the rectum, and the short length of the urethra provide a conducive environment for the growth and ascension of potential uropathogenic microorganisms into the urinary system.
The presence of bacteria in the urine is called bacteriuria. In non-pregnant women, bacteriuria in the absence of symptoms is not considered an indication for treatment; however, during pregnancy, bacteriuria is associated with increased risk of pyelonephritis as well as prematurity and possibly other complications and therefore, UTI in pregnancy requires special consideration (Lumbiganon et al., 2009). Cystitis often has a sudden onset. Pregnant women may present with contractions and suprapubic pain, with dysuria possibly having been mistaken for normal polyuria of pregnancy. Women with lower UTI often complain of feeling achy, crampy, or ‘just not feeling well.’ Pyelonephritis commonly has a gradual onset, although it can seem sudden if preceded by lower UTI, and is associated with not only urinary symptoms, but generalized symptoms such as fever, chills, nausea, malaise, and mild to extremely severe lower to middle back discomfort. Patients with pyelonephritis may appear quite ill. It is critical to differentiate between the symptoms of cystitis and pyelonephritis, as the latter requires more aggressive treatment and carries greater risks, particularly during pregnancy. Cystitis may resolve spontaneously; however, effective treatment lessens the duration of symptoms and reduces the incidence of progression to upper urinary tract infection as an ascending infection. Pyelonephritis is associated with substantial morbidity. Complications include acute papillary necrosis with possible development of urethral obstruction, septic shock, and perinephric abscess. Chronic pyelonephritis may lead to scarring with diminished renal function (Aviva et al., 2010).
INCIDENCE OF URINARY TRACT INFECTION
It is estimated that several hundred million women suffer from urinary tract infection annually, with costs to health care providers amounting to over $6 billion annually worldwide, a figure that may even be an underestimate (Aviva et al., 2010). Additional costs to society of urinary tract infections are tremendous in terms of the personal suffering of millions of women annually, lost work days, and childcare costs. Over 56% of women will experience a urinary tract infection in their lifetimes, and among those experiencing uncomplicated acute urinary tract infections, as many as 20% will have a recurrence within 6 months. Overall urinary tract infection recurrence rate is between 27% and 48% (Aviva et al., 2010). Even with treatment, symptoms typically last for an average of 6 days, with nearly 2.5 days of limited activity. The rates of urinary tract infection are slightly higher in the young, sexually active women because of factors affecting the urethra and the presence of uropathogenic organisms. Urinary tract infection rates increase during pregnancy and with age, the former because of mechanical pressure of the growing uterus on the ureters and bladder preventing complete voiding, and the latter because of declining estrogen levels, declining mucin (a surface coating of the bladder epithelium that prevents bacterial adhesion), inability to void completely, incontinence, inadequate nutrition, and the occurrence of other diseases and excessive catheter use as a result of medical procedures (Aviva et al., 2010).
CHAPTER THREE
MATERIALS AND METHODS
MATERIALS
Media
Bacteriological media used in this study include Cetrimide Agar, Cystine-LactoseElectrolyte-Deficient (C.L.E.D) agar, MacConkey Agar, Mannitol Salt Agar, Mueller Hilton Agar, Nutrient agar, Nutrient Broth all from Oxoid Ltd, U.K. Yeast Extract was from Biotech Laboratory Ltd., UK, while Peptone water was product from Fluka, Spain.
Antibiotic Disks
Antibiotic discs were obtained fron Oxoid Ltd, UK. They are:
Ampicillin (AMP) 10µg, Amoxicillin-clavulanic acid (AMT) 30µg, Cefotaxime
(CTX) 30µg, Cefpodoxime (CPD) 10µg, Ceftazidime (CAZ) 30µg, Ceftriaxone
(CRO) 30µg, Ciprofloxacin (CIP) 5µg, Co-trimoxazole (SXT) 25µg, Erythromycin
(E) 15µg, Gentamicin (CN) 10µg, Methicillin (MET) 5µg, Nitrofurantoin (F) 300µg, Ofloxacin (OFX) 5µg, Streptomycin (S) 10µg.
CHAPTER FOUR
RESULTS
INCIDENCE OF ASYMPTOMATIC BACTERIURIA
Questionnaires that were administered was used to identified Subjects that will be included in the sampling and the outcome was used in Tables 4.1 – 4.4
Out of 250 urine samples examined for asymptomatic bacteriuria, 146 were positive for significant bacteriuria (105cfu/ml) giving a prevalence rate of 58.4% among these pregnant women.
Total number of isolates obtained from the urine samples was 197. Most samples had more than one isolates but at most three.
CHAPTER FIVE
DISCUSSION
This study showed asymptomatic bacteriuria prevalence of 58.4% amongst the sampled population of 250 pregnant women attending ante-natal clinic. This level of prevalence is comparable to results of other researchers. Obiogbolu et al., 2009 reported a prevalence of 54% in a study carried out among 100 pregnant women in Akwa metropolice, South-eastern-Nigeria which is similar to the findings of Onifade et al, 2005, who found out that asymptomatic bacteriuria was present in 58% of 1,020 pregnant women sampled in Ondo State, South-western-Nigeria. However, these figures are substantially lower than the figure (86.6%) reported by Akerele et al, (2001) in a study on 500 pregnant women in Benin City, South-south-Nigeria although the number of samples diferred considerably in each study. The similarity of the result of this study to those of Obiogbolu et al., (2009) and Onifade et al., (2005) even though the studies were not done in the same area, could be due to increase in awareness and improved health facilities as well as the increase in the usage of antimicrobial agents as compared to the time when Akerele et al., (2001) carried out their investigation.
The findings that women in their second trimester had higher incidence of asymptomatic bacteriuria in this study (61.6%), is in agreement with the report of
Lindsay (2003), who attributed this high incidence to the increased gestational period. There is usually an increased hormonal activity with increase in gestational age, and this aids the growth of bacteria. It was not surprising that the age group of 31- ≥40 years had the highest incidence of asymptomatic bacteriuria since women in the age group (25-40) are more sexually active and multiparity is also a risk factor in acquiring asymptomatic bacteriuria (Antoni et al, 1997; Kumar et al, 2002; Obirikorang et al, 2012).
CHAPTER SIX
SUMMARY, CONCLUSION AND RECOMMENDATIONS
SUMMARY
This study was designed to determine the incidence of asymptomatic bacteriuria
(ASB) among pregnant women attending ante-natal clinics in Sabon-Gari LGA–Zaria, Nigeria. An incidence rate of 58.4% was found. This level of incidence is in consonance with findings from other parts of the country. Higher incidence was recorded among 31- ≥40 years age group and also among those who were in their second trimester.
The most common organisms isolated from asymptomatic bacteriuric pregnant subjects were Gram-negative bacteria, notably Klebsiella, Proteus, E. coli and Pseudomonas constituting 74.1%. Among the Gram-positive bacteria, Staph. aureus and Staph. xylosus were the most predominant. Further identification to specie level with API kits revealed the presence of E. coli (30.3%), Ent. cloacae (15.1%), Citro. freundii (6.1%), Citro. braakii (6.1%), and Kleb. pneumoniae (6.1%). Others are Staph. aureus (18%), Staph. xylosus (12.82%), Staph. lentus (7.7%), Staph. auriculous (5.1%), Staph. cohnii (2.56%) and Micrococcus (10.3%). Ps. aeruginosa (6.4%), Aeromonas aerohydrophila/caviae (2.4%), Ps. leutiola (0.8%), and Burkhol pseudomallei (0.8%)
Antimicrobial susceptibility test revealed varying susceptibility profiles for the isolates. Most Staphylococcus spp were only susceptible to ciprofloxacin, ofloxacin, nitrofurantoin, gentamicin and cotrimoxazole but resistant to other agents tested.
Escherichia spp isolates were moderately susceptible to (F), (CIP), (OFX), (SXT) and erythromycin and were resistant to other agents. Isolates of Proteus spp showed good susceptibility to OFX and CIP, F, CN and streptomycin, they were resistant to other agents. Similarly, isolates of Klebsiella spp were susceptible to OFX, CN, CIP, F and SXT.
MULTIPLEX PCR
Multiplex PCR showed that most of the test E.coli isolates harbour genes that encode for β-lactamase and ESBL as well as genes that code for resistance to β-lactam antibiotics. The detection of TEM, SHV, OXA-2 encoding genes (though they seem to be mutant strains) for resistance to ESBLs shows that these resistance determinants are found in our environment. These resistant traits call for surveillance in clinical settings because ESBLs gene is a world growing trait for resistance but its epidemiological effect and evaluation is still under estimated with low awareness.
RECOMMENDATIONS
- It has been reported that approximately 25-30% of asymptomatic bacteriuria in pregnancy will progress to symptomatic infection, which is 3-4 times as in non-pregnant women (Dominic, 2006), hence there is need for early routine screening of all antenatal patients presenting or not presenting with clinical symptoms of urinary tract infection in order to prevent adverse maternal and neonatal outcome.
- Proper routine bacterial culture test should be carried out by clinicians for their antenatal patients. The strip urinalysis method which is been utilized by most clinicians for assessing the urine of these pregnant women can not quantify the extent of infection as well as provide adequate antimicrobial therapy, so this should be discouraged in antenatal clinics. Asymptomatic bacteriuria occurs without the usual clinical symptoms of UTI, most of these pregnant women might be infected with some uropathogens without their knowledge; and this could lead to adverse maternal and neonatal outcome.
- Asymptomatic bacteriuria must be treated in pregnancy in order to prevent complications such as pyelonephritis, premature labour, still birth, hypertension, preeclampsia and septicemia. (Raz, 2003).
- Rational use of antibiotics should be encouraged in all antenatal clinics to help fight the war against the emergence and transmission of multiple antibiotic resistant strains.
- There is the need to improve patients record keeping in the Primary Health Care System. As at now, virtually no records of patients are being kept making it impossible for follow-up and monitoring of patients that may be placed on antibiotic therapy /management.
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