Asymptomatic Bacteriuria Among Pregnant Women Attending Antenatal Clinic of General Hospital

Asymptomatic Bacteriuria Among Pregnant Women Attending Antenatal Clinic of General Hospital

ABSTRACT

Studies on asymptomatic bacteriuria among pregnant women attending antenatal clinic of the General Hospital Ekwulobia was undertaken, hundred urine samples were collected then centrifuged and 1 ml of the supernatant was inoculated on the prepared Nutrient Agar and Macconkey agar then incubated at 370c for 48 hours. Pure colonies were obtained by subculturing. Morphological and biochemical characterization of the isolates identified bacteria of the genera Staphylococcus, Streptococcus, Proteus and Escherichia. The result showed that 72(72%) of the pregnant women are asymptomatic. E. coli was sensitive to Reflacine but resistant to Tarivid, Staphylococcus aureus was sensitive to gentamicin and resistant to Nalidixic acid. There is a need for routine screening of urine of pregnant women as part of antenatal health care for pregnant women in Nigeria.

CHAPTER ONE

INTRODUCTION

Asymptomatic bacteriuria refers to the presence of bacteria in Urine. It is conduction in which urine reveals a significant growth of pathogens that is greater than 10⁵ bacteria/ml, but without the patient showing symptoms of urinary tract infection (UTI) (Gilbert et al; 2005).

This is common during pregnancy. The apparent reduction in immunity of pregnant women appears to encourage the growth of both commensal and non-commensal microorganisms (Scott et al; 1990).

The physiological increase in plasma volume during pregnancy decrease urine concentration and up to 70% of pregnant women develop glycosuria, which encourages bacteria growth in urine (Patterson et al; 1987 luces et al; 1993).

Pregnancy enhances the progression from asymptomatic bacteriuria which could lead to pyelonephritis and adverse obstetric outcomes such as prematurity, low birth weight (Connolly et al; 1999) and higher foetal mortality rates (Nicolle, 1994, Delzell et al; 2000) the adverse effects of undiagnosed asymptomatic bacteriuria on mother and child have made researchers to suggest routine culture screening for all pregnant women attending antenatal clinic (Kirlam, 2005) to prevent mother and child from any form of complication that may arise due to infection.

However, in many hospitals in developing countries including Nigeria, routine urine culture test is not carried out for antenatal patients. Probably due to cost implication and time factors for culture results (Usually 48 hour period) instead of many clinicians opt for the strip urinalysis method for accessing urine in pregnant women.

The true picture of such urine specimen cannot be fully accessed as the strip cannot qualify the extent of infection in such a patient as well as provide antimicrobial therapy which is usually seen in the case of culture test. In many health centres in developing countries. The attention of clinicians and health care providers is usually on the presence of glucose and protein in urine specimens with less attention on possible asymptomatic infection.

The incidence of asymptomatic bacteriuria is reported as 2-4% during pregnancy. Pregnant women and their unborn foetuses may be at risk of complications Guyton, 1996, Lindsay, 2003, Blumberg et al; 2005).

Quantitative criteria for identifying significant bacteriuria in an asymptomatic person is at least 100 CFU/mc of urine from a catheterized specimen (Warren et al; 1982, husky et al; 1987, saint et al; 2003). According to the infections disease society of America (IDSA) guideline. The diagnosis of asymptomatic bacteriuria in pregnant women is appropriate only if the same species is present in quantities at least 10 CFU/ml in at least two consecutive voided specimens (Nicolle, 2003, Nicolle et al; 2005).

AIM OF STUDY

Asymptomatic bacteriuria is common in pregnant women and if untreated could lead to serious complications. Although asymptomatic bacteriuria could also lead to such complications, this fact is not well known.

This study is to determine the prevalence of asymptomatic bacteriuria among pregnant women attending antenatal clinics at the General Hospital Ekwulobia.

SIGNIFICANCE OF STUDY

The importance of this study is to determine the bacterial load, kinds or species that would be recovered from urine samples of pregnant women attending antenatal at General Hospital Ekwulobia.

SCOPE OF STUDY

This study is therefore undertaken to determine the prevalence of asymptomatic bacteriuria in pregnant women attending antenatal clinic at General Hospital Ekwulobia and to identify the microorganism involved, determine their relative proportions and their antibiotic sensitivity.

CHAPTER TWO

LITERATURE REVIEW

PREVALENCE OF ASYMPTOMATIC BACTERIURIA IN PREGNANCY

Asymptomatic bacteriuria is common, with varying prevalence by age sex, sexual activity and prevalence of genitourinary abnormalities (Bakke, et al: 1999, Weities et al; 1993, Chaudhry et al (1993). Escherichia coli is the most common organism isolated from patients with asymptomatic bacteriuria.

Infecting organisms are diverse and include Enterobacteriaceae, Pseudomonas aeruginosa, Enterococcus species and the group of Streptococcus. Organisms isolated in patients with asymptomatic bacteriuria will be influenced by patient variables. A healthy person will likely have E. Coli, whereas a nursing home resident with a catheter is more likely to have multidrug-resistant polymicrobial flora (e.g P. aeruginosa).

Some studies have postulated that since asymptomatic bacteriuria, usually caused by aerobic gram-negative bacilli or staphylococcus haemolyticus can lead to urinary tract infection (UTI), a urine culture should be stained from all women early in pregnancy even in the absence of urinary tract infection symptoms (Connolly et al; 1999, Delzell et al; 2000).

In Ghana, Turpin et al; (2007) reported a prevalence of 7.3% at Komfo Anokye Teaching Hospital. The predominant organism were Escherichia coli and Staphylococcus aureus. Akerele et al; (2001) also reported 8.6.6% in Benin City. A prevalence rate of 7% in pregnant women has been reported in Ethiopia (Gebre-Selsassic 1998). In Canada, the prevalence rate varies from 4-7%. The prevalence is higher among individuals in lower socioeconomic classes and those with a history of asymptomatic urinary tract infection (Nicolle, 1994).

In Nigeria, Olusanya et al: (1993) reported a prevalence rate of 23.9% in Sagamu. Also in a research paper published by (Onyeagba et al; 2007) on asymptomatic bacteriuria among pregnant women attending antenatal in Abakaliki Ebonyi State, out of the 150 subjects screened 78.7% (118) had asymptomatic bacteriuria while 21.3%(32) had none. Thirty (30% )of the subjects had one type of bacteria. The frequency of isolation of bacteria. The frequency of isolation of organisms was Staphylococcus aureus (27.1%). Escherichia coli (25.2%), Klebsiella (23.7%), Proteus (10.2%), Streptococcus (8,.5%) and Pseudomonas aeruginosa (5.1%) pregnant women in their third trimester had the higher prevalence of asymptomatic bacteriuria (36.4%, the age group 31-35 years had the highest prevalence concerning age while farmers had the highest (90%) concerning the occupation.

More so, the incidence of asymptomatic bacteriuria in pregnant women attending antenatal clinic in Usmanu Danfodiyo University Teaching hospital Sokoto state revealed that (8.0%) was significant, mainly caused by Escherichia coli

PREDISPOSING FACTORS

The apparent reduction in immunity of pregnant women appears to encourage the growth of both commensal and non-commensal microorganisms (Scott et al; 1990). Other factors to be considered include, age of the mother, gestational age, socioeconomic factors ( occupation), parity, kidney transplant patients, pregnant mother, patients with cord injuries, Patients with indwelling urethral catheters.

In healthy women, the prevalence of bacteriuria increase with age, from 1% in females 5-14 years of age to more than 20% in women at least 80 years of age living in the community (Nicolle, 2003).

Studies of women with diabetes show no difference between initially asymptomatic bacteriuria and non-bacteriuria women in the incidence of urinary tract infection mortality progression to diabetic complications at 18 months or 14 years (semet Kowalska et al; 1995, Geerlings et al; 2001)

Patients with chronic indwelling foley catheters are uniformly bacteriuric, but catheters are warranted only if the patient is symptomatic (warren et al; 1982).

The highest prevalence of asymptomatic bacteriuria was observed among women in their third trimester (33.1%) and least in the first trimester (30.5%) (Onyeagba et al; 2007).

Also based on occupation, farmers had the highest prevalence of asymptomatic bacteriuria (90%). Olusanya et al; (1993) observed that most pregnant women with significant bacteriuria belong to a low socio-economic group.

SYMPTOMS

By definition, asymptomatic bacteriuria showing no symptoms. The symptoms of a urinary tract infection (UTI) include burning during urination, an increased urgency to urinate and an increase in the frequency of urination (Richard et al; 2006).

COMPLICATION OF ASYMPTOMATIC BACTERIURIA IN PREGNANCY

Acute pyelonephritis, foetal growth restriction and stillbirth in pregnant women have been associated with asymptomatic bacteriuria (Ryan et al; 1990, Zhao and Wu 2014, Hill et al; 2005).

Individuals in high risks group have a significant risk of progressing to a true kidney infection if a bacteria is not treated. In certain cases, such as renal transplant recipients, kidney infection may lead to loss of kidney functions (warren et al; 1999).

Women with asymptomatic bacteriuria during pregnancy are more likely to deliver premature or low-birth infants and have a 20 to 30 fold increase risk of developing pyelonephritis during pregnancy compared with women without bacteriuria (Kincaid et al; 1965).

EXPECTATION (PROGNOSIS)

Most pregnant women with asymptomatic bacteriuria who do not have risk factors for complications do extremely well and do not have any increased rates of symptoms, infection or decrease in kidney function or (Warren et al; 1999).

The prognosis for treatment in the high-risk group category is good if the infection is detected early, but the outlook depends on the asymptomatic person underlying conditions or illnesses.

TREATMENT OF ASYMPTOMATIC BACTERIURIA

Not all patients with asymptomatic bacteriuria respond to treatment or even need treatment. The infections disease society of America (IDSA) recommends a course of 3-7 days of antimicrobial therapy for pregnant women with asymptomatic bacteriuria (Nicole et al; 2005).

Because leucocyte esterase and nitrite test have low sensitivity for identifying bacteriuria in women who are pregnant, this patient should be screened with urine culture (Bachman et al; 1993). However, the optimal frequency of urine culture screening has not been established.

Single urine culture at the end of the first trimester generally is recommended based on clinical outcome and cost-effectiveness (Stenguist et al; 1989, Wadland et al; 1989).

Women with asymptomatic bacteriuria or asymptomatic urinary tract infection during pregnancy should be treated and should undergo periodic screening for the during of their pregnancy. Urine that is cloudy or foul-smelling often prompts a call from a long-term care facility to the physical with an expectation that an evaluation, if an antibiotic therapy, will be ordered.

However, in the asymptomatic patient cloudy or foul-smelling urine is not an indication for urinalysis, culture, or antimicrobial treatment. A study of residents in long-term care facilities with chronic indwelling catheters and bacteriuria who were treated with cephalexin (Keflex) or no therapy showed no difference in the incidence of fever or reinfection, however, patients who received antibiotic therapy had twice the incidence of subsequent microbial resistance to cephalexin (warren et al;1982). When possible, the indwelling catheter should be removed, and the patient should receive clean intermittent catheterization to reduce the risk of symptomatic urinary tract infection. The replacement of a chronic indwelling Foley catheter is associated with a low risk for bacteriuria and antimicrobial treatment or prophylaxis is not indicated for this procedure (Bregenzer et al; 1997). A study in young women with short term catheterization reported increased symptomatic infection over two weeks following catheter removal when asymptomatic bacteriuria persisted 48hours after the removal of the indwelling catheter (Harding et al; 1991).

According, the IDSA recommended that symptomatic bacteriuria should not be screened for or treated in patients with an indwelling urethral catheter, but that treatment of women with persistent catheter-acquired bacteriuria at least 48hours after catheter removal may be considered (Nicolle et al; 2005).

The presence of simultaneous pyuria does not warrant treatment by itself.

• Screening for asymptomatic bacterium with urine culture and treatment with antibiotics is recommended during pregnancy because it significantly reduces symptomatic urinary tract infections, low birth weight, and preterm delivery (Lin 2008, Small et al; 2007).
• This has not been proven for older people or people with diabetes, bladder catheters or spinal cord injuries (Colgan et al; 2005).
• Kidney transplant recipients children with vesicoureteral reflux or others with structural abnormalities of the urinary tracts, people with infected kidney stones and those who are having urological procedures might be more likely to benefit from treatment with antibiotics for asymptomatic bacteriuria (Nicolle et al; 2005).

DIAGNOSIS

Bacteria can be detected with a urine dipstick test for urinary microscopy, although bacterial culture remains the most specific and formal tact (the gold standard). Bacteriuria can be confirmed if a single bacterial species is isolated in a concentration greater than 100,000 colony-forming units per millilitre of urine in a clean-catch midstream urine specimen (one for men, two consecutive specimens with the same bacteriuria for women). For urine collected via bladder catheterization, the threshold is 100 colony-forming units of a single species per millilitre for women displaying urinary tract infection symptoms(sam et al;1991).