Study design
A cross sectional study was conducted from 16th April 2018 to 10th September 2018 at the Tamale Teaching Hospital (TTH) and Tamale Central hospital (TCH). The Tamale Teaching Hospital is an 800 bed capacity tertiary care facility which provides referral services to three Regions in the northern sector of Ghana and affiliated to the Medical School of the University for Development Studies. The Tamale Central Hospital is a secondary care facility which supports the teaching hospital in providing healthcare services to the populace in Tamale and its environs.
Recruitment of study participants
A total of 530 pregnant women of all ages attending these hospitals for antenatal care within the study period were recruited. Informed consent was sought from all the women before enrollment. Attendees who refused consent were excluded from the study. Socio-demographic information and diagnosis were obtained from the laboratory report form and their medical folders.
Specimen collection and processing
Pregnant women were provided with sterile urine containers and tutored on how to collect midstream urine. Approximately 10mls of urine were collected from each participant. The urine samples were transported to the Spanish laboratory of the University for Development Studies for processing and analysis, within four hours of collection.
Urine microscopy
About 5 mL of adequately mixed urine sample was centrifuged at 3000 rpm for 10 min. A drop of the sediment was placed on a glass slide, cover slipped and examined under the microscope to detect pus cells, red blood cells, casts and crystals. The presence of 10 or more pus cells/high-power field (HPF) was indicative of pyuria. Sterile pyuria in this study was defined as specimens scoring 10 or more pus cells but recorded no growth on CLED plates after adequate incubation period of 24hrs.
Urine culture and identification
Urine samples were cultured on cysteine lactose electrolyte deficient agar (CLED) using a standardized (0.01mL) wire loop. The plates were incubated at 37°C and read after 24 hours for significant bacteriuria. Significant bacteriuria was defined as a quantitative count of ≥105CFU/ml. Pathogens were identified using standardized biochemical tests, Mannitol salt agar and sugar fermentation using Triple Sugar Iron agar from 24h pure culture colonies. Asymptomatic bacteriuria in this study was considered when the bacterial value was ≥105 but participants had no symptoms of acute urinary tract infections.
Antibiotic susceptibility test
Antibiotic susceptibility tests were conducted using Kirby Bauer disc diffusion method. Mueller-Hinton agar plates were inoculated with 0.5 McFarland standard saline suspension and incubated at 37°C for 24hours [21]. The antibiotics analysed included, ciprofloxacin 10µg, gentamicin 10 µg, erythromycin 15 µg, ceftriaxone 30 µg, chloramphenicol 30 µg, nitrofurantoin 50 µg, tetracycline 30 µg, ampicillin 10 µg, clindamycin 10 µg, vancomycin 30 µg, cefoxitin 30 µg, amikacin 30 µg, trimethoprim-sulfamethoxazole 25 µg, imipenem 10 µg, amoxacillin clavulanic acid 30 µg and norfloxacin 10 µg. The recorded inhibition zones were interpreted using CLSI breakpoints. Quality control strains of Escherichia coli (ATCC 25922) and Staphylococcus aureus (ATCC 25923) were used. Multidrug resistance in this study was defined as resistance of isolates to three (3) or more classes of antibiotics.
Data management
Collected data was analysed by descriptive statistics using frequencies and percentages using IMB SPSS version 20. Results were presented in tables. Associations between categorical outcome variables were conducted using the Pearson- Chi square test at the 95% confidence level. A two tailed p-value of <0.05 was considered statistically significant.
Ethical consideration
Ethics approval was obtained from the Ethical Review Committee of the Tamale Teaching Hospital (TTHERC/25/06/19/14).Verbal informed consent was sought from the pregnant women after sufficient information regarding the study was provided. This is because while some of the women were unable to read and write others felt reluctant to write and saw the process as a bother.