Diagnostic accuracy of dipsticks test among clinically suspected urinary tract infected patients at National Hospital, Tanzania

Abstract

Background: Dipstick test is a rapid test for diagnosis of urinary track infections (UTIs). Rapid test should be accurate so that does not give a lot of false results that may subject patients to wrong treatments especially when used alone. Therefore, this study was set to determine the diagnostic performance of dipsticks tests by comparing with a standard urine culture Methods: Microbiological investigations of urine samples suspected of UTIs were performed at Central Pathology laboratory, Muhimbili National Hospital, Dar es Salaam. Dipsticks tests (leucocyte esterase and nitrite) were immediately performed from the submitted urine samples. Both positive and negative samples by dipsticks were subjected to quantitative urine culture using cysteine lactose electrolyte defi cient agar (CLED). Diagnostic performance such as sensitivity, specifi city and predictive values were determined by cross tabulation using GraphPad prisms whereas the distributions of the culture-isolated bacteria were expressed in frequency and percentage. Type 1 error for signifi cance was 0.05. Results:Overall 300 urine samples were simultaneously tested for dipsticks and urine culture. Of 300 urine samples, 218 (73%) tested dipsticks positive while 134 (45%) had signifi cant culture growth. Of 134 culture positive samples, Escherichia coli were mostly isolated by 47.4% while Proteus species were less isolated by 3.8%. Staphylococcus saprophyticus were the most isolated gram-positive bacteria by 6.3%. The sensitivity, specifi city, positive and negative predictive values of dipsticks tests were 56%[95%CI (confi dence interval); 49%-62%)], 85%(95%CI; 76%-91%), 91%(95%CI; 85%-95%) and 42%(95%CI; 35% -50%) respectively. The diagnostic accuracy of dipsticks test was 1 (p = 0.1213). Conclusion:The study found a moderate accuracy of dipsticks tests. Almost half of the patients diagnosed with UTIs by dipsticks tests were not found infected by urine cultures. The study recommends that, in resource available settings, urine culture should be done to confi rm the dipsticks tests results.

Evaluation of the Diagnostic Performance of the LINEAR Cromatest and Laboquick URS 10-T Dipsticks Among Urinary Tract Infection Suspects in Addis Ababa, Ethiopia: A Cross-Sectional Study

“…In this study, the SN, SP, PPV, and NPV of LINEAR Cromatest and Laboquick URS 10–10 dipsticks for leukocyte esterase, nitrite, and blood, individual parameters and in combination, were assessed. The current study contradicted a finding at National Hospital, Tanzania 12 revealing urine dipstick results of 56% SN and 85% SP and 91% PPV and 42% NPV. We reported better sensitivity through the utilization of leukocyte esterase, nitrites and blood used in combination with both LINEAR Cromatest and Laboquick URS 10–10 dipsticks, a finding supported by a study in Turkey 9 whereby a combination of leukocyte esterase, nitrite, and blood significantly improved the SN value from 65% to 80%.…”

“…In Ethiopia many health care set-ups utilize rapid dipstick analysis using leukocyte esterase, nitrites, and blood for screening purposes of UTI, but different studies revealed the poor SN and PPV of rapid dipstick tests to detect UTIs. 5,10,12,25,26 In this study, nitrite and blood dipstick found low SN and PPV that resulted in poor detection of culturepositive bacteriuria cases. Similarly, a study conducted in 2015 at the PSG Institute of Medical Sciences and Research, Coimbatore, Tamil Nadu, India showed that dipstick analysis in outpatient settings and primary health centers for firstlevel screening always needs to be correlated with a clinical presentation because the assay is not reliable for considering and predicting a definitive diagnosis of UTI.…”

“…10 On the positive side, the urine dipstick test is a user-friendly method to perform, is easier to interpret, has a short turnaround time, and has the potential of being applicable on a larger scale in different health settings. [10][11][12] An effort to establish an effective laboratory diagnosis, such as that of a urine dipstick, could provide great benefits, such as a rapid and inexpensive test that allows the practitioner to plan targeted, more effective therapy and indirectly reduce unnecessary time wastage and expense. 2 However, there is a paucity of data in our setting narrating the diagnostic effectiveness of such diagnostic tools.…”

The diagnostic accuracy of the point-of-care urine dipstick test in detecting urinary tract infection among symptomatic patients in Nairobi County, Kenya

“…In this study, consideration of urine dipstick positivity as 'either NIT+ or LE+' reported a positivity rate of 34%. This compares to prior dipstick positivity reports of 54% by Maina et al in a similar study in Kenya [11], 73% by Katunzi et al in Tanzania [20] and 34% by Dadzie et al in Ghana [17].…”

“…In this study, consideration of urine dipstick positivity as ‘either NIT+ or LE+’ reported a positivity rate of 34%. This compares to prior dipstick positivity reports of 54% by Maina et al in a similar study in Kenya[11], 73% by Katunzi et al in Tanzania[20] and 34% by Dadzie et al in Ghana[17]. Differences in the care setting and population-specific estimates have been cited as the main sources of heterogeneity of dipstick results between studies[21].…”