Alkaline peptone water enrichment with a dipstick test to quickly detect and monitor cholera outbreaks

Abstract

BackgroundDetection, confirmation and monitoring of cholera outbreaks in many developing countries including Uganda is a big challenge due to lack of the required resources and the time the test takes. Culture method which takes 24–48 h to get the feedback and requires highly skilled laboratory staff plus other complex resources is the standard test.This study evaluated the new cholera rapid detection method that relies on Crystal VC dipsticks after enrichment with alkaline peptone water (APW) against the culture method for monitoring the progress of cholera outbreaks in rural setting.MethodsWe conducted the study between March and June 2015. Fresh stool samples and rectal swabs were incubated in 1% APW for 6 h at room temperature before testing with RDT following the manufacturer’s instruction. The same stool sample was cultured to isolate V. cholerae in the standard manner. We also reviewed patient registers to epidemiologically describe the cholera epidemic.ResultsWe tested stool from 102 consenting suspected cholera patients reporting during daytime at Bwera Hospital (n = 69), Kilembe Mines Hospital (n = 4) and Kinyabwama Health Centre (n = 29). Ninety one (91) samples were positive and nine samples were negative according to both methods. One (1) sample was positive only by dipstick and one sample was positive only by culture (sensitivity of 99%, specificity of 90%, Positive Predictive Value of 99% and Negative Predictive Value of 90%). Overall, 146 suspected cholera cases and two deaths, (case fatality rate of 1.36%) were recorded during the study period. Among the cases aged 1–9 years, 63% (50/79) were males while in those aged 20–49 years, 76% (34/45) were females.ConclusionsOur findings showed that the modified dipstick test after enrichment with 1% APW had high level of accuracy in detection of V. cholerae and is quick, affordable alternative cholera outbreak monitoring tool in resource constrained settings. However, culture method should remain for cholera epidemic confirmation, for monitoring of antibiotic sensitivity and for production of pure isolates for molecular characterization. Further studies should be done to better understand the observed age and sex case distribution, in Kasese district.

Whole-genome sequence analysis of Vibrio cholerae from three outbreaks in Uganda, 2014 - 2016

“…Cholera remains a serious public health problem in Uganda and Africa as a whole 1,2 . It is characterized by a large disease burden, recurrent outbreaks, high case fatality rates, as well as tenacious endemicity 1,2 . Over the last four decades, Uganda has experienced several cholera outbreaks 2 .…”

“…It is characterized by a large disease burden, recurrent outbreaks, high case fatality rates, as well as tenacious endemicity 1,2 . Over the last four decades, Uganda has experienced several cholera outbreaks 2 . The detection, monitoring, and surveillance of cholera in Uganda rely upon the isolation of Vibrio cholerae using culture-based methods in microbiology laboratories 2,3 .…”

“…Over the last four decades, Uganda has experienced several cholera outbreaks 2 . The detection, monitoring, and surveillance of cholera in Uganda rely upon the isolation of Vibrio cholerae using culture-based methods in microbiology laboratories 2,3 . However, these methods are faced with several challenges, including: associated long turn-around times (24-48 hours); limited microbiology laboratory capacity; lack of laboratory supplies; poor laboratory infrastructure, particularly electricity necessary to operate laboratory equipment; as well as limited reliable and rapid diagnostic tests 2 .…”

Evaluation of the SD bioline cholera rapid diagnostic test during the 2016 cholera outbreak in Lusaka, Zambia

“…First, the sample size was limited, in particular for cholera‐confirmed cases, leading to wide confidence intervals in the estimates. Whereas studies set up in outbreak situations with comprehensive outbreak response measures often have limited sample sizes , larger sample sizes can be obtained in endemic settings . Alternately, performing meta‐analyses using data from different studies and settings with similar study methods might be another way forward to get better insights into the performance of these tests.…”

Comprehensive genomic analysis of Vibrio cholerae from three outbreaks in Uganda, 2014 - 2016

“…Cholera remains a serious public health problem in Uganda and Africa as a whole (1,2). In Uganda, the detection, monitoring, and surveillance of cholera rely upon the isolation of V. cholerae using culturebased methods (2).…”