Cholera diagnosis in human stool and detection in water: A systematic review and meta-analysis

Abstract

Background Cholera continues to pose a problem for low-resource, fragile and humanitarian contexts. Evidence suggests that 2.86 million cholera cases and 95,000 deaths due to cholera are reported annually. Without quick and effective diagnosis and treatment, case-fatality may be 50%. In line with the priorities of the Global Task Force on Cholera Control, we undertook a systematic review and meta-analysis of diagnostic test accuracy and other test characteristics of current tests for cholera detection in stool and water. Methods We searched 11 bibliographic and grey literature databases. Data was extracted on test sensitivity, specificity and other product information. Meta-analyses of sensitivity and specificity were conducted for tests reported in three or more studies. Where fewer studies reported a test, estimates were summarised through narrative synthesis. Risk of Bias was assessed using QUADAS-2. Results Searches identified 6,637 records; 41 studies reporting on 28 tests were included. Twenty-two tests had both sensitivities and specificities reported above 95% by at least one study, but there was, overall, wide variation in reported diagnostic accuracy across studies. For the three tests where meta-analyses were possible the highest sensitivity meta-estimate was found in the Cholera Screen test (98.6%, CI: 94.7%-99.7%) and the highest specificity meta-estimate in the Crystal VC on enriched samples (98.3%, CI: 92.8%-99.6%). There was a general lack of evidence regarding field use of tests, but where presented this indicated trends for lower diagnostic accuracy in field settings, with lesser-trained staff, and without the additional process of sample enrichment. Where reported, mean test turnaround times ranged from over 50% to 130% longer than manufacturer’s specification. Most studies had a low to unclear risk of bias. Conclusions Currently available Rapid Diagnostic Tests can potentially provide high diagnostic and detection capability for cholera. However, stronger evidence is required regarding the conditions required to secure these levels of accuracy in field use, particularly in low-resource settings. Registration PROSPERO (CRD42016048428).

Cholera rages in Africa and the Middle East: A narrative review on challenges and solutions

“…Table 3 shows the characteristics of the most common RDTs, including their sensitivity and specificity. 135,143 T A B L E 3 Characteristics of most common RDTs for cholera diagnosis (adapted from Falconer et al 135 ). There are four main vaccines for the prevention of cholera in the market.…”

“…Table 3 shows the characteristics of the most common RDTs, including their sensitivity and specificity. 135 , 143 …”

“…These advantages of RDTs lead us to believe that they are more appropriate for use in refugee camps and impoverished regions of Africa and the Middle East. Table 3 shows the characteristics of the most common RDTs, including their sensitivity and specificity 135,143 …”

Vibrio cholerae: Epidemiology, Surveillance and Occurrence in Iraq

“…Culture should be on alkaline peptone water then streak on the media TCBS, or taurocholate-tellurite gelatin agar to grow the bacteria taken by the swabs. After initial culture in non-selective media, V. cholerae O1 and O139 detection must be confirmed by slide agglutination using specific monoclonal or polyclonal antibodies (Somboonwit et al 2017;Falconer et al 2022). However, the distinguishable darting motility of V. cholerae, which is inhibited by V. cholerae specific antibody, allows for rapid detection using dark field microscopy, which is only about 50% as sensitive as culture (Martinez et al 2010).…”

“…Unfortunately, there are currently a few tests available, including the the Sensitive Membrane Antigen Rapid Test, co-agglutination test, Medicos and the Institute Pasteur and Crystal VC rapid dipsticks. The use of PCR assays is restricted, and they are only performed in specialized labs (Falconer et al 2022).…”