Authors	Year	Title	Methods, setting and study limitations	Results	Conclusion	Level of evidence
Leibovici-Weissman Y, Neuberger A, Bitterman R, et al. [1]	2014	Antimicrobial drugs for treating cholera (review)	•Systematic review and meta-analysis •All age ranges •Search included Cochrane, CENTRAL, PubMed, EMBASE, African Index Medicus, LILACS, Science Citation Index, metaRegister of Controlled Trials, WHO International Clinical Trials Registry Platform, conference proceedings and reference lists; to March 2014 •Selection criteria: Randomised and quasi-randomised controlled clinical trials in adults and children with cholera that compared: ◦Any antimicrobial treatment with placebo or no treatment; ◦Different antimicrobials head-to-head; or ◦Different dosing schedules or different durations of treatment with the same antimicrobial •Diarrhoea duration and stool volume were defined as primary outcomes •The mean difference (MD) or ratio of means (ROM) were calculated for continuous outcomes, with 95% CI and pooled data using a random-effects meta-analysis •The quality of evidence was assessed using the GRADE approach	•39 trials were included in this review with 4623 participants •Overall, antimicrobial therapy shortened the mean duration of diarrhoea by approximately 1.5 days compared with placebo or no treatment (MD 36.77 h, 95% CI −43.51 to −30.03, 19 trials, 1013 participants, moderate-quality evidence). •Antimicrobial therapy also reduced the total stool volume by 50% (ROM 0.5, 95% CI 0.45 to 0.56, 18 trials, 1042 participants, moderate-quality evidence) and reduced the amount of rehydration fluids required by 40% (ROM 0.60, 95% CI 0.53–0.68, 11 trials, 1201 participants, moderate-quality evidence) •The mean duration of faecal excretion of vibrios was reduced by almost 3 days (MD 2.74 days, 95% CI −3.07 to - 2.40, 12 trials, 740 participants, moderate-quality evidence) •There was substantial heterogeneity in the size of these benefits, probably owing to differences in the antibiotic used, the trial methods (particularly effective randomisation) and the timing of outcome assessment •The benefits of antibiotics were seen both in trials recruiting only patients with severe dehydration and in those recruiting patients with mixed levels of dehydration • Comparisons of antimicrobials: In head-to-head comparisons, no differences were detected in diarrhoea duration or stool volume for tetracycline compared with doxycycline (three trials, 230 participants, very low-quality evidence); or tetracycline compared with ciprofloxacin or norfloxacin (3 trials, 259 participants, moderate-quality evidence) •In indirect comparisons with substantially more trials, tetracycline appeared to have greater benefits than doxycycline, norfloxacin and trimethoprim-sulfamethoxazole for the primary review outcomes • Single-dose azithromycin shortened the duration of diarrhoea by over a day compared with ciprofloxacin (MD −32.43, 95% CI −62.90 to −1.95, two trials, 375 participants, moderate-quality evidence) and by half a day compared with erythromycin (MD −12.05, 95% CI - 22.02 to −2.08, two trials, 179 participants, moderate-quality evidence). It was not compared with tetracycline	•In treating cholera, antimicrobials result in substantial improvements in clinical and microbiological outcomes, with similar effects observed in severely and non-severely ill patients • Azithromycin and tetracycline may have some advantages over other antibiotics	B
Das J, Salam R, Bhutta Z [2]	2013	Antibiotics for the treatment of cholera, Shigella and Cryptosporidium in children	•Systematic review which included 2 studies from Bangladesh only •Children <16 years •Search covered PubMed, Cochrane, Embase and WHO Regional databases for literature published up to February 2012 to identify studies describing the effectiveness of antibiotics for the treatment of cholera in children ≤5 years; following CHERG systematic review guidelines •Additional studies were identified by hand-searching references from included studies •Search terms for cholera included combinations of ‘cholera’, ‘diarrhea’, ‘antibiotics’ •No language or date restrictions were applied •Inclusion criteria: Studies were included if they reported the effect of antibiotics on morbidity and mortality associated with diarrhoea owing to cholera in children, as observed by clinical and bacteriological failure and mortality •Only studies with a placebo group or no antibiotic control group were included •Only studies with a confirmed diagnosis of the infection and on immunocompetent patients were included	•374 titles were identified, 21 of which were reviewed and two included in the final dataset (the only two studies with a suitable control or placebo group assessing children up to 16 years of age). Both studies were RCTs conducted in Bangladesh (both hospital-based) •One trial compared erythromycin, ampicillin and tetracycline, and the other compared erythromycin and trimethoprim/sulfamethoxazole (TMP/SMX) against a placebo group •Antibiotics reduce clinical signs of 63% (CI 29–81%) of cholera cases, with a RR of 0.37 (0.19–0.71) •Antibiotics successfully cleared cholera pathogens in 75% (47–88%) of cases; RR 0.25 (0.12–0.53)	•‘Antibiotics for cholera reduce the clinical and bacteriological failure rates; however the evidence for reducing morbidity in children in insufficient to recommend antibiotic use in all cases’ •However: included studies were >10 years old and may not represent current AMR patterns •‘Although the evidence is weak as there are a few studies evaluated and more research is needed, we propose that antibiotics have a potential in moderate and severe Cholera’ •No adverse events were identified by any study	C
Chattaway M, Aboderin A, Fashae K, et al. [3]	2016	Fluoroquinolone-resistant enteric bacteria in sub-Saharan Africa: clones, implications and research needs	•Systematic review •Sub-Saharan Africa •All ages •Conducted according to PRISMA guidelines •Databases searched: PubMed, AJOL databases until October 2015. 43 studies met inclusion criteria, all from 17 African countries •The search retrieved articles focused on cholera as well as E. coli, other enterobacteriaceae and Campylobacter •6 papers were included which assessed resistance of cholera to fluoroquinolones •Fluoroquinolone resistance was defined as those with MIC above the CLSI breakpoints	•Despite toxigenic cholera strains becoming increasingly problematic across Africa in the past two decades, the authors note that fluoroquinolone resistance has been studied only recently •A study of the cholera outbreak in Nigeria/Cameroon in 2009 found resistance to nalidixic acid, and MICs to ciprofloxacin were 0.25–0.5 µg/mL (placing them in the susceptible category) •High levels of resistance to nalidixic acid or reduced susceptibility to ciprofloxacin in likely similar V. cholerae 01 clones causing epidemics in DRC and Kenya were also noted (Mercy et al., 2014; Miwanda et al., 2015; Table 1), but a lack of standard methodology for clonal analysis prevents an understanding of clonal spread across Africa	•Methods to identify fluroquinolone-resistant bacterial clones across Africa vary, making between-study and cross-country comparisons difficult •For toxigenic V. cholerae, serotyping and biotyping are only occasionally performed outside clinical reference laboratories •Resistance to nalidixic acid and susceptibility or reduced susceptibility to ciprofloxacin was reported in outbreaks in Africa in the past decade •Although ciprofloxacin has only reduced susceptibility in these strains and continues to be used for cholera management, if additional mutations occur in these circulating clones, resistance to ciprofloxacin may develop	C
Mahapatra T, Mahapatra S, Babu G, et al. [4]	2014	Cholera outbreaks in South and South-East Asia: descriptive analysis, 2003–2012.	•A descriptive analysis conducted following a systematic search •South and SE Asia •All ages •Review of information regarding the epidemiology of cholera outbreaks in South and Southeast Asia 2003–2012 •58 articles analysed, 8 reports and WHO databases •PubMed and Google Scholar were searched using MeSH terms cholera, disease, outbreaks •Included studies published 2003–2012	•66 articles met the inclusion criteria •113 cholera outbreaks were studied, 69% in South-east Asia (52% of which occurred in India), the remainder in Asia •Several genotypes and phenotypes were identified, including V. cholerae 01 E Tor (Ogawa and Inaba) and V. cholerae 0139 •3 studies (in Vietnam, Dhaka and Bangladesh) identified issues of multi-drug resistance, and the number of isolates with resistance was described as increasing [4–6]. These papers are discussed in the main paper (Antimicrobial resistance)	•Qualitative description of multi-drug resistance only; no quantitative data apart from individual laboratory analysis of antibiotic non-susceptibility (not clinically correlated)	D
Khan W, Saha D, Ahmed S, et al. [5]	2015	Efficacy of ciprofloxacin for treatment of cholera associated with diminished susceptibility of ciprofloxacin to Vibrio cholerae 01	•Adult male patients •Bangladesh •Assessed data from 4 clinical trials of antimicrobial agents in the treatment of cholera conducted between 1992 and 2005 were examined, comparing single or multiple-dose ciprofloxacin •Clinical cure was defined as cessation of watery stools within 48 h of initiation of antimicrobial therapy •Bacterial cure was defined as inability to isolate V. cholerae after 48 h of administration of study medication (single or multiple-dose ciprofloxacin) • V. cholerae were isolated and identified by standard microbiological techniques using disc-diffusion method using nalidixic acid and ciprofloxacin disks according to NCCLS/CLSI methods •Clinical response was compared with V. cholerae 01 susceptibility	•All 275 strains of V. cholerae 01 collected were susceptible to ciprofloxacin by MIC and disc diffusion testing using standard threshold criteria; however, the MIC 50 and MIC 90 for ciprofloxacin increased significantly during this period, from 0.002 μg/mL in 1994 to 0.250 μg/mL in 2003 (a 125-fold increase) and MIC 90 during the same period from 0.010 μg/mL to 0.250 μg/mL (a 25-fold increase) •During this period, all isolates also became resistant to nalidixic acid •Isolates resistant by disc-diffusion to nalidixic acid (n = 167) had a median ciprofloxacin MIC of 0.190 μg/mL (10th–90th centiles 0.022–0.380) compared with 0.002 μg/mL for nalidixic acid-susceptible (n = 38) isolates (10th–90th centiles 0.002–0.012) •Ciprofloxacin treatment was dramatically more effective in patients infected with nalidixic acid-susceptible strains of V. cholerae. The rate of clinical success was 95% compared with 27% in those infected with nalidixic acid-resistant isolates (p < 0.001) and the rate of bacteriological success was 97 vs 17% (p<0.001) •The group with infection resistant to nalidixic acid also fared worse on all secondary measures of disease outcome — diarrhoea duration, volume of stool and volume of fluids required •Single-dose ciprofloxacin was significantly inferior in treating patients with nalidixic acid-resistant V. cholerae infection: clinical success was achieved in only 18% of patients with nalidixic acid-resistant V. cholerae 01 infections treated with a single dose compared with 67%of those who received 3-day therapy	• V. cholerae 01 is becoming less susceptible to ciprofloxacin in Bangladesh (45-fold increase over 19 years covered in this study) • Current thresholds for determining antimicrobial susceptibility of V. cholerae to ciprofloxacin in vitro are not predictive of clinical response to therapy •Determining susceptibility to nalidixic acid using the disc diffusion method is a good screening tool for identifying V. cholerae 01 strains with diminished susceptibility to ciprofloxacin •Decreased resistance to fluoroquinolones is almost invariably associated with frank resistance to nalidixic acid, and usually results from a single mutation to the gyrA gene coding the enzyme-DNA gyrase, the target for the quinolones, although additional mutations (either in gyrA or other genes encoding fluoroquinolone targets) is required for frank resistance to fluoroquinolones. •The sub-optimal clinical response in patients infected with strains of V. cholerae 01 resistant to nalidixic acid and with diminished susceptibility to ciprofloxacin is worse with short-course therapy	B
Bhattaharya M, Kanungo S, Ramamurthy T, et al. [6]	2014	Comparison between single-dose azithromycin and six dose, 3 day norfloxacin for treatment of cholera in adults.Int J Biomed Sci. 2014;10:248–251. Publisjed 15 December 2014	•RCT •120 male adults •India •Patients with acute watery diarrhoea and mod-severe dehydration compared the efficacy of 1 g azithromycin (single dose) vs 400 mg norfloxacin bd for 3 days in Kolkata, India (Oct 2010–Feb 2012) •Data were analysed for 64 patients who were stool culture-positive for Vibrio cholera (large loss to follow-up)	•There were statistically insignificant differences between total stool output, total duration of diarrhoea after starting treatment, total fluid requirement and total urine output between the 2 treatment groups	•Azithromycin is as effective as norfloxacin (and may be clinically superior to norfloxacin owing to its single-dosing regimen)	C
Kaushik J, Gupta P, Faridi M, et al. [7]	2010	Single-dose azithromycin vs ciprofloxacin for cholera in children: a randomised controlled trial	•Open-labelled clinical controlled randomised trial •Children aged 2–12 years •Bangladesh •180 V. cholerae positive patients with watery diarrhoea for <24/24 and severe dehydration •Single dose azithromycin 20 mg/kg (n = 91) was compared with single-dose ciprofloxacin (20 mg/kg) (n = 89) •Clinical success defined as resolution of diarrhoea within 24 h •Bacteriological success defined as resolution of V. cholerae in the stool sample from day 3 onwards • Exclusion criteria: Children with severe malnutrition, coexisting systemic illness, blood in stool or having received treatment with an antibiotic within 24 h were excluded	•Frequency of stool and vomiting was significantly lower in children receiving azithromycin vs ciprofloxacin in the first 72 h •The rate of decline in frequency of stool and vomiting was comparable between treatment groups •Clinical success: ciprofloxacin 70.6%, azithromycin 95%, RR 1.33 (0.65–0.86, p<0.001) •Bacteriological success: ciprofloxacin 96%, azithromycin 100%, RR 1.04 (0.91–0.99, p = 0.06)	•Single-dose azithromycin is superior to single-dose ciprofloxacin for cholera in children •Clinical success was significantly greater in patients treated with azithromycin than in those treated with ciprofloxacin, although the rate of bacteriological success was comparable between the two groups •Those who received azithromycin had a shorter duration of diarrhoea (p<0.001), shorter excretion of V. cholerae (p<0.001) and lower requirement for IVF (p<0.001)	B
Saha D, Karim M, Khan W, et al. [8]	2006	Single-dose azithromycin for the treatment of cholera in adults	•Double-blind RCT comparing equivalence of azithromycin and ciprofloxacin (1 g) in 195 men with severe cholera caused by V. cholerae 01 or 0139 in Bangladesh •195 male adults •Bangladesh	•Clinical success in 73% of patients receiving azithromycin and 27% of patients receiving ciprofloxacin •Patients treated with azithromycin had a shorter duration of diarrhoea than patients treated with cipro (30 vs 78 h) and fewer stools (36 vs 52) •The median MIC of cipro for the 177 isolates of V. cholerae 01 was 0.25 μg/ml which was 11–83 times higher than in previous studies at this site	•Single-dose azithromycin was effective in treating severe cholera in adults •Single-dose ciprofloxacin is clinically and bacteriologically ineffective in cholera caused by strains of V. cholerae 01 which have diminished in vitro susceptibility to ciprofloxacin •The current thresholds of antimicrobial susceptibility to ciprofloxacin may be inappropriate for V. cholerae 01 •The lack of efficacy of ciprofloxacin may result from its diminished activity against V. cholerae 01 strains •Single-dose azithromycin is therefore established as an effective drug for the treatment of cholera caused by susceptible strains of V. cholearae in adults and children	C