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Journal of Travel Medicine Dec 2019Exposure to cholera is a risk for individuals and groups travelling to endemic areas, and the bacteria can be imported to cholera-free countries by returning travellers....
Exposure to cholera is a risk for individuals and groups travelling to endemic areas, and the bacteria can be imported to cholera-free countries by returning travellers. This systematic review of the literature describes the circumstances in which cholera infection can occur in travellers and considers the possible value of the cholera vaccine for prevention in travellers. PubMed and EMBASE were searched for case reports of cholera or diarrhoea among travellers, with date limits of 1 January 1990-30 April 2018. Search results were screened to exclude the following articles: diarrhoea not caused by cholera, cholera in animals, intentional cholera infection in humans, non-English articles and publications on epidemics that did not report clinical details of individual cases and publications of cases pre-dating 1990. Articles were reviewed through descriptive analytic methods and information summarized. We identified 156 cases of cholera imported as a consequence of travel, and these were reviewed for type of traveller, source country, serogroup of cholera, treatment and outcomes. The case reports retrieved in the search did not report consistent levels of detail, making it difficult to synthesize data across reports and draw firm conclusions from the data. This clinical review sheds light on the paucity of actionable published data regarding the risk of cholera in travellers and identifies a number of gaps that should drive additional effort. Further information is needed to better inform evidence-based disease prevention strategies, including vaccination for travellers visiting areas of cholera risk. Modifications to current vaccination recommendations to include or exclude current or additional traveller populations may be considered as additional risk data become available. The protocol for this systematic review is registered with PROSPERO (registration number: 122797).
Topics: Cholera; Cholera Vaccines; Humans; Travel; Vaccination
PubMed: 31804684
DOI: 10.1093/jtm/taz085 -
PloS One 2019Vibrio vulnificus necrotizing skin and soft tissue infections (VNSSTIs) are associated with a high mortality rate that varies remarkably with host susceptibility.... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Vibrio vulnificus necrotizing skin and soft tissue infections (VNSSTIs) are associated with a high mortality rate that varies remarkably with host susceptibility. Hepatic disease (HD) is considered the key risk factor for high VNSSTIs incidence and mortality; however, there is limited evidence in the literature to support this observation.
METHODOLOGY
We examined all reported cases of VNSSTIs and associated mortality rates between 1966 and mid-2018. The PubMed, Medline and Cochrane Library databases were systematically searched for observational studies on patients with VNSSTIs. Twelve studies with 1157 total patients with VNSSTIs were included in the analysis. From the pooled dataset, nearly half (46.8%) of the patients with VNSSTIs had HD. The mortality rate in HD patients with VNSSTIs was 53.9% (n = 292/542), which was considerably higher than the mortality rate of 16.1% (n = 99/615) in non-HD patients. Patients with HD contracted VNSSTIs were found to be two or more times (RR = 2.61, 95% CI = 2.14-3.19) as likely to die compared with those without HD. Besides, liver cirrhosis (LC), the end-stage HD, was confirmed to be a significant risk factor, with risk ratios of 1.84 (95% CI 1.21-2.79) and 2.00 (95% CI 1.41-2.85) when compared to non-LC and non-HD, respectively.
CONCLUSIONS
HD with or without LC can be associated with infections and complications from V. vulnificus. Clinicians should aggressively approach care and management of acutely and/or critically ill patients with VNSSTIs.
Topics: Humans; Incidence; Liver Diseases; Mortality; Odds Ratio; Skin Diseases, Bacterial; Soft Tissue Infections; Vibrio Infections; Vibrio vulnificus
PubMed: 31652263
DOI: 10.1371/journal.pone.0223513 -
International Journal of Infectious... Dec 2019Epidemic intelligence (EI) for emerging infections is the process of identifying key information on emerging infectious diseases and specific incidents. Automated...
BACKGROUND
Epidemic intelligence (EI) for emerging infections is the process of identifying key information on emerging infectious diseases and specific incidents. Automated web-based infectious disease surveillance technologies are available; however, human input is still needed to review, validate, and interpret these sources. In this study, entries captured by Public Health England's (PHE) manual event-based EI system were examined to inform future intelligence gathering activities.
METHODS
A descriptive analysis of unique events captured in a database between 2013 and 2017 was conducted. The top five diseases in terms of the number of entries were described in depth to determine the effectiveness of PHE's EI surveillance system compared to other sources.
RESULTS
Between 2013 and 2017, a total of 22 847 unique entries were added to the database. The top three initial and definitive information sources varied considerably by disease. Ebola entries dominated the database, making up 23.7% of the total, followed by Zika (11.8%), Middle East respiratory syndrome (6.7%), cholera (5.5%), and yellow fever and undiagnosed morbidity (both 3.3%). Initial reports of major outbreaks due to the top five disease agents were picked up through the manual system prior to being publicly reported by official sources.
CONCLUSIONS
PHE's manual EI process quickly and accurately detected global public health threats at the earliest stages and allowed for monitoring of events as they evolved.
Topics: Cholera; Communicable Diseases, Emerging; Coronavirus Infections; Disease Outbreaks; Epidemiological Monitoring; Hemorrhagic Fever, Ebola; Humans; Intelligence; Public Health; Yellow Fever; Zika Virus Infection
PubMed: 31629079
DOI: 10.1016/j.ijid.2019.10.011 -
Vaccine Feb 2020Development of oral cholera vaccines (OCVs) experienced exciting times over the last two decades. A two-dose OCV, found efficacious through field trials, has obtained...
Development of oral cholera vaccines (OCVs) experienced exciting times over the last two decades. A two-dose OCV, found efficacious through field trials, has obtained license for use in India. However, the current policy discussion revolves around 'to use or not to use' this vaccine covering entire population in the country, which has its own cost implications. We conducted a systematic review to address this conundrum. The disease burden and distribution, potential impact, programmatic issues, and competing priorities were kept in consideration. Peer reviewed articles and 'Integrated Disease Surveillance Program' data, generated by Government of India, were accessed. Our synthesis highlights that cholera burden estimates for India have been hamstrung by their extrapolation from a single incidence study conducted in Kolkata. Heterogeneity of 685 Indian districts regarding vulnerability to cholera is also obvious. Analysis of outbreak reports indicated that some settlements and sub-populations were more vulnerable to diarrhea/cholera than others. Infrastructure failure leading to contamination of drinking water and behavioral issues were of concern. Investment in safe water, sanitation and hygiene (WASH) and addressing inequity of health services pertaining to vulnerable population groups are the needs of the hour. OCV could play an important role as one of the elements in such multi-component cholera prevention effort. OCV administration through public health system in Odisha identified logistic challenges, with low uptake of the second dose at 46%, while 61% of the target population received the first dose. We identified accumulating global evidence on the advantage and efficacy of single-dose based approach, where the same OCV, as licensed in India, was used. The short-lasting nature of cholera outbreaks in India also argue in favor of such pragmatism. Failure to implement multi-component prevention strategy today runs the risk of perpetuating inequity, recurring cholera outbreaks in future, and its retinue of costs.
Topics: Administration, Oral; Cholera; Cholera Vaccines; Disease Outbreaks; Health Policy; Humans; India; Vaccination Coverage
PubMed: 31405636
DOI: 10.1016/j.vaccine.2019.07.029 -
Tropical Medicine & International... Oct 2019Uncertainty persists regarding cholera transmission routes. We conducted a structured review of case-control studies on cholera transmission and provide a qualitative...
OBJECTIVE
Uncertainty persists regarding cholera transmission routes. We conducted a structured review of case-control studies on cholera transmission and provide a qualitative summary of reported exposures in order to inform public health efforts and future cholera research.
METHODS
We searched two electronic databases for published case-control studies that investigated risk factors for cholera and included any publications that did not match our exclusion criteria. From the included studies, we grouped exposures using two parameters, whether transmission domain was public or domestic, and also on the vehicle of transmission. We extracted data on study location, method of case and control inclusion, type of statistical analysis performed and which exposures were included. Additionally, two parallel subgroup analyses were performed. The first included the subgroup of all studies that used culture-confirmed cholera cases, and the second included the subgroup of all studies employing a multivariate analysis. In the second analysis, we calculated the population attributable risk (PAR).
RESULTS
Our search yielded 2347 peer-reviewed publications, of which 65 did not match our exclusion criteria, comprising 69 individual studies. Water-based exposures were investigated in 97% of these studies, of which 70% found a significant association with cholera infection. Food-based exposures were investigated in 75% of studies, of which 63% found a significant association with risk of cholera infection. Close personal contact with cholera cases was investigated in 30% of studies, of which 52% found a significant association with risk of cholera infection. Hygiene-related exposures were investigated in 51% of studies, of which 63% found a significant association with cholera transmission. Among studies that examined at least one exposure related to the domestic domain, 76% found a significant association with cholera infection vs. 71% of studies investigating at least one public domain exposure. The subgroup analyses produced similar results.
CONCLUSIONS
Despite strong evidence for cholera transmission via foodborne-, hygiene-, waterborne- and close personal contact-related pathways in both domestic and public domains, we found that non-waterborne-related factors are understudied. Future cholera case-control studies would benefit from investigating all transmission vehicles and transmission domains.
Topics: Case-Control Studies; Cholera; Disease Outbreaks; Family Characteristics; Humans
PubMed: 31343805
DOI: 10.1111/tmi.13293 -
Annali Di Igiene : Medicina Preventiva... 2019Cholera, an acute diarrheal disease caused by Vibrio cholerae (V. cholerae), is an endemic disease and a major public health problem in Iran. Antibiotic therapy can... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Cholera, an acute diarrheal disease caused by Vibrio cholerae (V. cholerae), is an endemic disease and a major public health problem in Iran. Antibiotic therapy can decrease duration of the disease, transmission of infection and contamination of the environment. Considering different pattern of V. cholerae antibiotic resistance around the world, the aim of the current systematic review and meta-analysis was to evaluate the prevalence of antibiotic resistance of V. cholerae in Iran.
METHODS
A systematic review of the literature was performed using related keywords in the electronic national and international databases including SID, Irandoc, Iran Medex and Magiran as well as PubMed, Scopus, Google Scholar and ISI web of knowledge. Up to July 31, 2018, 27 eligible papers were included in our meta-analysis based on the defined inclusion criteria.
RESULTS
V. cholerae O1 was the most prevalent strain isolated in Iran and exhibited a high resistance rate against numerous antibiotics including chloramphenicol (33.6%), oxytetracycline (40.2%), trimethoprim/sulphamethoxazole (86%), tetracycline (34.5%), furazolidone (69.8%), streptomycin (93.8%), polymyxin (80.7%), ampicillin (32.1%), nalidixic acid (88.9%), kanamycin (29%) and amoxicillin (30.5%).
CONCLUSIONS
According to the meta-analysis results, antibiotic therapy with ciprofloxacin, doxycycline, erythromycin, gentamicin, azithromycin, cefixime and cefepime could be effective for the treatment of severe cases of cholera in Iran.
Topics: Anti-Bacterial Agents; Cholera; Drug Resistance, Microbial; Drug Resistance, Multiple, Bacterial; Humans; Iran; Vibrio cholerae; Vibrio cholerae O1
PubMed: 31069372
DOI: 10.7416/ai.2019.229 -
The Lancet. Infectious Diseases Feb 2019Oral vaccines underperform in low-income and middle-income countries compared with in high-income countries. Whether interventions can improve oral vaccine performance... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Oral vaccines underperform in low-income and middle-income countries compared with in high-income countries. Whether interventions can improve oral vaccine performance is uncertain.
METHODS
We did a systematic review and meta-analysis of interventions designed to increase oral vaccine efficacy or immunogenicity. We searched Ovid-MEDLINE and Embase for trials published until Oct 23, 2017. Inclusion criteria for meta-analysis were two or more studies per intervention category and available seroconversion data. We did random-effects meta-analyses to produce summary relative risk (RR) estimates. This study is registered with PROSPERO (CRD42017060608).
FINDINGS
Of 2843 studies identified, 87 were eligible for qualitative synthesis and 66 for meta-analysis. 22 different interventions were assessed for oral poliovirus vaccine (OPV), oral rotavirus vaccine (RVV), oral cholera vaccine (OCV), and oral typhoid vaccines. There was generally high heterogeneity. Seroconversion to RVV was significantly increased by delaying the first RVV dose by 4 weeks (RR 1·37, 95% CI 1·16-1·62) and OPV seroconversion was increased with monovalent or bivalent OPV compared with trivalent OPV (RR 1·51, 95% CI 1·20-1·91). There was some evidence that separating RVV and OPV increased RVV seroconversion (RR 1·21, 95% CI 1·00-1·47) and that higher vaccine inoculum improved OCV seroconversion (RR 1·12, 95% CI 1·00-1·26). There was no evidence of effect for anthelmintics, antibiotics, probiotics, zinc, vitamin A, withholding breastfeeding, extra doses, or vaccine buffering.
INTERPRETATION
Most strategies did not improve oral vaccine performance. Delaying RVV and reducing OPV valence should be considered within immunisation programmes to reduce global enteric disease. New strategies to address the gap in oral vaccine efficacy are urgently required.
FUNDING
Wellcome Trust, Bill & Melinda Gates Foundation, UK Medical Research Council, and WHO Polio Research Committee.
Topics: Administration, Oral; Adolescent; Adult; Child; Child, Preschool; Cholera; Cholera Vaccines; Female; Humans; Immunogenicity, Vaccine; Infant; Infant, Newborn; Male; Poliomyelitis; Poliovirus; Poliovirus Vaccine, Oral; Rotavirus; Rotavirus Infections; Rotavirus Vaccines; Salmonella typhi; Seroconversion; Treatment Outcome; Typhoid Fever; Typhoid-Paratyphoid Vaccines; Vaccination; Vibrio cholerae; Young Adult
PubMed: 30712836
DOI: 10.1016/S1473-3099(18)30602-9 -
The Journal of Infectious Diseases Oct 2018Water, sanitation, and hygiene are one part of a cholera control strategy. Household water treatment (HWT) in particular has been shown to improve the microbiological...
Water, sanitation, and hygiene are one part of a cholera control strategy. Household water treatment (HWT) in particular has been shown to improve the microbiological quality of stored water and reduce the disease burden. We conducted a systematic review of published and gray literature to determine the outcomes and impacts of HWT in preventing cholera specifically. Fourteen manuscripts with 18 evaluations of HWT interventions in cholera were identified. Overall, a moderate quality of evidence suggests that HWT interventions reduce the burden of disease in cholera outbreaks and the risk of disease transmission. Appropriate training for users and community health worker follow-up are necessary for use. Barriers to uptake include taste and odor concerns, and facilitators include prior exposure, ease of use, and links to preexisting development programming. Further research on local barriers and facilitators, HWT filters, scaling up existing development programs, program sustainability, integrating HWT and oral cholera vaccine, and monitoring in low-access emergencies is recommended.
Topics: Cholera; Disease Outbreaks; Humans; Hygiene; Sanitation; Water; Water Purification
PubMed: 30215739
DOI: 10.1093/infdis/jiy488 -
The Journal of Infectious Diseases Oct 2018Cholera has caused 7 global pandemics, including the current one which has been ongoing since 1961. A systematic review of risk factors for symptomatic cholera infection... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Cholera has caused 7 global pandemics, including the current one which has been ongoing since 1961. A systematic review of risk factors for symptomatic cholera infection has not been previously published.
METHODS
In accordance with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, we performed a systematic review and meta-analysis of individual and household risk factors for symptomatic cholera infection.
RESULTS
We identified 110 studies eligible for inclusion in qualitative synthesis. Factors associated with symptomatic cholera that were eligible for meta-analysis included education less than secondary level (summary odds ratio [SOR], 2.64; 95% confidence interval [CI], 1.41-4.92; I2 = 8%), unimproved water source (SOR, 3.48; 95% CI, 2.18-5.54; I2 = 77%), open container water storage (SOR, 2.03; 95% CI, 1.09-3.76; I2 = 62%), consumption of food outside the home (SOR, 2.76; 95% CI, 1.62-4.69; I2 = 64%), household contact with cholera (SOR, 2.91; 95% CI, 1.62-5.25; I2 = 89%), water treatment (SOR, 0.37; 95% CI, .21-.63; I2 = 74%), and handwashing (SOR, 0.29; 95% CI, .20-.43; I2 = 37%). Other notable associations with symptomatic infection included income/wealth, blood group, gastric acidity, infant breastfeeding status, and human immunodeficiency virus infection.
CONCLUSIONS
We identified potential risk factors for symptomatic cholera infection including environmental characteristics, socioeconomic factors, and intrinsic patient factors. Ultimately, a combination of interventional approaches targeting various groups with risk-adapted intensities may prove to be the optimal strategy for cholera control.
Topics: Cholera; Family Characteristics; Food; Humans; Risk Factors; Water
PubMed: 30137536
DOI: 10.1093/infdis/jiy444 -
The American Journal of Tropical... Aug 2018Case-control studies are conducted to identify cholera transmission routes. Water, sanitation, and hygiene (WASH) exposures can facilitate cholera transmission (risk... (Meta-Analysis)
Meta-Analysis
Case-control studies are conducted to identify cholera transmission routes. Water, sanitation, and hygiene (WASH) exposures can facilitate cholera transmission (risk factors) or interrupt transmission (protective factors). To our knowledge, the association between WASH exposures and cholera from case-control studies has not been systematically analyzed. A systematic review was completed to close this gap, including describing the theory of risk and protection, developing inclusion criteria, searching and selecting studies, assessing quality of evidence, and summarizing associations between cholera and seven predicted WASH protective factors and eight predicted WASH risk factors using meta-analysis and sensitivity analysis. Overall, 47 articles describing 51 individual studies from 30 countries met the inclusion criteria. All eight predicted risk factors were associated with higher odds of cholera (odds ratio [OR] = 1.9-5.6), with heterogeneity () of 0-92%. Of the predicted protective factors, five of seven were associated with lower odds of cholera (OR = 0.35-1.4), with heterogeneity of 57-91%; exceptions were insignificant associations for improved water source (OR = 1.1, heterogeneity 91%) and improved sanitation (OR = 1.4, heterogeneity 68%). Results were robust; 3/70 (5%) associations changed directionality or significance in sensitivity analysis. Meta-analysis results highlight that predicted risk factors are associated with cholera; however, predicted protective factors are not as consistently protective. This variable protection is attributed to 1) cholera transmission via multiple routes and 2) WASH intervention implementation quality variation. Water, sanitation, and hygiene interventions should address multiple transmission routes and be well implemented, according to international guidance, to ensure that field effectiveness matches theoretical efficacy. In addition, future case-control studies should detail WASH characteristics to contextualize results.
Topics: Association; Case-Control Studies; Cholera; Hand Disinfection; Humans; Odds Ratio; Risk Factors; Sanitation; Water; Water Microbiology; Water Supply
PubMed: 29968551
DOI: 10.4269/ajtmh.17-0897