-
Clinical Infectious Diseases : An... Jun 2018In addition to improved water supply and sanitation, the 2-dose killed oral cholera vaccine (OCV) is an important tool for the prevention and control of cholera. We... (Meta-Analysis)
Meta-Analysis
In addition to improved water supply and sanitation, the 2-dose killed oral cholera vaccine (OCV) is an important tool for the prevention and control of cholera. We aimed to document the immunogenicity and protection (efficacy and effectiveness) conferred by a single OCV dose against cholera. The metaanalysis showed that an estimated 73% and 77% of individuals seroconverted to the Ogawa and Inaba serotypes, respectively, after an OCV first dose. The estimates of single-dose vaccine protection from available studies are 87% at 2 months decreasing to 33% at 2 years. Current immunologic and clinical data suggest that protection conferred by a single dose of killed OCV may be sufficient to reduce short-term risk in outbreaks or other high-risk settings, which may be especially useful when vaccine supply is limited. However, until more data suggest otherwise, a second dose should be given as soon as circumstances allow to ensure robust protection.
Topics: Administration, Oral; Cholera; Cholera Vaccines; Disease Outbreaks; Humans; Immunization Schedule; Immunogenicity, Vaccine; Seroconversion; Serogroup; Vaccination; Vaccine Potency; Vaccines, Inactivated; Vibrio cholerae
PubMed: 29177437
DOI: 10.1093/cid/cix1039 -
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 -
Journal of Water and Health Apr 2020Cholera is a severe diarrhoeal disease affecting vulnerable communities. A long-term solution to cholera transmission is improved access to and uptake of water,... (Meta-Analysis)
Meta-Analysis
Cholera is a severe diarrhoeal disease affecting vulnerable communities. A long-term solution to cholera transmission is improved access to and uptake of water, sanitation and hygiene (WASH). Climate change threatens WASH. A systematic review and meta-analysis determined five overarching WASH factors incorporating 17 specific WASH factors associated with cholera transmission, focussing upon community cases. Eight WASH factors showed lower odds and six showed higher odds for cholera transmission. These results were combined with findings in the climate change and WASH literature, to propose a health impact pathway illustrating potential routes through which climate change dynamics (e.g. drought, flooding) impact on WASH and cholera transmission. A causal process diagram visualising links between climate change dynamics, WASH factors, and cholera transmission was developed. Climate change dynamics can potentially affect multiple WASH factors (e.g. drought-induced reductions in handwashing and rainwater use). Multiple climate change dynamics can influence WASH factors (e.g. flooding and sea-level rise affect piped water usage). The influence of climate change dynamics on WASH factors can be negative or positive for cholera transmission (e.g. drought could increase pathogen desiccation but reduce rainwater harvesting). Identifying risk pathways helps policymakers focus on cholera risk mitigation, now and in the future.
Topics: Causality; Cholera; Climate Change; Humans; Hygiene; Risk Factors; Sanitation; Water; Water Supply
PubMed: 32300088
DOI: 10.2166/wh.2020.088 -
Scandinavian Journal of Gastroenterology Dec 2020Emergence of molecular methods to screen stools could provide a more complete picture of pathogens causing gastroenteritis, allowing to adequately treat patients... (Meta-Analysis)
Meta-Analysis
OBJECTIVE
Emergence of molecular methods to screen stools could provide a more complete picture of pathogens causing gastroenteritis, allowing to adequately treat patients whenever required but, so far, no aggregate data have been released. Our objective was to report pathogens identified in patients suffering from gastroenteritis using a multiplex molecular array.
DESIGN
Medline and Embase were searched for original publications reporting pathogens identified with FilmArray GI panel in patients suffering from gastroenteritis. Proportions of pathogens were extracted and pooled using a model with random effects.
RESULTS
Fourteen studies (17,815 patients) were included in the analysis. Among the 7,071 patients (39.7%) with positive FilmArray, identified pathogens were (27.5%), (19.3%), (15.1%), (15%), (11.8%), (8.1%), (7.3%), (7.3%), (7.1%), (5.2%), (4.9%), (4%), (3.8%), (3.8%), (2.8%), (1.7%), O157 (1.1%), (1.1%), (0.7%), (0.5%), (0.3%) and (0.3%). When considering only studies with control group (microbiological examination of the stools performed by other methods), FilmArray identified at least one pathogen in 48.2% of patients versus 16.7% when using comparative diagnostic methods.
CONCLUSIONS
FilmArray GI panel was positive in 39.7% of patients suffering from gastroenteritis. This proportion has to be mitigated by the carriage rates of identified organisms. Ultimately, restricted ordering of molecular panels to those patients who might benefit from specific treatment could provide medical value by swift identification of the pathogen and more targeted therapy.
Topics: Cryptosporidiosis; Cryptosporidium; Diarrhea; Feces; Gastroenteritis; Giardia lamblia; Humans
PubMed: 33147077
DOI: 10.1080/00365521.2020.1839128 -
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 -
BJOG : An International Journal of... Aug 2020Cholera has harmful effects on the fetus but safety data on the oral cholera vaccine in pregnant women are controversial. (Meta-Analysis)
Meta-Analysis
BACKGROUND
Cholera has harmful effects on the fetus but safety data on the oral cholera vaccine in pregnant women are controversial.
OBJECTIVES
We conducted the first meta-analysis of studies in pregnant women comparing the effect of oral cholera vaccination on pregnancy outcomes with unvaccinated women. Outcomes of interest were adverse pregnancy outcome, miscarriage, stillbirth, preterm delivery, low birthweight, abortion and malformation.
SEARCH STRATEGY
The search was run in MEDLINE/PubMed, SCOPUS and Embase databases from inception up to December 2019.
SELECTION CRITERIA
Inclusion criteria were: (1) studies that investigated the association between oral cholera vaccines and adverse pregnancy outcomes; (2) studies that reported outcomes with appropriate estimates; and (3) studies that contained an unvaccinated control group.
DATA COLLECTION AND ANALYSIS
A random-effects model (DerSimonian and Laird) was run to evaluate the overall treatment effect (relative risk, RR). The PRISMA statement was followed in reporting this meta-analysis.
MAIN RESULTS
Five studies included in meta-analysis with 5584 women (2920 exposed and 2664 not exposed). No significant increase in adverse pregnancy outcome (RR 1.03, 95% CI 0.79-1.34), miscarriage (RR 1.15, 95% CI 0.84-1.57) or stillbirth (RR 1.11, 95% CI 0.69-1.80) following cholera vaccine administration was found compared with control group. There was also no association with an increased risk of preterm delivery (RR 0.61, 95% CI 0.35-1.06) low birthweight (RR 0.84, 95% CI 0.56- 1.26), accidental abortion (RR 1.02, 95% CI 0.77-1.35) or malformation (RR 0.70, 95% CI 0.22-2.25).
CONCLUSIONS
This study shows no evidence of an association between oral cholera vaccination and adverse pregnancy outcomes. The findings do not rigorously exclude the possibility that the vaccine protocol may result in some degree of harm.
TWEETABLE ABSTRACT
There is no evidence of an association between oral cholera vaccination and adverse pregnancy outcomes. The findings do not rigorously exclude the possibility that the vaccine protocol may result in some degree of harm.
Topics: Abortion, Spontaneous; Case-Control Studies; Cholera; Cholera Vaccines; Congenital Abnormalities; Female; Humans; Infant, Low Birth Weight; Infant, Newborn; Mass Vaccination; Pregnancy; Pregnancy Outcome; Premature Birth; Stillbirth
PubMed: 32289871
DOI: 10.1111/1471-0528.16260 -
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