Recent Cholera Publications on PubMed

Genomic epidemiology reveals multidrug resistant plasmid spread between Vibrio cholerae lineages in Yemen

September 28, 2023

Nat Microbiol. 2023 Oct;8(10):1787-1798. doi: 10.1038/s41564-023-01472-1. Epub 2023 Sep 28.


Since 2016, Yemen has been experiencing the largest cholera outbreak in modern history. Multidrug resistance (MDR) emerged among Vibrio cholerae isolates from cholera patients in 2018. Here, to characterize circulating genotypes, we analysed 260 isolates sampled in Yemen between 2018 and 2019. Eighty-four percent of V. cholerae isolates were serogroup O1 belonging to the seventh pandemic El Tor (7PET) lineage, sub-lineage T13, whereas 16% were non-toxigenic, from divergent non-7PET lineages. Treatment of severe cholera with macrolides between 2016 and 2019 coincided with the emergence and dominance of T13 subclones carrying an incompatibility type C (IncC) plasmid harbouring an MDR pseudo-compound transposon. MDR plasmid detection also in endemic non-7PET V. cholerae lineages suggested genetic exchange with 7PET epidemic strains. Stable co-occurrence of the IncC plasmid with the SXT family of integrative and conjugative element in the 7PET background has major implications for cholera control, highlighting the importance of genomic epidemiological surveillance to limit MDR spread.

PMID:37770747 | DOI:10.1038/s41564-023-01472-1

Draft genomes of <em>Aeromonas caviae</em> from patients with cholera-like illness during the 2022-2023 cholera outbreak in Malawi

September 28, 2023

Microbiol Resour Announc. 2023 Sep 28:e0058023. doi: 10.1128/MRA.00580-23. Online ahead of print.


Aeromonas caviae is an increasingly recognized etiological agent of acute gastroenteritis. Here, we report five draft genomes of A. caviae isolated from suspected cholera cases during the 2022-2023 cholera outbreak in Malawi.

PMID:37768056 | DOI:10.1128/MRA.00580-23

Cholera vaccine clinical trials: A cross-sectional analysis of clinical trials registries

September 27, 2023

Hum Vaccin Immunother. 2023 Aug;19(2):2261168. doi: 10.1080/21645515.2023.2261168. Epub 2023 Sep 27.


Cholera has been one of the world's biggest public health challenges for centuries. The presence of this disease brings into focus the social determinants of health in different parts of the world. Research and development efforts to find safe and effective Cholera vaccines are critical to decreasing the disease burden from Vibrio cholerae. We searched the International Clinical Trials Registry Platform (ICTRP) and Cochrane Central Register of Controlled Trials (CENTRAL) on 5 March 2023. We included all registered randomized trials studying Cholera vaccines. We used Microsoft Excel to perform a descriptive analysis of the source registry, geographic distribution, recruitment status, phase of trials, and type of trial sponsor and presented the findings using tables and graphs. The search of ICTRP yielded 84 trials, and 315 trials were identified from CENTRAL. Seventy-four trials were included in the analysis. Most of the trials (66%, n = 49) were registered in, followed by Clinical Trials Registry - India (9%, n = 7) and the Cuban Public Registry of Clinical Trials (8%, n = 6). The geographical distribution of the trials indicates that 48% (n = 36) of the trials were conducted in Asia, followed by 23% (n = 17) in North America, 15% (n = 11) in Africa, and 11% (n = 8) in Europe. Results further indicate that 81% (n = 60) of trials have a recruitment status "Not recruiting," followed by 12% (n = 9) with a status "recruiting." With the recent surge in Cholera cases and the limited supply of Cholera vaccines, research indicates the need for Cholera vaccine trials to ensure the availability of vaccines, especially in populations affected.

PMID:37759348 | DOI:10.1080/21645515.2023.2261168

Seafood-Associated Outbreak of ctx-Negative Vibrio mimicus Causing Cholera-Like Illness, Florida, USA

September 22, 2023

Emerg Infect Dis. 2023 Oct;29(10):2141-2144. doi: 10.3201/eid2910.230486.


Vibrio mimicus caused a seafood-associated outbreak in Florida, USA, in which 4 of 6 case-patients were hospitalized; 1 required intensive care for severe diarrhea. Strains were ctx-negative but carried genes for other virulence determinants (hemolysin, proteases, and types I-IV and VI secretion systems). Cholera toxin-negative bacterial strains can cause cholera-like disease.

PMID:37735754 | DOI:10.3201/eid2910.230486

Ancestral Origin and Dissemination Dynamics of Reemerging Toxigenic Vibrio cholerae, Haiti

September 22, 2023

Emerg Infect Dis. 2023 Oct;29(10):2072-2082. doi: 10.3201/eid2910.230554.


The 2010 cholera epidemic in Haiti was thought to have ended in 2019, and the Prime Minister of Haiti declared the country cholera-free in February 2022. On September 25, 2022, cholera cases were again identified in Port-au-Prince. We compared genomic data from 42 clinical Vibrio cholerae strains from 2022 with data from 327 other strains from Haiti and 1,824 strains collected worldwide. The 2022 isolates were homogeneous and closely related to clinical and environmental strains circulating in Haiti during 2012-2019. Bayesian hypothesis testing indicated that the 2022 clinical isolates shared their most recent common ancestor with an environmental lineage circulating in Haiti in July 2018. Our findings strongly suggest that toxigenic V. cholerae O1 can persist for years in aquatic environmental reservoirs and ignite new outbreaks. These results highlight the urgent need for improved public health infrastructure and possible periodic vaccination campaigns to maintain population immunity against V. cholerae.

PMID:37735743 | DOI:10.3201/eid2910.230554

Estimating the proportion of clinically suspected cholera cases that are true Vibrio cholerae infections: A systematic review and meta-analysis

September 14, 2023

PLoS Med. 2023 Sep 14;20(9):e1004286. doi: 10.1371/journal.pmed.1004286. Online ahead of print.


BACKGROUND: Cholera surveillance relies on clinical diagnosis of acute watery diarrhea. Suspected cholera case definitions have high sensitivity but low specificity, challenging our ability to characterize cholera burden and epidemiology. Our objective was to estimate the proportion of clinically suspected cholera that are true Vibrio cholerae infections and identify factors that explain variation in positivity.

METHODS AND FINDINGS: We conducted a systematic review of studies that tested ≥10 suspected cholera cases for V. cholerae O1/O139 using culture, PCR, and/or a rapid diagnostic test. We searched PubMed, Embase, Scopus, and Google Scholar for studies that sampled at least one suspected case between January 1, 2000 and April 19, 2023, to reflect contemporary patterns in V. cholerae positivity. We estimated diagnostic test sensitivity and specificity using a latent class meta-analysis. We estimated V. cholerae positivity using a random-effects meta-analysis, adjusting for test performance. We included 119 studies from 30 countries. V. cholerae positivity was lower in studies with representative sampling and in studies that set minimum ages in suspected case definitions. After adjusting for test performance, on average, 52% (95% credible interval (CrI): 24%, 80%) of suspected cases represented true V. cholerae infections. After adjusting for test performance and study methodology, the odds of a suspected case having a true infection were 5.71 (odds ratio 95% CrI: 1.53, 15.43) times higher when surveillance was initiated in response to an outbreak than in non-outbreak settings. Variation across studies was high, and a limitation of our approach was that we were unable to explain all the heterogeneity with study-level attributes, including diagnostic test used, setting, and case definitions.

CONCLUSIONS: In this study, we found that burden estimates based on suspected cases alone may overestimate the incidence of medically attended cholera by 2-fold. However, accounting for cases missed by traditional clinical surveillance is key to unbiased cholera burden estimates. Given the substantial variability in positivity between settings, extrapolations from suspected to confirmed cases, which is necessary to estimate cholera incidence rates without exhaustive testing, should be based on local data.

PMID:37708235 | DOI:10.1371/journal.pmed.1004286

Global diversity and antimicrobial resistance of typhoid fever pathogens: Insights from a meta-analysis of 13,000 <em>Salmonella</em> Typhi genomes

September 12, 2023

Elife. 2023 Sep 12;12:e85867. doi: 10.7554/eLife.85867.


BACKGROUND: The Global Typhoid Genomics Consortium was established to bring together the typhoid research community to aggregate and analyse Salmonella enterica serovar Typhi (Typhi) genomic data to inform public health action. This analysis, which marks 22 years since the publication of the first Typhi genome, represents the largest Typhi genome sequence collection to date (n=13,000).

METHODS: This is a meta-analysis of global genotype and antimicrobial resistance (AMR) determinants extracted from previously sequenced genome data and analysed using consistent methods implemented in open analysis platforms GenoTyphi and Pathogenwatch.

RESULTS: Compared with previous global snapshots, the data highlight that genotype 4.3.1 (H58) has not spread beyond Asia and Eastern/Southern Africa; in other regions, distinct genotypes dominate and have independently evolved AMR. Data gaps remain in many parts of the world, and we show the potential of travel-associated sequences to provide informal 'sentinel' surveillance for such locations. The data indicate that ciprofloxacin non-susceptibility (>1 resistance determinant) is widespread across geographies and genotypes, with high-level ciprofloxacin resistance (≥3 determinants) reaching 20% prevalence in South Asia. Extensively drug-resistant (XDR) typhoid has become dominant in Pakistan (70% in 2020) but has not yet become established elsewhere. Ceftriaxone resistance has emerged in eight non-XDR genotypes, including a ciprofloxacin-resistant lineage ( in India. Azithromycin resistance mutations were detected at low prevalence in South Asia, including in two common ciprofloxacin-resistant genotypes.

CONCLUSIONS: The consortium's aim is to encourage continued data sharing and collaboration to monitor the emergence and global spread of AMR Typhi, and to inform decision-making around the introduction of typhoid conjugate vaccines (TCVs) and other prevention and control strategies.

FUNDING: No specific funding was awarded for this meta-analysis. Coordinators were supported by fellowships from the European Union (ZAD received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 845681), the Wellcome Trust (SB, Wellcome Trust Senior Fellowship), and the National Health and Medical Research Council (DJI is supported by an NHMRC Investigator Grant [GNT1195210]).

PMID:37697804 | DOI:10.7554/eLife.85867

The gut microbiome of the healthy population in Kolkata, India, is a reservoir of antimicrobial resistance genes emphasizing the need of enforcing antimicrobial stewardship

September 12, 2023

FEMS Microbiol Lett. 2023 Sep 11:fnad090. doi: 10.1093/femsle/fnad090. Online ahead of print.


Antimicrobial resistance (AMR) alleviation warrants antimicrobial stewardship (AS) entailing indispensability of epidemiological surveillance. We undertook a small-scale surveillance in Kolkata to detect the presence of antimicrobial resistance genes (ARGs) in the healthy gut microbiome. We found that it was a reservoir of ARGs against common antibiotics. A targeted PCR and sequencing-based ARGs detection against tetracyclines, macrolides, trimethoprim, sulfamethoxazole, aminoglycosides, amphenicol and mobile genetic element (MGE) markers was deployed in twenty-five fecal samples. Relative abundance and frequency of ARGs was calculated. We detected markers against all these classes of antibiotics. 100% samples carried aminoglycoside resistance marker and int1U. A comparison with our previously published diarrheal resistome from the same spatial and temporal frame revealed that a higher diversity of ARGs were detected in the community and a higher rate of isolation of tetC, msrA, tmp and sul-2 was found. The presence of common markers in the two cohorts proves that the gut microbiome has been contaminated with ARGs and which are being disseminated among different ecosystems. This is an issue of discerning concern for public health. The study raises an alarming picture of the AMR crisis in low-middle and emergent economies. It emphasizes the strict enforcement of AS in the community.

PMID:37697657 | DOI:10.1093/femsle/fnad090

The Global, Regional, and National Burden of Adult Lip, Oral, and Pharyngeal Cancer in 204 Countries and Territories: A Systematic Analysis for the Global Burden of Disease Study 2019

September 7, 2023

JAMA Oncol. 2023 Sep 7. doi: 10.1001/jamaoncol.2023.2960. Online ahead of print.


IMPORTANCE: Lip, oral, and pharyngeal cancers are important contributors to cancer burden worldwide, and a comprehensive evaluation of their burden globally, regionally, and nationally is crucial for effective policy planning.

OBJECTIVE: To analyze the total and risk-attributable burden of lip and oral cavity cancer (LOC) and other pharyngeal cancer (OPC) for 204 countries and territories and by Socio-demographic Index (SDI) using 2019 Global Burden of Diseases, Injuries, and Risk Factors (GBD) Study estimates.

EVIDENCE REVIEW: The incidence, mortality, and disability-adjusted life years (DALYs) due to LOC and OPC from 1990 to 2019 were estimated using GBD 2019 methods. The GBD 2019 comparative risk assessment framework was used to estimate the proportion of deaths and DALYs for LOC and OPC attributable to smoking, tobacco, and alcohol consumption in 2019.

FINDINGS: In 2019, 370 000 (95% uncertainty interval [UI], 338 000-401 000) cases and 199 000 (95% UI, 181 000-217 000) deaths for LOC and 167 000 (95% UI, 153 000-180 000) cases and 114 000 (95% UI, 103 000-126 000) deaths for OPC were estimated to occur globally, contributing 5.5 million (95% UI, 5.0-6.0 million) and 3.2 million (95% UI, 2.9-3.6 million) DALYs, respectively. From 1990 to 2019, low-middle and low SDI regions consistently showed the highest age-standardized mortality rates due to LOC and OPC, while the high SDI strata exhibited age-standardized incidence rates decreasing for LOC and increasing for OPC. Globally in 2019, smoking had the greatest contribution to risk-attributable OPC deaths for both sexes (55.8% [95% UI, 49.2%-62.0%] of all OPC deaths in male individuals and 17.4% [95% UI, 13.8%-21.2%] of all OPC deaths in female individuals). Smoking and alcohol both contributed to substantial LOC deaths globally among male individuals (42.3% [95% UI, 35.2%-48.6%] and 40.2% [95% UI, 33.3%-46.8%] of all risk-attributable cancer deaths, respectively), while chewing tobacco contributed to the greatest attributable LOC deaths among female individuals (27.6% [95% UI, 21.5%-33.8%]), driven by high risk-attributable burden in South and Southeast Asia.

CONCLUSIONS AND RELEVANCE: In this systematic analysis, disparities in LOC and OPC burden existed across the SDI spectrum, and a considerable percentage of burden was attributable to tobacco and alcohol use. These estimates can contribute to an understanding of the distribution and disparities in LOC and OPC burden globally and support cancer control planning efforts.

PMID:37676656 | DOI:10.1001/jamaoncol.2023.2960


September 5, 2023

Acta Med Hist Adriat. 2023 Jul 18;21(1):141-156.

ABSTRACT This paper provides an analysis of Andrija Štampar's activities after World War II on the establishment of effective international health. Analyzed archival materials have confir- med with numerous evidence that Štampar as the president of the Interim Commission of the World Health Organization (WHO) played a crucial role in the establishment of the ideological starting points and organization of the WHO system, which remain relevant to date. Apart from the strategic foundations, it has been shown that his principles regarding the need for practical action based on the best professional knowledge and experience have no alternatives. The above is presented in the paper with the details of Štampar's activities during the cholera epidemic in Egypt and associated with the experiences of the recent global crisis caused by the COVID pandemic.


Antibiotic sensitivity profile of bacterial isolates from stool samples among children below five years in Murang'a County, Kenya

September 4, 2023

Pan Afr Med J. 2023 Jun 20;45:87. doi: 10.11604/pamj.2023.45.87.17909. eCollection 2023.


INTRODUCTION: the discovery of antibiotics led to the optimistic belief of completely eradicating infectious diseases during the golden era following their discovery. Countries are grappling with the burden of microbial resistance bringing a near paralysis of all facets of mankind. Enterobacteriaceae and other hard-to-treat Gram-negative bacteria have become resistant to nearly all antibiotic options available, and this is a bad taste in the fight against microbial resistance.

METHODS: during the months of April-October 2017, 163 children below five years presenting with diarrhea were randomly selected in Murang´a and Muriranja´s Hospitals. Bacterial agents were identified and antibiotic susceptibility profile was determined. Design: a cross-sectional study approach was used. Statistical analyses were performed using STATA v. 13.

RESULTS: a total of 188 bacteria belonging to 11 genera were isolated, and identified and their antibiotic susceptibility profiles were determined. Susceptibility testing showed that almost all the Enterotoxigenic Escherichia coli (ETEC), Enteropathogenic Escherichia coli (EPEC), Enteroaggregative Escherichia coli (EAEC), Salmonella, Klebsiella, Shigella, Vibrio, Enterobacter, Proteus, Pseudomonas, Aeromonas, Citrobacter and Yersinia species were resistant to the following antibiotics: ampicillin, amoxicillin, chloramphenicol, ciprofloxacin, ceftriaxone and kanamycin. Other than ETEC (90.9%), all the rest of the isolates were resistant to nalidixic acid. Other than ETEC (9.1%), EAEC (33.3%) and Salmonella species (95.2%), all the rest of the isolates were resistant to gentamicin. Other than V. cholerae, all the other isolates were resistant to trimethoprim-sulfamethoxazole. Isolates were sporadically resistant to erythromycin, streptomycin, doxycycline, and ofloxacin.

CONCLUSION: the high resistance rate of enteric Gram-negative bacterial pathogens in Murang´a County is alarming. The need for urgent, efficient, and sustainable actions and interventions, such as culture and susceptibility testing, is needed and must be taken into account to minimize and prevent the establishment and spread of enteric pathogenic bacteria.

PMID:37663642 | PMC:PMC10474812 | DOI:10.11604/pamj.2023.45.87.17909

Seasonality of cholera in Kolkata and the influence of climate

September 2, 2023

BMC Infect Dis. 2023 Sep 2;23(1):572. doi: 10.1186/s12879-023-08532-1.


BACKGROUND: Cholera in Kolkata remains endemic and the Indian city is burdened with a high number of annual cases. Climate change is widely considered to exacerbate cholera, however the precise relationship between climate and cholera is highly heterogeneous in space and considerable variation can be observed even within the Indian subcontinent. To date, relatively few studies have been conducted regarding the influence of climate on cholera in Kolkata.

METHODS: We considered 21 years of confirmed cholera cases from the Infectious Disease Hospital in Kolkata during the period of 1999-2019. We used Generalised Additive Modelling (GAM) to extract the non-linear relationship between cholera and different climatic factors; temperature, rainfall and sea surface temperature (SST). Peak associated lag times were identified using cross-correlation lag analysis.

RESULTS: Our findings revealed a bi-annual pattern of cholera cases with two peaks coinciding with the increase in temperature in summer and the onset of monsoon rains. Variables selected as explanatory variables in the GAM model were temperature and rainfall. Temperature was the only significant factor associated with summer cholera (mean temperature of 30.3 °C associated with RR of 3.8) while rainfall was found to be the main driver of monsoon cholera (550 mm total monthly rainfall associated with RR of 3.38). Lag time analysis revealed that the association between temperature and cholera cases in the summer had a longer peak lag time compared to that between rainfall and cholera during the monsoon. We propose several mechanisms by which these relationships are mediated.

CONCLUSIONS: Kolkata exhibits a dual-peak phenomenon with independent mediating factors. We suggest that the summer peak is due to increased bacterial concentration in urban water bodies, while the monsoon peak is driven by contaminated flood waters. Our results underscore the potential utility of preventative strategies tailored to these seasonal and climatic patterns, including efforts to reduce direct contact with urban water bodies in summer and to protect residents from flood waters during monsoon.

PMID:37660078 | DOI:10.1186/s12879-023-08532-1

Comparison of collection methods for Phlebotomus argentipes sand flies to use in a molecular xenomonitoring system for the surveillance of visceral leishmaniasis

September 1, 2023

PLoS Negl Trop Dis. 2023 Sep 1;17(9):e0011200. doi: 10.1371/journal.pntd.0011200. eCollection 2023 Sep.


BACKGROUND: The kala-azar elimination programme has resulted in a significant reduction in visceral leishmaniasis (VL) cases across the Indian Subcontinent. To detect any resurgence of transmission, a sensitive cost-effective surveillance system is required. Molecular xenomonitoring (MX), detection of pathogen DNA/RNA in vectors, provides a proxy of human infection in the lymphatic filariasis elimination programme. To determine whether MX can be used for VL surveillance in a low transmission setting, large numbers of the sand fly vector Phlebotomus argentipes are required. This study will determine the best method for capturing P. argentipes females for MX.

METHODOLOGY/PRINCIPAL FINDINGS: The field study was performed in two programmatic and two non-programmatic villages in Bihar, India. A total of 48 households (12/village) were recruited. Centers for Disease Control and Prevention light traps (CDC-LTs) were compared with Improved Prokopack (PKP) and mechanical vacuum aspirators (MVA) using standardised methods. Four 12x12 Latin squares, 576 collections, were attempted (12/house, 144/village,192/method). Molecular analyses of collections were conducted to confirm identification of P. argentipes and to detect human and Leishmania DNA. Operational factors, such as time burden, acceptance to householders and RNA preservation, were also considered. A total of 562 collections (97.7%) were completed with 6,809 sand flies captured. Females comprised 49.0% of captures, of which 1,934 (57.9%) were identified as P. argentipes. CDC-LTs collected 4.04 times more P. argentipes females than MVA and 3.62 times more than PKP (p<0.0001 for each). Of 21,735 mosquitoes in the same collections, no significant differences between collection methods were observed. CDC-LTs took less time to install and collect than to perform aspirations and their greater yield compensated for increased sorting time. No significant differences in Leishmania RNA detection and quantitation between methods were observed in experimentally infected sand flies maintained in conditions simulating field conditions. CDC-LTs were favoured by householders.

CONCLUSIONS/SIGNIFICANCE: CDC-LTs are the most useful collection tool of those tested for MX surveillance since they collected higher numbers of P. argentipes females without compromising mosquito captures or the preservation of RNA. However, capture rates are still low.

PMID:37656745 | PMC:PMC10501600 | DOI:10.1371/journal.pntd.0011200

Current status of infectious diseases among migrants and non-citizens in Malaysia

August 31, 2023

Trop Biomed. 2023 Jun 1;40(2):138-151. doi: 10.47665/tb.40.2.003.


The mass movement of migrants to Malaysia for employment is one of the factors contributing to the emergence and re-emergence of infectious diseases in this country. Despite mandatory health screening for migrants seeking employment, prevalence records of infectious diseases amongst migrant populations in Malaysia are still within negligible proportions. Therefore, the present review highlights the incidence, mortality and overall status of infectious diseases amongst migrants' populations in Malaysia, which maybe be useful for impeding exacerbation of inequalities among them and improving our national health system thru robust and effective emergency responses in controlling the prevalent diseases found among these populations and maybe, Malaysian citizens too. Peer-reviewed articles from January 2016 to December 2020 were searched through online platform including SCOPUS, PubMed, Science Direct, and Google Scholar. Non-peer-reviewed reports and publications from ministry and government websites including data from related agencies were also scoured from in order to ensure that there are no cases being overlooked, as most published articles did not have migrants as the research subjects. A total of 29 studies had been selected in the final analysis. Migrants in Malaysia were at higher risk for tuberculosis, malaria, lymphatic filariasis, cholera, leprosy and leptospirosis. Lymphatic filariasis was still endemic among this population while thousand cases of TB and cholera had been reported among them due to cramp living conditions and poor sanitation in their settlements respectively. While malaria had gradually decreased and become sporadic, the influx of migrant workers had led to the rising of imported malaria cases. Low cases of leprosy had been recorded in Malaysia but a significant proportion of it was contributed by migrant workers. As for leptospirosis, studies found that there are prominent cases among migrant workers, which particularly highest within workers with lower educational attainment. Infectious diseases are still prevalent among migrants in Malaysia due to various interplay factors including their working sectors, country of origin, immunization status, type of settlement, impoverished living conditions, and language and cultural barriers that impeding access to health facilities.

PMID:37650399 | DOI:10.47665/tb.40.2.003

Spatio-temporal pattern and associate factors of intestinal infectious diseases in Zhejiang Province, China, 2008-2021: a Bayesian modeling study

August 29, 2023

BMC Public Health. 2023 Aug 29;23(1):1652. doi: 10.1186/s12889-023-16552-4.


BACKGROUND: Despite significant progress in sanitation status and public health awareness, intestinal infectious diseases (IID) have caused a serious disease burden in China. Little was known about the spatio-temporal pattern of IID at the county level in Zhejiang. Therefore, a spatio-temporal modelling study to identify high-risk regions of IID incidence and potential risk factors was conducted.

METHODS: Reported cases of notifiable IID from 2008 to 2021 were obtained from the China Information System for Disease Control and Prevention. Moran's I index and the local indicators of spatial association (LISA) were calculated using Geoda software to identify the spatial autocorrelation and high-risk areas of IID incidence. Bayesian hierarchical model was used to explore socioeconomic and climate factors affecting IID incidence inequities from spatial and temporal perspectives.

RESULTS: From 2008 to 2021, a total of 101 cholera, 55,298 bacterial dysentery, 131 amoebic dysentery, 5297 typhoid, 2102 paratyphoid, 27,947 HEV, 1,695,925 hand, foot and mouth disease (HFMD), and 1,505,797 other infectious diarrhea (OID) cases were reported in Zhejiang Province. The hot spots for bacterial dysentery, OID, and HEV incidence were found mainly in Hangzhou, while high-high cluster regions for incidence of enteric fever and HFMD were mainly located in Ningbo. The Bayesian model showed that Areas with a high proportion of males had a lower risk of BD and enteric fever. People under the age of 18 may have a higher risk of IID. High urbanization rate was a protective factor against HFMD (RR = 0.91, 95% CI: 0.88, 0.94), but was a risk factor for HEV (RR = 1.06, 95% CI: 1.01-1.10). BD risk (RR = 1.14, 95% CI: 1.10-1.18) and enteric fever risk (RR = 1.18, 95% CI:1.10-1.27) seemed higher in areas with high GDP per capita. The greater the population density, the higher the risk of BD (RR = 1.29, 95% CI: 1.23-1.36), enteric fever (RR = 1.12, 95% CI: 1.00-1.25), and HEV (RR = 1.15, 95% CI: 1.09-1.21). Among climate variables, higher temperature was associated with a higher risk of BD (RR = 1.32, 95% CI: 1.23-1.41), enteric fever (RR = 1.41, 95% CI: 1.33-1.50), and HFMD (RR = 1.22, 95% CI: 1.08-1.38), and with lower risk of HEV (RR = 0.83, 95% CI: 0.78-0.89). Precipitation was positively correlated with enteric fever (RR = 1.04, 95% CI: 1.00-1.08), HFMD (RR = 1.03, 95% CI: 1.00-1.06), and HEV (RR = 1.05, 95% CI: 1.03-1.08). Higher HFMD risk was also associated with increasing relative humidity (RR = 1.20, 95% CI: 1.16-1.24) and lower wind velocity (RR = 0.88, 95% CI: 0.84-0.92).

CONCLUSIONS: There was significant spatial clustering of IID incidence in Zhejiang Province from 2008 to 2021. Spatio-temporal patterns of IID risk could be largely explained by socioeconomic and meteorological factors. Preventive measures and enhanced monitoring should be taken in some high-risk counties in Hangzhou city and Ningbo city.

PMID:37644452 | DOI:10.1186/s12889-023-16552-4

Drivers of the dynamics of the spread of cholera in the Democratic Republic of the Congo, 2000-2018: An eco-epidemiological study

August 28, 2023

PLoS Negl Trop Dis. 2023 Aug 28;17(8):e0011597. doi: 10.1371/journal.pntd.0011597. eCollection 2023 Aug.


BACKGROUND: The dynamics of the spread of cholera epidemics in the Democratic Republic of the Congo (DRC), from east to west and within western DRC, have been extensively studied. However, the drivers of these spread processes remain unclear. We therefore sought to better understand the factors associated with these spread dynamics and their potential underlying mechanisms.

METHODS: In this eco-epidemiological study, we focused on the spread processes of cholera epidemics originating from the shores of Lake Kivu, involving the areas bordering Lake Kivu, the areas surrounding the lake areas, and the areas out of endemic eastern DRC (eastern and western non-endemic provinces). Over the period 2000-2018, we collected data on suspected cholera cases, and a set of several variables including types of conflicts, the number of internally displaced persons (IDPs), population density, transportation network density, and accessibility indicators. Using multivariate ordinal logistic regression models, we identified factors associated with the spread of cholera outside the endemic eastern DRC. We performed multivariate Vector Auto Regressive models to analyze potential underlying mechanisms involving the factors associated with these spread dynamics. Finally, we classified the affected health zones using hierarchical ascendant classification based on principal component analysis (PCA).

FINDINGS: The increase in the number of suspected cholera cases, the exacerbation of conflict events, and the number of IDPs in eastern endemic areas were associated with an increased risk of cholera spreading outside the endemic eastern provinces. We found that the increase in suspected cholera cases was influenced by the increase in battles at lag of 4 weeks, which were influenced by the violence against civilians with a 1-week lag. The violent conflict events influenced the increase in the number of IDPs 4 to 6 weeks later. Other influences and uni- or bidirectional causal links were observed between violent and non-violent conflicts, and between conflicts and IDPs. Hierarchical clustering on PCA identified three categories of affected health zones: densely populated urban areas with few but large and longer epidemics; moderately and accessible areas with more but small epidemics; less populated and less accessible areas with more and larger epidemics.

CONCLUSION: Our findings argue for monitoring conflict dynamics to predict the risk of geographic expansion of cholera in the DRC. They also suggest areas where interventions should be appropriately focused to build their resilience to the disease.

PMID:37639440 | PMC:PMC10491302 | DOI:10.1371/journal.pntd.0011597

Multidrug resistance pattern and molecular epidemiology of pathogens among children with diarrhea in Bangladesh, 2019-2021

August 26, 2023

Sci Rep. 2023 Aug 26;13(1):13975. doi: 10.1038/s41598-023-41174-6.


Antimicrobial and multidrug resistance (MDR) pathogens are becoming one of the major health threats among children. Integrated studies on the molecular epidemiology and prevalence of AMR and MDR diarrheal pathogens are lacking. A total of 404 fecal specimens were collected from children with diarrhea in Bangladesh from January 2019 to December 2021. We used conventional bacteriologic and molecular sequence analysis methods. Phenotypic and genotypic resistance were determined by disk diffusion and molecular sequencing methods. Fisher's exact tests with 95% confidence intervals (CIs) was performed. Prevalence of bacterial infection was 63% (251 of 404) among children with diarrhea. E. coli (29%) was the most prevalent. E. coli, Shigella spp., V. cholerae, and Salmonella spp., showed the highest frequency of resistance against ceftriaxone (75-85%), and erythromycin (70-75%%). About 10-20% isolates of E. coli, V. cholerae and Shigella spp. showed MDR against cephem, macrolides, and quinolones. Significant association (p value < 0.05) was found between the phenotypic and genotypic resistance. The risk of diarrhea was the highest among the patients co-infected with E. coli and rotavirus [OR 3.6 (95% CI 1.1-5.4) (p = 0.001)] followed by Shigella spp. and rotavirus [OR 3.5 (95% CI 0.5-5.3) (p = 0.001)]. This study will provide an integrated insight of molecular epidemiology and antimicrobial resistance profiling of bacterial pathogens among children with diarrhea in Bangladesh.

PMID:37634040 | DOI:10.1038/s41598-023-41174-6

VP3 Phage Combined with High Salt Promotes the Lysis of Biofilm-Associated <em>Vibrio cholerae</em>

August 26, 2023

Viruses. 2023 Jul 27;15(8):1639. doi: 10.3390/v15081639.


Cholera, caused by pathogenic Vibrio cholerae, poses a significant public health risk through water and food transmission. Biofilm-associated V. cholerae plays a crucial role in seasonal cholera outbreaks as both a reservoir in aquatic environments and a direct source of human infection. Although VP3, a lytic phage, shows promise in eliminating planktonic V. cholerae from the aquatic environment, its effectiveness against biofilm-associated V. cholerae is limited. To address this limitation, our proposed approach aims to enhance the efficacy of VP3 in eliminating biofilm-associated V. cholerae by augmenting the availability of phage receptors on the surface of Vibrio cholerae. TolC is a receptor of VP3 and a salt efflux pump present in many bacteria. In this study, we employed NaCl as an enhancer to stimulate TolC expression and observed a significant enhancement of TolC expression in both planktonic and biofilm cells of V. cholerae. This enhancement led to improved adsorption of VP3. Importantly, our findings provide strong evidence that high salt concentrations combined with VP3 significantly improve the elimination of biofilm-associated V. cholerae. This approach offers a potential strategy to eliminate biofilm-formation bacteria by enhancing phage-host interaction.

PMID:37631982 | DOI:10.3390/v15081639

Seroprevalence of Vibrio cholerae in Adults, Haiti, 2017

August 23, 2023

Emerg Infect Dis. 2023 Sep;29(9):1929-1932. doi: 10.3201/eid2909.230401.


In Haiti in 2017, the prevalence of serum vibriocidal antibody titers against Vibrio cholerae serogroup O1 among adults was 12.4% in Cerca-la-Source and 9.54% in Mirebalais, suggesting a high recent prevalence of infection. Improved surveillance programs to monitor cholera and guide public health interventions in Haiti are necessary.

PMID:37610182 | DOI:10.3201/eid2909.230401

Spatiotemporal dynamics of cholera in the Democratic Republic of the Congo before and during the implementation of the Multisectoral Cholera Elimination Plan: a cross-sectional study from 2000 to 2021

August 23, 2023

BMC Public Health. 2023 Aug 22;23(1):1592. doi: 10.1186/s12889-023-16449-2.


BACKGROUND: The Democratic Republic of the Congo (DRC) implemented the first strategic Multisectoral Cholera Elimination Plan (MCEP) in 2008-2012. Two subsequent MCEPs have since been implemented covering the periods 2013-2017 and 2018-2021. The current study aimed to assess the spatiotemporal dynamics of cholera over the recent 22-year period to determine the impact of the MCEPs on cholera epidemics, establish lessons learned and provide an evidence-based foundation to improve the implementation of the next MCEP (2023-2027).

METHODS: In this cross-sectional study, secondary weekly epidemiological cholera data covering the 2000-2021 period was extracted from the DRC Ministry of Health surveillance databases. The data series was divided into four periods: pre-MCEP 2003-2007 (pre-MCEP), first MCEP (MCEP-1), second MCEP (MCEP-2) and third MCEP (MCEP-3). For each period, we assessed the overall cholera profiles and seasonal patterns. We analyzed the spatial dynamics and identified cholera risk clusters at the province level. We also assessed the evolution of cholera sanctuary zones identified during each period.

RESULTS: During the 2000-2021 period, the DRC recorded 520,024 suspected cases and 12,561 deaths. The endemic provinces remain the most affected with more than 75% of cases, five of the six endemic provinces were identified as risk clusters during each MCEP period (North Kivu, South Kivu, Tanganyika, Haut-Lomami and Haut-Katanga). Several health zones were identified as cholera sanctuary zones during the study period: 14 health zones during MCEP-1, 14 health zones during MCEP-2 and 29 health zones during MCEP-3. Over the course of the study period, seasonal cholera patterns remained constant, with one peak during the dry season and one peak during the rainy season.

CONCLUSION: Despite the implementation of three MCEPs, the cholera context in the DRC remains largely unchanged since the pre-MCEP period. To better orient cholera elimination activities, the method used to classify priority health zones should be optimized by analyzing epidemiological; water, sanitation and hygiene; socio-economic; environmental and health indicators at the local level. Improvements should also be made regarding the implementation of the MCEP, reporting of funded activities and surveillance of cholera cases. Additional studies should aim to identify specific bottlenecks and gaps in the coordination and strategic efforts of cholera elimination interventions at the local, national and international levels.

PMID:37608355 | DOI:10.1186/s12889-023-16449-2