Recent Cholera Publications on PubMed

The BMJ Appeal 2022-23: Cholera on the rise and how IFRC is working to fight it

January 7, 2023

BMJ. 2023 Jan 6;380:o3007. doi: 10.1136/bmj.o3007.


PMID:36609439 | DOI:10.1136/bmj.o3007

Haiti: Hospitals face critical oxygen shortages and warn of lack of fluids to treat cholera

January 2, 2023

BMJ. 2022 Dec 7;379:o2961. doi: 10.1136/bmj.o2961.


PMID:36593562 | DOI:10.1136/bmj.o2961

Genomic Microevolution of Vibrio cholerae O1, Lake Tanganyika Basin, Africa

December 27, 2022

Emerg Infect Dis. 2023 Jan;29(1):149-153. doi: 10.3201/eid2901.220641.


Africa's Lake Tanganyika basin is a cholera hotspot. During 2001-2020, Vibrio cholerae O1 isolates obtained from the Democratic Republic of the Congo side of the lake belonged to 2 of the 5 clades of the AFR10 sublineage. One clade became predominant after acquiring a parC mutation that decreased susceptibility to ciprofloxacin.

PMID:36573719 | DOI:10.3201/eid2901.220641

The forgotten threat of cholera in Syria

December 27, 2022

J Water Health. 2022 Dec;20(12):1755-1760. doi: 10.2166/wh.2022.262.


Cholera is an ancient disease that persists as an issue of public health in many conflict-affected countries worldwide. Cholera is a diarrheal infection caused by ingested water or food contaminated with the bacterium Vibrio cholerae. On 10 September 2022, the Ministry of Health in Syria declared a cholera outbreak. Poor water and sanitation systems, disease surveillance breakdown, the collapse of the health system, and deteriorated socioeconomic conditions are potential risk factors for the outbreak's spread. Identifying the context-related factors associated with the spread of disease is a core to developing practical response mechanisms. In this study, we suggested a multisectoral approach that addresses context-specific elements contributing to the cholera outbreak spread in Syria; public health determinants, geopolitics, risk factors, and pandemic fatigue.

PMID:36573678 | DOI:10.2166/wh.2022.262

Vertical transmission rate of HIV exposed twin pregnancies and associated factors in West Bengal, India; A retrospective cohort study

December 27, 2022

Jpn J Infect Dis. 2022 Dec 28. doi: 10.7883/yoken.JJID.2022.562. Online ahead of print.


Twin pregnancy is often associated with adverse obstetric outcomes. Mother to child transmission of HIV in twin pregnancy is less explored. The present study aimed to determine the risk of vertical transmission of HIV in HIV exposed twin pregnancy in comparison to singleton and to explore associated factors. We conducted a retrospective cohort study involving 348 HIV exposed babies (58 twin and 290 singleton) through systematic sampling from program database of West Bengal, India from April 2016 to March 2021. HIV vertical transmission rate was compared between single and twin live births. The effects of factors like maternal age, timing of maternal HIV diagnosis, duration of Antiretroviral Treatment, mode of delivery, birth weight and gender of baby etc. were determined. The HIV transmission rate for twin pregnancy (15.52% ) was significantly higher than single live-birth (5.5%) [Adjusted Odds Ratio = 3.08 (1.15-8.23)]. Among twin deliveries, maternal HIV diagnosis during intrapartum and postpartum period was associated with HIV transmission [Crude Odds Ratio= 11.0 (2.2-54.9)]. In conclusion perinatal HIV transmission is more common in twin pregnancies and linked with time of detection of maternal HIV. Early HIV detection and additional Antiretroviral regimen may be thought of for twin pregnancies.

PMID:36575026 | DOI:10.7883/yoken.JJID.2022.562

Acquisition of T6SS Effector TseL Contributes to the Emerging of Novel Epidemic Strains of Pseudomonas aeruginosa

December 22, 2022

Microbiol Spectr. 2023 Feb 14;11(1):e0330822. doi: 10.1128/spectrum.03308-22. Epub 2022 Dec 22.


Pseudomonas aeruginosa is an opportunistic pathogen with multiple strategies to interact with other microbes and host cells, gaining fitness in complicated infection sites. The contact-dependent type VI secretion system (T6SS) is one critical secretion apparatus involved in both interbacterial competition and pathogenesis. To date, only limited numbers of T6SS-effectors have been clearly characterized in P. aeruginosa laboratory strains, and the importance of T6SS diversity in the evolution of clinical P. aeruginosa remains unclear. Recently, we characterized a P. aeruginosa clinical strain LYSZa7 from a COVID-19 patient, which adopted complex genetic adaptations toward chronic infections. Bioinformatic analysis has revealed a putative type VI secretion system (T6SS) dependent lipase effector in LYSZa7, which is a homologue of TseL in Vibrio cholerae and is widely distributed in pathogens. We experimentally validated that this TseL homologue belongs to the Tle2, a subfamily of T6SS-lipase effectors; thereby, we name this effector TseL (TseLPA in this work). Further, we showed the lipase-dependent bacterial toxicity of TseLPA, which primarily targets bacterial periplasm. The toxicity of TseLPA can be neutralized by two immunity proteins, TsiP1 and TsiP2, which are encoded upstream of tseL. In addition, we proved this TseLPA contributes to bacterial pathogenesis by promoting bacterial internalization into host cells. Our study suggests that clinical bacterial strains employ a diversified group of T6SS effectors for interbacterial competition and might contribute to emerging of new epidemic clonal lineages. IMPORTANCE Pseudomonas aeruginosa is one predominant pathogen that causes hospital-acquired infections and is one of the commonest coinfecting bacteria in immunocompromised patients and chronic wounds. This bacterium harbors a diverse accessory genome with a high frequency of gene recombination, rendering its population highly heterogeneous. Numerous Pa lineages coexist in the biofilm, where successful epidemic clonal lineage or strain-specific type commonly acquires genes to increase its fitness over the other organisms. Current studies of Pa genomic diversity commonly focused on antibiotic resistant genes and novel phages, overlooking the contribution of type VI secretion system (T6SS). We characterized a Pa clinical strain LYSZa7 from a COVID-19 patient, which adopted complex genetic adaptations toward chronic infections. We report, in this study, a novel T6SS-lipase effector that is broadly distributed in Pa clinical isolates and other predominant pathogens. The study suggests that hospital transmission may raise the emergence of new epidemic clonal lineages with specified T6SS effectors.

PMID:36546869 | PMC:PMC9927574 | DOI:10.1128/spectrum.03308-22

Pre-emptive oral cholera vaccine (OCV) mass vaccination campaign in Cuamba District, Niassa Province, Mozambique: feasibility, vaccination coverage and delivery costs using CholTool

December 22, 2022

BMJ Open. 2022 Sep 7;12(9):e053585. doi: 10.1136/bmjopen-2021-053585.


INTRODUCTION: Mozambique suffers from regular floods along its principal river basins and periodic cyclones that resulted in several cholera epidemics during the last decades. Cholera outbreaks in the recent 5 years affected particularly the northern provinces of the country including Nampula and Niassa provinces. A pre-emptive oral cholera vaccine (OCV) mass vaccination campaign was conducted in Cuamba District, Niassa Province, and the feasibility, costs, and vaccination coverage assessed.

METHODS: WHO prequalified OCV (Euvichol-Plus), a killed whole-cell bivalent vaccine containing Vibrio cholerae O1 (classical and El Tor) and O139, was administered in two doses with a 15-day interval during 7-31 August 2018, targeting around 180 000 people aged above 1 year in Cuamba District. Microplanning, community sensitisation, and training of local public health professionals and field enumerators were conducted. Feasibility and costs of vaccination were assessed using CholTool. Vaccination coverage and barriers were assessed through community surveys.

RESULTS: The administrative coverage of the first and second rounds of the campaign were 98.9% (194 581) and 98.8% (194 325), respectively, based on the available population data that estimated total 196 652 inhabitants in the target area. The vaccination coverage survey exhibited 75.9% (±2.2%) and 68.5% (±3.3%) coverage for the first and second rounds, respectively. Overall, 60.4% (±3.4%) of the target population received full two doses of OCV. Barriers to vaccination included incompatibility between working hours and campaign time. No severe adverse events were notified. The total financial cost per dose delivered was US$0.60 without vaccine cost and US$1.98 including vaccine costs.

CONCLUSION: The pre-emptive OCV mass vaccination campaign in remote setting in Mozambique was feasible with reasonable full-dose vaccination coverage to confer sufficient herd immunity for at least the next 3 to 5 years. The delivery cost estimate indicates that the OCV campaign is affordable as it is comparable with Gavi's operational support for vaccination campaigns.

PMID:36547726 | PMC:PMC9454037 | DOI:10.1136/bmjopen-2021-053585

Molecular Basis of the Toxigenic Vibrio cholerae O1 Serotype Switch from Ogawa to Inaba in Haiti

December 20, 2022

Microbiol Spectr. 2023 Feb 14;11(1):e0362422. doi: 10.1128/spectrum.03624-22. Epub 2022 Dec 20.


Toxigenic Vibrio cholerae O1 serotype Ogawa was introduced involuntarily into Haiti in October 2010, and virtually all of the clinical strains isolated during the first 5 years of the epidemic were Ogawa. Inaba strains were identified intermittently prior to 2015, with diverse mutations resulting in a common phenotype. In 2015, the percentage of clinical infections due to the Inaba serotype began to rapidly increase, with Inaba supplanting Ogawa as the dominant serotype during the subsequent 4 years. We investigated the molecular basis of the serotype switch and confirmed that all Inaba strains had the same level of mRNA expression of the wbeT genes, as well as the same translation levels for the truncated WbeT proteins in the V. cholerae Inaba isolates. Neither wbeT gene expression levels, differential mutations, or truncation size of the WbeT proteins appeared to be responsible for the successful Inaba switch in 2015. Our phylodynamic analysis demonstrated that the V. cholerae Inaba strains in Haiti evolved directly from Ogawa strains and that a significant increase of diversifying selection at the population level occurred at the time of the Ogawa-Inaba switch. We conclude that the emergence of the Inaba serotype was driven by diversifying selection, independent of the mutational pattern in the wbeT gene. IMPORTANCE Our phylodynamic analysis demonstrated that Vibrio cholerae Inaba strains in Haiti evolved directly from Ogawa strains. Our results support the hypothesis that after an initial Ogawa-dominated epidemic wave, V. cholerae Inaba was able to become the dominant strain thanks to a selective advantage driven by ongoing diversifying selection, independently from the mutational pattern in the wbeT gene.

PMID:36537825 | PMC:PMC9927444 | DOI:10.1128/spectrum.03624-22

Genomic and Evolutionary Insights into Australian Toxigenic Vibrio cholerae O1 Strains

December 19, 2022

Microbiol Spectr. 2023 Feb 14;11(1):e0361722. doi: 10.1128/spectrum.03617-22. Epub 2022 Dec 19.


Vibrio cholerae O1 is the causative agent of cholera, a severe diarrheal disease which can cause death if left untreated. In this study, a collection of clinical and environmental V. cholerae serogroup O1 isolates from Australia (1977 to 1987) (from local cases and cases acquired through international travel) and publicly available international isolates were characterized for genotypic features (virulence genes, mobile genetic elements [MGEs], and antimicrobial resistance gene profiles). Whole-genome sequencing (WGS) was used to investigate and compare the genetic relatedness between the 44 Australian and nine travel-associated isolates and the 60 publicly available international V. cholerae sequences representing pre-seventh-pandemic (pre-7PET) isolates and different waves of 7PET isolates. In this study, 36 (81%) Australian clinical and aquatic isolates harbored the cholera toxin-producing genes located in the CTX bacteriophage region. All the Australian environmental and clinical isolates lacked the seventh-pandemic virulence-associated genomic islands (VSP-I and -II). In silico multilocus sequence typing (MLST) classified all nine internationally acquired isolates as sequence type 69 (ST69), 36 clinical and aquatic isolates as ST70, and eight isolates from Australia as ST71. Most of the nontoxigenic clinical and aquatic isolates of ST71 had diverse genetic variations compared to ST70 Australian strains. The antimicrobial resistance-associated genes gyrA, parC, and parE had no mutations in all the environmental and clinical isolates from Australia. The SXT genetic element and class 1 integron gene sequences were not detected in Australian strains. Moreover, in this study, a Bayesian evolutionary study suggests that two distinct lineages of ST71 (new set of strains) and ST70 strains were prevalent around similar times in Australia, in ~1973 and 1969. IMPORTANCE Australia has its own indigenous V. cholerae strains, both toxigenic and nontoxigenic, that are associated with disease. Exotic strains are also detected in Australian patients returning from overseas travel. The clinical and aquatic V. cholerae O1 toxin gene-positive isolates from Australia responsible for cases in 1977 to 1987 were linked to acquisition from Queensland waterways but until now had not been characterized genetically. It is important to determine the genetic relatedness of Australian strains to international strains to assist in understanding their origin. This is the first extensive study to provide sequences and genomic analysis focused on toxigenic O1 V. cholerae clinical and environmental strains from Australia and its possible evolutionary relationship with other publicly available pre-7PET and 7PET V. cholerae strains. It is important to understand the population genetics of Australian V. cholerae from a public health perspective to assist in devising control measures and management plans for reducing V. cholerae exposure in Australia, given previous Australian disease clusters.

PMID:36533913 | PMC:PMC9927200 | DOI:10.1128/spectrum.03617-22

Skin disease and military conflicts: Lessons from the Crimean War (1854-56)

December 14, 2022

J R Coll Physicians Edinb. 2022 Dec;52(4):336-340. doi: 10.1177/14782715221139950. Epub 2022 Dec 14.


PMID:36515578 | DOI:10.1177/14782715221139950

Ukraine-Russia Crisis and COVID-19 Pandemic: Impending Danger over Public Health

December 13, 2022

Disaster Med Public Health Prep. 2022 Dec 13;17:e307. doi: 10.1017/dmp.2022.273.


PMID:36510820 | DOI:10.1017/dmp.2022.273

Knowledge, Attitudes and Practices on Cholera and Water, Sanitation, and Hygiene among Internally Displaced Persons in Cabo Delgado Province, Mozambique

December 12, 2022

Am J Trop Med Hyg. 2022 Dec 12;108(1):195-199. doi: 10.4269/ajtmh.22-0396. Print 2023 Jan 11.


In disaster situations, cholera outbreaks represent a public health emergency due to their high fatality rates and high spreading risk through camps for refugees and internally displaced persons (IDPs). The aim of this study is to examine water, sanitation, and hygiene attitudes and cholera knowledge, attitude, and practice (KAP) among people living in resettlement sites in Cabo Delgado, the northernmost province of Mozambique. Between January 1 and March 31, 2022, a cross-sectional survey was conducted by administering a face-to-face interview to IDPs and residents in six relocation sites in Cabo Delgado Province. A total of 440 people were enrolled in the study. Overall, 77.8% (N = 342) were female, 61% (N = 268) were younger than 35 years old, and 60.5% (N = 266) reported primary school to be the highest education level. Seventy-five percent (N = 334) of participants lived with children under 5 years old. Thirty-one percent (N = 140) and 11.8% (N = 52) of the respondents reported, respectively, at least one cholera case and at least one diarrheal-related death among their family members in the previous 2 years. In multivariate analysis, being female, being younger than 35 years old, having attained a higher education level, owning a phone, or having soap at home were factors significantly associated with improved cholera KAP. In severely deconstructed social contexts, continuous education and community sensitization are crucial to achieve and maintain positive cholera prevention attitudes.

PMID:36509049 | DOI:10.4269/ajtmh.22-0396

Etiology of Acute Diarrheal Disease and Antimicrobial Susceptibility Pattern in Children Younger Than 5 Years Old in Nepal

December 12, 2022

Am J Trop Med Hyg. 2022 Dec 5:tpmd211219. doi: 10.4269/ajtmh.21-1219. Online ahead of print.


PMID:36509064 | DOI:10.4269/ajtmh.21-1219

Epidemics and epidemiology: back to the future

December 12, 2022

Gac Sanit. 2022 Dec 9;37:102277. doi: 10.1016/j.gaceta.2022.102277. Online ahead of print.


PMID:36508988 | DOI:10.1016/j.gaceta.2022.102277

Knowledge, Attitude, and Practice in a Sample of the Lebanese Population Regarding Cholera

December 11, 2022

Int J Environ Res Public Health. 2022 Dec 4;19(23):16243. doi: 10.3390/ijerph192316243.


PMID:36498316 | PMC:PMC9735709 | DOI:10.3390/ijerph192316243