Category Archives: Vibrio cholera

Nepal – Nepalese cholera outbreak: Kathmandu bans Panipuri

World Akkam

Kathmandu, June 26: Kathmandu, the capital of Nepal, is currently facing another outbreak of cholera. As of Sunday, at least 12 people have been infected with the disease, and authorities are struggling to contain the outbreak.

Cases of cholera have been found in several parts of the city, and health authorities have not yet identified the source. It was found that the water sources in many areas contained Vibrio cholerae.

Meanwhile, Kathmandu’s affiliated city, Lalitpur, has banned the sale of Panipuri and chat from Sunday for fear of cholera.

Lalitpur Metropolitan City (LMC) has decided to stop selling and distributing Panipuri and Chatpate in big cities from Saturday. LMC has banned the sale of Panipuri and Chapati, claiming that Vibrio cholerae was found in the water used in Panipuri.

RASFF Alerts – Vibrio cholerae – Shrimps


Presence of Vibrio cholerae in shrimps from Ecuador in Spain


Vibrio cholerae in shrimps from Ecuador in Spain

RASFF Alert – Vibrio cholerae – Prawns


Vibrio cholerae in prawns from Ecuador in Spain

Research – France – Cholera

Sante Publique

Food Illness

Digestive poisoning , cholera is a notifiable disease caused by the ingestion of water or food contaminated by Vibrio cholerae bacilli of the toxigenic serogroups O1 and O139.

Cholera: the disease

A rare imported pathology in France

Cholera is an acute digestive poisoning caused by ingestion of water or food contaminated by Vibrio cholerae bacilli of toxigenic serogroups O1 and O139 (cholera vibrios).

Today, collective and individual sanitation and hygiene measures have led to the disappearance of cholera in France (excluding Guyana and Mayotte, where sporadic and limited epidemics were described in the decades 1990-2000 in the two previous decades). In mainland France, cholera, which is subject to mandatory notification , is indeed a rare imported pathology. Symptomatic cases of cholera are mainly linked to the absorption of contaminated drinks or food abroad.

Early reporting of suspected and confirmed cases, and notification of confirmed cases takes place from a single case. They allow the management of imported cholera cases as soon as possible. Between 0 and 2 cases of cholera have been declared each year in France since 2000, they concern travelers returning from endemic areas . This is a small and decreasing number.

Although rare in France, cholera can cause severe digestive symptoms and dehydration. Even if the risks of contamination and epidemic are very limited on French territory, the epidemiological surveillance of Public Health France requires the early notification of cases as soon as this infection is suspected in order to prevent its spread.

Human-to-human and environmental transmission

Man is the main reservoir of cholera. But in some regions, the environment can also play this role, resulting in the circulation of cholera vibrios in an endemic mode . Cholera is linked to the absorption of contaminated water or food. Bacilli , or cholera vibrios, secrete cholera toxin in the intestine, which causes the loss of water and electrolytes (up to 15-20 liters per day). Diarrheal stools released in large quantities spread bacilli in the environment and faecal-oral transmission .

High population concentrations, combined with poor environmental hygiene, favor the appearance and development of cholera epidemics.

Prevention through hygiene and vaccination

When the basic rules of hygiene are respected, the vibrio responsible for cholera is not very transmissible. Appropriate chlorination of water and basic hygiene measures are generally sufficient to prevent contamination.
In the event of a trip to these endemic areas , compliance with hygiene measures (food hygiene with consumption of cooked and hot food, capsulated bottled water, avoidance of ice cubes, and hand washing) remains the best prevention.

There is no active vaccine against Vibrio cholerae serogroup O139. On the other hand, health personnel going to work with patients or in refugee camps during an epidemic can benefit from the anti-cholera vaccine (against different Vibrio cholerae O1 strains and a recombinant cholera toxin B subunit) administered orally (2 doses one week apart for adults and 3 doses one week apart for children 2 to 6 years of age).

Severe intestinal symptoms

The incubation period of cholera is short, from a few hours to five days.

Most people infected with Vibrio cholerae show few or no symptoms, although the bacillus can be found in their stool for one to two weeks. In case of illness, 80 to 90% of episodes are mild or moderately severe and it is then difficult to distinguish them clinically from other types of acute diarrhoea.

Less than 20% of patients develop all the typical symptoms of cholera, with symptoms of moderate to severe dehydration: violent diarrhea profuse with “rice water”, vomiting, without fever.

In the absence of treatment, death occurs in 1 to 3 days, by cardiovascular collapse in 25 to 50% of cases. Mortality is higher in children, the elderly and vulnerable individuals.

The diagnosis of cholera is clinical and biological. It is based on the detection of V. cholerae serogroup O1 or O139 producing cholera toxin in the stools of a patient. In the event of suspected isolation of a strain of cholera vibrio, immediate contact should be made with the National Reference Center for vibrios and cholera for typing and confirmation of the diagnosis: public-health/cnr/the-cnr/vibrions-cholera

A treatment based on rehydration

The treatment of cholera essentially consists of compensating for the digestive losses of water and electrolytes. Depending on the degree of dehydration, rehydration takes place orally or intravenously. An improvement in the subject’s condition is visible quickly (in a few hours) and healing occurs in a few days. There are no sequels. Antibiotic therapy can be useful in certain severe cases, but multi-resistant strains may appear.

An endemic circulation in South Asia

Cholera is regularly the subject of epidemics in developing countries where it evolves according to the country on an endemic and/or epidemic mode .

The world has been experiencing the seventh cholera pandemic since 1961, caused by Vibrio cholerae serogroup O1 .

Cholera has been endemic in the Indian subcontinent for several centuries. Cholera spread from 1817 to all of Asia, the Middle East and part of Africa, during the first cholera pandemic. Subsequent pandemics also developed from Asia and were facilitated by improved transportation. The seventh pandemic started in Indonesia in 1961, affected Asia in 1962, the Middle East and part of Europe in 1965, Africa in 1970, and South America in 1991.
On the n the island of Hispaniola an epidemic has been ongoing since the emergence of V. cholerae serogroup O1 in 2010 in Haiti.
Today, Africa and Asia are the two areas most affected by cholera. The disease is spreading there. The outbreak declared in Yemen since 2016 is the largest ever documented.

In 1992, a strain of Vibrio cholerae belonging to the new  serogroup O139 appeared in India and Bangladesh. Since then, it has caused epidemics in several Asian countries and could one day be the cause of an eighth pandemic. Cholera is the first disease to have been the subject of international notification (since 1892).

Research – Vital Surveillances: Phylogenetic Analysis of Serogroup O5 Vibrio cholerae that Caused Successive Cholera Outbreaks — Guangdong Province, China, 2020–2021

China CDC

Food Illness

  • Abstract

    IntroductionGastroenteritis caused by non-O1/non-O139 Vibrio cholerae exhibited an increasing trend in recent years in China. Whole genome sequence (WGS) data could play an important role both in the identification of the outbreaks and in the determination of the serogroup. Here, we present the employment of WGS data in the investigation of two outbreaks caused by non-O1/non-O139 V. cholerae in Guangdong, China, 2020–2021.

    MethodsWe obtained the whole genome sequence of 66 V. cholerae strains isolated in two outbreaks with next generation sequencing technology. We retrieved the publicly available WGS data of non-O1/non-O139 V. cholerae from public database. We used a pipeline integrated in China Pathogen Identification Net (PIN) to complete the phylogenetic analysis.

    ResultsTwo outbreaks caused by non-O1/non-O139 V. cholerae were identified using WGS data. These V. cholerae strains were determined as serogroup O5. Type 3 and 6 secretion systems were detected in these serogroup O5 strains. These serogroup O5 strains belonged to sequence type (ST) 88.

    ConclusionsOur analysis indicated the risk of non-O1/non-O139 V. cholerae of leading to outbreaks of diarrheal diseases. The application of genomic data played important role in the identification of the serogroup of non-O1/non-O139 V. cholerae in the lack of antiserum, which gave an example of the application of genome data in disease surveillance and public health emergency response.

  • Vibrio cholerae consists of more than 200 serogroups. The classification of serogroups is based on the O antigen of the lipopolysaccharide (LPS) (1). The classical method of serogroup determination is based on the immune agglutination reaction between the O antigen and the corresponding specific antiserum. The molecular mechanisms of different serogroups are based on the variation in structure of O-antigen polysaccharide (O-PS) coding sequence (2). Therefore, the phenotype of O-antigen is correlated with the molecular type of O-PS coding sequence. Till now, only serogroup O1 and O139 V. cholerae caused cholera epidemics and pandemics (3). V. cholerae does not belong to serogroup O1 and O139 and are designated as “non-O1/non-O139” V. cholerae. Usually, these non-O1/non-O139 V. cholerae only cause sporadic infections and seldomly cause outbreaks (4). Several kinds of toxins, such as a heat-stable toxin, cholera toxin, and other enterotoxins, have been detected in the non-O1/non-O139 V. cholerae that caused an outbreak. Except for the toxins, secretion systems, for example type 3 secretion system (T3SS) and type 6 secretion system, have been detected in some V. cholerae strains that caused cholera outbreaks (5).

    In China, toxigenic serogroup O1 and O139 V. cholerae strains were rarely isolated after 2010 (6). In contrast, sporadic cholera cases even small scale of outbreaks caused by non-O1/non-O139 V. cholerae were reported from time to time (4). Here we report successive cholera outbreaks caused by non-toxin-producing serogroup O5 V. cholerae in 2020 and 2021 in Guangdong Province, China.

Research – Emergence of non-choleragenic Vibrio infections in Australia

1 Health


Vibrio infection was rarely reported in Tasmania prior to 2016, when a multistate outbreak of Vibrio parahaemolyticus associated with Tasmanian oysters was identified and 11 people reported ill. Since then, sporadic foodborne cases have been identified following consumption of commercially- and recreationally-harvested oysters. The increases in both foodborne and non-foodborne Vibrio infec-tions in Tasmania are likely associated with increased sea water temperatures. As oyster production increases and climate change raises the sea surface temperature of our coastline, Tasmania expects to see more vibriosis cases. Vibriosis due to oyster consumption has been reported in other Australian states, but the variability in notification requirements between jurisdictions makes case and outbreak detection difficult and potentially hampers any public health response to prevent further illness.

Research – Tracking down the origin of cholera pandemics

Science Direct

Food Illness

The bacterium Vibrio cholerae is the causative agent of the diarrheal disease cholera and is responsible for seven known pandemics. The seventh cholera pandemic began in 1961 and is still active. Unlike previous pandemics, it is caused by cholera strains of a slightly different type. How did the modified cholera strains develop and spread, and what might have contributed to their success? Scientists from the Max Planck Institute for Evolutionary Biology in Plön, Germany, and CAU Kiel, in an international team with colleagues from City College New York and the University of Texas Rio Grande Valley, have now gained new insights into a molecular mechanism that provides insight into the interactions between cholera bacteria and may have played a role in the emergence of the seventh pandemic.

In their natural environment, bacteria are subject to competition with other bacteria for space and nutrients. In this process, molecular mechanisms help them to hold their own. One such mechanism is the so-called “type 6 secretion system” (T6SS), with which a bacterium transports toxic proteins into a neighboring bacterium and thereby kills it. Thus, cholera bacteria of the seventh pandemic use their T6SS to keep other bacteria in check and presumably more easily cause infection.

Researchers now had the special opportunity to study the T6SS of cholera bacteria from previous pandemics. For this purpose, among other things, the T6SS genome sequence of cholera bacteria from the 2nd pandemic was reconstructed from a museum specimen from the 19th century in a complex procedure and recreated in the laboratory.

In the process, the scientists were able to show that 2nd and 6th pandemic cholera bacteria lack a functional T6SS. As a result, the bacteria of earlier pandemics not only lack the ability to attack other bacteria, they are themselves killed by bacterial strains of the seventh pandemic. This may have been one of the reasons that older cholera strains were displaced by modified cholera strains of the seventh pandemic and are now hard to find.

Data from new lab

Daniel Unterweger, one of the study’s authors and a group leader at the Max Planck Institute in Plön, Germany, says: “With these findings, we support the theory that microbial competition between bacteria is very important for understanding pathogens and bacterial pandemics. Our research on the cholera bacterium was made possible by an S2 laboratory newly established at the institute. Here, we can conduct experiments with bacterial pathogens under the necessary safety precautions. The study contains some of the first data from the new laboratory.”

Link to Article

RASFF Alert – Vibrio cholerae – Frozen Prawns


Vibrio cholerae (presence /25g) in frozen prawns (Litopenaeus vannamei) from Ecuador in Spain

Research – Editorial: Vibrio Species in the Food Processing Chain

Frontiers in Microbiology

Food Illness

Editorial on the Research Topic
Vibrio Species in the Food Processing Chain

Rising concern about the foodborne illnesses caused by pathogenic Vibrio species (mainly V. parahaemolyticus, V. cholera, and V. vulnificus) has led to a strengthening of research on the characterization of the presence of the genus in food matrices, virulence genes, pandemic markers, and the correlation between clinical and environmental isolates from different ecosystems. The emergence of antimicrobial resistance strains (AMR) in Vibrio spp. may produce a decrease in the effectiveness of commonly used antibiotics, thus posing a threat to public health. Progress in genomic studies has identified motile elements implied in gene transfer that may give birth to developing surveillance strategies for risk mitigation. The development of new infection models that can predict the pathogenesis of Vibrio spp. and the use of high-throughput sequencing techniques for serogroup genes may be useful tools for understanding molecular pathways and the infectivity of Vibrio spp. food isolates. In this Research Topic, different approaches, aiming at characterizing Vibrio spp. from aquaculture, marine, and vegetable ecosystems, together with the evaluation of microbial behavior and the development of new infection and serogroup models, are shown.

A mini-review by Dutta et al. discusses the role and antimicrobial resistance of pathogenic Vibrio spp. They present potential sources of antibiotic resistance genes for Vibrio spp., including the horizontal gene transmission from other pathogens as the main route. This has shown the genetic basis of the emergence of multidrug and extensively multidrug resistant Vibrio spp. through different types of highly mobile elements that can be extensively propagated among bacteria. The use of phage or probiotic therapies as alternative treatments for the inactivation of antibiotic resistant species of Vibrio may be helped by the maintenance of good hygiene practices and processing technologies to protect public health.

Antibiotic resistance genes can also originate from the environment, such as wastewater effluents or sediments in marine or aquaculture habitats. In this regard, Siddique et al. studied the characterization of pathogenic V. parahaemolyticus in a fish farm ecosystem (tilapia, rui, and shrimp). Among the 216 samples, 60.2% were positive for the pathogen, including 323 isolates of which 17 harboured the trh virulence gene gene. They confirm the presence of resistant strains to amoxicillin, ampicillin, and penicillin. Pathogenicity was further confirmed by the fluid accumulation in the ileal loop of rabbits being O8: KUT, the most predominant pathogenic serotype.

The presence and characterization of V. parahaemolyticus and V. vulnificus in marine and estuarine environments was studied by da Silva et al. They found 150 isolates of V. parahaemolyticus, including 52 positives for trh gene, and 129 of V. vulnificus from water and blue crab samples. PFGE and agglutination tests were used for molecular subtyping and determination of antibiotic resistance. The study showed the high presence of the O5 pathogenic serotype, together with the multidrug resistant isolates (41%) and the high genetic diversity of both Vibrio species, as no correlations were found among the sampling sites, antimicrobial resistance profiles, and pathogenicity.

The associated presence of Vibrio spp. in water ecosystems may underestimate their origin from other environmental and food sources. Ready-To-Eat vegetables can harbor pathogenic Vibrio spp. if poor manufacturing, hygiene, and storage practices are followed. Igbinosa et al. evaluated the presence of V. parahaemolyticus in minimally processed vegetables. Among the 63 isolates, they found microbial counts from 1.5 to 1,000 MPN/g and drug resistant isolates to ampicillin and cefotaxime mainly (>60%). They studied the biofilm formation finding that 23.8% of the isolates were strong biofilm producers. Regarding the presence of virulence genes, 100, 14.3, and 31.8% of the isolates harbored the toxR gene, trh, and tdh determinants, respectively.

The microbial behavior of Vibrio spp. can be quantified with predictive models. Posada-Izquierdo et al. investigated the fate of a Vibrio spp. cocktail inoculated in lye-treated table olives for 22 days. A predictive growth model was developed as a function of salt concentration (2–12%) and pH (4–9) using a synthetic medium and table olive brines. They found a higher effect of salt concentration than of pH for the growth inhibition of Vibrio spp. However, they were not able to proliferate in the table olives during fermentation, highlighting that phenolics compounds could exert a clear antimicrobial effect.

The disposal of reliable models to predict the pathogenesis of Vibrio spp. are increasingly needed since the use of virulence markers could not fully elucidate the presence of long-standing virulence indicators. This was demonstrated by Santos et al. using clinical and environmental V. parahaemolyticus isolates in two systemic infection models, namely mice and Galleria mellonella larvae. Interestingly, non-pathogenic environmental isolates produced lethal infections regardless of their source, serotype, and genotype (tdh, orf8, toxRSnew, and vpadF). A high correlation was found in the assayed models, supporting that G. mellonella larvae can be used as an alternative model to study the pathogenesis of V. parahaemolyticus.

Recently, the use of high-throughput sequencing technologies has aided researchers in deciphering the genome of different species. This was essential to provide complete knowledge of the molecular and metabolic pathways of microorganisms and the identification of virulence gene clusters. Bian et al. have developed VPsero, a rapid serotyping tool for V. parahaemolyticus using serogroup specific genes obtained from whole-genome sequencing data. The algorithm, based on the comparison of lipopolysaccharide and capsular polysaccharide gene clusters covered 43 K and 12 O serogroups. The authors showed the high sensitivity and specificity of the tool (>0.91), though limitations could be faced in future studies, such as the addition of new serogroups, the verification of the quality of assembled genomes and the availability of short reads.

This Research Topic presents a collection of manuscripts highlighting relevant findings in the pathogenesis of Vibrio spp. in the food chain and suggests future directions for research, enabling progress in the development of novel analytical methods and surveillance actions to mitigate the emerging risk posed by these human pathogens.

India – Operation Vibrio launched in Kozhikode to tackle waterborne diseases

The Hindu

Operation Vibrio, an action plan to tackle the recurring incidents of food poisoning and waterborne diseases, has been launched in Kozhikode. The Health Department has also issued an alert against cholera in the district.

District Medical Officer Ummer Farooque said on Tuesday that the effort was to detect diseases such as cholera, shigella, amoebiasis, typhoid and jaundice that spread through contaminated food and water. As many as 17 cases of food poisoning had been reported in the district between February and November this year. As many as 257 people were infected and two died. Family events and wedding receptions and the food supplied in shops and hostels were reported to be the source of the infection. Some others took ill through having ice cream and fruit juices. The presence of bacteria such as vibrio cholerae, coliform, and e-coli had been found in water sources in some parts of the district as well.