Bacteria

All You Need to Know About Cholera

Author Jaclynn Moskow , 28-May-2021

Table of contents

Vibrio cholerae

 

Vibrio cholerae (V. cholerae) is a species of Gram-negative facultatively anaerobic bacteria of curved rod-shaped with single polar flagella. V. Cholerae has been classified into approximately 200 serogroups. Strains belonging to serogroups O1 and O139 cause the vast majority of cholera cases (1).

Vibrio cholerae is found naturally in brackish riverine, estuarine, and coastal waters. Recognized hosts of the organism include algae, shellfish, chironomid egg masses, fish, waterfowl, amebae, and copepods (2). V. cholerae colonies can form biofilms on both biotic and abiotic surfaces – including on shells, zooplankton, macroalgae, ship hulls, and plastic pollution (3-5). 

 

Cholera Transmission and Disease Severity 

Cholera is primarily transmitted through the consumption of fecally contaminated water and food. Foodborne outbreaks are most frequently linked to fish, shellfish, crabs, oysters, clams, rice, millet gruel, and vegetables (6).

Most V. cholerae infections are asymptomatic or mild in nature. Individuals with asymptomatic infections may still shed bacteria in their feces and infect others (7). Approximately 10% of V. cholerae infections will progress to severe disease (8). In endemic settings, the most severe infections occur in children, while in epidemic settings, severe disease occurs in adults as frequently as it does in children (9). 

Individuals with blood type O are more likely to suffer from severe V. cholerae infection (10). The use of drugs that reduce stomach acid, such as antacids, histamine receptor blockers, and proton pump inhibitors, also increases the risk of severe infection (11). 

 

Vibrio cholerae bacteria on agar

Vibrio cholerae isolated from feces obtained from a patient with profuse diarrhea who had traveled to India. Photo courtesy of Nathan Reading

 

 

Signs and Symptoms of Cholera

Cholera has an average incubation period of 1-5 days. Patients will experience a sudden onset of painless, watery diarrhea that may be accompanied by vomiting. The diarrhea is often characterized as having a “rice water” appearance and fishy odor. Fever is uncommon in adults, but often present in children (12).

In severe cases, dehydration may lead to the rapid progression to acidosis and electrolyte imbalance. Coma may occur. Without the replacement of fluids and electrolytes, hypovolemic shock and death ensue (12).

If left untreated, cholera has a 25-50% mortality rate. Proper treatment reduces the mortality rate to less than 1% (13).

Cholera vector illustration. Labeled infection structure and symptoms scheme. Educational infographic with unsafe water and food vibrio microorganism that causes diarrhea, vomiting and dehydration.

Diagnosis and Treatment of Cholera

Cholera is diagnosed via stool culture. When a case is suspected, healthcare and medical laboratory personnel should follow stool precautions.

Mild and moderate cases of cholera can be successfully treated with oral rehydration salts, while severe cases require rehydration with intravenous fluids (14). The World Health Organization (WHO) recommends reserving antibiotics as a treatment for severe cases only, as antibiotic use has no proven effect on controlling the spread of the disease and may contribute to antimicrobial resistance (15). In severe cases, tetracycline, doxycycline, azithromycin, erythromycin, or ciprofloxacin may be used (12). Most people who recover from V. cholerae infection incur long-lasting immunity (16).

 

Cholera Prevalence

Cholera originated in India and spread across the world during the 19th century (17). Since that time, there have been seven cholera pandemics, including one that is ongoing today (18). 

Currently, approximately 1.3 billion people are at risk for cholera in endemic countries. An estimated 2.86 million cholera cases occur annually, resulting in an estimated 95,000 deaths (19).

Over the last decade, the countries reporting the most cases of cholera have included Yemen, Somalia, the Democratic Republic of Congo, Mozambique, Bangladesh, and Haiti. If you have a GIDEON account, click here to explore the Cholera outbreak map. Cholera is exceedingly rare in Europe and the United States.

 

Cholera cases by region, 1953 – 2018

Cholera-cases-by-region-1953-2018

 

Cholera Prevention

Cholera cases by region, 1953 - 2018

When traveling to an area where cholera is endemic, precautions should include adherence to proper hand hygiene, drinking only bottled water, and avoiding uncooked food.

Ongoing worldwide efforts to end the current cholera pandemic center on increasing access to clean water and sanitation and expanding accessibility to existing cholera vaccines.

 

The GIDEON Difference

GIDEON is one of the most well-known and comprehensive global databases for infectious diseases. Data is refreshed daily, and the GIDEON API allows medical professionals and researchers access to a continuous stream of data. Whether your research involves quantifying data, learning about specific microbes, or testing out differential diagnosis tools– GIDEON has you covered with a program that has met standards for accessibility excellence.

 

References 

(1) Morris, “Infections due to non-O1/O139 Vibrio cholerae“, Uptodate.com, 2019. [Online]. 

(2) “Cholera: Environmental Reservoirs and Impact on Disease Transmission”, One Health, pp. 149-165, 2014. Available: 10.1128/microbiolspec.oh-0003-2012

(3) B. Wucher, T. Bartlett, M. Hoyos, K. Papenfort, A. Persat, and C. Nadell, “Vibrio cholerae filamentation promotes chitin surface attachment at the expense of competition in biofilms”, Proceedings of the National Academy of Sciences, vol. 116, no. 28, pp. 14216-14221, 2019. Available: 10.1073/pnas.1819016116

(4) C. Lutz, M. Erken, P. Noorian, S. Sun and D. McDougald, “Environmental reservoirs and mechanisms of persistence of Vibrio cholerae”, Frontiers in Microbiology, vol. 4, 2013. Available: 10.3389/fmicb.2013.00375 

(5) J. Moskow, “What Do Plastics Have To Do With Infectious Diseases and the Immune System?“, GIDEON Informatics, Inc, 2021. [Online].

(6) G. Rabbani, W. Greenough. “Food as a vehicle of transmission of cholera”, J Diarrhoeal Dis Res, vol. 17, no. 1, pp. 1-9, 1999

(7) J. Lewnard, M. Antillón, G. Gonsalves, A. Miller, A. Ko and V. Pitzer, “Strategies to Prevent Cholera Introduction during International Personnel Deployments: A Computational Modeling Analysis Based on the 2010 Haiti Outbreak”, PLOS Medicine, vol. 13, no. 1, p. e1001947, 2016. Available: 10.1371/journal.pmed.1001947

(8) “Cholera – Vibrio cholerae infection: General Information“, Centers for Disease Control and Prevention (CDC0, National Center for Emerging and Zoonotic Infectious Diseases (NCEZID), Division of Foodborne, Waterborne, and Environmental Diseases (DFWED), 2020. [Online]

(9) J. Harris, R. LaRocque, F. Qadri, E. Ryan, and S. Calderwood, “Cholera”, The Lancet, vol. 379, no. 9835, pp. 2466-2476, 2012. Available: 10.1016/s0140-6736(12)60436-x

(10) J. Harris and R. LaRocque, “Cholera and ABO Blood Group: Understanding an Ancient Association”, The American Journal of Tropical Medicine and Hygiene, vol. 95, no. 2, pp. 263-264, 2016. Available: 10.4269/ajtmh.16-0440

(11) S. Handa, “Which classes of medications increase the risk of cholera infection?“, Medscape.com, 2018. [Online].

(12) “Cholera“, GIDEON Informatics, Inc, 2021. [Online]. 

(13) J. Fournier and M. Quilici, “Choléra”, La Presse Médicale, vol. 36, no. 4, pp. 727-739, 2007. Available: 10.1016/j.lpm.2006.11.029 

(14) “WHO | WHO position paper on Oral Rehydration Salts to reduce mortality from cholera“, Who.int, 2021. [Online]

(15) “Cholera“, Who.int, 2021. [Online]. 

(16) J. Harris, “Cholera: Immunity and Prospects in Vaccine Development”, The Journal of Infectious Diseases, vol. 218, no. 3, pp. S141-S146, 2018. Available: 10.1093/infdis/jiy414

(17) D. Lippi, E. Gotuzzo and S. Caini, “Cholera”, Paleomicrobiology of Humans, pp. 173-180, 2016. Available: 10.1128/microbiolspec.poh-0012-2015 

(18) S. Handa, “What are the 7 pandemics of cholera“, Medscape.com, 2018. [Online].

(19) M. Ali, A. Nelson, A. Lopez and D. Sack, “Updated Global Burden of Cholera in Endemic Countries”, PLOS Neglected Tropical Diseases, vol. 9, no. 6, p. e0003832, 2015. Available: 10.1371/journal.pntd.0003832

Author
Jaclynn Moskow

Jaclynn M Moskow D.O. is a professional medical writer and freelance healthcare consultant. Dr. Moskow has an extensive research background, having conducted and published bench research, clinical research, and translational research. She attended the University of Pittsburgh Honors College, where she designed and earned a Bachelor of Philosophy in Molecular Biology, Chemistry, and the History of Medicine. She earned her Doctor of Osteopathic Medicine from Nova Southeastern University, where she went on to serve as a Clinical Instructor of Public Health.

Articles you won’t delete.
Delivered to your inbox weekly.