Vibrio cholerae (VC)

Characteristics
Morphology	Part of the Vibronaceae family, Vibrio cholerae (VC) is a gram negative, non-spore forming, curved rod that is oxidase positive. The bacterium is 1- 3 µm by 0.5-0.8 µm, is a facultative anaerobe, and is very motile with a single polar flagellum. Serogroups O1 (classical and El Tor biotypes) and O139 are primarily responsible for cholera outbreaks. Pathogenic serogroups produce cholera toxin (CT) which is the factor that causes to diarrhea in infected individuals (through causing an electrolyte imbalance in the intestinal regions)
Growth Conditions	Cary Blair media is ideal for transport, and the selective thiosulfate–citrate–bile salts agar (TCBS) is ideal for isolation and identification.

Characteristics

Morphology

Part of the Vibronaceae family, Vibrio cholerae (VC) is a gram negative, non-spore forming, curved rod that is oxidase positive. The bacterium is 1- 3 µm by 0.5-0.8 µm, is a facultative anaerobe, and is very motile with a single polar flagellum. Serogroups O1 (classical and El Tor biotypes) and O139 are primarily responsible for cholera outbreaks. Pathogenic serogroups produce cholera toxin (CT) which is the factor that causes to diarrhea in infected individuals (through causing an electrolyte imbalance in the intestinal regions)

Growth
Conditions

Cary Blair media is ideal for transport, and the selective thiosulfate–citrate–bile salts agar (TCBS) is ideal for isolation and identification.

Health Hazards
Host Range	Humans, water birds, shellfish, fish, and herbivores
Modes of Transmission	Cholera is typically spread by consumption of water that is contaminated with infectious feces. Epidemics caused by infectious raw fish and seafood have been reported. Casual contact with an infected person is not a risk factor for becoming ill.
Signs and Symptoms	Cholera infection is often mild or without symptoms, but can be severe. Approximately 1 in 10 people who get sick with cholera will develop severe symptoms such as watery diarrhea, vomiting, and leg cramps. In these people, rapid loss of body fluids leads to dehydration and shock. Without treatment, death can occur within hours.
Infectious Dose	The infectious dose has been reported to be as low as 10 ingested vibrios
Incubation Period	The incubation period can range from a few hours to 5 days after infection

Medical Precautions/Treatment
Prophylaxis	Proper hygiene, sanitary measures, water treatment and careful food preparation are the best prophylactic measures in endemic areas
Vaccines	Oral vaccines are available, but are only recommended to people traveling to endemic areas
Treatment	Cholera can be simply and successfully treated by immediate replacement of the fluid and salts lost through diarrhea. Severe cases also require intravenous fluid replacement. With prompt appropriate rehydration, less than 1% of cholera patients die. Antibiotics can shorten the course and diminish the severity of the illness
Surveillance	Monitor for symptoms. Confirm diagnosis by dark field microscopy of a wet mount of fresh stool, PCR or ELISA
GWU Requirements	Report all incidents to the Office of Risk Management as well as the Office of Research Safety (ORS) IMMEDIATELY FOLLOWING THE OCCURRENCE.

Containment
BSL-2/ABSL-2	Risk Group 2 classification is applied VC. BSL-2 practices, containment equipment, and facilities are recommended for activities with cultures or potentially infectious clinical materials. ABSL-2 practices, containment equipment, and facilities are recommended for activities with naturally or experimentally infected animals.

Spill Procedures
Small Spills (<1 liter)	If the spill occurred inside a biological safety cabinet, close the sash and allow the cabinet to operate for 15 minutes before continuing with the spill cleanup. VC is not commonly transmitted via aerosols, but caution should be taken during a spill outside of a BSC. Leave the room immediately and allow the aerosols to dissipate for 15 minutes. Notify others working in the lab. Don appropriate PPE. Cover area of the spill with paper towels or any absorbent material and apply an EPA registered disinfectant effective against the bacteria (bleach, ethanol, glutaraldehyde), working from the perimeter towards the center. Allow 30 minutes of contact time before disposal and cleanup of spill materials.
Large Spills	Alert lab personnel in the laboratory to the spill and keep people out of the area to prevent spread of the contamination. Check if you have been contaminated or if any of your PPE has been breached. If so follow exposure procedures. Remove any contaminated clothing and place it the biohazard waste. Wash your hands and post a sign on the door. Notify your supervisor of the incident and call ORS (4-8258) for assistance. If the situation involves an imminently life-threatening injury or has catastrophic potential, call 911.

Spill Procedures

Small Spills (<1 liter)

If the spill occurred inside a biological safety cabinet, close the sash and allow the cabinet to operate for 15 minutes before continuing with the spill cleanup.

VC is not commonly transmitted via aerosols, but caution should be taken during a spill outside of a BSC. Leave the room immediately and allow the aerosols to dissipate for 15 minutes. Notify others working in the lab. Don appropriate PPE. Cover area of the spill with paper towels or any absorbent material and apply an EPA registered disinfectant effective against the bacteria (bleach, ethanol, glutaraldehyde), working from the perimeter towards the center. Allow 30 minutes of contact time before disposal and cleanup of spill materials.

Large Spills

Alert lab personnel in the laboratory to the spill and keep people out of the area to prevent spread of the contamination. Check if you have been contaminated or if any of your PPE has been breached. If so follow exposure procedures. Remove any contaminated clothing and place it the biohazard waste. Wash your hands and post a sign on the door. Notify your supervisor of the incident and call ORS (4-8258) for assistance. If the situation involves an imminently life-threatening injury or has catastrophic potential, call 911.

Exposure Procedures
Mucus Membrane	Flush eyes, mouth or nose for 15 minutes at eyewash station.
Other Exposure	For an area not protected by skin, wash with soap and water for 15 minutes (open wounds, sores, etc.)
Reporting	Report ALL injuries to the PI immediately and reported to the Office of Risk Management at [email protected] IMMEDIATELY FOLLOWING THE OCCURRENCE. Exposures that involve a bloodborne-pathogen or recombinant DNA also need to be reported to the Office of Research Safety at [email protected]. If the injury requires immediate medical attention, call GWPD at 202-994-6111 or call 911.
Medical Monitoring	Seek immediate medical evaluation, treatment, and post exposure follow-up at the Employee Health Office at GWU Hospital (900 23rd St., NW, Suite G-1090, Phone: 202-715-4275). Students should go to the Students Health Office at Marvin Center. After hours treatment can be received at the GWU hospital emergency room.

Stability
Disinfection	Susceptible to 2-5% phenol, 10% bleach, 4% formaldehyde, 2% glutaraldehyde, 70% ethanol, and 3-6% hydrogen peroxide
Inactivation	Vibrio cholerae is sensitive to cold (loss of viability after a cold shock at 0ºC)
Survival Outside Host	Cholera can survive in well water for 7.5 ± 1.9 days and the El Tor biotype can survive 19.3 ± 5.1 days. The bacterium can survive in a wide variety of foods and drinks for 1-14 days at room temperature and 1-35 days in an ice box. It has also been found on fomites at room temperature for 1-7 days

Personal Protective Equipment (PPE)
Minimum PPE Requirements	At minimum, personnel are required to don gloves, closed toed shoes, lab coat, and appropriate face and eye protection prior to working with VC. Additional PPE may be required depending on lab specific SOPs.
Additional Precautions	Additional protection may be worn over laboratory clothing when infectious materials are directly handled, such as solid-front gowns with tight fitting wrists, gloves, and respiratory protection. Wash hands with soap and water after removing gloves.

References
CDC (https://www.cdc.gov/cholera/) BMBL 6th Edition (https://www.cdc.gov/labs/BMBL.html) Canadian PHAC (https://www.canada.ca/en/public-health/services/laboratory-biosafety-bi…) Cholera toxin: A paradigm of a multifunctional protein (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3089049/)