Vibrio cholerae (VC)


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Characteristics

Morphology

Vibrio cholerae (VC) is a gram negative, non-spore forming, curved rod. There are many serogroups of V. cholerae, but only two – O1 and O139 – cause outbreaks. V. cholerae O1 (VC 01) has caused all recent outbreaks.

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 have been found to contain the infectious agent

Modes of Transmission

Consumption of contaminated food or water. Symptomatic patients may shed Vibrio before clinical signs of illness and up to 2 weeks after, whereas asymptomatic patients typically only shed Vibrio for 1 day.

Reservoirs: The bacterium has been found in birds and herbivores surrounding freshwater lakes and rivers as well as in algae, copepods (zooplankton), crustaceans and insects

Signs and Symptoms

Only 5-10% of persons infected with VC O1 may have illness requiring treatment at a health center. Symptoms include profuse watery diarrhea, vomiting, rapid heart rate, low blood pressure, dehydration, muscle cramps, irritability.

Infectious Dose

The infectious dose ranges between 106 and 1011 ingested Vibrio

Incubation Period

Ranges from a few hours to 5 days after infection


Medical Precautions/Treatment

Prophylaxis

Hand washing

Vaccines

FDA recently approved a single dose live oral cholera vaccine for use in the United States. It has been approved for vaccination of adults 18-64 yr old who are traveling to an area of active cholera.

Treatment

VC is susceptible to antibiotics.

Surveillance

Monitor for symptoms. Confirm diagnosis by dark field microscopy of a wet mount of fresh stool, PCR or ELISA

Emory Requirements

Report all exposures. Cholera is a U.S. nationally reportable disease.


Laboratory Hazards

Laboratory Acquired Infections (LAIs)

Rare cases of bacterial enteritidis due to LAI with either V. cholerae or V. parahaemolyticus have been reported

Sources

Pathogenic Vibrio can be found in in human fecal samples or in contaminated shellfish. Accidental ingestion of VC results from eating with contaminated hands, using contaminated syringes or the handling of contaminated marine samples without gloves


Supplemental References

Canadian PHAC

Pathogen Safety Data Sheets   

BMBL

Biosafety in Microbiological and Biomedical Laboratories 


Containment

BSL-2/ABSL-2

Containment Level 2 facilities, equipment, and operational practices. No open-bench work should be performed with VC. All work should be performed inside a Biosafety Cabinet. Use of needle-safe sharps is encouraged. Centrifuge rotors must have a lid, samples should be loaded/unloaded inside the BSC and the centrifuge should be decontaminated with appropriate disinfectant after use.

ABSL2 practices, containment and equipment are recommended for experimentally infected animals.


Spill Procedures

Small

Notify others working in the lab. Allow aerosols to settle. Don appropriate PPE. Cover area of the spill with paper towels and apply an EPA approved disinfectant, working from the perimeter towards the center. Allow 30 minutes of contact time before disposal and cleanup of spill materials.

Large

Contact Emory’s Biosafety Officer (404-727-8863),
the EHSO Office (404-727-5922), or
The Spill Response Team (404-727-2888).


Exposure Procedures

Mucous membrane

Flush eyes, mouth or nose for 15 minutes at eyewash station.

Other Exposures

Wash area with soap and water for 15 minutes.

Reporting

Immediately report incident to supervisor, complete an employee incident report in PeopleSoft.

Medical Followup 

7am-4pm (OIM): EUH (404-686-7941) EUHM (404-686-7106) WW (404-728-6431)

After Hours: OIM NP On Call 404-686-5500 PIC# 50464

Needle Stick (OIM): EUH (404-686-8587) EUHM (404-686-2352)

Yerkes: Maureen Thompson Office (404-727-8012) Cell (404-275-0963)


Viability

Disinfection

2% chlorine, 0.5% chlorine, 0.05% chlorine

Inactivation

VC can be inactivated by cold (loss of viability after a cold shock at 0oC).

Survival Outside Host

V. cholerae can survive in well water for 7.5 ± 1.9 days and the El Tor biotype can survive 19.3 ± 5.1 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 V. cholerae . Additional PPE may be required depending on lab specific SOPs.

Additional Precautions

Use respiratory protection if work will be performed outside the biosafety cabinet. Additional precautions should be considered with work involving animals or large scale activities.