Cholera (cont.)

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Is cholera contagious?

It takes about 100 million V. cholerae bacteria to infect a healthy adult. Because of this high number, significant contamination of food or water is required to transmit the disease, and direct person-to-person transmission is thought to be uncommon except in outbreaks. In outbreaks, cholera-causing bacteria become highly contagious indirectly and directly by the fecal-oral route because of widespread fecal contamination of food, water, and items like bedding and clothing.

What is the incubation period for cholera?

The incubation period (time period from exposure to the bacteria to the development of symptoms) may vary from a few hours (about six to 12 hours) to five days, with the average incubation period being about two to three days. About six to 12 hours is considered a very rapid incubation period and may suggest that rapid/immediate intervention is required for recovery.

What is the contagious period for cholera?

The contagious period for cholera begins as soon as organisms are excreted in the feces. This can occur as early as about six to 12 hours after exposure to the bacteria and can last for about seven to 14 days. Some individuals who are asymptomatic (infected but not having symptoms) will also excrete contagious organisms for about seven to 14 days.

How do health-care professionals diagnose cholera?

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Preliminary diagnosis is usually done by a caregiver who takes a history from the patient and observes the characteristic rice-water diarrhea, especially if a local outbreak of cholera has identified. The diarrhea fluid is often teeming with motile, comma-shaped bacteria (presumptively V. cholerae) that can be seen with a microscope. The definitive diagnosis is made by isolation of the bacteria from diarrhea fluid. All state health department laboratories in the U.S. are able to perform tests for Vibrio cholerae. Readers may see terms like serotypes Inaba, Ogawa, and Hikojima to describe V. cholerae; they simply indicate which O antigens (O antigens designated A, B, or C) are found on these strains of V. cholerae. PCR tests have also been developed to detect the genetic material of cholera, but currently they are not as widely used as the immunologic tests based on type-specific antiserum.

Definitive diagnosis helps to distinguish cholera from other diseases caused by other bacterial, protozoal, or viral pathogens that cause dysentery (gastrointestinal inflammation with diarrhea).

What is the treatment for cholera?

The CDC (and almost every medical agency) recommends rehydration with ORS (oral rehydration salts) fluids as the primary treatment for cholera. ORS fluids are available in prepackaged containers, commercially available worldwide, and contain glucose and electrolytes. The CDC follows the guidelines developed by the WHO (World Health Organization) as follows:

WHO Fluid Replacement or Treatment Recommendations (as per the CDC)
Patient conditionTreatmentTreatment volume guidelines; age and weight
No dehydrationOral rehydration salts (ORS)Children < 2 years: 50 mL-100 mL, up to 500 mL/day
Children 2-9 years: 100 mL-200 mL, up to 1,000 mL/day
Patients > 9 years: As much as wanted, to 2,000 mL/day
Some dehydrationOral rehydration salts (amount in first four hours)Infants < 4 mos (< 5 kg): 200-400 mL
Infants 4 mos-11 mos (5 kg-7.9 kg): 400-600 mL
Children 1 yr-2 yrs (8 kg-10.9 kg): 600-800 mL
Children 2 yrs-4 yrs (11 kg-15.9 kg): 800-1,200 mL
Children 5 yrs-14 yrs (16 kg-29.9 kg): 1,200-2,200 mL
Patients > 14 yrs (30 kg or more): 2,200-4,000 mL
Severe dehydrationIV drips of Ringer Lactate or, if not available, normal saline and oral rehydration salts as outlined aboveAge < 12 months: 30 mL/kg within one hour*, then 70 mL/kg over five hours
Age > 1 year: 30 mL/kg within 30 min*, then 70 mL/kg over two and a half hours

*Repeat once if radial pulse is still very weak or not detectable

  • Reassess the patient every one to two hours and continue hydrating. If hydration is not improving, give the IV drip more rapidly. 200 mL/kg or more may be needed during the first 24 hours of treatment.
  • After six hours (infants) or three hours (older patients), perform a full reassessment. Switch to ORS solution if hydration is improved and the patient can drink.

In general, antibiotics are reserved for more severe cholera infections; they function to reduce fluid rehydration volumes and may speed recovery. Although good microbiological principles dictate it is best to treat a patient with antibiotics that are known to be effective against the infecting bacteria, this may take too long a time to accomplish during an initial outbreak (but it still should be attempted); meanwhile, severe infections have been effectively treated with tetracycline (Sumycin), doxycycline (Vibramycin, Oracea, Adoxa, Atridox, and others), furazolidone (Furoxone), erythromycin (E-Mycin, Eryc, Ery-Tab, PCE, Pediazole, Ilosone), or ciprofloxacin (Cipro, Cipro XR, ProQuin XR) in conjunction with the following antibiotics in conjunction with IV hydration and electrolytes:

Many antibiotics are listed; however, because of widespread antibiotic resistance, including multi-resistant Vibrio strains, antibiotic susceptibility testing is advised so the appropriate antibiotic is chosen. In addition, quinolones (for example, ciprofloxacin, norfloxacin) should not be used in children if other antibiotics can be effective because of possible musculoskeletal adverse effects.

What physicians usually treat cholera?

Because most individuals have either mild or no symptoms, these people are either not treated or treated by their primary-care physician. However, in some children and in individuals who have more severe disease, besides the primary-care physician or pediatrician, an infectious-disease specialist, a critical-care specialist, a gastroenterologist, and/or an internist may be needed to help the team manage and treat the patient.

In addition, specialists in travel medicine and/or epidemiology can help individuals avoid cholera and/or can give advice about prevention, treatment, and prognosis to those individuals traveling to or living in endemic areas.

Medically Reviewed by a Doctor on 11/18/2015

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Cholera - Symptoms Question: What were the symptoms experienced with cholera in you or someone you know?
Cholera - Treatments Question: What treatment has been effective for your cholera?
Cholera - Diagnosis Question: What types of tests or exams led to a diagnosis of cholera in you or someone you know?
Cholera - Prevention in Community Question: If you live in a community that experiences cholera outbreaks, how do you prevent an infection?