Vibrio cholerae

Introduction

Average case fatality rates for Europe and the Americas continue to hover around 1% (Medscape)

Hosts

Humans

Transmission / Exposure Route

Fecal-oral transmission ^[1]

Case Fatality Ratio

Burden of Disease

The incidence of Vibrio infection in the United States continues to be low, with highest number documented in the age group older than 50 years, which has been around 0.50 cases per 100,000 population from 2003-2008. The frequency of cholera among international travelers returning to the United States has averaged 1 case per 500,000 population, with a range of 0.05-3.7 cases per 100,000 population, depending on the countries visited. (Medscape)

Duration of Infectiousness and disease

Symptomology

Very often, there are no symptoms associated with Cholera. However, more severe cases may be characterized by watery diarrhea, vomiting, and leg cramps. Individuals can become extremely dehydrated which can cause shock. In extreme cases, death can occur within hours. ^[3]

Latency

Asymptomatic Rates

Excretion Rates (see Exposure)

Immunity

Injectable, killed WC cholera vaccines date back to the nineteenth century, but fell in popularity due to unfavorable safety levels and low levels of effectiveness. Oral vaccines are now the preferred method of vaccination because they serve as an efficient method of eliciting the primary intestinal mucosal immune responses. There are two major oral vaccines; killed whole cell (WC)-based and genetically attenuated live vaccines. (S. Plotkin)Killed WC variants of the vaccine that contain both Vibrio cholerae O1 and O139 provides 50% protection for 3 years. (Verma, Khanna, and Chawla)

Incubation Period

Four hours to five days with an average of 2-3 days ^[2]

Microbiology

A comma-shaped, gram-negative aerobic or facultatively anaerobic bacillus that varies in size from 1-3 µm in length by 0.5-0.8 µm in diameter (Medscape)