Vibrio Cholerae: Biology, History, and Disease Management

Introduction to Vibrio Cholerae

There are four major types of infectious agents: bacteria, viruses, fungi, and parasites. This paper elaborates on one selected infectious agent — Vibrio cholerae, also known as Asiatic cholera — one of the numerous types of bacteria. The history of this bacterium, its morphology, characteristics, mechanisms of pathogenicity, and available treatments are discussed in the sections that follow, with the aim of informing relevant management strategies and public health policies.

Taxonomic Classification

The taxonomic classification of Vibrio cholerae places it within the class Gammaproteobacteria ("Vibrio Cholerae"). It belongs to the family Vibrionaceae, and its two primary disease-causing serogroups are O1 and O139.

History, Outbreaks, and Interesting Facts

Vibrio cholerae lives in contaminated water and food and primarily attacks the human gut. People become infected when they consume contaminated water or food, which may include undercooked seafood or raw food items ("Cholera"). Scientists have identified various kinds of Vibrio cholerae; however, only two cause disease in humans. The subgroups responsible for these diseases are O1 and O139. Outbreaks and pandemics caused by these bacteria have resulted in hundreds of thousands of deaths throughout history.

The bacterium is mostly comma-shaped and is responsible for triggering intestinal cells to release excessive amounts of water. This forces the stomach to become upset, resulting in severe diarrhea and rapid water loss from the body. The body's electrolytes and essential salts are simultaneously lost, as a single bacterium entering the body can multiply millions of times over.

Historical texts do not pinpoint when this disease first appeared. There are accounts from India and Greece dating to the 5th century BC that describe similar epidemic symptoms ("Cholera"). The disease's detailed narration first appeared in the writing of a Portuguese historian in 1543, describing an outbreak along the Ganges Delta. It spread rapidly, killing large numbers of people within only eight hours of infection.

Interesting facts about Vibrio cholerae include the scale of deaths it causes each year, ranging from 21,000 to 143,000 annually ("10 Facts on Cholera"). Most cases can be treated effectively with oral rehydration treatments, particularly oral rehydration salts (ORS). The foundational cause of outbreaks is poor hygiene and sanitation. People who lack access to clean drinking water are most susceptible to cholera. Remarkably, in areas where the bacterium is endemic, approximately 75% of people do not carry it. Surveillance is useful for controlling and preventing outbreaks and for identifying hotspots for Vibrio cholerae in geographically prone areas, particularly coastal regions. Anticipating seasonal bacterial infections becomes easier when readiness plans, health personnel training, and supply provision are established in advance.

The first cholera pandemic — the primary disease produced by Vibrio cholerae — was observed in 1817 in India ("Cholera"). It originated from contaminated rice and quickly spread to what are now Myanmar and Sri Lanka. By 1820, it had reached Europe, Thailand, and Indonesia, killing approximately 100,000 people in those regions. Passengers aboard ships from these areas carried the disease through contaminated water to China and Japan. Great Britain was not spared, with the epidemic arriving there in 1831 and reaching London in 1832. Quarantines and local health boards were soon established, imposing a state of emergency.

There have been seven cholera pandemics over the past two centuries. The most recent was witnessed in Yemen, beginning in 2016 and ending in 2020. Because cholera is a waterborne disease, conditions worsened dramatically during wartime, as there were no proper health facilities and infrastructure was badly damaged (Camacho et al. 680). The Yemeni government was unable to fund healthcare providers, and garbage collection management had broken down — factors that severely aggravated the spread of cholera in the region.

Morphological and Growth Characteristics

Vibrio cholerae is comma-shaped, gram-negative, and possesses a single polar flagellum ("Vibrio Cholerae, Serovar O1"). It is part of the Vibrionaceae family, with serogroups O1 and O139 considered hazardous to human health. It exists and grows in colonies because of its rapid growth rate once it enters the body. Sporadic cholera-like diarrhea is observed in patients infected with serogroups O1 and O139. The bacterium measures 0.5 to 0.8 micrometers in diameter (Handa). It can grow prolifically even in the absence of salt — which corresponds to the chief symptom of cholera, since the body loses water and electrolytes rapidly. It grows most quickly at temperatures above 30°C and up to 45°C (Huq et al. 11). It also thrives in water environments characterized by poor hygiene, excessive rainfall, crowding, and inadequate infrastructure (Ackerman). Another notable attribute of this bacterium is that its characteristics can be used to differentiate it from other human-pathogenic vibrios.