Rise and fall of cholera-causing bacteria lineage

Subject: Science and Technology

Section: Disease

Context:

Researchers identify the decline of antimicrobial resistance in O139 as a key determining factor in its downfall

Cholera

It is a life-threatening infectious disease and a public health hazard.
It is caused by a comma-shaped bacterium known as Vibrio cholerae.
More than two hundred serogroups of this bacterium are known, of which only O1 and O139 are known to cause such infection that leads to epidemics and pandemics. Most of the serogroups only cause mild cholera-like diarrhea and food-associated outbreaks.
Of these two serogroups, O1 was responsible for seven pandemic waves, only to be temporarily displaced by O139. This emerged late and came up around 1992. It was first spotted in Chennai (then Madras).
It was anticipated that this would cause the eighth round of pandemic but it subsided as mysteriously as it had originated.
A rapid dipstick test is available to determine the presence of V. cholera
The World Health Organization (WHO) has three prequalified oral cholera vaccines (OCVs): Dukoral, Sanchol, and Euvichol.