El Tor is the abbreviated name of a specific strain of the cholera bacteria, which is called Vibrio cholerae. Its symptoms are often unnoticeable, and it can remain in the systems of carriers for months or even years, sometimes going completely undiagnosed. Formally known as V. cholera biotype eltor, it was responsible for the seventh worldwide pandemic.
It is both similar to, and different from, the standard strain of cholera. Both contain similar serotypes, which are specific variations within subtypes of viruses and bacteria. They both show characteristics of the Ogawa, Hikojima, and Inaba serotypes and are of the serogroup O1. El Tor, however, produces hemolysins, distinguishing it from standard biotypes.
El Tor has been identified to spread through oral and fecal methods. For example, drinking contaminated water from a public water source or eating partially uncooked foods that have been fertilized with fecal matter can cause the spread of the bacteria. Outbreaks can be minimized or even prevented through much better sanitation and by boiling water before drinking it. In addition, thoroughly washing fruits and vegetables before consumption, and fully cooking food will minimize the potential for an outbreak.
Although El Tor was responsible for outbreaks in the early 1900s, it did not cause a pandemic until 1937 in Indonesia. From there, it spread throughout Asia, then to Africa, the Middle East and ultimately into heavily-populated Europe, responsible for small outbreaks along the way. In 1993, a specific test identified the El Tor strain in Calcutta, and that particular strain has been blamed for causing an epidemic in Guinea-Bissau, a small country in West Africa.
These outbreaks, pandemics and epidemics have been so prevalent because the disease masks itself with very few major symptoms and is highly contagious. Treatment of El Tor is the same for most bacterial infections: antibiotics and plenty of fluid. Water and electrolytes must be replaced because the disease drains these fluids from the system. Treatment is available only if the condition is diagnosed, which is not often the case. The El Tor strain in particular has been known to live in a woman's system for up to nine years after her first initial contact. It can live much longer than the classic cholera vibrios.
The strain of virus is named for the location in which it was discovered: El-Tor, Egypt. E. Gotschlich, a German physician, identified the virus in 1905 while at a quarantine camp. Throughout the years, scientists have struggled to categorize El Tor, first naming it as its own species, and then after study, grouping it together into the same serogroup because of similar characteristics.