How is diphtheria related to leather? Why does “influenza” sound like the word “influence”? And what does rabies have to do with Greek mythology?

Disease names are so commonly used these days that many of the decades- or centuries- old origins are long forgotten or clouded by the modern meanings. This article takes a trip back to the past, exploring the roots of these words – whether it be from Latin or Greek words, from place names or from the clinician who discovered them.


The term “dengue” is a West Indian Spanish homonym for the Swahili word ki denga pepo, a condition described by a sudden, cramp-like seizure caused by an evil spirit. But, medical historians date the first recording of the disease back to 265 to 420 A.D. in a Chinese medical encyclopaedia from the Chin Dynasty. The Chinese called the illness “water poison” and associated it with flying insects.

Today indeed, it is well-established that dengue is carried by mosquitoes, which tend to inhabit substantial amounts of standing water. The disease spread to the West Indies as early as 1827. In Spanish, dengue is defined as “prudery”, and this is perhaps related to the symptoms where dengue sufferers walk stiffly and erect due to painful joints.


It was believed that Epidemics III, the work of Hippocrates that was written 2,500 years ago, contains one of the earliest accounts of what may have been symptoms of diphtheria.

The word diphtheria originates from the French word diphthérie, which evolved from the Greek word diphtheria. It means “prepared hide, leather”. As such, French physician, Pierre Bretonneau described the unique clinical characteristics of the disease, during an epidemic in southern France, and named it diphtérite due to the formation of a leathery pseudomembrane in the throat.

The disease was formerly known in England as the Boulogne sore throat as it spread from France.


Influenza, also commonly known as the “flu”, is caused by the influenza virus.
Influenza, also commonly known as the “flu”, is caused by the influenza virus.

The Latin word influentia is defined as “to flow into” in Medieval Latin. It is also used in the astrological sense to describe an intangible fluid released by stars, which was believed to affect humans. In Italian, the term influenza was then used to refer to any disease outbreak thought to be influenced by stars.

Since 1504, the term was used in Italian for diseases such as influenza di febbre scarlattina, or “scarlet fever”. However, it was not until 1743 when an outbreak of the disease called influenza di catarro (“epidemic of catarrh”) spread across Europe, that the term stuck. The disease eventually came to be known in English as simply influenza.


Leptospirosis commonly occurs in animals such as rodents, dogs and other mammals, which can be transmitted to humans. It is caused by bacteria belonging to the genus Leptospira, which is derived from the combination of Greek words leptos, which means “slender”, and speira, which means “coil”.

The genus Leptospira was suggested by Hideyo Noguchi in 1917 due to its fine and minute windings. Leptospirosis was also known as Weil’s disease, as it was first described by German physician Adolf Weil in 1886, characterised by splenomegaly, jaundice and nephritis. However, back in ancient China, the disease was likely recognised as an occupational hazard of rice farming.


The word “rabies” originated from the Latin word rabere, which means “to rage”.
The word “rabies” originated from the Latin word rabere, which means “to rage”.

The history of the word rabies dated back to the 1590s, originating from the Latin word rabere which means “to rage”. This word may also have roots in the Sanskrit word rabhas, meaning “to commit violence”.

Rabies is caused by neurotropic viruses belonging to the genus Lyssavirus. According to Greek mythology, Lyssa was the goddess of rage, fury and rabies, known to cause madness in dogs of hunter Acteon, eventually killing their master.

It is believed that this was the disease that Hippocrates was referring to when he said that “persons in a frenzy drink very little, are disturbed and frightened, tremble at the least noise, or are seized with convulsions.” This is because in humans, rabies is characterised by hydrophobia, an aversion to swallowing water. Rabies was also described by Aristotle, who stated that “Dogs suffer from the madness. This causes them to become irritable and all animals they bite to become diseased.” MIMS

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Beware the symptoms of leptospirosis