What does alastrim mean?
Alastrim is the name given to a mild form of smallpox caused by the variola minor virus. Unlike classical smallpox, which was caused by the more dangerous variola major strain and could kill up to a third of those infected, alastrim ran a much gentler course: its rash was lighter, its fever lower, and its fatality rate typically around one percent. The term entered English through Portuguese, reflecting the disease's prominence in Brazil and other parts of South America, where outbreaks were common in the late nineteenth and early twentieth centuries. It was also known by regional names such as amaas in southern Africa and milkpox or Cuban itch elsewhere. Because infection with variola minor conferred immunity against variola major, alastrim played an interesting role in the epidemiology of smallpox. Since the global eradication of smallpox, certified in 1980, alastrim survives chiefly as a term in medical history and virology.
nounA mild form of smallpox caused by the variola minor virus, characterized by a less severe rash and a much lower fatality rate than ordinary smallpox.
- The mild form of smallpox caused by the variola minor virus, with low mortality and a comparatively light rash.
"Physicians in early twentieth-century Brazil distinguished alastrim from classical smallpox by its milder course and far lower mortality."
"The 1910 epidemic in São Paulo was attributed to alastrim rather than the more virulent variola major."
"Because alastrim produced lasting immunity to smallpox, some epidemiologists studied it as a natural vaccine of sorts."
Rarely pluralized; when referring to multiple cases, writers more often use phrases such as 'cases of alastrim' or 'an outbreak of alastrim'.
"Historical accounts describe several distinct alastrims sweeping through the region in successive decades."
Alastrim was smallpox's gentler twin — so mild it killed only about one patient in a hundred, yet it was still eradicated alongside its deadly sibling by 1980.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of alastrim
Alastrim entered English from Portuguese, in which the word referred to this mild eruptive fever; the borrowing reflects the disease's particular prominence in Brazil during the nineteenth and twentieth centuries. English medical writers adopted the term in the early twentieth century as they sought to distinguish the benign variola minor from the deadly variola major. Its precise deeper roots are uncertain, so no cognates are asserted here.
How alastrim is actually used
A technical term used mainly in medical history and virology; since smallpox was declared eradicated in 1980, the word now appears almost exclusively in historical and scientific literature rather than everyday speech.
Easily confused with alastrim
Alastrim is specifically the mild variety of smallpox caused by variola minor, whereas 'smallpox' broadly refers to the disease including its severe variola major form.