epidemiological terms such as pandemic, endemic and outbreak
can be confusing, especially as more news emerges about Zika
virus and dengue fever.
Clinic infectious diseases specialist Dr. Pritish Tosh offers
THE DIFFERENCE AMONG A PANDEMIC, ENDEMIC AND AN OUTBREAK?
pandemic refers to a global epidemic — one that has spread
over several countries or continents affecting a large number
epidemiologic terms, an outbreak refers to a number of cases
that exceeds what would be expected," says Tosh. "A
pandemic is when there is an outbreak that affects most of the
world. We use the term endemic when there is an infection
within a geographic location that is existing perpetually.
we’re talking about endemic infections, we’re talking
about viruses, bacteria and pathogens that exist within a
geographic location," he says.
Outbreak: refers to the number of cases (disease) that exceeds
what would be expected
Endemic: an infection within a geographic location that is
Pandemic: a global endemic
example of this is dengue fever," says Tosh. "There
are parts of the world where dengue fever is endemic, meaning
that there are mosquitoes that are carrying dengue fever and
transmitting it from person to person. But we also see
imported cases and imported outbreaks in parts of the world
where a disease is not endemic.
recently we saw an outbreak in the Big Island of Hawaii where
somebody, unknown, must have come in with dengue fever, got
bitten by mosquitoes, and then you had local chains of
transmission where those mosquitoes then bit other people,
they got dengue fever, and so on and so on. In this case,
dengue fever is not endemic in the Big Island, however, there
was an outbreak due to an imported disease with subsequent