By Kate Kelland
LONDON, Oct 23 (Reuters) - Global health officials will on
Thursday announce a partial victory in the decades-long fight to
end polio, with a second of three strains of the crippling virus
certified as eradicated worldwide.
The ending of wild polio virus type 3 - also known as WPV3 -
will be the third human disease-causing pathogen to be
eradicated in history, after smallpox was declared wiped out in
1980 and wild polio virus type 2 (WPV2) in 2015.
Polio spreads in vulnerable populations in areas where there
is no immunity and sanitation is poor. It invades the nervous
system and can cause irreversible paralysis within hours.
It cannot be cured, but infection can be prevented by
vaccination - and a dramatic reduction in case numbers worldwide
in recent decades has been largely due to intense national and
regional immunisation campaigns in babies and children.
The last case of polio type 3 was detected in northern
Nigeria in 2012, and global health officials have since been
conducting intense surveillance to ensure it has gone.
"With no wild poliovirus type 3 detected anywhere in the
world since 2012, the Global Commission for the Certification of
Poliomyelitis Eradication is anticipated to officially declare
this strain as globally eradicated," the Global Polio
Eradication Initiative (GPEI) said in a statement.
The success in ending type 3 means that only type 1 of the
wild virus is still circulating and causing infections.
Polio type 1 is endemic in two countries - Afghanistan and
Pakistan - but efforts to wipe it out have faced setbacks in the
past two years.
After reaching a historic low of only 22 cases of wild polio
infection in 2017, the virus has caused 72 cases in Pakistan and
Afghanistan already this year - pushing back yet further the
potential date for the world to wipe polio out altogether.
The first target date for ending polio was set in 1988 by
the GPEI, a partnership of the World Health Organization, the
health charity Rotary International and others, which had aimed
to eradicate it by 2000.
GPEI said, however, that this week's declaration of the end
of WPV3 was a "significant milestone", while Carol Pandak,
director of Rotary's PolioPlus program, said it proves that a
polio-free world is achievable. "Even as the polio program
addresses major challenges, we're making important headway in
other areas," she said.