Emily Funk, an associate specialist at the University of California Davis, collects a mucus sample from a Chinook salmon to determine its exact species while on a research vessel on the San Joaquin River off Antioch, California, U.S., May 25, 2021. Picture taken May 25, 2021. REUTERS/Nathan Frandino

Respiratory therapist Annette James wears personal protective equipment as she explains how to use a mucus extractor to her patient Geraldine Sprys, who is suffering from pneumonia, at Medical Arts Hospital in Lamesa, Texas, U.S., December 17, 2020. Picture taken December 17, 2020. REUTERS/Go Nakamura

Guatemalan migrant Eliceo Tzi Mucu and his son, returned from the U.S. to Nuevo Laredo in Mexico under the Migrant Protection Protocol (MPP) to wait for their court hearing for asylum seekers, are seen at "Casa INDI" migrant shelter in Monterrey, Mexico July 31, 2019. Picture taken July 31, 2019. REUTERS/Daniel Becerril

Guatemalan migrant Eliceo Tzi Mucu and his son, returned from the U.S. to Nuevo Laredo in Mexico under the Migrant Protection Protocol (MPP) to wait for their court hearing for asylum seekers, are seen at "Casa INDI" migrant shelter in Monterrey, Mexico July 31, 2019. Picture taken July 31, 2019. REUTERS/Daniel Becerril

Guatemalan migrant Eliceo Tzi Mucu and his son, returned from the U.S. to Nuevo Laredo in Mexico under the Migrant Protection Protocol (MPP) to wait for their court hearing for asylum seekers, are seen at "Casa INDI" migrant shelter in Monterrey, Mexico July 31, 2019. Picture taken July 31, 2019. REUTERS/Daniel Becerril

Olympic and Paralympic track star Oscar Pistorius reacts as he listens to Judge Thokozile Masipa's judgement at the North Gauteng High Court in Pretoria, September 11, 2014. A South African judge cleared Oscar Pistorius of all murder charges on Thursday, saying prosecutors had failed to prove the Olympic and Paralympic track star intended to kill his girlfriend or an imagined intruder on Valentine's Day last year. REUTERS/Kim Ludbrook/Pool (SOUTH AFRICA - Tags: SPORT ATHLETICS ENTERTAINMENT CRIME LAW SOCIETY TPX IMAGES OF THE DAY)

Olympic and Paralympic track star Oscar Pistorius reacts during judgement at the North Gauteng High Court in Pretoria, September 11, 2014. A South African judge cleared Oscar Pistorius of all murder charges on Thursday, saying prosecutors had failed to prove the Olympic and Paralympic track star intended to kill his girlfriend or an imagined intruder on Valentine's Day last year. REUTERS/Phill Magakoe/Pool (SOUTH AFRICA - Tags: SPORT ATHLETICS ENTERTAINMENT CRIME LAW SOCIETY TPX IMAGES OF THE DAY)

A volunteer holds sputum samples from tuberculosis patients at the Indonesian Union Against Tuberculosis clinic in Jakarta, April 4, 2011. Tuberculosis remains a major global public health problem, with 9.4 million new cases and more than 1.7 million deaths recorded in 2009. Indonesia has the fifth highest tuberculosis rate in the world after India, China, South Africa, and Nigeria based on 2009 World Health Organization (WHO) data. REUTERS/Beawiharta (INDONESIA - Tags: HEALTH)

Norway's Ole Einar Bjoerndalen checks his time after crossing the finish line to win the Men's 20 km Individual event at the IBU World Cup Biathlon competition in Ostersund November 30, 2006. Bjoerndalen finished first followed by Germany's Andreas Birnbacher and Germany's Michael Greis in third. REUTERS/Bob Strong (SWEDEN)

A Thai man clears mucus from a cock's nostril during a daily cleansing session at cock fighting farm outside Bangkok. A Thai man clears mucus from a cock's nostril during a daily cleansing session at a cock fighting farm on the outskirts of Bangkok September 30, 2004. Thousands of Thailand's poultry farmers have been hard hit by the bird flu virus as the government plans to overhaul farming methods to stamp out the deadly H5N1 strain after the recent findings of the first probable case of human to human transmission this week. The virus has killed 20 Vietnamese and 10 Thais this year. Photo taken September 30. REUTERS/Adrees Latif

A Thai man clears mucus from a cock's nostril during a daily cleansing session at cock fighting farm outside Bangkok. A Thai man clears mucus from a cock's nostril during a daily cleansing session at a cock fighting farm on the outskirts of Bangkok September 30, 2004. Thousands of Thailand's poultry farmers have been hard hit by the bird flu virus as the government plans to overhaul farming methods to stamp out the deadly H5N1 strain after the recent findings of the first probable case of human to human transmission this week. The virus has killed 20 Vietnamese and 10 Thais this year. Photo taken September 30. REUTERS/Adrees Latif

Johann Muehlegg rests on his poles after crossing the finish line in
the men's 50 km cross country classical event in Soldier Hollow at the
Salt Lake 2002 Olympic Winter Games, February 23, 2002. Muehlegg won
his third gold medal of these Games in a time of two hours, six minutes
05.9 seconds, but later had the medal stripped from him after testing
positive for banned substances. REUTERS BOOKS The Art of Sport
REUTERS/Andrew Winning

RR/CRB

A Romanian woman walks behind her cattles on a hill August 3 in the Transylvanian village of Lechinta. Romania banned the Bulgarian imports of cattle and sheep after authorities in Sofia reported cases of so-called blue tongue disease. Animals contracting the virus develop a distinctive blue tongue, mucus membranes swell and the animals die within about three days. Analysts said the disease required the slaughter of an entire herd even if only a single animal was infected.

RS/WS