Iditarod: Celebrating the "Great Race of Mercy" to Stop Diphtheria Outbreak in Alaska
Years ago, diphtheria wiped out entire communities, sometimes killing all the children in a family. This is the story of a famous event that galvanized people in the United States to begin to use diphtheria vaccine—which has virtually wiped out the once dreaded disease in this country.
A Deadly Outbreak
In the winter of 1925, a lone physician and four nurses in Nome, Alaska faced a crisis too terrible to imagine—an outbreak of diphtheria that could kill most of the region’s population of about 10,000 people.
- DTaP vaccine: for infants and children
- Tdap vaccine: for preteens, teens and adults
- Td: for teens and adults who've already received Tdap
Upper-case letters in these abbreviations denote full-strength doses of diphtheria (D) and tetanus (T) toxoids and pertussis (P) vaccine. Lower-case 'd' and 'p' denote reduced doses of diphtheria and pertussis used in the adolescent/adult-formulations. The 'a' in DTaP and Tdap stands for 'acellular,' meaning that the pertussis component contains only a part of the pertussis organism.
Diphtheria is a highly contagious upper respiratory tract illness caused by the toxin-producing bacterium Corynebacterium diphtheriea. The disease can be treated with an antitoxin (serum containing antibody to neutralize the toxin) or prevented by vaccines (e.g., DTaP, Tdap or Td – “D/d” for diphtheria, “T” for tetanus, and “P/p” for pertussis). However, before these medicines were available, diphtheria was commonly known as the “strangling angel of children.” Diphtheria causes the throat to become blocked with a thick, leathery coating that makes breathing very difficult. Without treatment, death by suffocation is very likely, especially for young children.
In December 1924, Nome doctor Curtis Welch watched as an outbreak started—with cases first thought to be simple sore throats or tonsillitis. In January 1925, when 2 children died of diphtheria, the impending crisis became clear. Dr. Welch ordered a quarantine, but diphtheria is so contagious that many people were likely already exposed and he knew more cases would appear.
Help from Miles Away
Race dogs with shirts promoting immunization during the ceremonial beginning of the Iditarod race. Photo courtesy Doreen Stangel, State of Alaska Immunization Program.
Normally, Dr. Welch would have treated infected people with diphtheria antitoxin to fight off the effects of the poison that diphtheria releases into the body. But the town’s supply of antitoxin was not enough and it had expired. Not knowing if the expired antitoxin would work or if it might actually cause harm, Dr. Welch hesitated to use it.
To save lives, fresh diphtheria antitoxin was the only hope. On January 22, 1925, Dr. Welch sent dozens of telegrams pleading for help to find and deliver antitoxin. National leaders in Washington, D.C., helped to locate the closest large supply of diphtheria antitoxin—it was in Anchorage, hundreds of miles away.
The next problem—figuring out the fastest way get the antitoxin to Nome. There were no roads or railways to Nome, air service was unavailable, and ships could not reach the town because of sea ice around Nome. The only way in was overland via the Iditarod Trail, also known as the Seward-to-Nome Mail Trail. This crisis made newspaper and radio headlines across America.
A Team Effort
Celebrated sled dog Balto, who led the last 600 mile leg of the race, with Gunnar Kaasen. (Photo: Brown Brothers/Wikimedia Commons.) Norwegian immigrant Gunnar Kaasen was the musher on the dog team that successfully delivered diphtheria antitoxin to Nome, Alaska in 1925.
After weighing all possible solutions, Alaska’s Territorial Governor Scott Bone approved a relay of the 20 best mail carrier mushers (sled dog drivers) and 150 dogs along the 674-mile Nenana-to-Nome Trail, a trip that usually took 15 to 20 days.
On January 27, one of the story’s heroes, “Wild” Bill Shannon, picked up the package of antitoxin at the nearest station that could be reached by train and began the journey. Teams of mushers traveled day and night, enduring blizzards and temperatures of 50 degrees below zero, handing off the package to fresh teams. Leonhard Seppala’s team with lead dog, Togo, covered 91 miles —the most dangerous part of the relay — and Gunner Kaasen’s team and lead dog, Balto, finished the lifesaving race, reaching Nome on February 2. This Great Race of Mercy was completed in a record 5 days and 7 hours.
Just two weeks later, after the diphtheria antitoxin was given to the infected children, the quarantine was lifted. At least five children died during the outbreak. However, the collective efforts of hundreds of people to deliver the diphtheria antitoxin prevented the deaths of many other children in Nome and the surrounding area.
The solution to the crisis also became the founding of an event well known today—the Iditarod Trail Sled Dog Race.
A National Vaccine Campaign
In the 1920s, an estimated 100,000 to 200,000 diphtheria cases occurred in the United States each year. Even with treatment, the disease killed as many as 13,000 to 15,000 people every year. The publicity from this outbreak prompted a national campaign in the 1930s to use diphtheria vaccine. It became routinely used by the 1940s after being combined with tetanus and pertussis (whooping cough) vaccines.
In the end, many hundreds of lives in the community in and around Nome were saved because people in Alaska and across the United States worked together with unbridled creativity and drive. And news of this outbreak led to the first national campaign to promote diphtheria vaccination. Today’s high coverage with DTaP in children, which contains diphtheria vaccine, is keeping the United States free from this disease.
The Iditarod Today
Each year, the State of Alaska's Immunization Program teams up with the Iditarod to promote vaccination. This is Iditarod mascot Izzy with Senator Lisa Murkowski at the start of the race. Photo courtesy Doreen Stangel, State of Alaska Immunization Program.
The original “Great Race of Mercy” in 1925 occurred when dog mushers from around Alaska joined forces to carry life-saving diphtheria serum to Nome. Since 1973, the Iditarod Trail Race has been run annually in memory of this original sled dog relay. As part of the current race format, the Alaska Immunization Program, the Iditarod Trail Committee, and other partners in the “I Did It By Two!” campaign use the “Race to Vaccinate” to heighten awareness of the critical need for timely immunizations for children before they are two years old. The serum run of 1925 and the modern Iditarod race are very important events here in Alaska,” says Arctic Investigations Program (AIP) Director Dr. Thomas Hennessy. “The State of Alaska uses the Iditarod race to promote immunization and other local public health activities.”
CDC’s Arctic Investigations Program
The mission of AIP in the National Center for Emerging and Zoonotic Infectious Diseases is the prevention of infectious diseases in people of the Arctic and sub-Arctic. AIP places a special emphasis on diseases of high incidence and concern among the Alaska Native and other northern indigenous peoples. The program conducts infectious disease surveillance, evaluates prevention services, and conducts applied research in collaboration with its partners.
Approximately 35 staff members are based at the AIP facility on the Alaska Native Medical Center Campus. Staff members include epidemiologists, laboratorians, research nurses, statisticians, and support staff. AIP provides support for research studies on the control and prevention of infectious disease, with particular emphasis on vaccine-preventable infections. Research areas include medical care, applied epidemiology, laboratory diagnosis, and biostatistical sciences.