1947 New York City smallpox outbreak

1947 New York City smallpox outbreak
The Borough of Manhattan is represented in yellow.
Virus classification
Group:	Group I (dsDNA)
Order:	Unassigned
Family:	Poxviridae
Subfamily:	Chordopoxvirinae
Genus:	Orthopoxvirus
Type species
Vaccinia virus
Species
Variola virus

The 1947 New York City smallpox outbreak occurred in March, 1947 and was declared ended on April 24, 1947. The outbreak marked two milestones for America. The first, it was the largest mass vaccination effort ever conducted for smallpox in America, and the second, it marked the last outbreak of smallpox in America. Within three weeks time, following the discovery of the outbreak, the U.S. Public Health Service, in conjunction with New York City health officials, had procured vaccine and inoculated over 6,350,000 adults and children. Of that number, 5,000,000 had been vaccinated within the first two weeks. The rapid response was credited with limiting the outbreak to 12 people, 10 of whom recovered, while 2 died.^[1][2][3][4]

Background

On February 24, 1947, Eugene Le Bar, a 47 year-old rug merchant from Maine, and his wife, boarded a bus in Mexico City, where the couple had been vacationing, for the return trip to New York City. That evening, Le Bar fell ill with a headache and neck pain. Two days later, he developed a fine, red rash. The couple arrived in Manhattan on March 1 and checked into a mid-town hotel. The couple did some sightseeing and shopping. By March 5, Le Bar had developed a fever and pronounced rash. He was admitted to Bellevue Hospital, but because of the rash was transferred three days later to Willard Parker Hospital, a communicable disease hospital also in Manhattan.

On admission to Willard Parker, the differential diagnosis was drug reaction (since Le Bar had reported taking headache powders and aspirin), erythema multiforme, Kaposi's varicelliform eruption, and smallpox. However, because Le Bar had a smallpox vaccination scar, an atypical rash, and no history of exposure, smallpox was immediately ruled out. A biopsy of the skin lesions did not reveal the Guarnieri bodies characteristic of smallpox. Following further tests, Le Bar was diagnosed with having a drug reaction to the headache powders and aspirin he'd taken earlier. Despite supportive care, Le Bar's condition worsened and he died on March 10.^[5]

Epidemiology

Two patients on the same floor as Le Bar were discharged soon after Le Bar's death. However, both patients, one a 22-month-old baby girl who'd been earlier treated for the croup, and the other, Ishmael Acosta, a 27 year-old hospital worker who'd been treated for Mumps, were soon readmitted with the same rash and fever as Le Bar. Skin lesion biopsies performed on both patients confirmed the presence of Guarnieri bodies and the diagnosis of smallpox was made in both patients. As soon as the diagnosis was made, the entire staff of Willard Parker Hospital was vaccinated for smallpox, while the New York City Health Department and the U.S. Public Health Service were notified.

A review of Le Bar's autopy results and reexamination of the skin lesions this time demonstrated Guarnieri bodies and confirmed Le Bar had died of smallpox. Because he was the first case, he was identified as the index patient. The next concern for the health department was tracking down Le Bar's contacts.^[6]

The immediate contacts at the mid-town hotel included guests still there and those who had checked out starting on the day Le Bar checked in. Guests who were still there were all vaccinated. Those who had left and gone to other states were advised to see a physician and get vaccinated as soon as possible. The traceback included all passengers on the bus trip including those discharged and added at stops in seven states. The U.S. Public Health Service determined that all passengers had final destinations in 29 states. Warnings were sent to the public health services in all 29 states and all passengers were tracked down and advised to be inoculated as soon as possible. No cases were reported from either the hotel guests or the bus passengers.^[7][8]

Others who came into contact with Le Bar included patients and staff at Bellevue Hospital and Willard Parker Hospital. Coincidentally, Ishmael Acosta, the 27 year-old readmitted to Willard Parker, was an employee of Bellevue Hospital. However, no contact with Le Bar occurred there since Acosta was already a patient at Willard Parker when Le Bar was admitted to Bellevue. During the time between Acosta's discharge from Willard Parker and his readmission, Acosta had returned to work as an orderly at Bellevue. Three male patients he had prepped and transported to surgery later developed fever and rash. They were transferred to Willard Parker where all three were diagnosed with smallpox. All of Le Bar's contacts in New York City, which numbered several hundred, were vaccinated and sequestered to prevent further spread of the illness.^[9]

A 4 year-old boy being treated for whooping cough at Willard Parker Hospital was discharged on March 10, the day Eugene Le Bar died. He was transferred to a convalescent nursing facility in Millbrook, New York. He subsequently developed a rash and fever. It was later determined that he had smallpox and was the source of infection for three others at the facility including a 62 year-old nun, a 5 year-old boy, and a 2 year-old girl.

A 2 1/2 year-old boy admitted to Willard Parker Hospital for treatment of Whooping Cough just prior to Le Bar's death also came down with smallpox and was diagnosed on March 17. In addition, Ishmael Acosta's wife was admitted to Willard Parker Hospital on April 6 with a rash and fever. She was diagnosed with smallpox a day later. She died on April 12.

Eugene Le Bar's wife was contacted in Maine where she'd returned after Le Bar's death. She'd been vaccinated prior to her departure and remained healthy and free of disease.^[1][10]

Vaccination campaign

On April 4, 1947, New York City Mayor, William O'Dwyer announced plans to vaccinate everybody in the city. At the time, the New York City Health Department had 250,000 doses of Vaccinia vaccine and 400,000 doses in bulk. As soon as the hospital worker, Ishmael Acosta, and the twenty-two-month-old baby had been diagnosed with smallpox, O'Dwyer called an emergency meeting with the heads of the seven American pharmaceutical companies involved in vaccine production and asked them for a commitment to provide 6 million doses of the Vaccinia virus vaccine.^[11] The pharmaceutical companies accomplished the task by putting the vaccine into round-the-clock production. Additional vaccine doses were obtained from the Army and Navy.

Vaccination clinics were set up around the city at hospitals, health department clinics, police and fire stations, and schools. Volunteers drawn from the American Red Cross, the City Health Department, off-duty police and firefighters, and the disbanded, but vast, World War II Air Raid Warden networks located in all of New York's coastal towns, went door-to-door to urge residents to get vaccinated. A radio and print ad campaign called, "Be sure, be safe, get vaccinated!" advertised the vaccination clinic locations and emphasized that vaccination was free. Within days, long lines formed outside the clinics. More than 600,000 New Yorkers were vaccinated in the first week alone^[1][12][13]

The vaccination clinics began closing April 26, with the last closing May 3, 1947.^[1][14]

Morbidity and mortality

A total of 12 patients were confirmed to have smallpox, 9 in Manhattan and 3 in Millbrook, New York. Of those 12, 7 were adults and 5 were children, all aged 5 and under. The oldest patient was a 62 year-old nun. The youngest patient was a 22 month-old baby girl. These 12 were the only cases.

Two patients, Eugene Le Bar, and Ishmael Acosta's wife, aged 26, both died. There were no other deaths.

See also

• Super-spreader
• Herd immunity
• List of cutaneous conditions
• Mathematics of mass vaccination
• Vaccine-naive
• Willard Parker Hospital

References

External links

• New York Historical Society: 1947 Smallpox Vaccination Campaign
• CDC Smallpox Overview