Profiles in Nursing

Clara Maass (1876–1901), Nurse Martyr in the Battle Against Yellow Fever

She gave her life in pursuit of a cure

More than a century ago, Clara Maass, the first nurse to have an American medical center named after her, gave her life in the battle against a terrifying infectious disease: yellow fever. Before there were research ethics, human subject policies or review boards, there was Clara Maass.

The Most Feared Diseases

Every day, nurses make great sacrifices and practice in unprecedented conditions to care for patients with dangerous diseases, both known and unknown. The resilience and strength we see in nurses today confronting the COVID-19 pandemic echoes the heroic example of historical nurses like Clara Maass, who died in the line of duty 120 years ago.

Born in East Orange, N.J., the oldest of 10 siblings, Maass displayed leadership characteristics from the very beginning of her nursing career. After graduating from Newark German Hospital’s Christina Trefz Training School of Nursing in 1895, she quickly rose to the position of head nurse for the hospital.

Much of her short life was spent caring for the sick, a choice she made at every opportunity. She volunteered to serve as a contract nurse in the U.S. Army during the Spanish-American War in 1898, practicing in both the continental U.S. and Cuba.

After the war ended, Maass wrote to the Army surgeon general, asking to be sent across the world to provide care where it was needed most. Her service took her to the Philippines, where she was assigned to many patients ailed by highly infectious conditions.  Her resolve never weakened, even in the face of her era’s most feared diseases, including typhoid fever, malaria, smallpox and yellow fever.

Human Trials

Maass’s ultimate contribution to nursing and medical science came in 1901. During her tenure as a contract nurse, many of those Maass treated contracted yellow fever, a highly infectious and lethal disease common in tropical areas. Patients who survived a severe yellow fever infection became immune to the disease, but with case fatality rates of up to 60 percent, the odds of survival were poor.

At the turn of the last century, the fact that yellow fever was spread by mosquitos was still a theory. A human study conducted in Cuba by Johns Hopkins physician Jesse Lazear, M.D., produced inconclusive results until Lazear himself died after being bitten by an infected mosquito.

In late 1900, Lazear’s supervisor, Maj. Walter Reed, M.D., traveled to Cuba to oversee the next phase of the study. By early 1901, the focus of Reed’s experiments had shifted from confirming the link between mosquitos and yellow fever to inoculating patients in hopes of immunizing them against the disease. Reed’s staff began recruiting additional volunteers, including American servicemen and a number of Spanish immigrants.

The Seventh Bite

Clara Maass had arrived in Cuba shortly before Reed, answering a call for nurse volunteers. Because of her previous work with yellow fever victims, she soon became involved with the experimental work, which was conducted at Las Animas Hospital in Havana.

In May, she volunteered for Reed’s experiments,  allowing herself to be bitten by mosquitos infected with yellow fever. Each of the volunteers was paid $100 in gold — a lot of money back then — but she didn’t do it for financial gain. (She sent the money home to her mother.) Maass was drawn to the study because of the deadly toll she had seen the disease take on the soldiers and civilians she’d cared for. She was the only woman among the 19 volunteers.

Why would she participate in this dangerous effort? She must have known the high stakes. Perhaps she believed that having been exposed to afflicted patients had fortified her immune system against the disease or that her youth and strength would give her an advantage should she become ill. Undoubtedly, she believed that if she perished, it would be worth it for the sake of medical progress.

Hiring Now

Between May and June, Maass was bitten by infected mosquitos six times. In June, she developed a very mild case of yellow fever. Because the doctors weren’t sure this was enough to immunize her against the disease, she consented to be bitten a seventh time, on Aug. 14, 1901. This time, Maass was not so lucky. Four days after this last bite, she developed severe yellow fever. She died six days later, only 25 years old.

A Lasting Legacy

Maass’s death brought an end to Reed’s human experiments, but her sacrifice was not in vain. There was no longer any doubt that mosquitos could transmit the disease, which meant that public health officials could reduce yellow fever outbreaks through mosquito control measures.

The deadly experiments also demonstrated that trying to inoculate patients using the full-strength virus was much too dangerous. Work continued on alternatives, eventually leading to the development of a viable yellow fever vaccine in 1936.

The vaccine, which is now considered an “essential medicine” by the World Health Organization, uses an attenuated (weakened) live virus to provide lifelong immunity with far less risk.

Fifty-one years after Maass’s death, the Newark hospital where she trained and worked was renamed the Clara Maass Memorial Hospital (now called Clara Maass Medical Center) in her honor.

Maass once eloquently declared, “We nurse people, not diseases.” She saw that her patients were in need of nursing care and she stepped up to provide it, even at great personal risk. She would no doubt be proud to see the way nurses are continuing to step up and care for patients amid a deadly global pandemic.

Like Maass, nurses today don’t always know everything about the conditions our patients suffer, but we do know that we’ll be by their sides when they need us most.


Jessica Dzubak, RN, MSN, is the director of nursing practice for the Ohio Nurses Association and a freelance writer specializing in the healthcare industry. Her most recent feature is Combatting Workplace Violence.


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