Alone and in pain, Tulasi Shahi encountered a poisonous snake.
The Nepali woman had been banished to her uncle's cowshed as per the "chaupadi" tradition, a centuries-old practice common among Hindus in the western regions of Nepal, though it was outlawed in 2005. Some communities there consider women "impure" while they are menstruating. These women are prohibited from daily activities and left isolated in sheds with straw floors for the duration of their periods.
Shahi was bitten on the head and leg while banished, the mayor of the local district, Surya Bahadur Shahi, told CNN. It was unclear whether he was related to the woman.
Her family members tried to treat her with home remedies before taking Tulasi Shahi to a clinic near Dailekh, which did not have antivenin. Recent monsoon rains have flooded the area, making a trek to a distant hospital difficult.
She died seven hours later, CNN reported.
"If she was given proper treatment, she would have survived," said Shahi's cousin Kamala Shahi, a government health worker, according to the New York Times. "She died because of superstition."
Shahi, whose age has been reported as 19 by CNN and 18 by the Times, is the latest Nepali woman to die from events related to the chaupadi practice, which has been condemned by the United Nations and global health organizations as cruel treatment of women, often in unsanitary conditions.
Roshani Tiruwa, a 15-year-old girl, died in December from smoke inhalation after she lighted a fire in the hut where she was banished while menstruating.
Prime Minister Pushpa Kamal Dahal had called for an end to chaupadi a month earlier, after the death of a 21-year-old woman.
Chaupadi has survived global outcry. A 2015 State Department report on human rights in Nepal, citing a government survey from 2010, found that 50 percent of women ages 15 to 49 in the midwestern and far-western regions of the country practice chaupadi. One in five women in the country as a whole reported the practice.
Legislators agreed to a provision to fine and potentially jail family members if a woman dies after being forced into the practice, the Himalayan Times reported in February.
Chaupadi can be disruptive to the lives and families of women and affects women of all social strata. They are barred from cultural events; cannot touch people, cattle, some foods; or milk cows or buffalo for fear of contaminating the milk, a 2011 U.N. bulletin said.
The Times of India reported on a 2011 survey that found that barely 1 in 10 women in India used sanitary pads during their periods, while others used alternatives such as ashes and sand.
The survey found that nearly 1 in 4 Indian women dropped out of school after they began to menstruate.