Botswana has a small population, less than two million, but a big problem with AIDS.Forty percent of its people age thirty to thirty-four are infected with H.I.V., the virus that causes AIDS.The most recent report also shows that six percent of children are infected.

Yet, like other countries in southern Africa, Botswana does not have enough people trained to care for H.I.V. patients.One way it gets help is through a program with the University of Pennsylvania.

The American school sends doctors to provide training and to treat patients.Medical students also go.The Penn Medicine Program in Botswana is based at the Princess Marina Hospital in Gaborone.

Recently an American doctor named Richard Root went to help lead the training for two months.Doctor Root retired a few years ago from the University of Washington in Seattle with the honor of professor emeritus.

In the early nineteen seventies he had helped form the infectious disease division in the Department of Medicine at Penn.His specialty was how the body defends itself against bacterial infections.

Doctor Root also became known internationally for his teaching skills.He taught other doctors and helped medical schools develop teaching programs.He was known too for his ease with patients.

Doctor Root was married forty-one years to Marilyn Parletta Root.They had grandchildren.He took care of her after she developed a progressive neuromuscular disorder.After she died in two thousand one, he suffered depression.

Marilyn Root was a mental health counselor.She was known for her work with art to help women who had been mistreated as children.

In two thousand four Doctor Root remarried.Friends and family saw a new sense of purpose in his life.He had worked for a short time in the nineteen seventies as a visiting doctor in Iran.Now he was excited about the chance to help AIDS patients in Africa.

On March nineteenth he was in a canoe on the Limpopo River in Botswana, on a guided trip to see wildlife.All of a sudden, reports say, a crocodile pulled him into the river.His remains were found later and sent home to Seattle last week.

His wife of eighteen months, Rita O'Boyle, saw the attack from another boat.They had been in Botswana just short of a month.

Doctor Richard Root was sixty-eight years old.

This VOA Special English Health Report was written by Cynthia Kirk.Read and listen to our reports at WWW.51VOA.COM.I'm Steve Ember.