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Next wave of HIV researchers

Collaboration of Overbaugh lab, UW helps Kenyans tackle viral epidemic

Nov. 21, 2002
Bhavna Chohan

Funded by the International AIDS Research and Training Program, Bhavna Chohan, a second-year doctoral student in pathobiology, examines cells for infection by HIV-1. She is the first Kenyan basic-sciences student to join Dr. Julie Overbaugh's lab. In the background, a cell expresses viral particles.

Photo illustration by Caren Brinkema

When AIDS emerged as a rampant threat to public health, it galvanized Dr. Julie Overbaugh's professional calling in molecular virology. Yet she didn't realize that one day her interest would take her 9,000 miles away to the sub-Saharan nation of Kenya.

Overbaugh, of the Human Biology Division, has joined scientists from Kenya's University of Nairobi during the last decade in gathering virological and clinical data, publishing reports and training one another in the understanding and control of HIV.

The longstanding relationships blossomed with the help of Dr. Joan Kreiss, professor of medicine and epidemiology at the University of Washington.

Kreiss sparked the initial connection when she ventured to Kenya in the 1980s as part of her training in infectious diseases. Then, in the early 1990s, Overbaugh, as a UW professor of microbiology, teamed with Kreiss and her Kenyan infrastructure.

"It became clear to all of us that we could do more if we combined our expertise and, thus, tackle HIV with a broader perspective," said Overbaugh, who joined Fred Hutchinson in 1999.

First, the new Overbaugh-Kreiss team embarked on a journey to Seattle's sister city, Mombasa, Kenya, where they established a research base. Overbaugh also joined forces with Kreiss' International AIDS Research and Training Program, which is funded through the National Institutes of Health-sponsored Fogarty Center.

"The program funds 10 to 20 new trainees a year, about half of whom are connected with our Kenyan studies," Kreiss said.

New areas of research

Training for the foreign scientists last anywhere from three months to four years. Each year, about half a dozen trainees begin studying for master's degrees in such areas as epidemiology and public health. When these clinicians and scientists return to Kenya, they use their skills to initiate new areas of HIV research.

Africa as a whole is a concern for HIV researchers. Of 40 million people living with HIV worldwide, 28.5 million reside in Africa's sub-Saharan regions.

"HIV disease is really an epidemic in our continent, and we still don't have the answers," said Dr. Phelgona Otieno, a Kenyan pediatrician who is earning a master's in public health at the UW.

Otieno, who studies HIV transmission through breast milk, is one of many Kenyan clinicians and pediatricians seeking to slow the spread of HIV.

Yet initially, Kenyan HIV researchers faced many hurdles in their studies. The researchers lacked the expertise, equipment, and infrastructure for basic HIV laboratory testing. Even tests to detect the presence of HIV were costly and rarely budgeted for in most projects, Otieno said.

Surmounting those hurdles is a major goal of the international program, Overbaugh said.

Support of independence

"We aim to provide resources and support for Kenyans to receive research training that can be used by them in their country," she said. "Our goal is to support the development of these young scientists as independent investigators."

Seattle researchers also travel to Kenya to learn about international health and to similarly begin new HIV research projects, often in collaboration with Kenyan scientists. These interactions have led to lasting collaborations, and the Kenyan research studies provide valuable data for researchers in both Kenya and Seattle.

"We are really glad that we have the Fred Hutch collaboration so we can do all the molecular virology," said Kenyan researcher Bhavna Chohan. "We do not have the capability of doing it back home."

Last year, Chohan became the first Kenyan basic-sciences doctoral student to join Overbaugh's lab. Her interest in HIV research began in 1986 when she screened blood for HIV. The prevalence of HIV in Kenyan urban areas was just 2 percent.

In 1993, Chohan began screening high-risk groups in Mombasa, a port city that lies along the Indian Ocean and connects to a major African highway. She tested commercial sex workers and long-distance truck drivers, particularly high-risk groups. In 1993-95, she said, 55.2 percent of sex workers tested in Mombasa were HIV positive. The samples she collected were sent to Overbaugh and Kreiss for a more in-depth evaluation.

Witnessing the helpless, ailing patients posed a challenge for Chohan. "That was the reason why I joined the international program and sought my master's and Ph.D.," she said.

To further her education, Chohan completed a master's in molecular biology in London. She will study at the UW for the next four years to complete her doctoral degree. With this training, Chohan will return to Kenya and lead HIV studies.

Overbaugh imagines that Chohan will be as successful as Dr. Ruth Nduati, one of the international program's earliest Kenyan trainees. Since her training, Nduati has become what Overbaugh calls "one of the leading and most influential scientists in the area of mother-to-infant HIV transmission."

Example of success

"There's nobody who has more authority in this area," Overbaugh said of Nduati. "She's a clear example of the success of this program and one of the people I most admire in the world."

Overbaugh also credits Nduati and Kreiss for their trial of HIV infection through breastfeeding, which provided key information about mother-to-infant infection rates. The study also had implications beyond Kenya.

"As a result of this trial, HIV positive women throughout the world have more information about the risk associated with breastfeeding their infant," Overbaugh said.

Overbaugh and Kreiss study several aspects of HIV and focus their interest in determining what factors affect the amounts of virus that is shed in breast milk and genital secretions.

The two also examine the differences between HIV-positive men and women. Their studies suggest that women and men are not equal in regard to HIV transmission. Women tend to be infected by multiple genetic variants of the virus, whereas men acquire just one variant.

With the Mombasa team, Overbaugh continues to study how infection from multiple variants of the virus affects immunity and disease progression. In addition, the researchers have started to isolate viruses for vaccine studies.

While more and more of the epidemiology for the HIV studies is based in Kenya, much of the virology is centered at Fred Hutchinson. The Kenyan students hope that all of this research and expertise eventually will be based in Kenya as well.

"We really need to do this work back home so we don't have to transport the specimens," Otieno said. "We would be able to bring a Julie Overbaugh-type laboratory to Kenya."

Until then, students such as Otieno and Chohan will keep conducting HIV research as they further their education.

Told that Overbaugh imagines them as the next wave of HIV research experts, both women earnestly nod in agreement. "That's what we hope," Chohan said with a grin.

[Marita Graube, a graduate in technical communications at the University of Washington, is a writer for Northwest Science and Technology.]

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