Jonathan Stieglitz(r) in Bolivia
Jonathan Stieglitz, right, in Bolivia

UNM Department of Anthropology Research Assistant Professor Jonathan Stieglitz is lead author of a new paper published this week in PLoS ONE that examines the changes as part of a long running research project among Tsimane forager-farmers of the Bolivian Amazon.

The paper, "Modernization, Sexual Risk-Taking, and Gynecological Morbidity among Bolivian Forager-Horticulturalists" explores how sexual behavior changes with modernization for both men and women and the consequence of these behavior changes for women's reproductive health. The researchers were very interested in understanding whether Tsimane who lived closer to the market town of San Borja are more likely to take sexual risks, and whether that in turn led to greater exposure to sexually transmitted infections.

The Tsimane are forager-farmers in a rural area of Bolivia that still maintain their own small scale villages composed of closely related kin. They speak an indigenous language which is unrelated to the Spanish spoken in nearby towns. The Tsimane are in the early stages of modernization as they increasingly come into contact with a wider world. They lack material wealth, electricity and running water and their access to schooling and modern healthcare, including contraception, remains extremely limited. Tsimane men and some women are becoming a part of the local economy as they travel to regional town markets to sell wood, thatched roof panels and horticultural products. Sporadically, men engage in itinerant wage labor.

More than 500 sexually active women received gynecological exams and PAP smears as part of the Tsimane project's routine screening for cervical cancer.  Forty-eight percent exhibited inflammation of cervical cells and most inflammation is due to bacterial vaginosis (35 percent). In 11 percent, however, the inflammation results from trichomoniasis, a sexually transmitted infection.

The research group is currently funded by the National Institutes of Health (National Institute of Aging) to learn both about the aging process under pre-modern conditions and how modernization influences physiology, behavior and sociality over the lifespan. The project employs full-time Bolivian physicians and biochemists to visit villages annually. The project has also established a stationary health clinic in San Borja. Regardless of their participation in research, all Tsimane receive free health care from project physicians.

Stieglitz initially became interested in the issue as part of his Ph.D. research into marital conflict and cooperation. 

"People often think about modernization as being associated with improved health outcomes and greater access to schools," says Stieglitz. "But for indigenous, subsistence populations in the early stages of modernization, where money is scarce and its acquisition highly variable over time, where people may lack knowledge of how infections may be sexually transmitted and where people may be reluctant to communicate with medical professionals in town due to linguistic or geographical barriers, mistrust, or prior discrimination, modernization may lead to a new increase in risk of reproductive morbidity."

He says it is counter-intuitive that women who live near towns where there are hospitals are actually more likely to have a sexually transmitted infection, but that is one of their major findings.

Collaborators include Aaron Blackwell, UC Santa Barbara; Raúl Quispe (Tsimane project;) Edhitt Cortez (Tsimane Project;) Michael Gurven, UC Santa Barbara and Hillard Kaplan, UNM.

Media contact: Karen Wentworth (505) 277-5627; email: