HPV Infection and Cervical Screening in Socially Isolated Indigenous Women Inhabitants of the Amazonian Rainforest.

Objective: Indigenous women from the Amazon regions have some of the highest rates of cervical cancer in the world. This study evaluated cervical cytology and human papillomavirus (HPV) in native women that differ by lifestyle and interaction with western society. Yanomami women are isolated deep in the Amazon with a hunter/gatherer lifestyle. Macuxi and Wapishana women live in proximity to western society.

Methods: To select a representative group of women from each district, random cluster sampling was used, considering each registered village as a cluster. Cervical samples were collected for cytology and HPV detection and typing by PCR amplification and next generation sequencing. The study was approved by the National IRB and by tribal leaders.

Results: 664 native women were enrolled from 13 indigenous villages (76% participation rate). Yanomami women had higher rates of abnormal cytology (5.1% vs. 1.8%, p = 0.04) and prevalent HR-HPV (34.1% vs. 19.2%, p<0.001). Yanomami women >35 y of age were significantly more likely to have HR-HPV, whereas women ≤ 35 y did not significantly differ between groups. Prevalence of HPV was significantly different amongst geographically clustered Yanomami women (p<0.004). The most prevalent HPV types in the entire group were HPV31 (8.7%), HPV16 (5.9%) and HPV18 (4.4%).

Conclusion: Isolated endogenous Yanomami women were more likely to be HPV+ and rates increased with age. Study of HPV in isolated hunter-gather peoples suggests that long-term persistence is a characteristic of prehistoric humans and patterns reflecting decreased prevalence with age in western society represents recent change. These studies have implications for cervical cancer prevention and viral-host relationships.