Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. Mobility and HIV in Tanzanian couples: both mobile persons and their partners show increased risk Coleman Kishamawe a,b, , Debby C.J. Vissers b, , Mark Urassa a,c , Raphael Isingo a,c , Gabriel Mwaluko a,c , Gerard J.J.M. Borsboom b , He ´le `ne A.C.M. Voeten b , Basia Zaba d , J. Dik F. Habbema b and Sake J. de Vlas b Objective: To investigate how mobility is related to sexual risk behavior and HIV infection, with special reference to the partners who stay behind in mobile couples. Methods: HIV status, sexual behavior and demographic data of 2800 couples were collected in a longitudinal study in Kisesa, rural Tanzania. People were considered short-term mobile if they had slept outside the household at least once on the night before one of the five demographic interviews, and long-term mobile if they were living elsewhere at least once at the time of a demographic round. Results: Overall, whereas long-term mobile men did not report more risk behavior than resident men, short-term mobile men reported having multiple sex partners in the last year significantly more often. In contrast, long-term mobile women reported having multiple sex partners more often than resident women (6.8 versus 2.4%; P ¼ 0.001), and also had a higher HIV prevalence (7.7 versus 2.7%; P ¼ 0.02). In couples, men and women who were resident and had a long-term mobile partner both reported more sexual risk behavior and also showed higher HIV prevalence than people with resident/ short-term mobile partners. Remarkably, risk behavior of men increased more when their wives moved than when they were mobile themselves. Conclusions: More sexual risk behavior and an increased risk of HIV infection were seen not only in mobile persons, but also in partners staying behind. Interventions aiming at reducing risk behavior due to mobility should therefore include partners staying behind. ß 2006 Lippincott Williams & Wilkins AIDS 2006, 20:601–608 Keywords: mobility, sexual behavior, HIV, couples, Tanzania Introduction Mobility is one of the many factors that have contributed to the AIDS epidemic [1–3]. Several studies have shown that people who travel or who have recently migrated tend to be at higher risk for HIV and other sexually transmitted diseases (STD) [4–8]. The role of migration in the spread of HIV has been described primarily as the result of men who become infected while they are away from home, and infect their wives or regular partners when they return [1,4,9]. Married men often travel without their spouses. Being away from their families and communities, and thus from social and sexual control, may cause mobile men to change their behavior. They From the a Tanzania Essential Strategies Against AIDS (TANESA), Mwanza, Tanzania, the b Department of Public Health, Erasmus MC, University Medical Center Rotterdam, The Netherlands, the c National Institute for Medical Research, Mwanza, Tanzania, and the d Centre for Populations Studies, London School of Hygiene and Tropical Medicine, London, UK. Correspondence to Debby Vissers, Department of Public Health, Erasmus MC, University Medical Center Rotterdam. PO Box 1738, 3000 DR Rotterdam, The Netherlands. E-mail: d.vissers@erasmusmc.nl  Both authors contributed equally to this paper. Received: 30 August 2005; revised: 30 November 2005; accepted: 7 December 2005. ISSN 0269-9370 Q 2006 Lippincott Williams & Wilkins 601