Subjects preliminarily eligible who choose to receive PrEP will be included after obtaining the informed consent and confirmation of eligibility within 45 days after the screening visit.

Once included, participants will be examined in a follow-up visit performed four weeks later and evaluated for evidence of seroconversion to HIV, medication compliance and clinical toxicity. The second follow-up visit will occur at 12th week and every 12 weeks successively (quarterly). Quarterly visits include HIV testing, serum creatinine and counseling on medication compliance and risk reduction.

The study has a total of 6 visits plus 2 extra visits for those participants enrolled in the PK study. In all visits will be assessed the risks, HIV testing will be performed, monitoring of renal function and dispensing of the drug Truvada [emtricitabine 1 tablet (FTC) / tenofovir (TDF) (200/300 mg) once a day orally for 12 months].

Participants who have completed 48 weeks of follow-up or prematurely discontinue a PrEP will be encouraged to return for a follow-up visit after discontinuation of medication for monitoring of the status and evaluation of HIV as the resolution of side effects.

Inclusion Criteria:

• Male (at birth) AND transgender women identity;
• Willing and able to provide informed consent in writing;
• Age = or > 18 years;
• Not infected by HIV-1, in accordance with the flowchart of testing from Brazilian Ministry of Health;
• Evidence risk for acquiring HIV-1, including any of the following:
• Anal or vaginal sex without a condom with two or more men or transgender women in the last 12 months, or
• 2 or more episodes of anal sex with at least one HIV+ sexual partner HIV + in the last 12 months, or
• Sex with a man or trans woman and diagnosis or report of any of the following STDs in the last 12 months: syphilis, rectal gonorrhea or chlamydial infection in the rectum.;
• Report of exchanging sex for money, presents, shelter or drugs.
• Able to provide a residential address or contact phone itself, or two personal contacts who would know about his whereabouts during the study period demonstrative;
• Adequate renal function: Creatinine clearance > or = 60 ml / min, estimated by the formula modification of diet in renal disease (MDRD, from English 'Modification of Diet in Renal Disease') within 45 days of enrollment;
• urine Tape with negative result or showing only traces of protein within 45 days prior to enrollment;

Exclusion Criteria:

• Signs or symptoms of acute HIV infection,which is confirmed by laboratory examination in subsequent samples;
• Active and severe infections previously diagnosed, including active tuberculosis or osteomyelitis and all infections requiring parenteral antibiotics (except STD that require intramuscular injections of antibiotics);
• clinically significant active medical problems, including heart disease poorly controlled (eg, symptoms ischemia, congestive heart failure) previously diagnosed malignancy, or which will require additional treatment;
• Patients with positive tests for antigens of hepatitis B surface (HBsAg);
• History of pathological bone fractures unrelated to trauma;
• Patients using any of the following: ARV, including nucleoside inhibitors, non-nucleoside reverse transcriptase inhibitors, protease inhibitors and antiretroviral agents under study, treatment with interferon (alpha, beta, or gamma) or interleukin (e.g. ,IL-2), with potential significant nephrotoxic agents, other agents which may inhibit or compete for renal elimination via active tubular secretion (eg probenecid) and / or other agents under study;
• Participation in a clinical trial using concomitant agents under investigation, including placebo-controlled trials using such agents;
• Patients who have any condition at the time of inclusion in the study, according to the opinion of the investigator, may prevent the provision of informed consent, make study participation unsafe, complicate data interpretation, or interfere anyway with the achievement of project objectives.

Male (at birth) AND transgender women identity;