Human immunodeficiency virus infection and syphilis among homeless people in a large city of Central-Western Brazil: prevalence, risk factors, human immunodeficiency virus-1 genetic diversity, and drug resistance mutations Raquel Silva Pinheiro; Paulie Marcelly Ribeiro dos Santos Carvalho; Marcos André de Matos; Karlla Antonieta Amorim Caetano; Andressa Cunha de Paula; Megmar Aparecida dos Santos Carneiro; Mônica Nogueira da Guarda Reis; Regina Maria Bringel Martins; Mariane Martins de Araújo Stefani; Sheila Araujo Teles;