NEW: Sexually transmitted infections
Guest edited by Jesse L. Clark, Weiming Tang and Vicente Estrada
NEW: HIV and TB co-infection
Guest Edited by Francesco Di Gennaro, Harriet Mayanja-Kizza, Peter Nyasulu and Sheela Shenoi
Animal models in infectious diseases
Guest edited by Zulqarnain Baloch, Hin Chu and Luis Martinez-Sobrido
Neglected tropical diseases
Guest edited by Rodrigo Feliciano do Carmo and Wei Wang