title: Multiple human papillomavirus infections are highly prevalent in the anal canal of human immunodeficiency virus-positive men who have sex with men.
abstract: BACKGROUND
  Anal cancer has become one of the most common non-AIDS-defined tumors among Human Immunodeficiency Virus-positive (HIV+) individuals, and a rise in its incidence among HIV+ Men who have Sex with Men (MSM) has been shown, despite the introduction of Highly Active Anti-Retroviral Therapy (HAART). Human Papillomavirus (HPV) infections are highly prevalent among HIV+ MSM and recent studies have shown high rates of HPV-associated anal intraepithelial neoplasia (AIN) and anal cancer among this population.
  
  
  METHODS
  In the present study we determined the prevalence and nature of HPV co-infections in the anal canal of 324 HIV+ MSM attending a high specialty medical center in Mexico City, DNA extraction and amplification with generic primers for HPV was performed, followed by detection of specific types and co-infections with INNO-Lipa, and identification of variants by amplification and sequencing of the E6 and LCR region of HPV 16.
  
  
  RESULTS
  We found a very high prevalence of HPV infections among this cohort (86%), with more than one fourth of them (28%) positive for type 16. Among HPV16-positive patients, European variants were the most prevalent, followed by Asian-American ones. Among these individuals (HPV-16+), we identified co-infections with other 21 HPV types namely; 11, 51, 52, 6, 66, 68, 74, 18, 45, 35, 26, 44, 70, 53, 54, 82, 31, 33, 56, 58, 59.
  
  
  CONCLUSIONS
  HIV+ MSM show a very high rate of HPV infections in the anal canal and those with type 16 exhibited a multiplicity of associated types. This study emphasizes the need for an early detection of HPV infections among HIV+ MSM in order to establish its utility to prevent anal neoplasia and cancer.
authors.affiliation: División de Investigación, Instituto Nacional de Cancerología, Secretaría de Salud (SSA), México D.F., Mexico. rocmenmar@yahoo.com.
authors.forename: Rocío
authors.initials: R
authors.lastname: Méndez-Martínez
authors.affiliation: Instituto Nacional de Ciencias Médicas y Nutrición "Salvador Zubirán," SSA, México D.F., Mexico. normaerm@hotmail.com.
authors.forename: Norma E
authors.initials: NE
authors.lastname: Rivera-Martínez
authors.affiliation: Instituto Nacional de Ciencias Médicas y Nutrición "Salvador Zubirán," SSA, México D.F., Mexico. brendcrabtree@hotmail.com.
authors.forename: Brenda
authors.initials: B
authors.lastname: Crabtree-Ramírez
authors.affiliation: Instituto Nacional de Ciencias Médicas y Nutrición "Salvador Zubirán," SSA, México D.F., Mexico. jsmadero@yahoo.com.
authors.forename: Juan G
authors.initials: JG
authors.lastname: Sierra-Madero
authors.affiliation: Instituto Nacional de Ciencias Médicas y Nutrición "Salvador Zubirán," SSA, México D.F., Mexico. yaninkc@yahoo.com.mx.
authors.forename: Yanink
authors.initials: Y
authors.lastname: Caro-Vega
authors.affiliation: Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México D.F., Mexico. sgalvan@servidor.unam.mx.
authors.forename: Silvia C
authors.initials: SC
authors.lastname: Galván
authors.affiliation: Dirección de Investigación Clínica, Instituto Nacional de Cancerología, Secretaría de Salud (SSA), México D.F., Mexico. dcantu3@excite.com.
authors.forename: David Cantú
authors.initials: DC
authors.lastname: de León
authors.affiliation: Unidad de Investigación Biomédica en Cáncer, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México and Instituto Nacional de Cancerología, SSA, México D.F., Mexico. carranca@biomedicas.unam.mx.|Laboratory of Virus & Cancer Instituto Nacional de Cancerología, Av. San Fernando No. 22, Colonia Sección XVI, México D.F., Tlalpan, 14080, México. carranca@biomedicas.unam.mx.
authors.forename: Alejandro
authors.initials: A
authors.lastname: García-Carrancá
mesh_terms: D000328:Adult; D001003:Anal Canal / Q000821:virology*; D023241:Antiretroviral Therapy, Highly Active; D001005:Anus Neoplasms / Q000821:virology; D002278:Carcinoma in Situ / Q000821:virology; D002294:Carcinoma, Squamous Cell / Q000821:virology; D060085:Coinfection; D004279:DNA, Viral / Q000032:analysis*; D015658:HIV Infections / Q000188:drug therapy / Q000453:epidemiology*; D006679:HIV Seropositivity; D018451:Homosexuality, Male; D006801:Humans; D015994:Incidence; D008297:Male; D008800:Mexico; D008875:Middle Aged; D017720:Molecular Epidemiology; D027383:Papillomaviridae / Q000235:genetics* / Q000302:isolation & purification; D030361:Papillomavirus Infections / Q000453:epidemiology* / Q000821:virology; D015995:Prevalence
chemical_list: D004279:DNA, Viral