title: A meta-analysis of human papillomavirus type-distribution in women from South Asia: implications for vaccination.
abstract: OBJECTIVE
  To determine human papillomavirus (HPV) prevalence and type-distribution in women from South Asia, with and without cervical lesions, in order to estimate the impact of an HPV 16/18 prophylactic vaccine in this region and to assess additional types that should be incorporated in new vaccines.
  
  
  METHODS
  A meta-analysis was conducted that included studies using polymerase chain reaction to detect HPV-16, -18, -6, -11 and at least one other HPV type, with a minimum of 20 cases in each grade of lesion. Total as well as type-specific prevalence of various HPV types were estimated, stratified by cervical lesion grade, using Stata 9.0 software package.
  
  
  RESULTS
  Nine studies from India fulfilled the inclusion criteria. A total of 558, 52, 52 and 3061 women, respectively with invasive cervical cancer (ICC), high-grade squamous intraepithelial lesions (HSIL), low-grade squamous intraepithelial lesions (LSIL) and normal cytology/histology were included. Overall HPV prevalence was 94.6%, 86.5%, 65.4% and 12.0% in women with ICC, HSIL, LSIL and normal cytology/histology, respectively. In ICC, HPV-16 was the predominant type (64.8%), followed by HPV-18, -45, -33, -35, -58, -59 and -31. The estimated HPV-16/18 positive fraction was 78.9% in women with ICC (87.7% in North and 77.2% in South India), 61.5% with HSIL, 30.8% with LSIL and 3.9% in women with normal cytology/histology. There was no difference in overall HPV prevalence in cervical cancer between North and South India (P=0.063). However, HPV-16 and -45 appeared to be more prevalent in North India (P=0.018 and 0.013, respectively), while HPV-35 appeared to be more prevalent in South India (P=0.033).
  
  
  CONCLUSIONS
  It is estimated that HPV-16/18 vaccines will provide over 75% protection against ICC in South Asia. HPV-45, -33, -35 and -58 account for an additional 20% of cervical cancer in this region. The addition of these additional HPV types in a second-generation vaccine could provide optimal cervical cancer prevention in this region.
authors.affiliation: Department of Obstetrics & Gynaecology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India. nbhatla@aiims.ac.in
authors.forename: Neerja
authors.initials: N
authors.lastname: Bhatla
authors.forename: Neena
authors.initials: N
authors.lastname: Lal
authors.forename: Yan-Ping
authors.initials: YP
authors.lastname: Bao
authors.forename: Timothy
authors.initials: T
authors.lastname: Ng
authors.forename: You-Lin
authors.initials: YL
authors.lastname: Qiao
mesh_terms: D001210:Asia, Southeastern / Q000453:epidemiology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D030361:Papillomavirus Infections / Q000453:epidemiology* / Q000517:prevention & control* / Q000821:virology; D053918:Papillomavirus Vaccines / Q000627:therapeutic use*
chemical_list: D053918:Papillomavirus Vaccines