title: Factors responsible for mother-to-child HIV transmission in Ontario, Canada, 1996-2008.
abstract: OBJECTIVE
  Despite a high uptake of HIV screening and anti-retroviral prophylaxis in Ontario, several cases of mother-to-child (MTC) transmission occur every year. We wished to examine the modifiable factors responsible for MTC HIV transmission in Ontario, in particular HIV testing, antiretroviral prophylaxis and breast-feeding.
  
  
  METHODS
  Using the Ontario data from the Canadian Perinatal HIV Surveillance Program, we examined potential correlates of late maternal HIV diagnosis (i.e., diagnosed at or after delivery) among women delivering from 1996 to 2008. To better understand the factors responsible for MTC HIV transmission, we reviewed the medical charts of 35 HIV-infected infants born in Ontario.
  
  
  RESULTS
  Among the 645 HIV-infected mothers, 85 (13.2%) had late HIV diagnosis. The proportion with late HIV diagnosis significantly decreased during the study period, but did not differ by race/ethnicity group or maternal exposure category. With respect to the mothers of the 35 HIV-infected infants, 27 (77%) were diagnosed with HIV at or after delivery. The reasons no prenatal HIV test was performed were: not offered, offered but refused, no prenatal care, denied HIV testing history, and offered but not done. Reasons for no or incomplete antiretroviral  prophylaxis (ARP) among eight mothers diagnosed prior to or during pregnancy were: refused or non-compliant with ARP, and failed to inform care provider of HIV status.
  
  
  CONCLUSIONS
  Despite the recommendation for universal prenatal HIV counseling and voluntary testing adopted in Ontario, MTC transmission continued to occur, mostly due to late HIV diagnosis of the mother. Future work to reduce perinatal HIV infection should focus on enhancing timely HIV testing of pregnant women.
authors.forename: Dayu
authors.initials: D
authors.lastname: Lu
authors.forename: Juan
authors.initials: J
authors.lastname: Liu
authors.forename: Lindy
authors.initials: L
authors.lastname: Samson
authors.forename: Ari
authors.initials: A
authors.lastname: Bitnun
authors.forename: Sandra
authors.initials: S
authors.lastname: Seigel
authors.forename: Jason
authors.initials: J
authors.lastname: Brophy
authors.forename: Lynne
authors.initials: L
authors.lastname: Leonard
authors.affiliation: Dalla Lana School of Public Health, University of Toronto. editor@cpha.ca.
authors.forename: Robert S
authors.initials: RS
authors.lastname: Remis
mesh_terms: D019380:Anti-HIV Agents / Q000627:therapeutic use; D001942:Breast Feeding / Q000009:adverse effects; D057210:Delayed Diagnosis; D005260:Female; D015658:HIV Infections / Q000517:prevention & control / Q000635:transmission*; D006801:Humans; D007231:Infant, Newborn; D018445:Infectious Disease Transmission, Vertical; D008403:Mass Screening; D009864:Ontario; D056990:Post-Exposure Prophylaxis / Q000706:statistics & numerical data; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000175:diagnosis* / Q000188:drug therapy; D011295:Prenatal Care / Q000458:organization & administration*; D012307:Risk Factors
chemical_list: D019380:Anti-HIV Agents
keywords: Canada; HIV; Ontario; antiretroviral prophylaxis (ARP); late diagnosis; mother-to-child transmission
references.citation: J Acquir Immune Defic Syndr. 2002 Apr 15;29(5):484-94
references.pmid: 11981365
references.citation: Obstet Gynecol. 2003 Oct;102(4):782-90
references.pmid: 14551009
references.citation: Med J Aust. 2009 Apr 20;190(8):416-20
references.pmid: 19374612
references.citation: Acta Paediatr Suppl. 1994 Aug;400:43-5
references.pmid: 7833560
references.citation: JAMA. 2004 Jul 14;292(2):219-23
references.pmid: 15249571
references.citation: Obstet Gynecol. 2010 Jun;115(6):1247-1255
references.pmid: 20502297
references.citation: Clin Infect Dis. 2005 Feb 1;40(3):458-65
references.pmid: 15668871
references.citation: J Obstet Gynaecol Can. 2006 Dec;28(12):1103-1107
references.pmid: 17169235
references.citation: N Engl J Med. 1994 Nov 3;331(18):1173-80
references.pmid: 7935654
references.citation: AIDS. 2012 Mar 27;26(6):757-63
references.pmid: 22210635
references.citation: AIDS. 2008 May 11;22(8):973-81
references.pmid: 18453857
references.citation: PLoS One. 2012;7(11):e48077
references.pmid: 23152762