title: Measures of viral load using Abbott RealTime HIV-1 Assay on venous and fingerstick dried blood spots from provider-collected specimens in Malawian District Hospitals.
abstract: BACKGROUND
  Viral suppression is a key indicator of antiretroviral therapy (ART) response among HIV-infected patients. Dried blood spots (DBS) are an appealing alternative to conventional plasma-based virologic testing, improving access to monitoring in resource-limited settings. However, validity of DBS obtained from fingerstick in field settings remains unknown.
  
  
  OBJECTIVE
  Investigate feasibility and accuracy of DBS vs plasma collected by healthcare workers in real-world settings of remote hospitals in Malawi. Compare venous DBS to fingerstick DBS for identifying treatment failure.
  
  
  METHODS
  We recruited patients from ART clinics at two district hospitals in Malawi, collecting plasma, venous DBS (vDBS), and fingerstick DBS (fsDBS) cards for the first 149 patients, and vDBS and fsDBS only for the subsequent 398 patients. Specimens were tested using Abbott RealTime HIV-1 Assay (lower detection limit 40 copies/ml (plasma) and 550 copies/ml (DBS)).
  
  
  RESULTS
  21/149 (14.1%) had detectable viremia (>1.6 log copies/ml), 13 of which were detectable for plasma, vDBS, and fsDBS. Linear regression demonstrated high correlation for plasma vs. DBS (vDBS: β=1.19, R(2)=0.93 (p<0.0001); fsDBS β=1.20, R(2)=0.90 (p<0.0001)) and vDBS vs. fsDBS (β=0.88, R(2)=0.73, (p<0.0001)). Mean difference between plasma and vDBS was 1.1 log copies/ml [SD: 0.27] and plasma and fsDBS 1.1 log copies/ml [SD: 0.31]. At 5000 copies/ml, sensitivity was 100%, and specificity was 98.6% and 97.8% for vDBS and fsDBS, respectively, compared to plasma.
  
  
  CONCLUSIONS
  DBS from venipuncture and fingerstick perform well at the failure threshold of 5000 copies/ml. Fingerstick specimen source may improve access to virologic treatment monitoring in resource-limited settings given task-shifting in high-volume, low-resource facilities.
authors.affiliation: Department of Health Policy and Management, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States; Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States. Electronic address: srutstein@unc.edu.
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Rutstein
authors.affiliation: UNC Project, Lilongwe, Malawi.
authors.forename: Deborah
authors.initials: D
authors.lastname: Kamwendo
authors.affiliation: Johns Hopkins University, United States.
authors.forename: Lebah
authors.initials: L
authors.lastname: Lugali
authors.affiliation: UNC Project, Lilongwe, Malawi.
authors.forename: Isaac
authors.initials: I
authors.lastname: Thengolose
authors.affiliation: UNC Project, Lilongwe, Malawi.
authors.forename: Gerald
authors.initials: G
authors.lastname: Tegha
authors.affiliation: UNC Center for AIDS Research and Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States.
authors.forename: Susan A
authors.initials: SA
authors.lastname: Fiscus
authors.affiliation: UNC Center for AIDS Research and Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States.
authors.forename: Julie A E
authors.initials: JA
authors.lastname: Nelson
authors.affiliation: Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States; UNC Project, Lilongwe, Malawi.
authors.forename: Mina C
authors.initials: MC
authors.lastname: Hosseinipour
authors.affiliation: Centers for Disease Control, Malawi.
authors.forename: Abdoulaye
authors.initials: A
authors.lastname: Sarr
authors.affiliation: Centers for Disease Control, Malawi.
authors.forename: Sundeep
authors.initials: S
authors.lastname: Gupta
authors.affiliation: Ministry of Health, Lilongwe, Malawi.
authors.forename: Frank
authors.initials: F
authors.lastname: Chimbwandira
authors.affiliation: Ministry of Health, Lilongwe, Malawi.
authors.forename: Reuben
authors.initials: R
authors.lastname: Mwenda
authors.affiliation: School of Public Health, Loma Linda University, United States.
authors.forename: Ronald
authors.initials: R
authors.lastname: Mataya
mesh_terms: D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use; D023241:Antiretroviral Therapy, Highly Active; D001800:Blood Specimen Collection; D059788:Dried Blood Spot Testing / Q000379:methods*; D005260:Female; D015658:HIV Infections / Q000097:blood* / Q000175:diagnosis* / Q000188:drug therapy / Q000821:virology; D015497:HIV-1 / Q000235:genetics; D006761:Hospitals; D006801:Humans; D008295:Malawi; D008297:Male; D018962:Phlebotomy / Q000379:methods; D012367:RNA, Viral / Q000097:blood; D012680:Sensitivity and Specificity; D019562:Viral Load / Q000379:methods*; D014766:Viremia / Q000097:blood / Q000821:virology
chemical_list: D019380:Anti-HIV Agents; D012367:RNA, Viral