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Table 2 Collection and laboratory analysis of samples included in the Project Accept pilot study*

From: HIV Surveillance in a Large, Community-Based Study: Results from the Pilot Study of Project Accept (HIV Prevention Trials Network 043)

  Thailand Tanzania Zimbabwe Soweto South Africa Vulindlela South Africa Subtype C (3 sites) All five sites
Prevalent HIV subtype(s) a CRF01_AE Multiple C C C   
In-country sample collection and testing
# household membersb 512 683 663 780 574 2,017 3,212
# eligible participantsc 348 417 553 625 509 1,687 2,452
# participants with two HIV rapid test resultsd 341 379 504 530 493 1,527 2,247
   # HIV NEG samples 336 348 426 430 366 1,222 1,906
   # HIV DISC samples 3 13 3 3 2 8 24
   # HIV POS samples 2 18 75 97 125 297 317
HIV prevalencee 0.6% 4.7% 14.9% 18.3% 25.4% 19.4% 14.1%
Analysis of HIV NEG samples
# HIV Combo reactivef   3 1 10   11 14
   # confirmed HIV-negative   2 1 4   5 7
   # HIV-positive, WB positive     6   6 6
   # HIV-positive, WB indeterminate   1      1
Analysis of HIV DISC samples
# HIV-negativeg 3 13 3 3 1 7 23
# HIV-positive, WB positiveh      1 1 1
Analysis of HIV POS samples
# HIV-negativei    1   1 2 2
Corrected sample numbers j        
Corrected # HIV NEG samples 339 360 430 427 368 1,225 1,924
Corrected # HIV POS samples 2 19 74 103 125 302 323
Corrected HIV prevalence 0.6% 5.0% 14.7% 19.4% 24.4% 19.8% 14.4%
  1. *WB: Western blot; OD-n: normalized optical density units; POS: positive; DISC: discordant; NEG: negative.
  2. aThe prevalent HIV subtypes at each site are indicated. Most HIV strains in Thailand are CRF01_AE. Multiple HIV subtypes are prevalent in Tanzania, including HIV subtypes A, C, and D. Most HIV infections in South Africa and Zimbabwe are subtype C. The column labeled "Subtype C" shows combined results from Vulindlela and Soweto, South Africa, and Zimbabwe.
  3. bAll household members (see Methods)
  4. cNumber (#) eligible participants excludes participants who had no contact, declined participation, were ineligible for the study, or had missing status.
  5. dSamples were characterized based on the results of the two HIV rapid tests (see Methods): HIV POS: two reactive HIV rapid tests. HIV DISC: one reactive and one non-reactive HIV rapid test. HIV NEG: two non-reactive HIV rapid tests.
  6. eHIV prevalence based on in-country testing: # HIV POS samples/total # samples × 100.
  7. fFourteen samples were initially reactive with the ARCHITECT HIV Ag/Ab Combo assay (HIV Combo, signal/cutoff >1). Note that according to the package insert, specimens that are initially reactive with HIV Combo must be retested in duplicate and only repeatedly reactive specimens are considered reactive. In this study, samples were analyzed only once because sample volumes were limiting.
  8. gTwenty-two samples were non-reactive with the Vitros EIA and non-reactive with the Aptima HIV RNA test; one sample was reactive with the Vitros EIA and non-reactive with the Aptima HIV RNA test.
  9. hOne sample was reactive with the Vitros EIA and was Western blot positive.
  10. iTwo samples were non-reactive with the Vitros EIA and non-reactive with the Aptima HIV RNA test.
  11. jCorrected sample numbers: The numbers of HIV POS and HIV NEG samples were adjusted by taking into account reclassification of samples based on quality control testing performed at the HPTN Network Laboratory.