Dried blood spots perform well in viral load monitoring of patients who receive antiretroviral treatment in rural Tanzania.
BACKGROUND
Monitoring of antiretroviral treatment (ART) with human immunodeficiency virus (HIV) viral loads, as recommended in industrialized countries, is rarely available in resource-limited settings because of the high costs and stringent requirements for storage and transport of plasma. Dried blood spots (DBS) can be an alternative to plasma, but the use of DBS has not been assessed under field conditions in rural Africa. The present study investigates the performance of DBS in HIV viral load monitoring of patients who received ART in rural Tanzania.


METHODS
From November 2007 through June 2008, parallel plasma and DBS specimens were obtained from patients who received ART at Haydom Lutheran Hospital in rural Tanzania. DBS specimens were stored at tropical room temperature for 3 weeks before testing with the NucliSENS EasyQ HIV-1 v1.2 assay. Results obtained with DBS were compared with results obtained with use of a gold-standard plasma assay.


RESULTS
Ninety-eight plasma-DBS pairs were compared, and plasma viral loads ranged from <40 to >1,000,000 copies/mL. The correlation between plasma and DBS viral load was strong (R(2) = 0.75). The mean difference (+/- standard deviation) was 0.04 +/ 0.57 log(10) copies/mL, and only 8 samples showed >1 log(10) copies/mL difference. HIV type 1 RNA was detected in 7%, 60%, and 100% of DBS specimens with corresponding plasma viral loads of 40-999, 1000-2999, and 3000 copies/mL, respectively.


CONCLUSIONS
DBS, in combination with the NucliSENS EasyQ HIV-1 v1.2 asay, performed well in monitoring HIV viral loads in patients who received ART in rural Tanzania, although the sensitivity was reduced when viral burden was low. The use of DBS can simplify virological monitoring in resource-limited settings.
Johannessen
Asgeir
A
Ulleval Department of Infectious Diseases, Oslo University Hospital, Oslo, Norway. asgeir.johannessen@medisin.uio.no
Garrido
Carolina
C
Zahonero
Natalia
N
Sandvik
Leiv
L
Naman
Ezra
E
Kivuyo
Sokoine L
SL
Kasubi
Mabula J
MJ
Gundersen
Svein G
SG
Bruun
Johan N
JN
de Mendoza
Carmen
C
D000293:Adolescent; D000328:Adult; D000368:Aged; D044966:Anti-Retroviral Agents / Q000627:therapeutic use; D001769:Blood / Q000821:virology*; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D003906:Developing Countries; D005260:Female; D015658:HIV Infections / Q000097:blood / Q000188:drug therapy / Q000821:virology*; D015497:HIV-1 / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010949:Plasma / Q000821:virology*; D011933:Reagent Kits, Diagnostic; D012424:Rural Population; D012680:Sensitivity and Specificity; D013048:Specimen Handling / Q000379:methods; D013636:Tanzania; D019562:Viral Load; D055815:Young Adult
D044966:Anti-Retroviral Agents; D011933:Reagent Kits, Diagnostic