Development and implementation challenges of a quality assured HIV infant diagnosis program in Nigeria using dried blood spots and DNA polymerase chain reaction.
Nigeria has one of the highest HIV burdens as well as mother-to-infant transmission rates in the world. A pilot program using polymerase chain reaction (PCR)-based testing of dried blood spot (DBS) specimens was implemented to enable early identification of HIV-infected infants and timely referral and linkage to care. From February 2007 to October 2008, whole blood was collected by finger prick to prepare DBS from infants <18 months presenting in six public mother-and-child health facilities in Lagos, Nigeria. The DBS were tested using the Roche Amplicor HIV-1 DNA Test, v1.5. To monitor laboratory testing quality, all of the PCR-positive and 10% of the PCR-negative DBS were retested by the same method at another reference laboratory. Three hundred and sixty-five randomly selected infants were screened using HIV rapid tests (RT) according to the national algorithm and RT-negative and PCR-positive specimens were also tested using Genscreen enzyme-linked immunosorbent assay (EIA) (Bio-Rad, France). The turnaround time (TAT) from sample collection, testing, and dispatching of results from each health facility was monitored. A total of 1,273 infants with a median age of 12.6 weeks (1 day to 71.6 weeks) participated in the program and 280 (22.0%) were PCR positive. HIV transmission levels varied greatly in the different health facilities ranging from 7.1% to 38.4%. Infants aged 48 to 72 weeks had the highest level of PCR positivity (41.1%). All PCR-positive specimens were confirmed by retesting. The mean turnaround time from DBS collection to returning of the laboratory result to the health facilities was 25 days. Three infants were found to be HIV antibody negative by rapid tests but were positive by both PCR and the fourth generation EIA. The DBS-based PCR program accurately identified all of the HIV-infected infants. However, many programmatic challenges related to the laboratory and TAT were identified.
1 Nigerian Institute of Medical Research (NIMR) , Lagos, Nigeria .
Rosemary
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Chika
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Onwuamah
Olumuyiwa
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Azuka
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Okwuraiwe
Chin-Yih
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Omotayo
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Bolu
Kyle B
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Karidia
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Diallo
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Tapdiyel
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McPaul
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Vertefeuille
D000818:Animals; D001769:Blood / Q000821:virology*; D003890:Desiccation; D005260:Female; D015658:HIV Infections / Q000175:diagnosis*; D015497:HIV-1 / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009549:Nigeria; D016133:Polymerase Chain Reaction / Q000379:methods*; D013048:Specimen Handling / Q000379:methods*