Use of rapid tests for perinatal HIV infection in resource-limited settings

The performance of 5 rapid HIV tests using whole blood in infants and children: selecting a test to achieve the clinical objective

BACKGROUND

Rapid tests have the potential to improve the identification of HIV-infected children in resource-limited settings. However, they remain underutilized because of a lack of data on their performance in the field using whole blood specimens. This study aimed to assess the accuracy of rapid tests for detecting HIV exposure, excluding HIV infection in HIV-exposed infants, and diagnosing HIV infection in children older than 18 months of age.

METHODS

Five rapid tests (First Response, Pareekshak, Determine, Smart Check, and Insti) were performed using whole blood from children enrolled in a multisite, cross-sectional study in South Africa. HIV enzyme-linked immunosorbent assay and DNA polymerase chain reaction results defined HIV exposure and infection, respectively, and were the standards used for comparison.

RESULTS

Of the 851 children enrolled, 186 (21.9%) were infected with HIV. For detecting HIV exposure, Determine demonstrated the highest sensitivity of 99.3% (95% confidence interval, 98.0-99.8) in early infancy, but sensitivity declined with age as seroreversion occurred. After 8 months of age, all tests except First Response excluded HIV infection in 82% to 100% of HIV-uninfected infants and, in conjunction with a clinical assessment, did not miss any HIV-infected children. Insti was the only test that detected all HIV-infected infants, albeit on the smallest number of samples. The performance of all rapid tests in children older than 18 months of age was similar to that in adults.

CONCLUSIONS

Determine was the only rapid test that had a high enough sensitivity for detecting HIV exposure in early infancy, but it identified seroreversion later in life than the other tests. Insti warrants further investigation for both indications.

Mother-to-child transmission of HIV: a global perspective

HIV-1 infection is a significant global source of childhood morbidity and mortality, and mother-to-child transmission (MTCT) is the major mode of infection. Research over the past two decades has improved our understanding of the pathogenesis of MTCT and pediatric HIV-1 infection, lending to the development of effective preventive and therapeutic strategies. However, successful implementation of these strategies has been limited in resource-constrained settings, where the majority of new pediatric HIV infections now occur. Continued efforts are necessary to better understand MTCT and to refine preventive and therapeutic strategies to allow their successful implementation in the most needed places.

Evaluation of seven rapid HIV tests to detect HIV-exposure and seroreversion during infancy

BACKGROUND

Failure to determine the HIV status of all pregnant women impedes progress in preventing and treating paediatric HIV because vertically exposed infants are not identified for prophylaxis, early HIV diagnosis and care.

OBJECTIVES

To assess the performance of rapid HIV tests in comparison to a laboratory-based HIV ELISA test for determining HIV-exposure and excluding HIV infection during infancy.

STUDY DESIGN

Seven rapid HIV tests were evaluated on 2266 stored samples from 116 HIV-exposed infants of known HIV status at four ages during infancy. The HIV ELISA for each sample was the standard against which rapid results were assessed to establish HIV-exposure.

RESULTS

Rapid tests did not perform uniformly during infancy. For detecting HIV-exposure the sensitivity of most rapid tests to 3 months of age approached that of an HIV ELISA however only Determine maintained this sensitivity (99.7%) throughout infancy. For excluding HIV infection (i.e. for correctly identifying HIV-uninfected infants) the specificity of all rapid tests except Determine exceeded that of the HIV ELISA from 7 months of age.

CONCLUSIONS

The use of rapid tests in infancy could improve identification and care of HIV-exposed infants. Further evaluation under field conditions is required before rapid tests can be incorporated into evidence-based diagnostic algorithms.