Rapid Diagnostic Testing of Hospitalized Malawian Children Reveals Opportunities for Improved HIV Diagnosis and Treatment

New diagnosis of mother-to-child transmission of HIV in 8 Latin-American countries during 2018

BACKGROUND

Important prevention efforts have led to a reduction in mother-to-child transmission of HIV (MTCT) globally. However, new cases of paediatric HIV infections still occur. Early diagnosis of new HIV infections is essential to start an appropriate antiretroviral treatment to avoid childhood morbidity and mortality related to infection. The aim of this study was to describe the new cases of MTCT in Latin-American referral hospitals.

METHODS

A retrospective, multicentre and descriptive study of the new cases of MTCT diagnosed during 2018 in 13 referral hospitals from 8 Latin-American countries (Costa Rica, Ecuador, El Salvador, Guatemala, Honduras, Mexico, Nicaragua, and Panama) belonging to PLANTAIDS (Paediatric Network for Prevention, Early Detection and Treatment of HIV in Children), was conducted. PLANTAIDS is included in CYTED (Ibero-American Programme of Science and Technology for Development).

RESULTS

Eighty-one children (40.7% males) were included, median age at diagnosis of 2.33 years (IQR:0.7-4.7). Less than 3% of women knew their HIV diagnosis before pregnancy. More than 80% of them were diagnosed after delivery, 8.7% during pregnancy, and 2.9% at delivery. Only one patient underwent antiretroviral therapy (ART) prior to pregnancy. At diagnosis, 50.0% of the children presented with an advanced stage of disease (stage C following the current CDC classification for HIV infection), and 34.4% had less than 15% CD4+ cells/mm3. The time elapsed between delivery and the maternal diagnosis was correlated with the age of children at diagnosis, ρ = 0.760, p < 0.001. Younger age at diagnosis (p = 0.03), a smaller number of previous hospitalizations (p < 0.01), and better immunovirological status (p < 0.01) were found in children whose mothers knew their HIV status at delivery, compared to mothers who were not aware of it.

CONCLUSIONS

Although MTCT in Latin America has declined in recent years, our series shows there are still cases that indicate some failures in prevention, being a critical point to improve an earlier diagnosis of pregnant women. Half of the children were diagnosed in an advanced stage of disease and the delay in maternal diagnosis entailed a worse clinical and immunological child' prognosis.

Point-of-care tests detecting HIV nucleic acids for diagnosis of HIV-1 or HIV-2 infection in infants and children aged 18 months or less

BACKGROUND

The standard method of diagnosing HIV in infants and children less than 18 months is with a nucleic acid amplification test reverse transcriptase polymerase chain reaction test (NAT RT-PCR) detecting viral ribonucleic acid (RNA). Laboratory testing using the RT-PCR platform for HIV infection is limited by poor access, logistical support, and delays in relaying test results and initiating therapy in low-resource settings. The use of rapid diagnostic tests at or near the point-of-care (POC) can increase access to early diagnosis of HIV infection in infants and children less than 18 months of age and timely initiation of antiretroviral therapy (ART).

OBJECTIVES

To summarize the diagnostic accuracy of point-of-care nucleic acid-based testing (POC NAT) to detect HIV-1/HIV-2 infection in infants and children aged 18 months or less exposed to HIV infection.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (until 2 February 2021), MEDLINE and Embase (until 1 February 2021), and LILACS and Web of Science (until 2 February 2021) with no language or publication status restriction. We also searched conference websites and clinical trial registries, tracked reference lists of included studies and relevant systematic reviews, and consulted experts for potentially eligible studies.

SELECTION CRITERIA

We defined POC tests as rapid diagnostic tests conducted at or near the patient site. We included any primary study that compared the results of a POC NAT to a reference standard of laboratory NAT RT-PCR or total nucleic acid testing to detect the presence or absence of HIV infection denoted by HIV viral nucleic acids in infants and children aged 18 months or less who were exposed to HIV-1/HIV-2 infection. We included cross-sectional, prospective, and retrospective study designs and those that provided sufficient data to create the 2 × 2 table to calculate sensitivity and specificity. We excluded diagnostic case control studies with healthy controls.

DATA COLLECTION AND ANALYSIS

We extracted information on study characteristics using a pretested standardized data extraction form. We used the QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies) tool to assess the risk of bias and applicability concerns of the included studies. Two review authors independently selected and assessed the included studies, resolving any disagreements by consensus. The unit of analysis was the participant. We first conducted preliminary exploratory analyses by plotting estimates of sensitivity and specificity from each study on forest plots and in receiver operating characteristic (ROC) space. For the overall meta-analyses, we pooled estimates of sensitivity and specificity using the bivariate meta-analysis model at a common threshold (presence or absence of infection).

MAIN RESULTS

We identified a total of 12 studies (15 evaluations, 15,120 participants). All studies were conducted in sub-Saharan Africa. The ages of included infants and children in the evaluations were as follows: at birth (n = 6), ≤ 12 months (n = 3), ≤ 18 months (n = 5), and ≤ 24 months (n = 1). Ten evaluations were field evaluations of the POC NAT test at the point of care, and five were laboratory evaluations of the POC NAT tests.The POC NAT tests evaluated included Alere q HIV-1/2 Detect qualitative test (recently renamed m-PIMA q HIV-1/2 Detect qualitative test) (n = 6), Xpert HIV-1 qualitative test (n = 6), and SAMBA HIV-1 qualitative test (n = 3). POC NAT pooled sensitivity and specificity (95% confidence interval (CI)) against laboratory reference standard tests were 98.6% (96.1 to 99.5) (15 evaluations, 1728 participants) and 99.9% (99.7 to 99.9) (15 evaluations, 13,392 participants) in infants and children ≤ 18 months. Risk of bias in the included studies was mostly low or unclear due to poor reporting. Five evaluations had some concerns for applicability for the index test, as they were POC tests evaluated in a laboratory setting, but there was no difference detected between settings in sensitivity (-1.3% (95% CI -4.1 to 1.5)); and specificity results were similar.

AUTHORS' CONCLUSIONS

For the diagnosis of HIV-1/HIV-2 infection, we found the sensitivity and specificity of POC NAT tests to be high in infants and children aged 18 months or less who were exposed to HIV infection.