Early Infant Diagnosis

Export Indicator

Percentage of infants born to women living with HIV receiving a virological test for HIV within two months of birth
What it measures

Progress in the extent to which infants born to women living with HIV are tested within the first two months of life to determine their HIV status and eligibility for antiretroviral therapy disaggregated by test results

Rationale

Infants acquiring HIV during pregnancy, delivery or early postpartum often die before they are recognized as having HIV infection. WHO recommends that national programmes establish the capacity to provide early virological testing of infants for HIV at six weeks or as soon as possible thereafter to guide clinical decision-making at the earliest possible stage. HIV disease progresses rapidly among children; they need to start treatment as early as possible because, without early treatment, almost 50% of children would be dead by the second year.

Numerator

Number of infants who received an HIV test within two months of birth during the reporting period. Infants tested should only be counted once.

Denominator

Number of pregnant women living with HIV giving birth in the past 12 months

Calculation

Numerator/denominator

Method of measurement

For the numerator. Early infant diagnosis testing laboratories.

For the denominator. Estimation models such as Spectrum or antenatal clinic surveillance surveys in combination with demographic data and appropriate adjustments related to the coverage of antenatal clinic surveys

Measurement frequency

Annual or more frequently, depending on a country’s monitoring needs

Disaggregation

The numerator should be disaggregated by the result: positive, negative, indeterminate or rejected for testing

Explanation of the numerator

To be collected from the databases held at early infant diagnosis testing laboratories. The numerator should represent the number of infants who received virological testing within two months of birth; it should not represent the number of samples tested at the laboratory. Data should be aggregated from the laboratory databases. Where possible, double counting should be minimized when the data are aggregated to produce national-level data. The number of infants receiving more than one virological test in the first two months of life is expected to be low. Efforts should be made to include all health facilities operated by public, private and NGOs that are providing HIV testing for HIV-exposed infants.

The test results should be reported as positive, negative, indeterminate or rejected for testing by the laboratory. This information should only include the most recent test result for an infant tested in the first two months of life.

Explanation of the denominator

This is a proxy measure for the number of infants born to women living with HIV. Two methods can be used to estimate the denominator: an estimation model, such as Spectrum software, using the output, the number of pregnant women needing services to prevent mother-to-child transmission as a proxy; or if Spectrum projections are unavailable, multiplying the total number of women giving birth in the past 12 months (which can be obtained from central statistics office estimates of births or United Nations Population Division estimates) by the most recent national estimate of HIV prevalence for pregnant women (which can be derived from HIV sentinel surveillance in antenatal clinics and appropriate adjustments related to the coverage of antenatal clinic surveys).

To ensure comparability, the Spectrum output will be used for the denominator for global analysis.

Strengths and weaknesses

This indicator allows countries to monitor progress in providing early HIV virological testing to HIV-exposed infants two months or younger, which is critical for appropriate follow-up care and treatment. Limiting the age to two months or younger also eliminates the potential for repeat tests for the same infant, which can lead to double counting. The only three fields needed for this indicator—date of sample collection, age at collection (actual or calculated based on the date of birth) and results—are systematically entered into central early infant diagnosis testing databases at testing laboratories.

Because of the small number of testing laboratories and the electronic format of testing databases, this indicator should not have a heavy collection burden. The data quality of the laboratories is generally high, resulting in a robust indicator. The indicator does not capture the number of children with a definitive diagnosis of HIV infection or measure whether appropriate follow-up services were provided to the child based on interpretation of the test results. It also does not measure the quality of testing or the system in place for testing. A low value of the indicator could, however, signal systemic weaknesses, including poor country-level management of supplies of HIV virological test kits, poor data collection, poor follow-up and mismanagement of testing samples.

Disaggregation by test results cannot be used as a proxy for overall mother-to-child transmission rates. If either the overall national early infant diagnosis coverage or the early infant diagnosis testing coverage in the first two months of life is low, low positivity rates among the infants tested will not necessarily mean programme success, since this sample does not include many other infants who are likely positive.

Although early virological testing is a critical intervention for identifying infants living with HIV, countries should also strengthen the quality of followup of HIV-exposed infants and train health providers to recognize the signs and symptoms of early HIV infection among exposed infants, especially if access to virological testing is limited. Inappropriate management of supplies can negatively affect the value of the indicator and significantly reduce access to HIV testing for the infants born to women living with HIV. Countries should ensure that appropriate systems and tools, especially tools for logistics management information systems, are in place to procure, distribute and manage supplies at the facility, district and central levels.

Further information

Progress reports on HIV (http://www.who.int/hiv/pub/progressreports/en).

Next generation indicators reference guide. Washington (DC): United States President’s Emergency Plan for AIDS Relief; 2013 (http://www.pepfar. gov/documents/organization/206097.pdf).

Measuring the impact of national preventing the mother-to-child transmission of HIV programmes: towards the elimination of new HIV infections among children by 2015 and keeping their mothers alive. A short guide on methods. Geneva: World Health Organization; 2012 (http://apps.who.int/ iris/bitstream/10665/75478/1/9789241504362_eng.pdf).