HIV drug resistance surveillance protocols

In 2004, WHO in collaboration with HIVResNet developed a global strategy for surveillance and monitoring of HIV drug resistance (HIVDR).

As part of the strategy, WHO has developed surveillance protocols to assess the prevalence of HIVDR.

The current version of these protocols is available below. However, they are currently being modified. To obtain the latest drafts, please contact hiv-aids[at]who[dot]int.

1. HIVDR in populations starting and during ART (acquired HIVDR)

Two alternative protocols have been developed, one using a prospective design and one using a cross-sectional design. Due to issues surrounding feasibility of implementation with the assessment of HIV drug resistance in cohorts using the prospective protocol, WHO has shifted focus to the cross sectional method. The implementation of which also revealed constraints. Consequently, new protocols to assess the prevalence of HIV drug resistance in patients initiating ART, and to assess the effectiveness and emergence of HIV drug resistance at different time points while treatment is administered, are under development and will be released in early 2014.

The cross sectional survey method to assess HIV drug resistance during the course of ART provides a snapshot of rates of viral load suppression and HIV drug resistance amongst people with virological failure at representatively chosen ART clinics in a country. Specifically, results from this protocol:

  • Classify the proportion of adult or pediatric patients failing first line ART (defined as viral load > 1000 copies/ml) at sentinel ART clinics
  • Describe the pattern of HIV drug resistance in patients with detectable viral load

The objective of the prospective method were to:

  • Describe HIV drug resistance at baseline and 12 months after ART initiation
  • Evaluate the percentage of the cohort achieving “HIV drug resistance prevention” (defined as viral load suppression after 12 months of ART) and describe the pattern of HIV drug resistance among those with treatment failure.

2. HIVDR in infants less than 18 months of age

Surveillance to assess HIV drug resistance prevalence among HIV-infected children < 18 months of age is important for improving health outcomes and minimizing subsequent accumulation of drug resistant mutations among HIV infected children. This generic protocol describes a survey method to assess HIV drug resistance using remnant dried blood spot specimens from a representative sample of children <18 months being tested for early infant diagnosis in resource-limited countries. Results from this survey will support choice of first-line ART in this population.


3. HIVDR in recently infected populations (transmitted HIV drug resistance)

The present version of this protocol assesses the prevalence of HIV drug resistance among a limited number (N<47) people with recent HIV infection. It enables to assess whether there are high (>15%), moderate (5-15%) or low (<5%) levels of transmission of HIV drug resistance in the area where the survey is carried out. The protocol and instruction on how to interpret the data can be found below.