WHO HIV drug resistance strategy
Introduction
The emergence of HIV drug resistance (HIVDR) is inevitable, given HIV's high replication and mutation rates and the necessity for lifelong antiretroviral treatment (ART). To maintain the effectiveness of first- and second-line antiretroviral (ARV) regimens, WHO recommends that countries develop a national strategy for HIVDR prevention and assessment.
WHO has brought together experts and institutions working in the area of HIV drug resistance to form WHO HIVResNet, a global network of individuals, institutions, and countries advising WHO on development and implementation of a public health approach to HIV drug resistance prevention and assessment. With the support of this group, WHO has developed a comprehensive strategy to minimize the emergence and transmission of HIV drug resistance, including technical briefing documents and generic protocols.
Key elements of WHO-recommended strategy
The WHO-recommended strategy provides country-level guidance for the following activities:
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National HIVDR working groups
Ministries of Health in coordination with National AIDS Councils should form national HIV drug resistance working groups, made up of ART programme planners, clinicians, epidemiologists, laboratorians, monitoring and evaluation specialists, community members, and partner organizations, to develop the strategy.
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HIVDR Early Warning Indicators (EWI)
Monitoring the extent to which ART sites function to minimize preventable HIV drug resistance (HIVDR) is the highest priority. The HIVDR Early Warning Indicators are ART site-based indicators associated with HIVDR prevention. Data are abstracted from medical and pharmacy records for a limited time period each year; ARV prescribing practices, on-time ART drug pick-up and clinic appointment-keeping, percentages of patients lost to follow-up and still on first-line ART at 12 months, and ARV drug stock-outs and shortages, are monitored. Data collection may be integrated with other monitoring of ART or assessing ART data quality.
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Surveys to assess acquired HIV drug resistance
The WHO generic protocol for monitoring HIVDR prevention during treatment in sentinel sites utilizes a standardized minimum-resource prospective survey methodology to assess the success of ART programmes in preventing HIVDR during the first year of treatment and identifies factors associated with the emergence of HIVDR which can be successfully addressed at the level of ART site and programmes.
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Surveillance of transmitted HIV drug resistance
(also called HIV drug resistance "threshold surveys") should be limited initially to geographic areas where transmitted HIVDR is likely to be seen first: cities or health planning areas where ART has been widely available for >3 years. WHO recommends genotyping remnant specimens collected from individuals < 25 years of age (and, for females, without previous pregnancies) consecutively diagnosed with HIV in serosurveys or at diagnostic sites, within each area. Separate surveys may be performed in different subgroups of interest in each area.
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Surveillance of initial HIV drug resistance
Overall Purpose: to assess initial drug-resistant HIV among children < 18 months of age and newly diagnosed with HIV in resource-limited countries in order to inform selection of first-line ART regimens for this population in each participating country and support global decision-making on regimens for this population.
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National drug resistance database
Development of a national database to hold HIVDR data is recommended. Selected data items will contribute to the WHO HIVResNet regional and global databases. Database applications are available from WHO to record and analyze data from WHO-recommended surveys. The applications were developed to minimize data entry and to utilize data collected routinely in HIV surveillance and patient care.
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Global drug resistance laboratory network
National HIVDR working groups coordinating WHO-recommended surveys should designate a national or regional WHO-accredited genotyping laboratory to provide quality-assured results for the surveys. WHO HIVResNet performs lab assessments for accreditation, which include lab reviews and an annual quality-assurance panel, and provides technical assistance.
- Review of HIVDR prevention activities implemented in the country and contributing to HIVDR prevention, includes:
- National guidelines on ART eligibility and prescribing
- Resources and training to support and monitor adherence
- Removal of barriers to continuous access to care, including patient charges and transport difficulties
- Resources and personnel for follow-up of ART patients
- Ongoing quality assurance for ARV drugs
- Continuity of ARV drug supplies; monitoring of shortages
- Minimum standard ART data recording
- Prevention programs to reduce HIV transmission from persons in treatment
- Analysis of data on HIVDR and HIVDR prevention
- Annual reports
National HIVDR working groups should report on all aspects of the strategy annually, and disseminate the reports. The annual reports should include recommendations for action to prevent HIVDR emergence and transmission.
Implementation of the WHO strategy
Support from our partners
In November 2006 the Bill & Melinda Gates Foundation awarded WHO a five-year grant for $15.2 million to implement the HIVDR strategy in countries most affected by the epidemic which are scaling up access to antiretroviral therapy. In 2007, the WHO global HIVDR strategy also received support from national governments, including Spain, Canada, Italy and the U.S., and support to specific countries from numerous other partners.