Developing Respiratory Syncytial Virus (RSV) Surveillance Capacity in Bhutan: A Collaborative Initiative with WHO Support

Bhutan’s National Public Health Laboratory, under the Royal Centers for Disease Control (RCDC) has been implementing Influenza-Like Illness (ILI) and Severe Acute Respiratory Infections (SARI) sentinel surveillance and testing for influenza since 2011. In 2022, RCDC integrated the monitoring of SARS-CoV-2 and influenza, leveraging seven ILI and eleven SARI sentinel surveillance sites within the national surveillance network. The National Public Health Laboratory, designated as the National Influenza Centre (NIC), received formal recognition from WHO in 2023.

In parallel with (a) establishing integrated monitoring of SARS-CoV-2 and influenza, and (b) strengthening laboratory capacity, Bhutan has expressed a strong interest in developing the country's capacity for conducting Respiratory Syncytial Virus (RSV) surveillance. This interest was sparked by an introduction to RSV surveillance through the Global Influenza Surveillance and Response System (GISRS), presented by WHO during the Sixteenth Bi-Regional Meeting of National Influenza Centers and Influenza Surveillance in the WHO Southeast Asia and Western Pacific Regions held on 1-3 August 2023 in Dhaka, Bangladesh.

In response to the request, WHO organized a mission to support the establishment of RSV surveillance in Bhutan from 24–28 June 2024, with the following objectives:

• To review Bhutan’s national operational plan for integrating RSV into the ILI/SARI sentinel surveillance system, in collaboration with national stakeholders, prior to implementation.
• To orient laboratory and sentinel surveillance site staff on WHO RSV surveillance standards and RSV disease burden estimation approaches.
• To assess the laboratory and sentinel sites for their capacity to conduct RSV surveillance.

The mission consisted of international surveillance and laboratory experts from WHO headquarters, the WHO South-East Asia Regional Office (SEARO), and the WHO Collaborating Centre (WHO CC) at the Victorian Infectious Diseases Reference Laboratory (VIDRL), Melbourne, Australia.

A combination of methods was used to address the objectives, including discussions with key national stakeholders and assessments of laboratory and sentinel surveillance sites using standard tools to evaluate the capacities of the National Influenza Centre(NIC) and sentinel SARI hospitals for RSV integration.

It was observed that, currently, no laboratory testing for RSV is conducted in Bhutan, and data is limited to the 2016-2018 period, when SARI specimens were tested for respiratory syncytial viruses alongside influenza. During that period, RSV was detected in 20% of all SARI cases tested, with a higher burden observed in children under 2 years of age compared to older children under 15 years.

Based on the assessment of the current surveillance and laboratory status in Bhutan, the mission experts made the following key recommendations specific to RSV surveillance:

• Develop a unified protocol and operational plan for national integrated respiratory surveillance, recommending alignment with WHO standards for the integrated surveillance of influenza, SARS-CoV-2, and RSV..
• Prioritize monitoring seasonality, trends, and hospitalization burden estimation as primary objectives for RSV integrated surveillance among children under 2 years old. After at least one year of operational RSV integration, develop a protocol for estimating RSV hospitalization burden in collaboration with WHO and partners.
• Evaluate the yield of SARI cases from the four sentinel hospitals using historical SARI surveillance data to ensure the annual sample size requirement for RSV testing is met. Based on this evaluation, adjust the sampling strategy and, if necessary, increase the number of pilot sites.
• Establish a “Community of Practice” for integrated surveillance to enhance engagement of sentinel site clinicians and nurses. This forum can also serve as a platform for sharing information on global public health events related to influenza and other respiratory viruses with pandemic or epidemic potential.
• Re-establish RT-PCR testing for influenza, SARS-CoV-2, and RSV at the four regional laboratories involved in RSV integrated surveillance.
• Implement an intra-laboratory quality assurance scheme and enroll regional laboratories in the international RSV EQA scheme. If this is not available, RCDC should establish its own EQAP for the regional laboratories.

The mission concluded with the key message that Bhutan is well-positioned by 2026 to make an informed, evidence-based decision regarding the introduction of RSV preventive products.

Mission members collaborated with national counterparts from the Royal Centre for Disease Control to review the national operational plan for integrating RSV into the ILI/SARI sentinel surveillance system. The discussions also included planning for laboratory and sentinel site assessments, as well as organising joint training sessions to orient staff on WHO RSV surveillance standards. Photo-IHM/WHE-SEARO

Mission members met with the Health Secretary of the Ministry of Health and briefed him on the objectives of the mission, as well as the global influenza program’s work on RSV as part of the expanded Global Influenza Surveillance and Response System (GISRS). Photo-IHM/WHE-SEARO