page 108 Monitoring results: goals, strategic objectives and indicators 6. SURVEILLANCE Strategic Objective 4: strong immunization sytems are an integral part of a well-functioning health system. Indicator SO4.4: number of countries with case-based surveillance for vaccine-preventable diseases: invasive bacterial vaccine-preventable and rotavirus disease surveillance Highlights Case-based sentinel hospital surveillance for meningitis, pneumonia/sepsis, and diarrhoea with clinical data linked to laboratory results is being received at WHO from globally representative, high-performing surveillance sites in all six WHO regions. The Global IB-VPD and Rotavirus Disease Surveillance Networks have built up national, regional and global laboratory capacity for identifying and monitoring circulating strains of Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis, and rotavirus. The surveillance networks are being leveraged to test for additional vaccine-preventable diseases and diseases with vaccines in development, such as typhoid and other enteric pathogens such as norovirus, Shigella and enterotoxigenic Escherichia coli. Surveillance data are being shared through the new revised global electronic bulletin, regional bulletins and peer-reviewed publications. Surveillance data have been used to inform decision-making, support evidence-based vaccine introduction and monitor the impact of pneumococcal conjugate, rotavirus and Hib vaccines. DEFINITION OF INDICATOR The number of countries that report conducting case-based surveillance, including laboratory confirmation, for rotavirus and invasive bacterial vaccine-preventable diseases (IB-VPDs), at one or more hospital-based sentinel sites, the data from which are included in WHO databases TARGET 75% of low- and middle-income countries for sentinel site surveillance by 2020 DATA SOURCES Data reported annually through the WHO-UNICEF JRF; and data reported by sentinel sites participating in a WHO-coordinated surveillance network
Monitoring results: goals, strategic objectives and indicators page 109 Overview of the WHO-coordinated Global IB-VPD and Rotavirus Disease Surveillance Networks, 2008 2015 In 2008, WHO brought together existing regional surveillance to establish standardized global sentinel hospital surveillance networks for rotavirus disease and IB-VPD. These active, syndromic sentinel site surveillance networks report case-based clinical and laboratory data for children aged under 5 years hospitalized with acute gastroenteritis (to monitor rotavirus) and IB-VPD (currently cases of meningitis, pneumonia or sepsis to monitor Streptococcus pneumoniae, Haemophilus influenzae and Neisseria meningitidis). When the networks were initiated, the main objectives were as follows: During the pre-vaccine introduction period: a. provide data for describing disease epidemiology, including disease burden estimates; b. establish a platform to measure impact of vaccine introduction; c. identify circulating serotypes of genotypes of the principal vaccine-preventable pathogens. In the post-vaccine introduction period: a. assess disease trends; b. monitor changes in circulating strains; c. use the platform to monitor programme impact and document vaccine effectiveness. WHO provides managerial oversight, technical assistance to countries and financial support to countries for surveillance activities, with a focus on Gavieligible countries. WHO has established networks of sentinel hospital and national laboratories supported by regional and global reference laboratories and conducts an annual external quality assessment (EQA) programme that targets participating laboratories; conducts sentinel site assessments; provides technical advice and laboratory supplies to sites; and shares data semi-annually via a global surveillance and information bulletin that was revised in 2015 (available at http:// eepurl.com/bztdaz). An online data management tool is in development and is currently being piloted. This tool will facilitate the case-based data collection, entry and analysis at the sentinel site and also the consolidation of data at WHO headquarters. In 2013, WHO, under the oversight of the internal Technical Advisory Group (itag) and with technical partner guidance, conducted a strategic review of the surveillance networks. As of 2015, all but two of 40 recommendations from the 2013 Strategic Review and 35 recommendations from the 2014 Global Surveillance Meeting have been implemented. Of the remaining two recommendations, work is under way to conduct studies of surveillance costs to help strengthen in-country support of the network and improve sustainability. The other recommendation to share specimens with the regional reference laboratories among all the target hospitals was deemed not to be feasible by April 2015 because of limitations of capacity and the human and financial resources required; however, some hospitals and regions participate in quality-control activities. In 2015, the Global Rotavirus Surveillance Network comprised 114 sentinel surveillance sites in 53 countries (Figure 6.1) and the Global IB-VPD Surveillance Network comprised 114 sentinel sites in 52 countries (Figure 6.2). In addition, in response to comments from the SAGE DoV working group and to better reflect the current status of surveillance globally, this year the GVAP Secretariat is reporting countries that conduct surveillance for IB-VPD and rotavirus but do not report surveillance data to WHO as part of the Global Rotavirus and IB-VPD Surveillance Networks. These countries may have either conducted surveillance according to WHO recommended methodology but not reported data to WHO, or they may have conducted surveillance using a method that is not recommended as the Network method, such as aggregated data instead of case-based, laboratory-based instead of syndromic surveillance, or limited to one pathogen, such as S. pneumoniae. For sites not participating in the WHO coordinated network, WHO does not currently have the resources or capacity to assess the quality of their surveillance. However, some of these countries and surveillance sites participate in WHO-organized training activities and data sharing dissemination and meetings. In 2015, there were at least 44 countries that conducted rotavirus surveillance but were not part of the WHO-coordinated Global Rotavirus Surveillance Network Figure 6.2) and 63 countries that conducted IB-VPD surveillance but were not part of the WHO-coordinated Global IB-VPD Surveillance Network (Figure 6.1).
page 110 Monitoring results: goals, strategic objectives and indicators Comparison of SO4.4 indicator and target with strategic review recommendations In 2014, SAGE accepted a change in the indicator and target for SO4.4, which was amended to read as follows: Number of countries meeting established surveillance standards with case-based surveillance for vaccinepreventable diseases and with viral and bacterial laboratory confirmation of suspect or probable cases. Seventy-five per cent of low- and middle-income countries have sentinel hospital surveillance that meets surveillance standards for rotavirus diarrhoea or other national priority vaccine-preventable diseases. WHO monitors the performance of sites globally each quarter when data are reported, and regional offices are given an in-depth report of sentinel site performance. Based on discussions with the sentinel sites, the performance indicators were revised and simplified in 2015 from 15 to 4, for each network. In addition, all sentinel hospital laboratories or laboratories that process surveillance specimens should participate in EQA. The surveillance standards for the IB-VPD sentinel surveillance sites are as follows: reporting a. Green: 100 suspected meningitis; 500 b. Yellow: 80 99 meningitis; 400 499 4. Laboratory-confirmed cases with serotype/group a. Green: 80% b. Yellow: 60% Most IB-VPD sites performed well and maintained or improved their performance in 2015 compared with previous years (Figure 6.3). However, the percentage of sites that consistently reported surveillance data decreased. A percentage of specimens with a serotype have not been presented for 2015 because laboratory testing data from 2015 are not yet complete. The surveillance standards for the rotavirus disease sentinel surveillance sites are as follows: reporting a. Green: 100 suspected meningitis b. Yellow: 80 99 meningitis 4. Specimens tested for rotavirus by enzyme immunoassays (EIAs) In general, the rotavirus sites performed better than the IB-VPD sites (Figure 6.4). Similar to the IB-VPD sites, the rotavirus sites maintained or improved their performance in 2015 compared with previous years, except for consistent reporting. There were highperforming sites in all regions for both networks. The future of IB-VPD and rotavirus surveillance The Global IB-VPD and Rotavirus Disease Surveillance Networks have met their objectives and have matured into strong, long-standing surveillance systems. Globally representative, long-term surveillance for IB-VPD and diarrhoeal diseases in a selected number of high-performing sites is essential for continued monitoring of pneumococcal, Hib, meningococcal, and rotavirus diseases after vaccine introduction. Sustainable, high-quality surveillance that produces data that are used nationally and globally is the goal of the networks. Although there are high-performing sites in all regions, performance in some sites needs to be strengthened, especially for consistent reporting, laboratory confirmation of organisms and monitoring of strains. This underscores the need for consistent support and funding of surveillance at country level and for continued coordination and monitoring at regional and global levels. The surveillance networks will need to work toward country ownership and finding sources of funding in addition to the Gavi Alliance, especially for Gavi-
Monitoring results: goals, strategic objectives and indicators page 111 graduating and middle-income countries. Within Gavi-eligible countries, funding for routine surveillance activities should as much as possible be transitioned to health systems strengthening funding, which is more sustainable than other sources of Gavi funds. The networks should consider collaborations and cost sharing with other VPD surveillance systems and projects, such as the Measles and Rubella Initiative and the Global Health Security Initiative. It will be important to consider how polio surveillance activities will affect these networks. As funding for polio activities decrease as the disease is eliminated, these networks will not be able to leverage polio-funded staff and support. In addition, polio containment affects collection and storage of diarrhoeal specimens as part of rotavirus surveillance. As the surveillance networks have matured, the objectives of surveillance have evolved. In addition to the original objectives, there is now a focus on burden and vaccine impact of pneumococcus and rotavirus in regions with gaps in data, namely Asia. Surveillance needs to monitor long-term changes after vaccine introduction, such as for pneumococcal serotype replacement, and to address new policy questions, such as for alternate and reduced PCV schedules. Antimicrobial resistance has also become a global concern that can be addressed through these networks. In November 2013, SAGE noted the opportunities for integration by building upon the enhanced capacity developed by these networks to conduct surveillance for other diseases using a similar case definition (e.g. Japanese encephalitis is included in meningitis surveillance in regions such as the Western Pacific and South-East Asia) and laboratory procedures (e.g. identification of other bacterial pathogens in laboratories conducting IB-VPD surveillance). Pilot testing of integrated typhoid surveillance at four IB- VPD surveillance sites (two each in Africa and Asia) is under way; sites have been selected and surveillance in all four sites will start before the end of 2016. A survey of norovirus testing capacity was conducted at all regional laboratories and many national laboratories affiliated with the Global Rotavirus Surveillance Network. In some regions, such as PAHO, influenza is commonly monitored in the same sentinel sites that conduct pneumonia surveillance, and other respiratory pathogens such as respiratory syncytial virus (RSV) and pertussis could potentially be monitored as well. One study leveraged a novel diagnostic test, the TaqMan Array Card (TAC), to test specimens gathered as part of the surveillance network for more than 25 enteric pathogens in addition to rotavirus. With support from the Bill & Melinda Gates Foundation (BMGF) and partners at the University of Virginia and the U.S. Centers for Disease Control and Prevention, TAC laboratory testing capacity was built at five regional references laboratories globally. More than 1200 specimens were tested from 11 countries in Africa, Asia and the Americas. The first phase of the project was completed in 2015 and showed that this novel diagnostic testing platform could be used successfully in many laboratories globally to identify the causes of diarrhoea in children, including those which have vaccines in development, such as norovirus, E. coli and Shigella. The role of WHO in VPD surveillance is to generate and monitor surveillance trends globally; to lead, coordinate, and advocate for surveillance activities with countries and partners, including EQA/QC; to set global norms and standards for surveillance; to support countries with technical assistance and in evidence-based policy decisions; and to support research that uses surveillance data, builds on surveillance platforms, and informs surveillance, vaccine impact and policy. Being part of the networks can provide benefits to countries: technical support on epidemiology, laboratory, and data management; EQA/QC; linkages with partners; opportunities for network activities and studies (e.g. norovirus, typhoid, TAC), and in some cases funding. WHO will continue to support and work with countries to strengthen their surveillance and help them analyse their data so that they can be used and are available at country, regional and global levels.
page 112 Monitoring results: goals, strategic objectives and indicators Figure 6.1: Countries that conducted IB-VPD surveillance in 2015 Non Gavi-eligible countries in the WHO IB-VPD Surveillance Network Gavi-eligible countries in the WHO IB-VPD Surveillance Network Non Gavi-eligible countries having a functioning surveillance system but not reporting to the WHO IB-VPD Surveillance Network Gavi-eligible countries having a functioning surveillance system but not reporting to the WHO IB-VPD Surveillance Network Not available Not applicable Data source: WHO/IVB Database. Figure 6.2: Countries that conducted rotavirus surveillance in 2015 Non Gavi-Eligible countries in the WHO Rotavirus Surveillance Network Gavi eligible countries in the WHO Rotavirus Surveillance Network Non Gavi-eligible countries having a functioning surveillance system but not reporting to the WHO Rotavirus Surveillance Network Gavi-eligible countries having a functioning surveillance system but not reporting to the WHO Rotavirus Surveillance Network Not available Not applicable Data source: WHO/IVB Database.
Monitoring results: goals, strategic objectives and indicators page 113 Figure 6.3: Global IB-VPD Surveillance Network sentinel site performance indicators 100 90 80 70 60 50 40 30 20 10 0 2013 2014 2015 2013 2014 2015 2013 2014 2015 2013 2014 2015 Month No. of cases Specimens Serotype Legend: reporting a. Green: 100 suspected meningitis; 500 b. Yellow: 80 99 meningitis; 400 499 4. Laboratory-confirmed cases with serotype/group a. Green: 80% b. Yellow: 60% Figure 6.4: Global Rotavirus Surveillance Network sentinel site performance indicators 100 90 80 70 60 50 40 30 20 10 0 2013 2014 2015 2013 2014 2015 2013 2014 2015 2013 2014 2015 Month No. of cases Specimens EIAs Legend: reporting a. Green: 100 suspected meningitis; 500 b. Yellow: 80 99 meningitis; 400 499 4. Laboratory-confirmed cases with serotype/group a. Green: 80% b. Yellow: 60%