Global public health intelligence: World Health Organization operational practices.

Early warning and response are key to tackle emerging and acute public health risks globally. Therefore, the World Health Organization (WHO) has implemented a robust approach to public health intelligence (PHI) for the global detection, verification and risk assessment of acute public health threats. WHO's PHI operations are underpinned by the International Health Regulations (2005), which require that countries strengthen surveillance efforts, and assess, notify and verify events that may constitute a public health emergency of international concern (PHEIC). PHI activities at WHO are conducted systematically at WHO's headquarters and all six regional offices continuously, throughout every day of the year. We describe four interlinked steps; detection, verification, risk assessment, and reporting and dissemination. For PHI operations, a diverse and interdisciplinary workforce is needed. Overall, PHI is a key feature of the global health architecture and will only become more prominent as the world faces increasing public health threats.

WHO Global Situational Alert System: a mixed methods multistage approach to identify country-level COVID-19 alerts.

BACKGROUND: Globally, since 1 January 2020 and as of 24 January 2023, there have been over 664 million cases of COVID-19 and over 6.7 million deaths reported to WHO. WHO developed an evidence-based alert system, assessing public health risk on a weekly basis in 237 countries, territories and areas from May 2021 to June 2022. This aimed to facilitate the early identification of situations where healthcare capacity may become overstretched. METHODS: The process involved a three-stage mixed methods approach. In the first stage, future deaths were predicted from the time series of reported cases and deaths to produce an initial alert level. In the second stage, this alert level was adjusted by incorporating a range of contextual indicators and accounting for the quality of information available using a Bayes classifier. In the third stage, countries with an alert level of 'High' or above were added to an operational watchlist and assistance was deployed as needed. RESULTS: Since June 2021, the system has supported the release of more than US$27 million from WHO emergency funding, over 450 000 rapid antigen diagnostic testing kits and over 6000 oxygen concentrators. Retrospective evaluation indicated that the first two stages were needed to maximise sensitivity, where 44% (IQR 29%-67%) of weekly watchlist alerts would not have been identified using only reported cases and deaths. The alerts were timely and valid in most cases; however, this could only be assessed on a non-representative sample of countries with hospitalisation data available. CONCLUSIONS: The system provided a standardised approach to monitor the pandemic at the country level by incorporating all available data on epidemiological analytics and contextual assessments. While this system was developed for COVID-19, a similar system could be used for future outbreaks and emergencies, with necessary adjustments to parameters and indicators.

Description of the first global outbreak of mpox: an analysis of global surveillance data.

BACKGROUND: In May 2022, several countries with no history of sustained community transmission of mpox (formerly known as monkeypox) notified WHO of new mpox cases. These cases were soon followed by a large-scale outbreak, which unfolded across the world, driven by local, in-country transmission within previously unaffected countries. On July 23, 2022, WHO declared the outbreak a Public Health Emergency of International Concern. Here, we aim to describe the main epidemiological features of this outbreak, the largest reported to date. METHODS: In this analysis of global surveillance data we analysed data for all confirmed mpox cases reported by WHO Member States through the global surveillance system from Jan 1, 2022, to Jan 29, 2023. Data included daily aggregated numbers of mpox cases by country and a case reporting form (CRF) containing information on demographics, clinical presentation, epidemiological exposure factors, and laboratory testing. We used the data to (1) describe the key epidemiological and clinical features of cases; (2) analyse risk factors for hospitalisation (by multivariable mixed-effects binary logistic regression); and (3) retrospectively analyse transmission trends. Sequencing data from GISAID and GenBank were used to analyse monkeypox virus (MPXV) genetic diversity. FINDINGS: Data from 82 807 cases with submitted CRFs were included in the analysis. Cases were primarily due to clade IIb MPXV (mainly lineage B.1, followed by lineage A.2). The outbreak was driven by transmission among males (73 560 [96·4%] of 76 293 cases) who self-identify as men who have sex with men (25 938 [86·9%] of 29 854 cases). The most common reported route of transmission was sexual contact (14 941 [68·7%] of 21 749). 3927 (7·3%) of 54 117 cases were hospitalised, with increased odds for those aged younger than 5 years (adjusted odds ratio 2·12 [95% CI 1·32-3·40], p=0·0020), aged 65 years and older (1·54 [1·05-2·25], p=0·026), female cases (1·61 [1·35-1·91], p<0·0001), and for cases who are immunosuppressed either due to being HIV positive and immunosuppressed (2·00 [1·68-2·37], p<0·0001), or other immunocompromising conditions (3·47 [1·84-6·54], p=0·0001). INTERPRETATION: Continued global surveillance allowed WHO to monitor the epidemic, identify risk factors, and inform the public health response. The outbreak can be attributed to clade IIb MPXV spread by newly described modes of transmission. FUNDING: WHO Contingency Fund for Emergencies. TRANSLATIONS: For the French and Spanish translations of the abstract see Supplementary Materials section.

COVID-19 Mortality and Progress Toward Vaccinating Older Adults - World Health Organization, Worldwide, 2020-2022.

After the emergence of SARS-CoV-2 in late 2019, transmission expanded globally, and on January 30, 2020, COVID-19 was declared a public health emergency of international concern.* Analysis of the early Wuhan, China outbreak (1), subsequently confirmed by multiple other studies (2,3), found that 80% of deaths occurred among persons aged ≥60 years. In anticipation of the time needed for the global vaccine supply to meet all needs, the World Health Organization (WHO) published the Strategic Advisory Group of Experts on Immunization (SAGE) Values Framework and a roadmap for prioritizing use of COVID-19 vaccines in late 2020 (4,5), followed by a strategy brief to outline urgent actions in October 2021.† WHO described the general principles, objectives, and priorities needed to support country planning of vaccine rollout to minimize severe disease and death. A July 2022 update to the strategy brief§ prioritized vaccination of populations at increased risk, including older adults,¶ with the goal of 100% coverage with a complete COVID-19 vaccination series** for at-risk populations. Using available public data on COVID-19 mortality (reported deaths and model estimates) for 2020 and 2021 and the most recent reported COVID-19 vaccination coverage data from WHO, investigators performed descriptive analyses to examine age-specific mortality and global vaccination rollout among older adults (as defined by each country), stratified by country World Bank income status. Data quality and COVID-19 death reporting frequency varied by data source; however, persons aged ≥60 years accounted for >80% of the overall COVID-19 mortality across all income groups, with upper- and lower-middle-income countries accounting for 80% of the overall estimated excess mortality. Effective COVID-19 vaccines were authorized for use in December 2020, with global supply scaled up sufficiently to meet country needs by late 2021 (6). COVID-19 vaccines are safe and highly effective in reducing severe COVID-19, hospitalizations, and mortality (7,8); nevertheless, country-reported median completed primary series coverage among adults aged ≥60 years only reached 76% by the end of 2022, substantially below the WHO goal, especially in middle- and low-income countries. Increased efforts are needed to increase primary series and booster dose coverage among all older adults as recommended by WHO and national health authorities.

The World Health Organization's public health intelligence activities during the COVID-19 pandemic response, December 2019 to December 2021.

The coronavirus disease (COVID-19) presented a unique opportunity for the World Health Organization (WHO) to utilise public health intelligence (PHI) for pandemic response. WHO systematically captured mainly unstructured information (e.g. media articles, listservs, community-based reporting) for public health intelligence purposes. WHO used the Epidemic Intelligence from Open Sources (EIOS) system as one of the information sources for PHI. The processes and scope for PHI were adapted as the pandemic evolved and tailored to regional response needs. During the early months of the pandemic, media monitoring complemented official case and death reporting through the International Health Regulations mechanism and triggered alerts. As the pandemic evolved, PHI activities prioritised identifying epidemiological trends to supplement the information available through indicator-based surveillance reported to WHO. The PHI scope evolved over time to include vaccine introduction, emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants, unusual clinical manifestations and upsurges in cases, hospitalisation and death incidences at subnational levels. Triaging the unprecedented high volume of information challenged surveillance activities but was managed by collaborative information sharing. The evolution of PHI activities using multiple sources in WHO's response to the COVID-19 pandemic illustrates the future directions in which PHI methodologies could be developed and used.