WHO Indicators for Infectious Disease Monitoring Performance and Data Sources

WHO Indicators for Monitoring Infectious Diseases

The World Health Organization (WHO) utilizes a comprehensive set of indicators to monitor, evaluate, and track the burden and control of infectious diseases globally. These indicators are essential for informed public health policy, resource allocation, and progress tracking towards targets like the Sustainable Development Goals (SDGs), specifically SDG Target 3.3, which aims to end the epidemics of AIDS, tuberculosis (TB), malaria, and neglected tropical diseases, and combat hepatitis, water-borne diseases, and other communicable diseases by 2030.

The indicators span various dimensions, including disease incidence and prevalence (burden), mortality, and the effectiveness of interventions like vaccination and treatment coverage.

Global Mortality Trends for Select Major Infectious Diseases (Deaths in Thousands)

Infectious Disease	Year 2000 (Deaths in '000s)	Year 2010 (Deaths in '000s)	Year 2019 (Deaths in '000s)	Year 2021 (Deaths in '000s)
COVID-19	N/A	N/A	N/A	8,740
Lower Respiratory Infections	3,365	2,746	2,370	2,377
Diarrhoeal Diseases	1,887	1,489	1,515	1,513
Tuberculosis (TB)	1,607	1,328	1,215	1,330
HIV/AIDS	2,056	1,273	647	650
Malaria	864	741	643	627

Source: World Health Organization (WHO) Global Health Estimates (GHE)

Core Infectious Disease Indicators (Selected)

The following table presents a selection of key infectious disease indicators tracked by WHO, often aligned with SDG 3.3, covering major global health challenges.

Disease/Area	Indicator	Measurement	Relevance/Goal
HIV/AIDS	New HIV infections	Rate per 1,000 uninfected population	Monitoring prevention and control efforts.
	People living with HIV receiving Anti-retroviral Therapy (ART)	Percentage (%)	Tracking treatment access and program coverage.
Tuberculosis (TB)	Tuberculosis incidence	Rate per 100,000 population per year	Measuring the annual burden of new cases.
	TB treatment success rate	Percentage (%)	Assessing the effectiveness of TB control programs.
Malaria	Malaria incidence	Rate per 1,000 population at risk	Tracking the risk and new cases in endemic areas.
	Malaria mortality rate	Rate per 100,000 population	Measuring deaths attributable to malaria.
Hepatitis	Hepatitis B surface antigen (HBsAg) prevalence among children under 5 years	Percentage (%)	Assessing the impact of Hepatitis B immunization.
Neglected Tropical Diseases (NTDs)	People requiring interventions against NTDs	Number	Monitoring the need for treatment and care.
	Population requiring mass drug administration (MDA) for specific NTDs	Number/Percentage	Tracking progress toward elimination goals.
Vaccine-Preventable Diseases	Diphtheria Tetanus Toxoid and Pertussis (DTP3) immunization coverage among 1-year-olds	Percentage (%)	A core measure of routine immunization system strength.
	Measles-containing-vaccine second-dose (MCV2) immunization coverage	Percentage (%)	Measuring protection against a highly contagious viral disease.
Antimicrobial Resistance (AMR)	Proportion of bloodstream infections due to specific resistant bacteria (e.g., E. coli resistant to 3rd-generation cephalosporins)	Percentage (%)	Monitoring the emergence and spread of drug-resistant pathogens.
Surveillance & Response	Average of International Health Regulations (IHR) core capacity scores	Score/Index	Assessing a country's readiness to detect and respond to public health events.
	Reported cases of selected epidemic-prone diseases (e.g., Cholera, Polio)	Number of cases	Crucial for early detection and outbreak response.

Indicator Categories and Utility

WHO's infectious disease indicators generally fall into several key categories, each serving a distinct purpose in public health:

1. Burden of Disease Indicators

These indicators quantify the scale of the disease problem.

Incidence: The rate of new cases of a disease in a specific population over a period (e.g., TB incidence per 100,000 population per year). This is vital for tracking current transmission and the speed of spread.
Prevalence: The total number or proportion of cases (new and existing) in a population at a given time (e.g., HBsAg prevalence). Useful for estimating the overall pool of infection.
Mortality: The number of deaths attributable to a disease (e.g., Malaria mortality rate). Essential for measuring the deadliest impact of a disease.

2. Intervention Coverage Indicators

These measure the extent to which effective public health tools are being used.

Vaccination Coverage: The percentage of the target population receiving recommended vaccines (e.g., DTP3 coverage). Directly measures preventive efforts.
Treatment Coverage: The percentage of people with a disease who are receiving the appropriate treatment (e.g., ART coverage for HIV). Measures access to life-saving care.

3. Health System and Preparedness Indicators

These assess the ability of a country's health system to manage infectious disease threats.

Surveillance Quality: Measures like the International Health Regulations (IHR) core capacity scores evaluate the functions necessary for detecting, assessing, reporting, and responding to public health events.
Laboratory Capacity: Availability and quality of laboratory testing for diagnosis and antimicrobial susceptibility.

4. Antimicrobial Resistance (AMR) Indicators

A growing area of focus, these indicators track the resistance of pathogens to therapeutic drugs, crucial for guiding treatment protocols and global surveillance.

By continuously monitoring these indicators, the WHO and its Member States can identify high-risk areas, measure the impact of interventions, and adapt strategies to control and eliminate infectious diseases.

WHO Burden of Disease Indicators

The World Health Organization (WHO) utilizes a set of core indicators, primarily housed within its Global Health Estimates (GHE), to quantify and compare the impact of various health problems across different populations. This comprehensive measurement, known as the Burden of Disease, goes beyond simple death counts to capture the full scope of health loss from illness, disability, and premature death. By providing standardized metrics, these indicators are crucial for informing health policy, prioritizing interventions, and monitoring progress towards global health goals.

Key WHO Burden of Disease Indicators

The foundational metric for calculating the burden of disease is the Disability-Adjusted Life Year (DALY). The DALY is a time-based measure that combines two components to represent the loss of a year of healthy life. One DALY can be thought of as one lost year of "healthy" life.

The main indicators used to assess the burden of disease are:

Indicator	Metric Type	Calculation/Description	Policy Relevance
Disability-Adjusted Life Years (DALYs)	Time-based summary measure	Sum of Years of Life Lost (YLL) due to premature mortality and Years Lived with Disability (YLD). Represents the total healthy life lost due to disease or injury.	Essential for overall prioritization and comparing the total impact of different diseases (e.g., cancer vs. mental health).
Years of Life Lost (YLL)	Mortality component of DALY	Calculated as the number of deaths multiplied by a standard life expectancy at the age of death. Measures the impact of premature mortality.	Highlights diseases/risks that cause early death and require prevention efforts like road safety or infectious disease control.
Years Lived with Disability (YLD)	Morbidity component of DALY	Calculated as the number of prevalent cases multiplied by a Disability Weight (DW) for the health condition. Measures the impact of non-fatal health outcomes.	Crucial for identifying conditions (like mental disorders, chronic pain, or non-fatal injuries) that impose a long-term drain on health and resources.
Healthy Life Expectancy (HALE)	Health Expectancy measure	The average number of years a person can expect to live in "full health" based on current mortality and morbidity rates.	Monitors the quality of life component of longevity, not just life span, aiding in planning for aging populations and chronic care.
Mortality	Event-based (Death)	The number of deaths, mortality rate (per 1,000 or 100,000 population), or cause-specific deaths (e.g., number of deaths from Ischaemic Heart Disease).	Provides the most fundamental measure of a disease's lethality and tracks progress in reducing deaths from major causes.

Understanding the DALY

The Disability-Adjusted Life Year (DALY) is the cornerstone of the WHO's burden of disease framework. It provides a single, comparable metric that simultaneously accounts for the time lost due to early death and the time lived in states of suboptimal health.

\text{DALY} = \text{YLL} + \text{YLD}

Years of Life Lost (YLL): This is a measure of premature death. It quantifies the difference between the age at which a person died and a standard life expectancy for that age. A high YLL indicates diseases or injuries that kill people early in life.
Years Lived with Disability (YLD): This accounts for non-fatal conditions. It is calculated by taking the number of people living with a specific disease or injury and multiplying it by a Disability Weight (DW), a value between 0 (perfect health) and 1 (death) that reflects the severity of the health condition. A high YLD suggests widespread or severe non-fatal chronic conditions.

By using DALYs, public health officials can compare the total impact of conditions like tuberculosis (high YLL due to early death) with depression (high YLD due to prolonged, disabling illness), ensuring that diseases causing long-term suffering are not overlooked in favor of those causing immediate death.

WHO Intervention Coverage Indicators

The World Health Organization (WHO) uses a strategic set of Intervention Coverage Indicators to monitor the performance of national health systems and track progress toward Universal Health Coverage (UHC), particularly under Sustainable Development Goal (SDG) 3.8. These indicators measure the proportion of a population in need of a service who actually receive that service, demonstrating how effectively essential health interventions are reaching the public.

The gold standard for tracking service delivery across countries is the UHC Service Coverage Index (SDG Indicator 3.8.1), which is a composite score based on 14 "tracer" indicators that cover a comprehensive range of health services, from promotion and prevention to treatment and care.

Key WHO Tracer Indicators for Universal Health Coverage

The UHC Service Coverage Index aggregates data from 14 tracer indicators, categorized into four broad areas to ensure a balanced assessment of a country's health service delivery. The primary measurement is a percentage ($\%$ coverage), defined as:

\text{Coverage} = \frac{\text{Number of people who received the intervention}}{\text{Number of people who need the intervention}} \times 100

The following table outlines representative examples of these key intervention coverage indicators:

Service Area	Tracer Indicator	Target Population/Condition	Purpose
I. Reproductive, Maternal, Newborn, and Child Health (RMNCH)	Antenatal Care (ANC 4+)	Pregnant women	Percentage of women receiving $\mathbf{4}$ or more ANC visits. Monitors access to quality maternal services.
	Skilled Birth Attendance (SBA)	All live births	Percentage of births attended by a physician, nurse, or midwife. Reflects access to safe delivery care.
	DTP3 Immunization Coverage	Infants (under 1 year)	Percentage of infants receiving the third dose of diphtheria-tetanus-pertussis vaccine. A proxy for the reach of essential child health services.
	Demand for Family Planning Satisfied with Modern Methods	Women of reproductive age (15-49)	Percentage of women (married/in-union) whose need for family planning is met by modern methods. Measures reproductive health equity and access.
II. Infectious Diseases	Tuberculosis Treatment Coverage	People with confirmed/diagnosed TB	Percentage of estimated incident TB cases successfully treated. Measures health system capacity to manage prevalent infectious diseases.
	Antiretroviral Therapy (ART) Coverage	People living with HIV (PLHIV)	Percentage of PLHIV receiving ART. Essential for epidemic control and chronic disease management.
	Basic Sanitation Services	Total population	Percentage of population using at least basic sanitation facilities. Measures environmental health protection and disease prevention.
III. Non-Communicable Diseases (NCDs)	Hypertension Treatment Coverage	Adults with hypertension	Percentage of adults with hypertension currently receiving treatment (medication). Tracks service delivery for common NCDs.
	Cervical Cancer Screening	Women (within a target age range)	Percentage of women screened in the past 3-5 years. Measures preventive care for high-burden NCDs.
IV. Service Capacity and Access	Hospital Bed Density	Total population	Number of hospital beds per 10,000 population (relative to a defined threshold). An indicator of available infrastructure.
	Health Worker Density	Total population	Number of physicians, nurses, and midwives per 10,000 population. An indicator of the human resources available in the system.

Significance of Intervention Coverage Indicators

Intervention coverage indicators are vital tools in global health for several reasons:

1. Guiding Universal Health Coverage (UHC)

The indicators provide a quantifiable way to monitor the breadth and depth of services a country is providing. High coverage across the four service categories suggests a robust health system that is moving closer to the ideal of UHC—where everyone receives the services they need without financial hardship.

2. Identifying Equity Gaps

Measuring coverage allows analysts to disaggregate data by factors like household wealth, geographic location (urban/rural), age, and education. This is critical for identifying equity gaps, where specific vulnerable groups are being left behind, thus guiding targeted resource allocation.

3. Reflecting Health System Performance

Unlike health impact indicators (like mortality rates), which can take years to show change, coverage indicators are sensitive to program implementation. An increase in childhood immunization coverage, for example, is a direct, measurable result of a successful health campaign or improved service delivery. This allows for rapid feedback to policymakers on the effectiveness of their policies and investments.

4. Moving Towards "Effective Coverage"

While simple coverage (receipt of service) is important, WHO increasingly emphasizes Effective Coverage. This advanced metric takes quality into account:

\text{Effective Coverage} = \text{Coverage} \times \text{Need} \times \text{Quality}

This ensures that services are not only delivered but are also of sufficient quality to produce the desired health outcome. For example, a woman receiving Antenatal Care is only effectively covered if the care she received included essential, high-quality interventions like blood pressure monitoring and syphilis screening, not just a registration visit.

WHO Health System and Preparedness Indicators 🌎

The World Health Organization (WHO) plays a crucial role in guiding countries to build robust, resilient health systems capable of delivering universal health coverage (UHC) and ensuring health security. To monitor progress and identify gaps, WHO utilizes a framework of Health System and Preparedness Indicators that cover the six core health system "building blocks," alongside specific metrics for health security and emergency readiness.

These indicators move beyond simply tracking health outcomes (like mortality rates) to assess the capacity, performance, and resilience of the underlying health infrastructure, workforce, financing, and governance. By monitoring these areas, countries can strategically invest in improvements, especially in the context of increasing global health challenges and the need to maintain essential services during emergencies.

Key WHO Health System and Preparedness Indicators

WHO's monitoring draws heavily on its six health system building blocks and specialized tools like the SCORE (Survey, Count, Optimize, Review, Enable) package for health information and the International Health Regulations (IHR) for preparedness. The table below outlines core indicators across these critical areas:

Area of Assessment	Indicator Category	Examples of Core Indicators	Purpose in Monitoring
I. Health Service Delivery	Access & Quality of Care	Coverage of essential health services (UHC service coverage index), Proportion of births attended by skilled health personnel, Immunization coverage.	Measures the reach and effectiveness of services to the population.
II. Health Workforce	Capacity & Distribution	Density of health workers (e.g., medical doctors, nurses, midwives) per 1,000 or 10,000 population, Geographical distribution/equity of staff.	Assesses the availability, competency, and equitable distribution of human resources.
III. Health Information	Data & Surveillance	Completeness of death registration (Civil Registration and Vital Statistics - CRVS), Availability of routine health facility data (e.g., outpatient visits), Implementation status of core surveillance systems.	Monitors the capacity to generate, analyze, and use reliable health data for decision-making.
IV. Medical Products, Vaccines & Technology	Availability & Accessibility	Availability and affordability of essential medicines and commodities, Percentage of health facilities with basic equipment/supplies.	Ensures the necessary tools and supplies for treatment and prevention are present and accessible.
V. Health Financing	Financial Protection & Investment	Current health expenditure (CHE) as a percentage of GDP, Domestic general government health expenditure as a percentage of general government expenditure, Catastrophic health expenditure incidence (Out-of-pocket spending).	Tracks resource allocation and financial protection for the population, moving towards UHC.
VI. Leadership/Governance	Policy & Accountability	Existence of a national health policy/strategy, Status of national essential public health functions (EPHFs), Legislative frameworks for health emergencies.	Evaluates the processes and structures that ensure strategic direction, regulation, and accountability.
VII. Health Security & Preparedness	IHR Core Capacities	Status of national IHR core capacities (e.g., surveillance, public health laboratory, points of entry), Capacity for rapid response to outbreaks, Availability of a national public health emergency plan.	Measures compliance with the International Health Regulations (2005) to prevent, detect, and respond to public health threats.

The Importance of an Integrated Approach

The indicators above are not assessed in isolation. WHO emphasizes an integrated approach, recognizing that a resilient health system is one that can withstand shocks—like pandemics or natural disasters—while continuing to deliver routine, essential services.

Health System Resilience

The concept of Health System Resilience ties together the building blocks and preparedness. Indicators in this space often measure the system’s capacity to:

Absorb shocks (e.g., surge capacity of hospitals, staffing flexibility).
Adapt to new conditions (e.g., repurposing facilities, implementing telemedicine).
Transform to mitigate future risks (e.g., investing in primary care networks).

Universal Health Coverage (UHC) and Health Security

Monitoring these indicators helps countries meet the Sustainable Development Goal 3 (SDG 3), particularly the targets for achieving UHC and strengthening the capacity for early warning, risk reduction, and management of national and global health risks (health security). The lessons learned from global events, like the COVID-19 pandemic, have reinforced that strong, well-governed health systems are the fundamental basis for both routine health service delivery and effective emergency response.

WHO Antimicrobial Resistance (AMR) Indicators

Antimicrobial Resistance (AMR) is a major global health threat, undermining the ability to treat common infectious diseases. The World Health Organization (WHO), in collaboration with its partners in the Quadripartite (FAO, UNEP, WOAH), plays a central role in coordinating the global response, primarily through the Global Action Plan on Antimicrobial Resistance (GAP-AMR).

To measure progress against the GAP-AMR's five strategic objectives and track the global burden of resistance, WHO employs a range of indicators, primarily categorized into Surveillance (AMR & Consumption) and Governance/Action Plan Implementation.

Key WHO Indicators for Monitoring AMR

The key indicators are drawn from various WHO monitoring frameworks, notably the Global Antimicrobial Resistance and Use Surveillance System (GLASS) and the framework for monitoring the Global Action Plan. These indicators follow a "One Health" approach, considering human, animal, food, and environmental sectors.

Indicator Category	Core Indicator / Focus Area	Measurement / Metric	Relevance to AMR Response
I. Surveillance of Antimicrobial Resistance (AMR)	Priority Pathogen-Antibiotic Combinations	Percentage of isolates resistant to a critical antibiotic, for specific pathogens in key specimen types (e.g., $E.$ $coli$ resistance to 3rd generation cephalosporins in bloodstream/urine).	Directly measures the burden and trends of drug-resistant infections in human health.
	Sentinel Surveillance Coverage	Number of national/subnational surveillance sites reporting data to GLASS.	Assesses the capacity and geographical representativeness of a country's AMR surveillance system.
	Carbapenem Resistance	Prevalence of Carbapenem-Resistant organisms (e.g., in Klebsiella spp. or Acinetobacter spp.).	Monitors resistance to "last-resort" antibiotics, indicating a critical public health emergency.
II. Surveillance of Antimicrobial Consumption (AMC/AMU)	Total Antimicrobial Consumption (Human)	Defined Daily Doses (DDD) per 1,000 inhabitants per day, for total systemic antibacterials.	Measures the volume of antibiotics used, a key driver of resistance.
	AWaRe Classification Use	Proportion of total consumption belonging to the WHO Access group of antibiotics.	Measures quality of use; goal is for $\ge 60\%$ of consumption to be from the Access group (first- or second-line, lower resistance potential).
	Consumption of Critically Important Antibiotics	Consumption of specific Watch and Reserve antibiotics.	Monitors the use of higher-priority antibiotics, which should be conserved and used judiciously.
III. Governance and National Action Plan (NAP) Implementation	NAP Status and Implementation	Status of the country's multisectoral NAP on AMR (Developed, Costed, Funded, Implemented).	Tracks political commitment and operational progress on the national response.
	Multisectoral Coordination Mechanism	Existence and functionality of a multisectoral coordination mechanism for the AMR NAP (e.g., One Health coordinating body).	Assesses the crucial collaboration between human health, animal health, agriculture, and environment sectors.
	National AMR Surveillance System Maturity	Level of maturity of the country's AMR surveillance system (e.g., based on data quality, completeness, and analysis capacity).	Measures the foundational infrastructure needed for evidence-based policy.
IV. Prevention and Control	Infection Prevention and Control (IPC)	Percentage of healthcare facilities with IPC programmes meeting minimum standards/guidelines.	Tracks efforts to prevent infections in the first place, thereby reducing the need for antibiotics.
	Water, Sanitation, and Hygiene (WASH)	Indicators related to WASH in healthcare facilities, communities, and national context.	Recognizes WASH as a critical foundation for reducing the spread of pathogens and resistance.

The Role of GLASS

The Global Antimicrobial Resistance and Use Surveillance System (GLASS) is the primary mechanism through which WHO collects, analyzes, and shares official national data on AMR and AMC.

Standardization: GLASS provides a standard methodology for collecting data, enabling meaningful comparison of resistance and consumption trends globally and regionally.
Data-Driven Action: The data generated by GLASS is vital for informing national policy, identifying emerging threats, and monitoring the impact of interventions such as antimicrobial stewardship and infection prevention programs.
One Health Expansion: GLASS is expanding to integrate a One Health approach, for example, through the "Tricycle" project which monitors Extended-Spectrum Beta-Lactamase (ESBL)-producing $E.$ $coli$ in humans, the food chain, and the environment.

The comprehensive set of indicators championed by the WHO and its partners represents a vital tool in the global fight against Antimicrobial Resistance. By standardizing surveillance through systems like GLASS and rigorously monitoring progress across governance, consumption, and infection prevention, countries are equipped with the evidence needed to implement effective, data-driven interventions. Ultimately, the successful containment of AMR depends on the continued, coordinated effort of all nations to prioritize, fund, and act upon these critical One Health indicators.

Leading Countries by GHS Index Score

The World Health Organization (WHO) monitors global health security through various frameworks, most notably the International Health Regulations (IHR) (2005). While the WHO does not publish a single, official, frequently updated "ranking" of countries based solely on infectious disease indicators, performance is typically assessed using tools like the Joint External Evaluation (JEE) and the State Party Annual Report (SPAR), which measure a country's core capacities to prevent, detect, and respond to public health threats.

A separate, independent index often cited for preparedness is the Global Health Security (GHS) Index, which provides a comprehensive, publicly available ranking based on a combination of open-source data across six categories, including Detection and Reporting.

The table below presents a snapshot of the top-ranking countries in the Global Health Security (GHS) Index 2021, which serves as a widely recognized proxy for assessing national capacity in line with many WHO-advocated indicators for monitoring infectious diseases and health security.

Table: Leading Countries in Global Health Security Preparedness

This table reflects the top countries from the 2021 Global Health Security Index, which uses a comprehensive set of indicators, including those for infectious disease surveillance and reporting (Detection, Reporting, and Rapid Response).

GHS Index Rank (2021)	Country	GHS Index Overall Score (Out of 100)	Region	Key Contributing Factor (IHR/GHS Indicator)
1	United States	75.9	Northern America	Strong Real-time Surveillance and Reporting
2	Australia	71.1	Oceania	High Capacity for Biosafety & Biosecurity
3	Finland	70.9	Europe	Robust Health System and Personnel
4	Canada	69.8	Northern America	Strong Emergency Preparedness and Response Planning
5	Thailand	68.2	Southeast Asia	Proven Zoonotic Disease Management & Risk Communication
6	Sweden	67.8	Europe	Cross-sectoral Coordination and IHR Commitment
7	United Kingdom	67.2	Europe	Advanced Laboratory Capacity and Diagnostics
8	Germany	66.0	Europe	Strong Compliance with International Norms & Financing
9	South Korea	65.4	Western Pacific	High Scores in Point of Entry Capacities
10	France	65.0	Europe	Advanced Immunization Systems

Note: The WHO's IHR core capacities, which include Surveillance and Response, are typically assessed via a Joint External Evaluation (JEE) that results in a score for specific capacity areas (1–5). A single, overall global ranking by the WHO is not standard practice, making the GHS Index the most accessible comparable data source.

Understanding the WHO Monitoring Framework

The World Health Organization's primary mechanism for monitoring a country's ability to handle infectious diseases and other public health threats is through the International Health Regulations (IHR) (2005).

The IHR Core Capacities

The IHR defines 15 core public health capacities that all 196 States Parties are legally obliged to develop and maintain. The most relevant capacities for monitoring infectious diseases include:

Surveillance: The ability to detect and report public health events (including novel diseases).
Laboratory: The capacity to rapidly and accurately diagnose pathogens.
Human Resources: Having sufficient, well-trained public health and laboratory personnel.
Response: The ability to manage and contain public health emergencies.
Points of Entry: Measures for preventing the international spread of disease at airports, ports, and ground crossings.
IHR Coordination, Communication, and Advocacy: Ensuring a national focal point and effective communication between sectors.

Joint External Evaluation (JEE)

The Joint External Evaluation (JEE) is a voluntary, collaborative process that assesses a country's capacities across these 15 areas. An international team of experts visits the country and assigns a score from 1 (No Capacity) to 5 (Sustainable Capacity). Countries with consistently high scores across the Surveillance and Response categories are generally considered the global leaders in infectious disease monitoring, as these scores directly reflect their ability to meet WHO standards.

Data Sources for WHO Indicators for Monitoring Infectious Diseases

The World Health Organization (WHO) relies on a robust and multi-layered system to collect, analyze, and disseminate data for monitoring infectious diseases and global health security. This system pulls information from routine national reporting, specialized global surveillance networks, and periodic international assessments.

The foundation of this monitoring is adherence to the International Health Regulations (IHR) (2005), which legally obligates WHO Member States to develop core capacities for surveillance and reporting.

Primary Data Sources for WHO Infectious Disease Indicators

Data Source/System	Type of Data Collected	Key WHO Indicator Monitored	Frequency
National IHR Focal Points (IHR)	Mandatory notification of events that may constitute a Public Health Emergency of International Concern (PHEIC), including the four 'always reportable' diseases (Smallpox, Polio, Human Influenza with new subtype, SARS).	Timeliness and completeness of outbreak notification.	Real-time (within 24 hours of assessment).
Routine National Surveillance Systems	Case counts, mortality, and morbidity data for nationally reportable diseases (e.g., HIV, TB, Malaria, Dengue, Influenza).	Incidence, prevalence, and mortality rates of specific infectious diseases.	Weekly, Monthly, or Annually.
Global Antimicrobial Resistance and Use Surveillance System (GLASS)	Data on AMR in priority human pathogens (e.g., E. coli, S. aureus) from participating national surveillance systems.	Prevalence of resistance in key bacterial-drug combinations.	Annually.
Global Health Estimates (GHE)	Comprehensive data on mortality and disability (DALYs) by cause, age, and sex, compiled using multiple country-level sources.	Years of Life Lost (YLL) and Disability-Adjusted Life Years (DALYs) attributable to infectious diseases.	Periodically updated (e.g., every few years).
Joint External Evaluation (JEE) & SPAR	Expert-assessed scores (1-5) of a country's capacity to Prevent, Detect, and Respond to public health threats across 15 IHR technical areas.	IHR core capacity scores for Surveillance, Laboratory, and Emergency Response.	Periodically (JEE: voluntary, SPAR: annual self-assessment).
Immunization Joint Reporting Form (JRF)	Country-reported data on vaccine coverage, stock, and new disease outbreaks (e.g., Measles, Polio).	National coverage rates for key vaccines (e.g., DTP3, MCV2).	Annually.

Key Global Surveillance Mechanisms

The WHO utilizes and coordinates several global and regional networks that aggregate data beyond routine national statistics to provide a more holistic view of infectious disease threats:

Global Outbreak Alert and Response Network (GOARN): A collaboration of institutions that pools human and technical resources for rapid identification, confirmation, and response to outbreaks of international importance.
WHO Global Influenza Surveillance and Response System (GISRS): A specialized global network of laboratories that monitors the evolution of influenza viruses and provides the scientific basis for selecting influenza vaccine viruses.
Event-Based Surveillance (EBS): This non-traditional system systematically monitors unstructured data sources (e.g., media reports, social media, rumors, unofficial alerts) to detect and verify public health events that may not yet be captured by formal, indicator-based surveillance.

Global Health Observatory (GHO)

All of the data collected through these diverse streams is ultimately synthesized and made publicly available through the WHO Global Health Observatory (GHO). The GHO serves as the central data gateway for WHO's 1000+ health-related indicators, allowing users to track global, regional, and national progress against infectious disease targets, the health-related Sustainable Development Goals (SDGs), and the mandates of the International Health Regulations.

Conclusion: A Data-Driven Mandate for Global Health Security

The system of indicators established under the WHO's framework for monitoring infectious diseases, primarily through the International Health Regulations (IHR) (2005) and specialized surveillance networks like GLASS and GISRS, provides a data-driven mandate for global health security. These indicators move beyond simple case counts to rigorously assess both the health impact (morbidity, mortality, DALYs) and the national capacity (surveillance, laboratory, response) required to contain threats. Ultimately, the collective success of this monitoring framework relies on the sustained political commitment of all Member States to ensure timely, transparent reporting and to act decisively upon the evidence revealed by these critical metrics, transforming surveillance data into effective public health action.