What is the most common infectious cause of death worldwide?

Tuberculosis Is the Most Common Infectious Cause of Death Worldwide

Tuberculosis (TB) is the most common infectious cause of death worldwide, surpassing all other infectious diseases in mortality. 1

Global Burden of Major Infectious Diseases

Tuberculosis

• TB has overtaken other infectious diseases to become the leading infectious cause of death globally 1
• TB disproportionately affects low and middle-income countries, with the highest burden concentrated in Asia and Africa
• The intersection of the AIDS epidemic with endemic tuberculosis in Asia and Africa has made tuberculosis the leading cause of death in people with HIV infection worldwide 1

Lower Respiratory Infections

• Lower respiratory infections (LRIs) are the second most common infectious cause of death globally 1, 2
• LRIs caused approximately 2.38 million deaths in 2016 across all age groups 3
• Streptococcus pneumoniae is the leading pathogen causing LRI mortality, contributing to more deaths than all other respiratory pathogens combined (1.19 million deaths) 3
• LRI mortality is particularly high among children under 5 years and adults over 70 years 2

Bacterial Pathogens

• A 2022 global analysis found that 33 bacterial pathogens were responsible for 7.7 million deaths in 2019 4
• The five deadliest bacterial pathogens globally are:
  1. Staphylococcus aureus
  2. Escherichia coli
  3. Streptococcus pneumoniae
  4. Klebsiella pneumoniae
  5. Pseudomonas aeruginosa
• These five pathogens account for approximately 55% of deaths among investigated bacteria 4

Regional Variations in Infectious Disease Mortality

• Sub-Saharan Africa has the highest age-standardized mortality rate associated with bacterial pathogens (230 deaths per 100,000 population) 4
• High-income regions have the lowest mortality rate (52.2 deaths per 100,000 population) 4
• 15 countries account for 70% of all pneumonia deaths worldwide: Afghanistan, Angola, Bangladesh, Chad, China, Democratic Republic of the Congo, Ethiopia, India, Indonesia, Niger, Nigeria, Pakistan, Somalia, Sudan, and Tanzania 1

Age-Related Patterns

• In children under 5 years, Streptococcus pneumoniae is the pathogen associated with the most deaths globally 4
• In individuals older than 15 years, Staphylococcus aureus is the leading bacterial cause of death 4
• Childhood mortality attributed to pneumonia decreases rapidly with age, from approximately 67% of all deaths at 6 months to 14% at 18 months, and reaches a plateau of 6% between 30 and 54 months of age 1

Risk Factors and Prevention

• Major risk factors for LRIs include household air pollution from solid fuels, child wasting, and ambient particulate matter pollution 2
• Household air pollution is a significant risk factor for acute lower respiratory infections in children (population attributable fraction of 52%) 1
• Improvements in socioeconomic status, child nutrition, HIV control, and availability of conjugate vaccinations for S. pneumoniae and H. influenzae have reduced pneumonia incidence 1

Clinical Implications

• Understanding the global distribution of infectious disease mortality is essential for prioritizing public health interventions
• Vaccination strategies should target the most prevalent pathogens in specific regions
• In resource-limited settings, focus should be on timely administration of antimicrobials and supportive care for sepsis management 1
• For TB specifically, early molecular diagnostic techniques are crucial to identify drug resistance patterns and guide appropriate therapy 1

TB remains the greatest infectious disease killer globally, highlighting the need for continued investment in TB prevention, diagnosis, and treatment programs worldwide.