Research Links Air Pollution to Increased Disease Risk from Bacteria

A recent study has established a link between air pollution and the risk of bacterial pneumonia, sepsis, and meningitis, contingent on the specific subtype of the bacteria Streptococcus pneumoniae (S. pneumoniae) present. Conducted by researchers from the Wellcome Sanger Institute, the National Institute for Communicable Diseases (NICD), and the Barcelona Supercomputing Center, the findings indicate how different subtypes of this bacterium react to air pollution exposure, affecting the rates and timing of invasive bacterial diseases.

Published on 14 September 2026 in the journal Nature Microbiology, the research highlights that certain strains of S. pneumoniae can lead to immediate infection responses following exposure to airborne pollutants, while others may result in delayed infections that emerge several weeks later. The conclusions drawn from this comprehensive study suggest older adults and young children are particularly susceptible during times of elevated air pollution, emphasising the urgent need for improved air quality measures.

Invasive pneumococcal disease (IPD), which includes conditions such as bacterial pneumonia and meningitis, represents a substantial public health concern globally. According to data from the NICD, over 1,800 cases of IPD were reported in South Africa in 2022, while in England, the UK Health Security Agency indicates there are over 5,000 cases annually, with young children and elderly individuals being the most affected demographics.

The research involved an analysis of roughly 59,000 IPD cases from South Africa's national GERMS-SA surveillance programme, covering a span of 19 years. The study revealed that between 40 to 60 per cent of South African children carry S. pneumoniae within their respiratory microbiomes. The team identified that subtypes 14, 19A, and 8 showed the highest correlation with increased IPD risk after exposure to air pollution.

Professor Anne von Gottberg, co-senior author of the study at the NICD, stated, "Invasive pneumococcal diseases are a significant public health issue in South Africa and globally. This research adds to the ongoing evidence that air quality greatly impacts our health and shows that it has different effects depending on the strain of bacteria that is found in an area."

The impact of environmental factors such as humidity and temperature on these infection rates also differs by bacterial subtype and age. For instance, it was noted that high temperatures are linked to an immediate rise in disease risk, whereas colder temperatures appear to delay increases in infection rates. Potential explanations include slowed bacterial transmission in cold weather or additional vulnerabilities caused by seasonal illnesses.

The findings also underline the importance of monitoring bacterial strains in conjunction with air quality assessments to better predict outbreaks and inform public health strategies. Understanding how environmental factors shape bacterial infection rates could ultimately lead to improved health outcomes for populations at risk.

Given the ongoing challenges posed by climate change and urbanisation, the researchers advocate for cross-sector collaboration to manage health risks related to shifting environmental conditions. This study marks a significant advancement in the endeavour to reduce air pollution and its role in infectious disease transmission.