Pandemics are infectious diseases that spread uncontrollably across populations, killing people over vast areas such as continents and even worldwide. Examples of recent pandemics include influenza and human immunodeficiency virus (HIV). Some examples of potential pandemics in the future are described below.

Viral hemorrhagic fevers – Fevers such as Rift Valley fever, Ebola virus, Marburg virus, and Bolivian hemorrhagic fever are highly infectious and fatal diseases that have the potential to turn into pandemics. However, these diseases are relatively difficult to transmit, requiring direct contact with a carrier, who does not survive for very long before becoming very ill or dying. Furthermore, a short incubation period means carriers develop symptoms quickly and can be rapidly identified and quarantined to help prevent spread to other people. Efforts are being made to contain the current Ebola epidemic that people fear will become pandemic and spread from Africa to the Americas and Europe. This involves various interventions, ranging from screening and isolation techniques through to the development of vaccines that are being trialled in an attempt to cut the spread of Ebola by at least 70%.

Antibiotic resistant microbes – Many microorganisms such as tuberculosis, and Staphylococcus aureus have developed resistance to antibiotics. These pathogens are referred to as “superbugs” and many experts fear they will lead to the re-emergence of diseases that are currently thought to be under control For example, almost half a million cases of multidrug-resistant tuberculosis (MDR-TB) are thought to occur globally every year, with the highest rates seen in Chin and India. According to estimates form the World Health Organization (WHO), around 50 million people are currently infected with MDR-TB worldwide, with the majority of those cases being resistant to at least three antibiotics.

Common bacteria such as Staphylococcus aureus and Enterococcus have also developed resistance to vancomycin and other antibiotics. Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) have become significantly more common over recent years.

Severe Acute Respiratory Syndrome (SARS) – In 2003, SARS was identified as a highly contagious and dangerous form of atypical pneumonia. Rapid intervention from local and international health authorities meant localized epidemics were contained and transmission eventually stopped, but the disease has still not been completely eliminated.