Scientists warn of ‘zombie pathogens’, new diseases

Scientists have warned that Sub-Saharan Africa and South East Asia are most at risk of bat viruses infecting humans and causing new and deadly diseases.

They also warned that as the globe warms, there would be melting ice caps, rising sea levels and extreme weather, which may cause new and old diseases to spread in places once thought safe.

They said melting permafrost might release ‘zombie pathogens’ frozen in ice for centuries, while warming temperatures could allow disease-spreading insects roam far.

According to the World Health Organisation (WHO), approximately 60 to 75 per cent of emerging infectious diseases is so-called ‘zoonotic events’, where animal diseases infect people. Bats, in particular, are known carriers of many zoonotic viruses.

A panel of scientists and public health experts convened by WHO prioritised the top five to 10 emerging pathogens likely to cause severe outbreaks in the near future, and for which little or no medical countermeasures exist.

According to the WHO, the initial list of disease priorities needing urgent Research and Development (R&D) comprise: Crimean Congo haemorrhagic fever, Ebola virus disease, Marburg, Lassa fever, Middle East Respiratory Syndrome (MERS), Severe Acute Respiratory Syndrome (SARS), coronavirus diseases, Nipah and Rift Valley fever.

Three others were designated ‘serious’, requiring R&D action by the WHO as soon as possible. These are: Chikungunya, severe fever with thrombocytopaenia syndrome, and Zika.

The WHO panel said other diseases with epidemic potentials, such as Human Immuno-deficiency Virus (HIV)/Acquired Immune Deficiency Syndrome (AIDS), Tuberculosis, Malaria, Avian influenza and Dengue, were not included in the list because there are major disease control and research networks for these, and an existing pipeline for improved interventions.

Scientists at the University College London (UCL), the Zoological Society of London and Edinburgh University mapped out the highest-risk areas, using a variety of factors including large numbers of bat viruses found locally, increasing population pressure, and hunting of bats as bush meat.

The research, using data published between 1900 and 2013, found that West Africa, the epicentre of the recent Ebola outbreak, is at highest risk for zoonotic bat viruses. The wider Sub-Saharan African region and South East Asia were also found to be hotspots.