Outbreaks of diseases that could lead to a serious global health emergency in the absence of vaccination

Recently, a group of WHO experts have given priority to some diseases considered potentially capable of causing an epidemic of international level due to their likelihood of emergence and the absence of effective prevention and control measures.

The diseases are MERS-CoV, Ebola, Nipah and Crimean-Congo hemorrhagic fever; to these are added other priority diseases of the Blueprint list such as Lassa fever, Rift Valley fever and Zika disease. An outbreak of any of these diseases could possibly lead to a serious global public health emergency.

Nowadays no vaccines or antiviral drugs are available for Nipah virus and CCHF; the treatment is only supportive and current prevention strategies focus on disease awareness in the affected areas. 

Use of an experimental vaccination against the Ebola virus disease was recently launched in the Democratic Republic of Congo targeting front-line health professionals, people who have been in contact with confirmed cases of Ebola, and contacts of these contacts. In addition, no vaccine or specific treatment has been developed for MERS-CoV and better control practices and prevention have been put in place.

Bats, mostly fruit bats from the Pteropodidae family, are believed to form the natural reservoir of Nipah Virus. The primary Ebola host may also be bats, but the virus has been detected in chimpanzees, gorillas, monkeys, antelopes, and other mammals. Current scientific evidence suggests dromedary camels are a major reservoir host for MERS-CoV and an animal source of MERS infection in humans. CCHF is caused by the tick-borne bunyavirus; its wide geographic range links with the global distribution of the Hyalomma tick.

A global commitment, also stimulated by consensus on an animal health plan, may be essential to limit spill-over; furthermore, the development of new animal vaccines can certainly contribute to the prevention of health emergencies. Further information is available on the following websites: 

Outbreak: epidemics in a connected world

https://naturalhistory.si.edu/exhibits/outbreak/

Ebola virus:

https://www.ecohealthalliance.org/2018/05/ebola

Nipah virus:

https://www.ecohealthalliance.org/2018/05/nipah-virus