The World Health Organization (WHO) closely monitors potential outbreaks of serious illnesses. The recent confirmation of Marburg disease in Equatorial Guinea is a stark reminder that infectious disease experts must always be ready for the next virus that could threaten public health. The WHO has compiled a list of priority pathogens since 2017, including diseases that can harm humans and require further research. Governments and public health organizations use the list to plan and prepare for potential outbreaks.
Recently, the WHO brought together 300 scientists to reassess the threat of 25 viruses and bacteria. Dr. Michael Ryan, the Executive Director of the WHO Emergency Program, emphasized the importance of focusing on priority pathogens for effective and rapid response to epidemics and pandemics. He also highlighted the significance of research and development investments, which were crucial in developing safe and effective vaccines for COVID-19.
Aside from COVID-19, here are the other eight viruses that are considered a concern by the WHO:
- Crimea-Congo Hemorrhagic Fever: Found in Africa, the Balkans, the Middle East, and Asia, this disease is often spread through infected ticks or contaminated livestock. It can damage internal organs and the cardiovascular system, causing severe bleeding, with a mortality rate ranging from 10 to 40%. A vaccine is authorized in Bulgaria but has yet to be approved elsewhere.
- Ebola and Marburg: These diseases, which are part of the filovirus family, are carried by bats and primates. They are spread through bodily fluids, direct contact, or contaminated surfaces in non-sterilized environments. The mortality rate ranges from 25 to 90% and varies during outbreaks. There are vaccines against Ebola in Guinea and the Democratic Republic of Congo, but they are not widely approved.
- Lassa Fever: Endemic in West Africa, this disease is spread through rats’ and rodents’ urine and feces. Humans can transmit it through their excrement or blood, or sexual contact. It threatens pregnant women in the third trimester and can cause deafness. The mortality rate is low (1%), but increases to 15% for severe cases that require hospitalization. Ribavirin is used for treatment, but there is no vaccine.
- MERS (Middle East Respiratory Syndrome): This disease causes acute respiratory tract infections and is transmitted by camels. Once contracted by a human, it can be spread through close contact. The mortality rate is high (35%) and has been diagnosed in 27 countries since 2012, but no vaccine exists.
- Nipah Virus: Found in Asia, this virus is spread through contact with fruit-eating bats and domestic animals like pigs, horses, cats, and dogs. It causes brain inflammation (encephalitis) and has a mortality rate of 40 to 70%. There is currently no vaccine.
- Rift Valley Fever: This blood disease is transmitted by mosquitoes and affects humans, livestock, sheep, goats, buffalo, and camels. It has spread from Africa to Saudi Arabia and Yemen. The mortality rate is less than 1%, but 8% and 10% of patients develop serious symptoms such as eye lesions, encephalitis, and hemorrhagic fever. A vaccine has been developed but has yet to be licensed anywhere.
- Zika Virus: Spread by mosquito bites and through sex, this disease can infect the blood and cause serious brain defects in fetuses, spontaneous abortions, and stillbirths. There is currently no vaccine.
- Disease X: This space is reserved for an unknown virus that could emerge in the future and cause problems
The World Health Organization’s list of priority pathogens serves as a reminder of the ongoing threat of infectious diseases. With new outbreaks constantly emerging, public health organizations and governments must remain vigilant and invest in research and development efforts to ensure we are prepared to respond effectively during a pandemic. Whether it be Ebola, Marburg, Lassa fever, MERS, Nipah virus, Rift Valley fever, Zika virus, or the mysterious “Disease X,” the need for continued vigilance and preparedness is imperative. By working together, we can stay one step ahead of the next outbreak and protect the health and well-being of people worldwide.
