Following the declaration of mpox as a global health emergency by WHO, it's time to take appropriate measures to guard against the deadly strain of the viral disease. The WHO's announcement has come in the light of more than 15,000 suspected and confirmed cases, and 537 deaths due to monkeypox virus this year.
A new deadlier strain of mpox clade 1b is said to be behind the current outbreak that has spilled into eastern parts of the central African nation and has been reported in other countries for the first time, which includes Kenya, Rwanda and Uganda.
There are two major types of mpox variants - clade 1 and clade 2. Viruses from the clade 1 classes tend to be more deadly and infectious. Clade 2 strain was behind the mpox cases globally in 2022 and 2023.
What is mpox virus?
Monkeypox, now named as mpox is an orthopoxvirus from smallpox family. It is caused by the monkeypox virus, which is divided into two distinct genetic classes or clades:
Clade 1 (formerly known as the Congo Basin clade) and Clade 2 (formerly known as the West African clade). These clades differ in their geographic distribution, severity, transmission rates, and clinical manifestations.
Let's understand more about these strains:
Clade 1 strain
Facts: It is historically found in Central Africa, particularly the Democratic Republic of Congo.
Symptoms: They are generally more severe, with higher rates of complications like encephalitis, pneumonia and respiratory distress, and secondary bacterial infections.
"Patients often experience more intense skin rashes, larger lesions, and more pronounced lymphadenopathy. It has a higher rate of person-to-person transmission, especially through respiratory droplets and close contact," says Dr Tushar Tayal, Consultant, Internal Medicine, CK Birla Hospital, Gurugram.
Severity: Clade 1 has a higher fatality rate, ranging from 1% to 10% in some outbreaks, making it deadlier than Clade 2.
"Clade 1 usually causes more severe symptoms like high fever, severe headache, myalgia and enlarged lymph nodes. The skin lesions are usually extensive and often can cause scarring of the affected regions whereas Clade 2 is associated with milder symptoms," says Dr Ajay Agarwal, Senior Director - Internal Medicine, Fortis Hospital, Noida.
Clade 2Facts: It is primarily found in West Africa, particularly in Nigeria and surrounding regions.
Symptoms: They tend to be milder, with fewer complications. Patients often have less severe skin lesions and fewer systemic symptoms. Lymphadenopathy is less pronounced.
Severity: Clade 2 is less infectious compared to Clade 1, with a lower rate of human-to-human transmission. The fatality rate for CLADE 2 is less than 1%, making it less deadly than Clade 1, says Dr Tayal.
"Clade 1 is associated with higher mortality rates. (estimated 1-10%), while Clade 2 is less infectious and is generally considered less deadly (estimated 0.1-1% mortality rate)," says Dr Aggarwal.
Why WHO declared mpox as a global health emergency?
When a disease is declared a global health emergency by the World Health Organization (WHO), it signals a situation that is "serious, sudden, unusual, or unexpected," with potential for international spread and requiring a coordinated global response, say experts.
"This declaration means that there will be increased awareness about the disease, enhanced surveillance and data sharing and coordination amongst different countries. There will be mobilisation of international resources, including financial aid, medical supplies, and expertise, to help contain the outbreak," says Dr Tayal.
