Mpox spreads through physical contact and causes a characteristic bumpy rash, fever, pain and discomfort. In some people with weakened immune systems, it can be fatal.
The first human case was discovered in northwestern DRC in 1970, when a nine-year-old boy developed a nasty rash that led doctors to believe it was smallpox. Scientists have since identified two distinct clades in Africa.
Clade 2 is found in West Africa and caused a global epidemic and its own PHEIC in 2022, when the disease spread to over 100 countries, mainly affecting gay and bisexual men.
The strain at the centre of the current alarm, however, is clade 1. Outbreaks of clade 1, which has a higher mortality rate, were often initially confined to a few households in remote areas and were associated with families killing and eating wild forest animals, also known as bushmeat.
However, scientists have warned for years that annual cases of clade 1 in DRC are steadily increasing. And as the numbers have been rising, researchers confirmed a new strain, dubbed clade 1b, in eastern DRC earlier this year.
“I knew this was something different”
Doctors in the region report seeing a spike in mpox patients with severe symptoms — including widespread lesions, high fevers and a higher death rate — in late 2023. It doesn’t require sexual contact to spread, and it infects both children and adults.
“I knew this was something different because the symptoms were so different from clade 1, which is what we normally see in the DRC,” said Dr Leandre Murhula Masirkika, a local scientist who has conducted groundbreaking research on the ground.
“We see many deaths, many miscarriages and rapid transmission in the community.”
Dr. Masirkika and a small team of local researchers traced the first case of clade 1b to a bar in Kamituga and a single patient: a local bartender.
The man, reportedly a pimp, regularly had sex with female sex workers. In September, he had sex with three women at the same time – all of whom were hospitalized shortly afterwards with a severe form of the disease.
Since then, thousands of patients have presented to clinics and hospitals in South Kivu with severe symptoms, many of them children. According to Dr. Masirkika, the mortality rate is as high as 5 percent in adults and 10 percent in children – compared to just 0.2 percent for clade 2.
Understanding the dynamics of the new strain and its outbreak is clouded by a lack of sequencing and because the original clade 1 strain also appears to be increasing.
Piero Olliaro, professor of poverty-related diseases at Oxford, said: “These are two parallel outbreaks of two variants with different modes of transmission and risk groups, requiring different containment strategies. They also differ in morbidity and mortality.”
Seven out of 10 cases in DRC are children and the disease is widespread in overcrowded hospitals, Save the Children reported this week.