A report presented Thursday at the American Society of Tropical Medicine and Hygiene (ASTMH) annual meeting revealed the potential for larger and deadlier outbreaks of monkeypox epidemics in Central Africa and around the world – as the Clade 1 more dangerous the virus becomes more transmissible.
“Many people at the US CDC (Centers for Disease Control), the World Health Organization and in the health and research departments institutions in sub-Saharan Africa were drawing attention to the growing danger of monkeypox long before we started seeing infections outside of Africa,” said ASTMH President Daniel Bausch. “This study provides important new information that underscores the urgent need to provide additional resources that can help Africans fight this disease.”
There are two “clades” of monkeypox virus. The one that has long been endemic to the Democratic Republic of Congo (DRC) – known as Clade 1 – has a mortality rate of up to 10% and can include serious complications such as blindness. Clade 2, the source of recent epidemics outside the West and Central African countries where it is endemic, is fatal less than 3% of the time.
The current concern, according to the report, is that Clade 1 is evolving to become more transmissible, at an increasing rate.
Deadliest variant has increased transmission rate
Data from DRC’s Tshuapa province collected between 2013 and 2017 showed an increase in the transmissibility of the Clade 1 variant. increased to 0.81 from a baseline of 0.3 to 0.5 observed throughout the 1980s. When the reproduction number reaches or exceeds 1, it is a tipping point where the number of new cases is growing even faster than the number of people cured or dead, creating the potential for transmission in much larger areas and populations.
“Our data show that transmission of monkeypox in the area we studied was significantly higher than previous estimates and approaching the point where it can cause large and sustained local epidemics,” said researcher Dr Kelly Charniga. effectiveness of prevention at the CDC and first author of the study. “This research puts the global health community on alert that there could be the possibility of larger outbreaks in the DRC on the horizon.”
The increased transmissibility of the disease has already led to longer outbreaks, increasing the possibilities for the virus to evolve to be able to support greater person-to-person spread. The researchers also found evidence of more regular “spillover” of monkeypox infections from rodents – thought to be the natural reservoir of the virus – to humans.
“With today’s interconnected world, outbreaks don’t necessarily stay at their source,” Charniga said. “The best way to prevent monkeypox from causing more outbreaks in the DRC and becoming a bigger global problem is to devote more attention to the areas where it is clearly causing the most suffering today.”
Burden of monkeypox is increasing in endemic countries
Cases of monkeypox in endemic African countries have been increasing for several years. The drop in cross-reactive immunity from the smallpox vaccination campaign ended after the victory over the smallpox virus in 1982 and led to the discontinuation of smallpox vaccination, which also protects against monkeypox. This, in turn, contributed to an increase in infections of both clades across Africa. The current global outbreak of Clade 2 Monkeypox virus began in the UK in May, after a traveler returned to the UK from Nigeria. has been declared infected. Since then, some 78,000 cases of monkeypox have been reported worldwide, with the most intensive areas of transmission being Europe and the Americas. Although the number of new reported cases has fallen sharply over the past two months, transmission remains a concern in many countries.
Improving surveillance in endemic rural areas is key to stemming the spread of the disease, but it’s easier said than done. Regions of the DRC with the most potent reservoirs of monkeypox — such as Tshuapa province where the study was conducted — are difficult to access, the researchers noted.
This complicates the distribution of vaccines and antivirals that are already in short supply, and many clinics still use paper forms to report suspected cases. Despite these challenges, Charniga emphasized that proactive measures by the health system will lead to the most favorable outcomes for all.
“The best way to prevent monkeypox from causing more outbreaks in the DRC and becoming a bigger global problem is to devote more attention to the areas where it is clearly causing the most suffering today,” he said. she declared.
Image credits: WikiCommons, United Nations.
Fight the infodemic in health information and support reporting on health policies from the Global South. Our growing network of journalists in Africa, Asia, Geneva and New York connects the dots between regional realities and major global debates, with evidence-based, open-access information and analysis. To make a personal or organizational contribution, click here on PayPal.