How is the monkeypox outbreak being handled?

The current, massive outbreak of monkeypox began earlier this year in the Democratic Republic of the Congo - the DRC. This country is about the size of western Europe, and it’s been beset by civil war, corruption and an exploding population. It neighbours 9 other African nations, and DRC’s health officials have struggled to contain the recent monkeypox virus within its borders. The problem - as Maria Van Kerkhove mentioned earlier - is particularly acute in the eastern part of the country where a United Nations force is fighting an uphill battle to keep the peace. So, what impact has the disease had on the DRC, and how is the current caseload there being managed? Boghuma Titanji is a Cameroonian-born doctor and an infectious disease specialist at Emory University in Atlanta…

Boghuma - Since the beginning of this year, the DRC has seen an increase in case numbers of mpox and it's reported that they now have about 17,000 cases with an estimated 550 deaths. And it is this surge in cases that has really triggered the international response that we're currently witnessing. And there's certain things that make this outbreak in particular stand out. Firstly, when you compare the number of cases that the DRC had reported, where mpox is concerned in 2022 and 2023, the number of cases this year actually marks 160% increase in the numbers of cases being recorded. So this is a really sharp increase in cases. Additionally, the strain of mpox that circulates in the Democratic Republic of Congo is called clade 1, and historically has been associated with more severe forms of the disease as well as a higher mortality level, which also raises the concern that we are seeing more cases of a more virulent strain of the virus. And then thirdly, we are also seeing it spread in a different manner compared to how it spread historically. And then the fourth and final piece is that beyond the DRC, we have now seen exportation of clade 1 virus to other African countries that are neighbouring countries to the Democratic Republic of Congo. And these are countries that historically had never reported mpox infections before. Again, highlighting the risk that this could spread to a broader scale and cause a more extensive outbreak. And of note that we know that Sweden has reported a case of mpox clade 1 in a returning traveller. As has Thailand. So really indicative of the real threat that it poses if we don't contain this effectively in the DRC.

Chris - What do you think, Boghuma, is the mechanism of the emergence all of a sudden? I guess the question is why here as in DRC and why now in these sorts of numbers?

Boghuma - When you look at the historical trends of how mpox has spread through the years, it's important to remember that really the countries that have mpox circulating in an endemic manner have been witnessing cases for the past five decades. The first human case of OCH was described in 1972 in a 9-year-old child in the Democratic Republic of Congo. And since that time, we have seen a steady increase in the numbers of outbreaks and in the sizes of these outbreaks. The reason for this is several fold. I think the primary reason is that first of all, smallpox vaccination, which is vaccination for another orthopox virus known as variola, which was the causal agent of smallpox, stopped in the late 70s to the early 80s in most African countries. Now these vaccines can offer cross protection for other orthopoxviruses, including mpox. The interruption or stopping of the smallpox vaccination in the early 80s means that a lot of people born after 1980 in these African countries are not immune to orthopoxviruses. So you have a large vulnerable population. Additionally, you have to imagine that the population has also grown significantly over that time, and there's also been increased movements of people. So all of these factors in combination essentially allow the virus an opportunity to infect a more vulnerable population as immunity wanes. But also because people are more interconnected and the population has grown, it means that there are also opportunities for more sustained spread and larger outbreaks.

Chris - With those considerations in mind. What therefore needs to be the response both locally in the short term, and that means in the DRC, and then locally in the long term. But also right now across the world, what do we need to be doing to be on our guard and also to help to reduce the risk that this continues to amplify in the way that it is.

Boghuma - So the first thing about the response is really trying to understand the drivers of the different outbreaks that the DRC is currently witnessing by better characterising the sources of zoonotic transmission, but also better characterising the drivers of human to human spread. Are these all primarily sexual contacts or are these close contacts of people who are infected in overcrowded settings, et cetera? And in order to do that, I think that the first thing would be to make sure that there's adequate resources for testing as well as contact tracing. Remember at the beginning of our conversation, I mentioned that the DRC has reported an estimated 17,000 cases since the beginning of this year. Now only 10 to 15% of these cases have actually had confirmatory testing demonstrating that they have mpox. So if you cannot confirm an infection, it makes it harder to trace and identify who else may be impacted by that infection. So surveillance through robust testing and contact tracing would help researchers on the ground define how the virus is being transmitted, who is being impacted, and with that knowledge you can then craft interventions to effectively interrupt the spread. Now coming to the interventions that can be utilised to interrupt the spread, we have several tools at hand. We know that the vaccines that have been developed for smallpox will confer a certain degree of protection against mpox infection and also have the possibility of attenuating mpox disease in people who have been vaccinated. So if you define who is being impacted, the next step will be to craft a vaccination strategy that is adapted to prioritise those that are most likely to come in contact with the virus and get an infection. And then the third piece of this, obviously, which is absolutely central to any response to an outbreak, is information and education. We saw in the 2022 outbreaks that a huge component of the public health response that led to the containment of that outbreak of mpox was changes in behaviour within populations that had high incidents of mpox. So if you educate the communities about what the disease looks like and how it's spreading, then you can provide them with tools that allow them to modify their behaviours in manners that would have the potential to reduce spread.