The Hidden Threat of Dengue Fever in West Africa

Ebola is obviously the headline-catching disease in West Africa and we must continue to take it seriously, in order to avoid new flareups. At the same time, malaria is still a bigger killer in the region, so we cannot take our eyes of prevention efforts for malaria. But, wait! It turns out that a significant fraction of children in Ghana who are diagnosed with malaria also have dengue fever. This tells us that dengue fever (transmitted by mosquitos, albeit a different species than carries the malaria parasite) is also prevalent in West Africa, despite the fact that few physicians are looking for it when they treat sick patients. These were the surprising findings of a paper just published by Justin Stoler of the University of Miami and associates of his in Ghana in the American Journal of Tropical Medicine and Hygiene. The article is behind a subscription, but Justin was interviewed today on Voice of America, where his findings were summarized.

“The best data we have is from Accra, Ghana’s capital. And we see there roughly 40 to 45 percent of all outpatient visits – anyone presenting at a hospital, a healthcare facility – for any reason – are walking out of there with a presumptive malaria diagnosis, which is a staggering number in and of itself. Now, what we’re just starting to learn in the last few years is that when you actually do confirmatory blood tests -- and you look at who really has malaria -- typically it’s less than 10 percent of that group, who’s presumed to have malaria,” he said.

So, if those figures are correct, what diseases could the rest actually have?

“Well, we started with dengue because it’s widespread across the tropics. It’s recognized. It’s something many people have heard of. But in reality it’s probably just a small piece of the pie. There are bacterial infections, other viral fevers, viral infections – things like influenza – fungal diseases, other parasitic infections…really a whole menu of things that people are dealing with on a regular basis,” said Stoler.

Stoler said the findings have the potential to cause donors to re-think their anti-malaria strategies. The Roll Back Malaria Global Action Plan estimates nearly $6 billion a year is spent to fight malaria.

“At least in parts of rapidly urbanizing Africa, maybe malaria is not their biggest problem. I don’t mean to undermine the importance of fighting malaria in sub-Saharan Africa and around the world, in general. But malaria has traditionally been a rural disease and that’s probably still where most of the burden exists. But really all the action is in urban places and there a lot of other things that people are dealing with there,” he said.