Republic of Congo health officials are calling risks to public health at a national level high, and at a regional level moderate, after confirmation that a man was infected with yellow fever in a city densely populated with about a million people, as well as with mosquitos capable of spreading the virus, according to a report from the World Health Organization today.
The case highlights both resource gaps and response readiness in the nation that neighbors the Democratic Republic of Congo across that country’s northwest border. After the man first visited a health facility in the port city of Pointe-Noire on July 5, a sample of his blood was sent to a national laboratory in the Democratic Republic of Congo where tests indicated he had yellow fever. Further testing in a Senegal laboratory confirmed the diagnosis, on August 21. At that point, WHO reports, national health officials moved quickly to declare an outbreak of the virus, to notify WHO, as mandated by international health regulations, and to launch mosquito control as well as public information campaigns.
While no further cases were confirmed in the investigation across 16 health centers that followed, entomological surveys found high numbers of Aedes aegypti mosquitos, the vector that can transmit yellow fever, as well as dengue, chikungunya, and Zika viruses. While yellow fever is a virus so easily spread that one confirmed case is all that is needed to recognize a local outbreak, challenges to confirming a diagnosis in Angola which saw a wide outbreak in 2016, and other countries where the virus has spread in recent years included lack of sterile and appropriate supplies to collect the samples needed to confirm yellow fever diagnoses, and time lost to shipping samples out of the country to laboratories where they can be tested.