The Democratic Republic of Congo is home to one of the largest and most biologically diverse rain forests in the world, featuring an incredible variety of animals including bonobos, forest elephants, and mountain gorillas. The country is also the stomping ground of a staggering array of microbial organisms and the region is well known as a wellspring of novel human pathogens, some with big household names and others little known. Some of these diseases, such as HIV/AIDS, have emerged as recognizably major pandemics; others, such as Ebola virus, have been limited to small, localized outbreaks; others still, such as the mosquito-borne Chikungunya virus, pose the risk of becoming new threats to global health. Amidst the emergence of novel viruses, the country’s 70 million residents battle some of the highest rates of infections caused by more familiar tropical pathogens. These include some of mankind’s most ancient microbial adversaries: malaria, leprosy, cholera, typhoid and human African trypanosomiasis (HAT). It's a depressing record: the country is considered to have the highest number of leprosy cases in Africa, and ranks second or third in the world for the highest number of cases of neglected tropical diseases (NTDs). Yet troublingly, the Democratic Republic of Congo, otherwise known as DR Congo, remains a black hole for public health surveillance, an epidemiology no-mans land in which we know little of the who, what and where of infectious diseases in the very heart of Africa. In a recent article from PLOS Neglected Tropical Diseases, Anne W. Rimoin from the University of California, Los Angeles School of Public Health and Peter J. Hotez, President of the Sabin Vaccine Institute, opined on the "dearth of surveillance activities and available epidemiologic data" in a country that is nearly a quarter of the size of the United States and the second largest country in the African continent (1).
The geographic distribution showing reported cases of human Chikungunya virus infections, a disease spread by mosquitoes. The virus first emerged from central Africa and has traveled eastwards as it infects new species of mosquitoes. Image: CDC. Click for source and more info. The country’s long record on novel, emerging diseases makes it an imperative that both the DR Congo and the global community keep a watchful eye on the current microbial state of affairs there. Without knowing the extent of disease incidence and prevalence and without adequate surveillance infrastructure in place, we can be little prepared for combating the currently woeful status of disease in the Congo or protect against unusual pathogens emerging from the jungle. As Rimon and Hote note, "Time and again DR Congo has shown us how this nation represents the cradle of a number of important emerging and reemerging viral infections, including some with pandemic potential."(1) In the past several decades, rare and never-before-seen viruses are causing outbreaks, leaving the Congo Basin to establish territory outside the country, and grabbing newspaper headlines.
Annually reported cases of human African trypanosomiasis (HAT), also known as “sleeping sickness”, in the Democratic Repulblic of Congo, 1926–2011. Image: E Hasker et al. (2012) Human African Trypanosomiasis in the Democratic Republic of the Congo: A Looming Emergency? PLoS Negl Trop Dis; 6(12): e1950. Click for source. Just last fall, the Congolese population was bedeviled by months of Ebola outbreaks throughout its northwestern provinces (2). Currently, the virus is traipsing its way eastwards from Africa, infecting mosquitoes and people in central and eastern Asia, due in part to genetic mutations that allow it to adapt to new mosquito vectors and insecticide resistance (3). In 2009, the newly discovered Bas-Congo virus introduced itself to the world by causing a small isolated outbreak that killed two people just outside of the nation's capital, Kinshasa (4). In their article, Rimon and Hotez urge the implementation of a comprehensive surveillance program to monitor and track the status of our most most ancient pathogenic adversaries, as well as the new ones emerging from the jungle. Thankfully, the DR Congo is poised to begin an ambitious program of NTD mapping and disease control thanks to the combined efforts of the United States Agency for International Development (USAID), World Health Organization, and the Belgium Development Agency (5). The goal? Strengthen health and surveillance infrastructures, finagle solid estimates of the burden of tropical diseases in the country, and provide mass drug administrations to treat and eliminate the persistence of pathogens from within the community. As Donald Rumsfield so poetically put it, “As we know, there are known knowns; there are things we know we know. We also know there are known unknowns; that is to say we know there are some things we do not know. But there are also unknown unknowns — the ones we don’t know we don’t know.” (6) There are many unknowns in the Congo Basin that are detrimental to the health, safety and well being of the nation's 70 million people. But the significant burden of disease and the threat of novel pathogens is not only a major public health dilemma in the Congo, nor in Central Africa, but a health issue that spans out of Africa. Resources The diverse population of pathogens simmering within the Congo Republic is merely a backdrop to the their much larger social and political problems. Since the 2008 end of its vicious, decade-long war, the country is slowly healing from the conflict and its attendant social destabilization, population loss and across-the-board breakdowns in critical infrastructures. An article in The Atlantic from this past June addresses the origins of a war that has killed has killed between 3.5 and 5.4 million people since 1996. From the WHO, a list of all known disease outbreaks in the DR Congo since March 1997 to the present. The anatomy of an outbreak: how tiny changes in the genome of the Chikungunya virus have created an epidemic African strain and a tamer Asian strain. References 1) AW Rimoin & PJ Hotez (2013) NTDs in the Heart of Darkness: The Democratic Republic of Congo's Unknown Burden of Neglected Tropical Diseases. PLoS Negl Trop Dis; 7(7): e2118. 2) World Health Organization (2013) Ebola. Retrieved Aug 19, 2013, from here. 3) AA Kelvi (2011) Outbreak of Chikungunya in the Republic of Congo and the global picture. J Infect Dev Ctries; 5(6): 441-4 4) G Grard et al (2012)A novel rhabdovirus associated with acute hemorrhagic fever in central Africa. PLoS Pathog; 8(9):e1002924. 5) Sabin Vaccine Institute (July 25, 2013) Neglected Tropical Diseases in the Heart of Darkness. Retrieved Aug 19, 2013, from here. 6) M Kakutani (February 3, 2011) Rumsfeld’s Defense of Known Decisions. The New York Times. Retrieved Aug 19, 2013, from here.