1. Leishmaniasis
Classified by the Centers for Disease Control and Prevention (CDC) as a “Neglected Tropical Disease,” Leishmaniasis is caused by the bite of a phlebotomine sand fly, which is about a third of the size of an average mosquito. Through these bites, Leishmania parasites are spread and result in infection. This major vector-borne disease is a big problem, particularly for Syrian refugees, and an increasing number of cases have been noted in Europe among migrants. In fact, according to the CDC, it is the only “tropical vector-borne disease that has been endemic to southern Europe for decades.” However, Europe isn’t the only country that has been affected by the disease. A recent study found that a unique strain, Leishmania braziliensis, were causing atypical Leishmaniasis cases in northeast Brazil. In addition, back in November, the disease made its way to US soil, as US soldiers who had been deployed in Iraq and Afghanistan, as well as ecotourists in South and Central America, returned home.
2. Rift Valley Fever
Rift Valley Fever (RVF) is an “acute, fever-causing viral disease,” that is spread to humans through mosquitoes who had previously bitten livestock, although, it can also be spread from the bites of other insects as well. Fortunately, transmission from human-to-human has not yet been documented. Those at highest risk of infection are those who spend much of their time sleeping outdoors or in rural areas. In addition, those working with animals, particularly in areas that are endemic, are also at increased risk. According to Dr. Gatherer, RVF has been spreading throughout Africa and seems to be heading into the Sahel region. Oftentimes, travelers who return from such affected areas are the vehicle in which RVF can travel to a number of different continents. Although only 1% of humans with RVF will die from the disease, the risk of fatality is much higher for livestock. In fact, the CDC reports that RVF causes abortion in almost 100% of pregnancies in infected livestock.
3. Oropouche virus
According to the CDC, Oropouche virus (OROV) “is the causative agent of Oropouche fever, an urban febrile arboviral disease widespread in South America.” Since the virus is spread through the mosquito in the genus Culex, which are known to have a wider distribution than the Aedes mosquitoes that tend to carry Zika virus, this is particularly troubling. Since it was first reported in Trinidad back in 1955, OROV has been expanding its range. In fact, between 1960 and 2009, more than 30 outbreaks have been reported in Panama, Peru, Brazil, Trinidad, and Tobago, and half a million individuals are estimated to have been infected with the virus. According to Dr. Gatherer, the virus “is normally a self-limiting fever with loss of appetite, headaches, and vomiting, but the occasional meningitis complication is more concerning.
4. Mayaro virus
First isolated in Trinidad in 1954, Mayaro virus (MAYV) is spread through the bite of an Aedes mosquito. “Mayaro made a recent surprise appearance in Haiti and beat its Amazonian rival Oropouche to the coveted title of ‘the next Zika,” according to Dr. Gatherer. Recently, University of Florida resarchers isolated Mayaro virus from a child “with acute febrile illness in rural Haiti,” thus, “confirming its role as a cause of mosquito-borne illness in the Caribbean region” for the first time. Since the 2010 earthquake that hit Haiti, the country has been struggling to rebuild itself and its health infrastructure, and, unfortunately, it appears that places that have been hardest hit seem to be where emerging diseases tend to flourish.
5. Elizabethkingia
Elizabethkingia is commonly found in the environment (in soil, river water, or reservoirs) and is the only emerging disease on the list that is found worldwide and is not spread through insect bites. It is a bacterial pathogen that rarely makes individuals sick, but can be problematic for those with weakened immune systems (causing meningitis, bloodstream, or respiratory infections) as well as for newborn babies (causing meningitis). Typically, about five to ten cases are reported each year in the United States, however, a recent outbreak in the Midwest managed to spread over a few states in 2016, resulting in a number of deaths. With pathogens increasingly acquiring resistance to current antibiotics, these bacteria may quickly turn into a serious problem.