Each downpour brings with it the risk of disease. Respiratory and gastrointestinal illnesses are common during and after hurricanes, aside from injuries and deaths sustained from drowning, electrocution and debris. And if these weren’t bad enough, you’ll have to add another threat to the list: mosquitoes.
Of the 3,000+ mosquito species all over the world, almost 200 can be found in the United States. Close cousins of flies, female mosquitoes usually feed on the blood of other animals, including humans. While blood-loss from mosquito bites shouldn’t be a problem, mosquito bites often cause irritating rashes on their human hosts. What’s crucial though is that these bites can transmit deadly diseases like West Nile virus (WNV), Eastern Equine Encephalitis (EEE), chikungunya, dengue, zika virus and a lot more.
Mosquitoes as Disease Carriers
Mosquitoes can carry and transmit bacteria, viruses and parasites that are harmful to humans. Each year, it’s estimated that nearly 700 million people worldwide get a mosquito-borne illness annually and out of this number, more than one million people die.
While the number of cases of mosquito-borne diseases and deaths in the U.S. are much lower than in less-developed countries, it still frequently happens, especially during the spring and summer months and after natural disasters like hurricanes. In 2016, Vector Disease Control International (VDCI) reported 2,038 cases of WNV in humans with 94 deaths. Five cases of EEE were also documented, as well as 216 cases of zika virus.
Know Your Enemy
The females of most species of mosquitoes are ectoparasites. They pierce their host’s skin with their proboscis to consume blood. While mammals are commonly used as hosts, other mosquito species also prey on birds, reptiles and amphibians. While mosquitoes typically feed on plant juices for sustenance, blood provides the necessary nutrients for the females of many species to lay eggs.
With the number of deadly diseases mosquitoes can transmit, the tiny mosquito is actually one of the deadliest animals on the planet, and with their evolution and resistance to modern pesticides, they’re poised to become even deadlier.
Hurricanes and Mosquitoes
While the high winds from hurricanes can make for a hostile environment for mosquitos, the flooding it leaves behind provide the perfect conditions for them to lay their eggs.
Most mosquitos need only a depth of less than half an inch of water to lay their eggs, while some only require damp mud to spawn. In as little as a couple of days for some species, these eggs go through their life cycle and mature into winged pests.
With the interruption of amenities and services, the chances of people getting bitten by mosquitoes increase. In the aftermath of hurricane Katrina in 2005, flooded pools became mosquito factories because it took time for them to get cleaned up. People may also leave their windows open in the absence of electricity to promote ventilation in their homes, letting the flying parasites in, while those cleaning up or repairing damage to their property in the aftermath spend more time outside and getting into contact with the insects.
Diseases You Can Get from Mosquitoes
While it’s not as common in the U.S. as in some countries, diseases from mosquitos are still a concern. These diseases include
- West Nile Virus (WNV)
The CDC reported 2,038 cases overall, in 2016, of WNV infection as of January 2017. While around 80 percent of those infected by WNV show little to no symptoms, those who do show signs get headaches, muscle pain, nausea or rashes.Severe symptoms include swelling of the brain (encephalitis) or the surrounding membranes and spinal cord (meningitis). While recovery from WNV is possible, around 10 percent of the people who develop severe symptoms of WNV die. - Dengue Fever
While rare in the continental U.S., dengue is endemic in Puerto Rico and can still be imported from other countries through people traveling to America.The major symptoms of dengue include joint and muscle pain (earning it the name “breakbone fever”), severe headache, rashes, and low white cell count. In some cases, nausea and vomiting may also occur. - Zika Virus
Formerly contained in countries within the equatorial belt from Africa to Asia, concerns about the Zika virus grew after the 2016 epidemic spread to the American continents. As of 2017, 452 symptomatic Zika cases were reported in the U. S.People infected by the Zika virus may not show symptoms of infection, but the most common ones include muscle and joint pain, headaches, rashes, fever and reddish eyes. Although symptoms may appear like minor ailments (if they even manifest), the Zika virus can be transmitted sexually, and may cause microcephaly in some infants.
Aside from humans, mosquitoes can also transmit serious diseases in animals. Heartworms in dogs can be transmitted through mosquito bites. Photo by Lance Wheeler - Malaria
While Malaria has been virtually eliminated in the United States in the 50’s, more than a thousand cases are still being reported every year, mostly by travelers who have been to sub-Saharan Africa and South Asia.Malaria symptoms manifest one to three weeks after infection. Like other mosquito-borne diseases, these can include headache, fever and joint pain. Malaria symptoms can also include convulsions, jaundice and dark-colored urine. In extreme cases, malaria can also cause death. - Chikungunya
While deaths from chikungunya are rare, they can still produce symptoms that could affect your way of life for a long time.Chikungunya symptoms may look like those of other mosquito-borne diseases, which include headaches and rashes, but it can also include joint pain and swelling that could last for months.
Mosquitoes can also cause encephalitis (swelling of the brain), yellow fever and transmit heartworm to dogs.
Although most mosquito-borne diseases have been removed from the continental U.S., outbreaks still occur occasionally and people visiting countries endemic for these diseases risk taking these with them when they come back. The disease can easily spread in the community when mosquitoes feed on the infected person, then bite another human.
Preventing Mosquito-Borne Diseases
One of the most effective ways to prevent the spread of mosquito-borne diseases is to control their population where you live.
- Eliminate breeding grounds
- Remove standing water which mosquitoes can use to lay their eggs.
- Throw away trash or debris that can collect water such as used tin cans or tires.
- Cover water containers
- Protect yourself from bites
- Insect repellent is a must when spending a lot of time outdoors, particularly while camping, gardening or even just cleaning your backyard
- Clothing that covers the arms, legs and neck serve as your “armor” from insidious bites
- Know your enemy’s habits
- Most species typically go into hibernation mode during winter and emerge during the warm season. Mosquitoes thrive in the spring and summer months.
- Because their life cycle depends on warm weather, mosquito season varies per state. It can be as early as February for southern states like Florida to as late as May for the northern ones, or even June in the case of Alaska.
- Mosquitoes are attracted to the following human scents: the carbon dioxide we exhale, sweat, and lactic acid.
The health department usually takes measures following a flood or a hurricane to minimize mosquito populations, but you should also do your part to be sure, especially if you’re in skeeter country.