Malaria

Malaria is a mosquito-borne illness caused by a plasmodium parasite. It is an acute febrile illness meaning it causes the symptoms of a fever.   Only certain species of the anopheles mosquito genus can transmit malaria. One such mosquito species is the Anopheles quadrimaculatus, which is common in the eastern United States. A female Anopheles quadrimaculatus can transmit this disease once she has taken a blood meal from an infected person. Malaria is a severe and sometimes fatal disease.

Malaria transmission from mosquito to humans is why the mosquito is considered the deadliest animal on the planet. According to the Gates Foundation, in 2015, 830,000 people died from mosquito-borne illnesses; 438,000 of these deaths were from malaria (CDC). Contrast that with six deaths caused by shark attack and fifty by tiger in 2015 (see image below).  Although Malaria is widespread in tropical and subtropical parts of the world, it was historically a killer in the United States. However, through drainage, window screens, increased use of air conditioning, the broad use of dicophane, malaria was effectively eliminated in the United States in the 1950s.

Unfortunately, malaria has been returning to the United States, albeit in smaller numbers. In the US, there are now around 1,500 cases reported annually. Most of these cases are from people who recently traveled to or immigrated from a part of the world where Malaria is widespread.

Transmission

Malaria is transmitted from an infected person to an uninfected person via mosquito bite from dusk throughout the night.  Therefore, mosquito nets are commonly used in parts of the world where malaria is endemic. Mosquito nets protect people while they sleep. People get malaria when the parasite passes from the mosquitoes’ saliva into a person’s blood. Malaria is not transmitted sexually. However, it can be transmitted from mother to child during pregnancy, through blood transfusion, organ transfer, or sharing of contaminated needles.  When traveling to places in the world where malaria is endemic, travelers should take malaria prevention medicines, use mosquito repellants, and sleep under mosquito nets.

Signs and Symptoms

Upon contracting malaria, flu-like symptoms may manifest from one week to a month.  These flu-like symptoms may include fever, chills, sweating, and fatigue. The most typical sign of malaria is called paroxysm, which is recurring coldness and shivering fits followed by fever and profuse sweating. Other symptoms include vomiting, diarrhea, headaches, and mental confusion. In severe cases, yellow skin, seizures, comas, and death occur. The severity of the illness often depends on which species of the parasite bit the person.

Treatment and Vaccines

There is currently no malaria vaccine on the market. Treatment for malaria depends on which of the five types of the malaria parasite is present in the blood, where it was acquired, and the severity of the symptoms. Certain anti-malarial drugs are used to combat specific species of malarial parasites.

Mosquitos that transmit malaria

Anopheles quadrimaculatus, the common malaria mosquito, is of most concern in the DC metropolitan area. This mosquito was the primary vector for malaria in the United States in the 17th, 18th, 19th, and first half of the 20th century and continues to be widespread on the Eastern Seaboard. Anopheles punctipennis is also a potential spreader of malaria in Northern Virginia and the greater Washington DC area. Out of the 430 species of anopheles mosquito species worldwide, only 30-40 of these species can transmit malaria.