By Barry C. Fox, M.D., University of Wisconsin
The deadliest malaria species is Plasmodia falciparum. During the blood stage, falciparum species can alter the red blood cell’s surface, causing them to stick to blood vessel walls. This induces a sludging of red blood cells and impairment of oxygen exchange to the brain. If untreated, the brain begins to swell, and malaria has reached its most deadly phase. Often this scenario results in coma and then death.
Outbreaks of Malaria in the United States
Some people might have thought that this only happens outside the United States, but malaria was actually present in the U.S. until the 1930s. The malaria problem in the U.S. was so concerning that the Centers for Disease Control, or CDC, was founded specifically to fight malaria.
In order to destroy mosquito habitats, three million acres of southern wetlands were drained and 30,000 miles of drainage ditches and canals were dug. Further spraying with the pesticide DDT also helped, as did building a public health infrastructure to treat patients. So malaria has had quite a grip on the U.S. in the past.
Actually, there are still around 2000 cases each year of malaria in the United States, with somewhere between six to eight deaths. Malaria cases in the U.S. reached a 40-year all-time high in 2011. Almost all of the nearly 2000 cases were contracted abroad—mostly in Africa and India—and brought back to the United States.
This is a transcript from the video series An Introduction to Infectious Diseases. Watch it now, on Wondrium.
The Deadliest Malaria Species and Its Treatment
Now, what about malaria treatments? Treatment for malaria was discovered in Peru in the 1600s. It came from the bark of the Cinchona tree and has been used as an inexpensive cure in some parts of the world—it is known as quinine—and it was of great value in World War II. Later, this ingredient was chemically modified into chloroquine, the first synthetic antimalarial medication.
All malaria used to be sensitive to chloroquine. However, malaria adapted to chloroquine and developed resistance over the course of a few decades. Now there are only a limited number of geographic locations in the world—only the Caribbean and Latin America—where chloroquine is still effective.
Other malaria medications are available, and they’re mainly targeted toward the prevention of falciparum malaria since it’s the deadliest. These include weekly treatments with Mefloquine, or daily Malarone, or doxycycline.
It’s interesting to note that in an ancient Chinese document, called ’52 Remedies’, a folk remedy for malaria from the Qinghao plant—also known as wormwood—was described. Its active ingredient is a compound known today as artemisinin. It’s a key ingredient in several current valuable antimalarial treatment drugs today.
World Health Organization’s Efforts to Prevent Malaria
In the international community in Madison, Wisconsin, the infectious disease department usually sees about a dozen cases of malaria every year, making the travel medicine department a fairly popular place. Doctors personally care for university students who have traveled abroad without preventative medications, which nearly costs them their lives. Obviously, preventive malaria medications when traveling to endemic areas are recommended.
Malaria is still prevalent in 106 countries. There are ongoing efforts today by the World Health Organization to try to prevent and reduce malaria—for example, by the distribution of treated mosquito netting, educational efforts for the native population, aggressive medication treatments, and the spraying of insecticides to reduce the mosquito population—but this is not enough.
Learn more about influenza.
Innovations for Malaria Eradication Worldwide
There are some novel ideas and innovations that are moving forward to eradicate malaria worldwide. The Bill and Melinda Gates Foundation has spent more than a billion dollars in an effort to eradicate malaria. They believe that the means to success will be by the total eradication of the mosquito. This changes the game plan. This means that it’s essential to use new technologies to develop and deliver sustainable responses to the mosquito population.
One effort involves genetically modifying the male mosquito and its ability to transmit the X chromosome. Female species need two X chromosomes. And at the Imperial College of London, scientists are injecting a biologically engineered gene into the male mosquito. This wipes out the X chromosome’s DNA, and thereafter the males can only donate the Y chromosome, consequently reducing female populations.
In their trials, 95 percent of the offspring were males, who then passed on the modified gene to the next generation. And over time, when released into the wild, and allowed to breed with wild mosquitoes, theoretically, this would lead to a reduction in the wild female population. Another technique using genetically engineered sterile mosquitoes in the Cayman Islands wiped out 80 percent of the mosquito population there in 2010.
Learn more about bioterrorism and how worried we should be.
Vaccination and Other Innovations to Prevent Malaria
There is also hope with trials of an RTSS vaccine that contains part of a sporozoite protein. This is the stage of malaria that’s inoculated by the feeding mosquito at the first moments of infection before malaria gets to the liver. Trials resulted in a 50 percent reduction in malaria in African children. And this falciparum malaria vaccine, hopefully, will substantially reduce malaria in African children.
The development of vaccines and the eradication of mosquitoes will continue to be the two most important efforts to prevent deaths from malaria. One innovative leap in the mobile healthcare movement, referred to as mHealth, may help diagnose patients with malaria, HIV, or TB in as little as 15 minutes. A British-based company developed a pocket-sized device, which not only tests for these diseases but also has a GPS tracking system for collecting disease-tracking information.
This ensures the appropriate medication for a specific disease can be delivered to an exact location, an exact patient, and provides helpful epidemiological information to public health systems.
Common Questions about the Deadliest Malaria Species
The first effective treatment for malaria was extracted from the bark of the Cinchona tree, from which the synthetic drug chloroquine was later developed. Other treatments include Mefloquine, Malarone, and doxycycline.
The World Health Organization is working tirelessly to prevent malaria, with methods such as medication treatments, educational programs for the native population, and spraying with insecticides.
Various methods have been devised to eradicate malaria mosquitoes, one of which is to genetically modify the male mosquito and destroy its ability to transfer the X chromosome. Via this method, the population of female mosquitoes is gradually reduced.
