Malaria is an infectious disease (mosquito-borne) caused by Plasmodium parasites. This parasitic infection in humans occurs mainly due to five parasitic species; they are, Plasmodium vivax, Plasmodium falciparum, Plasmodium ovale, Plasmodium malariae, and Plasmodium knowlesi. Globally around 1.5 to 3 million people die each year due to malaria, and the greatest threats are posed mostly by Plasmodium falciparum and Plasmodium vivax.
How Is Malaria Transmitted?
Malaria is transmitted from one person to other through the bite of infected female Anopheles mosquitoes. As these parasites affect red blood cells, malaria can also be transmitted through infected blood via,
What Are the Symptoms of Malaria?
The approximate incubation period is 12 days in the case of Plasmodium falciparum, 14 days for Plasmodium vivax and Plasmodium ovale, and 30 days for Plasmodium malariae. During that time, people will not develop any symptoms, but the malarial parasite will be multiplying. Following that, the typical symptoms seen are fever with chills and rigor.
This may also be associated with,
Pain in the muscles.
Pain in joints.
Initially, there will be shaking chills for a few hours (cold stage), followed by high fever (hot stage) and marked sweating (sweating stage). The fever is intermittent, which may occur every other day in Plasmodium vivax and Plasmodium ovale infection (tertian malaria), and in the case of Plasmodium malariae, fever occurs every third day (quartan malaria). However, Plasmodium falciparum has no specific pattern of fever. The patients may have anemia and mild jaundice due to the breakdown of red blood cells. As well as, there are chances for enlargement of the spleen when this occurs, mild liver enlargement may also be seen.
How Is Malaria Caused?
Malaria occurs with the bite of infected female Anopheles mosquitoes. When it bites, the uninfected humans undergo various stages with the breakdown of red blood cells to transmit malaria. The below flow chart will explain in detail how a mosquito causes malaria.
In the case of Plasmodium vivax and Plasmodium ovale infections, it is said that some sporozoites remain in a dormant form in the liver as hypnozoites for upto a year or more. These hypnozoites can get reactivated later and cause delayed primary infection or relapses. Relapse can also occur if treatment is not given to eradicate hypnozoites.
In the case of Plasmodium falciparum, it invades red blood cells of all ages, whereas Plasmodium vivax and Plasmodium ovale preferably invade immature red blood cells, and Plasmodium malariae invades the developing red blood cells (normoblasts). Parasitemia is most severe in Plasmodium falciparum infection, where more than 2 % of all red blood cells can be infected. Hence the breakdown of red blood cells is most severe in Plasmodium falciparum infection.
The red blood cells infected with Plasmodium falciparum get adhered to capillary endothelium and agglutinate with other infected RBCs and form into clusters with uninfected red blood cells. This leads to ischemia and dysfunction of various organs such as the brain, liver, kidney, lungs, and gut.
How Is Malaria Diagnosed?
Early diagnosis is highly essential for recovery from malaria. When there are signs and symptoms, it is better to reach the doctor at the earliest and get treatment accordingly. The World Health Organization (WHO) says that it is better to confirm the diagnosis through microscopic laboratory testing to identify the parasite, or a rapid diagnostic test can be performed depending on the facilities available.
If there is a combination of symptoms, malaria cannot be distinguished only by the symptoms available. In order to distinguish, a parasitological test is essential to identify and treat the disease. In malaria-endemic areas, the severity of the disease causes a large proportion of the population with mild immunity. So, some people will carry the parasite through the bloodstream but may not fall ill.
How Can Malaria Be Prevented?
Several ways to prevent malaria are,
Research is ongoing to develop safe vaccines for malaria. One vaccine has already been licensed in Europe; however, it is not licensed in the United States. So, consult a doctor when there are suspected symptoms.
Advice for Travelers:
Check if there is any risk for malaria in the traveling country.
Seek the doctor’s help for a precautionary prescription to prevent the disease before visiting the country or place.
Have antimalarial drugs with you before leaving home or while traveling.
Before traveling, consider the risk for pregnant women, children, and elderly patients.
Things to Carry:
People who travel should carry prevalent tools such as,
All these are not harmful to humans as the concentration of pesticides kills only the mosquitoes and does not pose any risk to humans.
Avoid situations that may increase the risk of getting a bite by mosquitoes. Things to remember are:
Choose an air-conditioned room.
Do not stay near stagnant waters.
Wear clothes that cover the whole body.
Up to around six months after traveling, a person may be able to develop symptoms, so it is not advisable to donate blood for some period.
How Is Malaria Treated?
Treatment of malaria mainly aims to eliminate the Plasmodium parasite from the blood. People without symptoms are treated to reduce the risk of disease transmission. There are several drugs for the treatment of malaria, and they are:
Malaria is a life-threatening disease leading to thousands of deaths yearly. In order to avoid this, we should create awareness and educate people properly to eradicate this disease. When immediate and proper treatment is given, the person will be able to recover from malaria. So reach out to the doctor when you notice any symptoms.
Frequently Asked Questions