By Medifit Education.
Malaria is a disease of the blood that is caused by the Plasmodium parasite, which is transmitted from person to person by a particular type of mosquito.
Malaria is caused by a parasite called Plasmodium, which is transmitted via the bites of infected mosquitoes. In the human body, the parasites multiply in the liver, and then infect red blood cells.
Symptoms of malaria include fever, headache, and vomiting, and usually appear between 10 and 15 days after the mosquito bite. If not treated, malaria can quickly become life-threatening by disrupting the blood supply to vital organs. In many parts of the world, the parasites have developed resistance to a number of malaria medicines.
Malaria is a mosquito-borne disease caused by a parasite. People with malaria often experience fever, chills, and flu-like illness. Left untreated, they may develop severe complications and die. In 2013 an estimated 198 million cases of malaria occurred worldwide and 500,000 people died, mostly children in the African Region.
The word malaria comes from 18th century Italian mala meaning “bad” and aria meaning “air”. Most likely, the term was first used by Dr. Francisco Torti, Italy, when people thought the disease was caused by foul air in marshy areas.
It was not until 1880 that scientists discovered that malaria was a parasitic disease which is transmitted by the anophelesmosquito. The mosquito infects the host with a one-cell parasite called plasmodium. By the end of the 18th century, scientists found out that Malaria is transmitted from person-to-person through the bite of the female mosquito, which needs blood for her eggs.
Approximately 40% of the total global population is at risk of Malaria infection. During the 20th century the disease was effectively eliminated in the majority of non-tropical countries.
According to the World Health Organisation (WHO):
- Approximately 660,000 people died from malaria in 2010 globally, most of them were African children.
- There were an estimated 219 million cases of malaria infection in 2010 worldwide.
- Malaria is a preventable and curable disease.
- Malaria mortality rates have fallen by over 25% since 2000. In the WHO African region rates have dropped by 33%.
- The malaria burden in many parts of the world is being dramatically reduced thanks to increased malaria prevention and control measures.
- Travelers from malaria-free areas who enter endemic areas are especially vulnerable to severe symptoms when they become infected.
- About 80% of all malaria cases occur in just 17 countries.
- Nigeria and the Democratic Republic of the Congo account for more than 40% of all malaria deaths worldwide.
The Centers for Disease Control and Prevention says that about 1,500 people are diagnosed in the U.S. with malaria each year. The vast majority were infected abroad.
Malaria is transmitted exclusively through the bites of Anopheles mosquitoes. The intensity of transmission depends on factors related to the parasite, the vector, the human host, and the environment.
About 20 different Anopheles species are locally important around the world. All of the important vector species bite at night. Anopheles mosquitoes breed in water and each species has its own breeding preference; for example some prefer shallow collections of fresh water, such as puddles, rice fields, and hoof prints. Transmission is more intense in places where the mosquito lifespan is longer (so that the parasite has time to complete its development inside the mosquito) and where it prefers to bite humans rather than other animals. For example, the long lifespan and strong human-biting habit of the African vector species is the main reason why about 90% of the world’s malaria deaths are in Africa.
Transmission also depends on climatic conditions that may affect the number and survival of mosquitoes, such as rainfall patterns, temperature and humidity. In many places, transmission is seasonal, with the peak during and just after the rainy season. Malaria epidemics can occur when climate and other conditions suddenly favour transmission in areas where people have little or no immunity to malaria. They can also occur when people with low immunity move into areas with intense malaria transmission, for instance to find work, or as refugees.
Human immunity is another important factor, especially among adults in areas of moderate or intense transmission conditions. Partial immunity is developed over years of exposure, and while it never provides complete protection, it does reduce the risk that malaria infection will cause severe disease. For this reason, most malaria deaths in Africa occur in young children, whereas in areas with less transmission and low immunity, all age groups are at risk.
SYMPTOMS OF MALARIA
It is important to be aware of the symptoms of malaria if you are travelling to areas where there is a high malaria risk (see below). Symptoms include:
- a high temperature (fever)
- sweats and chills
- muscle pains
Symptoms usually appear between seven and 18 days after becoming infected, but in some cases the symptoms may not appear for up to a year, or occasionally even longer.
EXAMS AND TESTS
During a physical examination, the doctor may find an enlarged liver or enlarged spleen. Malaria blood smears taken at 6 to 12 hour intervals confirm the diagnosis.
A complete blood count (CBC) will identify anemia if it is present.
DIAGNOSIS AND TREATMENT
Early diagnosis and treatment of malaria reduces disease and prevents deaths. It also contributes to reducing malaria transmission.
The best available treatment, particularly for P. falciparum malaria, is artemisinin-based combination therapy (ACT).
WHO recommends that all cases of suspected malaria be confirmed using parasite-based diagnostic testing (either microscopy or rapid diagnostic test) before administering treatment. Results of parasitological confirmation can be available in 15 minutes or less. Treatment solely on the basis of symptoms should only be considered when a parasitological diagnosis is not possible.
Malaria, especially falciparum malaria, is a medical emergency that requires a hospital stay. Chloroquine is often used as an anti-malarial medication. But chloroquine-resistant infections are common in some parts of the world.
Possible treatments for chloroquine-resistant infections include:
- Artemisinin derivative combinations, including artemether and lumefantrine
- Quinine-based regimen, in combination with doxycycline or clindamycin)
- Mefloquine, in combination with artesunate or doxycycline
Choice of medication depends in part on where you were when you were infected.
Medical care, including fluids through a vein (IV) and other medications and breathing (respiratory) support may be needed.
- Brain infection (cerebritis)
- Destruction of blood cells (hemolytic anemia)
- Kidney failure
- Liver failure
- Respiratory failure from fluid in the lungs (pulmonary edema)
- Rupture of the spleen leading to massive internal bleeding (hemorrhage)
Many cases of malaria can be avoided. An easy way to remember is the ABCD approach to prevention:
- Awareness of risk – find out whether you’re at risk of getting malaria before travelling.
- Bite prevention – avoid mosquito bites by using insect repellent, covering your arms and legs and using an insecticide-treated mosquito net.
- Check whether you need to take malaria prevention tablets – if you do,make sure you take the right antimalarial tablets at the right dose, and finish the course.
- Diagnosis – seek immediate medical advice if you develop malaria symptoms, including up to a year after you return from travelling.
Speak to your GP if you are planning to visit an area where there is a malaria risk. It may be recommended that you take antimalarial tablets to prevent infection.
By Medifit Education.