Malaria

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Malaria

Overview

Malaria is a life-threatening disease transmitted by a mosquito bite. The causative organism is a parasite called Plasmodium. While the disease is rare in temperate climates, malaria is still prevalent in tropical & subtropical countries. It is transmitted to humans by the bite of the Anopheles mosquito. There are five different types of malaria-causing parasites that can affect humans.

When the mosquito bites, the parasite is released into the bloodstream. Inside the body, parasites travel to the liver, where they develop and mature. After several days, the mature parasites enter the bloodstream & begin to infect RBC’s. In 48 to 72 hours, the parasites grow inside the RBC’s, causing the infected cells to burst open. The parasites continue to infect other RBC’s, resulting in symptoms that occur in cycles that last two to three days at a time. These symptoms include recurrent attacks of chills & fever.

In rare situations, malaria is transmitted from the mother to the unborn child during pregnancy, by blood transfusions, or when intravenous-drug users share needles.

Worldwide approximately 6,60,000 are killed due to malaria each year. The increase in international travel and migration of population, the risk has increased in areas where it does not commonly occur.

It is very common in developing countries, areas with high humidity & moderate temperatures. These include parts of Central & South America, Haiti, The Dominican Republic, Africa, Eastern Europe, and South & Southeast Asia. The deadliest types of malaria are more common in Africa. According to the World Health Organization (WHO), each year 300-500 million cases of malaria occur & more than 1 million people die of malaria, particularly in developing countries. Most of the deaths are of young children. In Africa, a child dies from malaria every 30 seconds. Because malaria causes severe illness & death, the disease causes a drain on national economies. The disease maintains a vicious cycle of disease & poverty in the poorer nations.

Causes of Malaria

Malaria is caused by a type of parasite known as Plasmodium.  The Plasmodium parasite is mainly spread by female Anopheles mosquitoes, which mainly bite at dusk & at night.

There are different types of Plasmodium parasite, but only five types cause malaria in humans.

These are:

  1. Plasmodium falciparum – It is mainly found in Africa. It is the most dangerous type of malaria parasite & is responsible for most malaria deaths worldwide.
  2. Plasmodium vivax – It is mainly found in Asia & South America. The parasite causes milder symptoms than Plasmodium falciparum. This parasite can stay in the liver for up to three years and result in relapses.
  3. Plasmodium ovale – It is uncommon & usually found in West Africa. It can remain in your liver for several years without producing any symptoms.
  4. Plasmodium malariae – This is found in Africa.
  5. Plasmodium knowlesi – This is found in parts of southeast Asia

Symptoms of Malaria

Malaria symptoms can be divided into two categories: uncomplicated or complicated malaria.

Uncomplicated malaria

In this condition symptoms are present, but there are no signs of severe infection or dysfunction of the vital organs. This form can become severe if left untreated, or if the host has lower or no immunity. Symptoms of this type of malaria typically last 6 to 10 hours & reappear every second day. Some strains of this parasite can have a longer cycle or cause mixed symptoms. As symptoms resemble those of flu, they may be undiagnosed or misdiagnosed in areas where malaria is less common.

In uncomplicated malaria, symptoms include:

  • Sensation of cold with shivering
  • Fever, headaches, & vomiting
  • Seizures may occur in younger people
  • Sweating followed by a recovery to normal temperature

Severe malaria

In severe malaria, clinical or laboratory evidence shows signs of vital organ dysfunction.

Symptoms of severe malaria include:

  • Fever & chills
  • Loss of or impaired consciousness
  • Prostration and exhaustion
  • Multiple convulsions
  • Deep breathing & respiratory distress
  • Abnormal bleeding & signs of anemia
  • Clinical jaundice & other evidence of vital organ dysfunction

Severe malaria can be fatal without treatment.

Risk factors

The main risk factor for acquiring malaria is living in or visiting tropical areas where the disease is common. Various subtypes of malaria parasites exist. The varieties that cause the most deadliest complications are usually found in:

  • African countries, south of the Sahara Desert
  • The Asian sub-continent
  • Solomon Islands, Papua New Guinea & Haiti

Risk of severe disease

People at risk of serious disease include:

  • Young children & infants
  • Travelers coming from areas with no malaria
  • Pregnant women & their unborn children

Poverty, lack of knowledge, & limited or no access to health care further contribute to malaria deaths worldwide.

Residents of a malaria region may be exposed to the disease so frequently that they acquire partial immunity, which can reduce the severity of malaria symptoms. But, this partial immunity can fade away if you move to a country where you’re no longer constantly exposed to the parasite.

Diagnosis of Malaria

  • The symptoms of malaria can imitate many other diseases, including influenza or viral syndrome. It is hence important to ask about a history of recent travel to an endemic area or other potential exposures.
  • You must seek medical help right away if you become ill while traveling in an area where malaria is found, or after returning from traveling, even if you’ve been taking antimalarial tablets.
  • Malaria can get worse very fast, so it is necessary that it is diagnosed & treated as soon as possible.
  • If you see the symptoms of malaria while still taking antimalarial tablets, either while you’re traveling or in the days & weeks after you return, remember to tell the doctor which type you have been taking. The same type of antimalarial shouldn’t be used to treat you as well.
  • If you see the symptoms after returning home, visit your general physician or a hospital doctor & tell them which countries you’ve traveled to in the last 12 months.
  • The correct diagnosis is made by looking at the blood of an infected patient under the microscope (blood smear) & identifying the presence of the parasite. The patient’s blood is prepared under a slide with a specific stain to help recognize the parasite. This is the most widely performed & accepted test.
  • Rapid diagnostic tests (antigen tests) are available that can give the diagnosis in a few minutes. It is advised that a positive test is followed by a blood smear examination.

Treatment of Malaria

If malaria is diagnosed & treated promptly, a full recovery can be expected. Treatment should begin as soon as the blood test confirms malaria.

Several antimalarial medicines are used to treat the disease. They can also be used to prevent malaria.

The type of antimalarial medicine & how long you must take it will depend on

  • The type of malaria
  • Where you got malaria
  • The severity of symptoms
  • Whether you used preventative antimalarial tablets
  • Age
  • Whether you’re pregnant

Your doctor may suggest using a combination of different antimalarial to treat types of malaria parasites that have become resistant to particular types of medication.

Antimalarial medication is normally given as tablets or capsules. If someone is seriously ill, it will be given as an injection or infusion in the arm in the hospital. Treatment for malaria can make you feel very tired & weak for many weeks.

The most common antimalarial drugs include

  • Chloroquine (Aralen)
  • Hydroxychloroquine (Plaquenil)
  • Quinine sulfate (Qualaquin)
  • Mefloquine
  • Combination of atovaquone and proguanil (Malarone)

Preventive treatment

In a few cases, you may be prescribed medication for malaria before you travel. This is done if there is a risk of you becoming infected with malaria while traveling to an area with a high prevalence of malaria and limited access to medical care.

Antimalarials in pregnancy

If you’re pregnant, it’s suggested to avoid traveling to areas wherever there is a risk of malaria.

Pregnant women have an enhanced risk of developing severe malaria, & both the baby & mother could encounter severe complications. It is important to take the right antimalarial medicine if you’re pregnant & unable to postpone/cancel your tour to an area where there is a malaria risk. Some of the medicines used to prevent & treat malaria are unsuitable for pregnant women because they can cause side effects for both mother & baby.

These include

  • Mefloquine – not normally prescribed during the first trimester of pregnancy. Pregnancy should be avoided during the first three months after the preventative antimalarial medication is stopped.
  • Doxycycline – never advised for pregnant or breastfeeding women as it could harm the baby.
  • Atovaquone plus proguanil – not advised in pregnancy or breastfeeding. Nevertheless, if the risk of malaria is high, they may be advised if there is no suitable alternative.
  • Chloroquine along with proguanil is suitable during pregnancy, but it is not always used as it is not so effective against the most common & dangerous type of malaria parasite.

Prevention of Malaria

There is a risk of getting malaria if you travel to an affected area. It is important to take care to prevent the disease. Malaria can usually be avoided using the ABCD approach for prevention:

  • Awareness of risk – check out the risk of getting malaria.
  • Bite prevention – avoid mosquito bites by using insect repellent, covering your arms & legs, or by using a mosquito mesh.
  • Check if you need to take malaria prevention tablets – if you do, make sure you take the right antimalarial tablets at the right dose & complete the course.
  • Diagnosis – ask immediate medical advice if you have malaria symptoms up to a year after you return from traveling.

Awareness of risk

Check whether you need to take preventative malaria treatment for the countries you’re visiting. It is also necessary to visit your general physician or local travel clinic for malaria information as soon as you know where you are going to be traveling. You still need to take precautions to protect yourself from infection if you’re traveling to a risk area, even if you grew up in a country where malaria is common. Nobody has complete immunity to malaria & any level of natural protection you may have had is quickly lost when you move out of a risk area.

Bite prevention

To avoid being bitten by the mosquitoes:

  • Stay around areas that have efficient air conditioning & screening on doors & windows. If this isn’t possible, make sure doors & windows close properly.
  • Use insect repellent on your skin & in sleeping environments. Remember to reapply it frequently. The most effective repellents contain diethyltoluamide (DEET) and are available in sprays, roll-ons, sticks & creams.
  • Wear light, loose-fitting trousers rather than shorts, & shirts with long sleeves. This is particularly important during early evening & at night when mosquitoes prefer to feed.

Check if you need to take malaria prevention tablets

There is currently no vaccine readily available that offers protection against malaria, so it is necessary to take antimalarial medication to reduce your chances of getting the disease.

Antimalarials only reduce your risk of infection by about 90%. Therefore taking steps to avoid bites is also important.

Types of antimalarial medication used to prevent malaria

Antimalarial medication is used to prevent malaria. The types of antimalarials used to treat or prevent malaria are given below.

Atovaquone + proguanil

  • Dosage – The adult dosage is one adult-strength tablet a day. Dosage for children depends on the child’s weight. It should be started one or two days before your trip & taken every day you’re in a risk area. The tablets must be continued for seven days after returning.
  • Recommendations – not advised in pregnant or breastfeeding women. It’s also not advised for people with severe kidney problems.
  • Possible side effects – stomach upset, headaches, skin rash & mouth ulcers.

Doxycycline

  • Dosage – the dose is 100mg daily as a tablet/capsule. You should start the medicines two days before you travel & take them each day you’re in a risk area, & for four weeks after you return.
  • Recommendations – not suitable for pregnant or breastfeeding women, children under the age of 12 (because of the risk of permanent tooth discoloration), people who are sensitive to tetracycline antibiotics, or people with liver problems.
  • Possible side effects – stomach upset, heartburn, thrush & sunburn as a result of light sensitivity.

Mefloquine

  • Dosage – the adult dose is one tablet weekly. Child dosage is also once a week, but the amount will depend on their weight. It should be started three weeks before you travel & taken all the time you’re in a risk area, & continued for four weeks after returning.
  • Recommendations – it’s not recommended if the person is suffering from epilepsy, seizures, depression or other mental health issues, or if a close relative has any of these conditions. It is not usually advised for people with severe heart or liver problems.
  • Possible side effects – dizziness, headache, sleep disturbances (insomnia & vivid dreams) & psychiatric reactions (anxiety, depression, panic attacks & hallucinations). It is important to tell the doctor of any previous mental health problems, including mild depression. Don’t take this medicine if you have a seizure disease.

Chloroquine & proguanil

A combination of antimalarial medications called chloroquine & proguanil is also available but they’re mostly ineffective against Plasmodium falciparum.

You are always advised of taking antimalarial medicine when traveling to areas wherever there’s a risk of malaria. Visit your general physician or local travel clinic for malaria advice as soon as you know when & where you’re going to be traveling.

It’s necessary to take the correct dose & complete the course of antimalarial medication. If you’re doubtful, ask your general physician or druggist how long you should take your medication.

DEET insect repellents

The chemical DEET is often used in insect repellents. It is not advised for babies who are less than two months old. DEET is safe for older children, adults & pregnant women.

  • Use on exposed skin
  • Don’t spray directly on to your face – spray into your hands & pat on to your face
  • Avoid contact with lips & eyes
  • Wash your hands after using
  • Do not apply to damaged or irritated skin
  • Make sure you apply DEET after applying sunscreen, not before

Faqs

  1. How does one get malaria?

When a mosquito carrying the malaria parasite bites, the parasite is released into the bloodstream and cause malaria

  1. How is malaria spread?

Malaria is spread by a mosquito bite.

  1. What are the symptoms of severe malaria?

Severe malaria

In severe malaria, clinical or laboratory evidence shows signs of vital organ dysfunction.

Symptoms of severe malaria include:

  • fever & chills
  • impaired consciousness
  • prostration, or adopting a prone position
  • multiple convulsions
  • deep breathing & respiratory distress
  • abnormal bleeding & signs of anemia
  • clinical jaundice & evidence of vital organ dysfunction
  1. What are the most common antimalarial drugs used?

  • Chloroquine (Aralen)
  • Hydroxychloroquine (Plaquenil)
  • Quinine sulfate (Qualaquin)
  • Mefloquine
  • Combination of atovaquone and proguanil (Malarone)