Malaria

Malaria

  • The term Malaria originates from Italian word; “Mala” and “aria”, which means “Bad Air”
  • Malaria kills more than 400,000 people each year worldwide.
  • Every 2 minutes a child dies of malaria.
  • Malaria causes illness in more than tens of millions of people.
  • Most of the deaths by malaria occur in young children living in sub-Saharan Africa.
  • According to World Health Organization (WHO), “In 2017,  falciparumaccounted for 99.7% of estimated malaria cases in the WHO African Region, as well as in the majority of cases in the WHO regions of South-East Asia (62.8%), the Eastern Mediterranean (69%) and the Western Pacific (71.9%)”.

What is Malaria?

Malaria is an acute infections disease. It is caused by five species of Plasmodium;

  • Plasmodium falciparum
  • Plasmodium vivax
  • Plasmodium malariae
  • Plasmodium ovale
  • Plasmodium knowlesi

The malaria parasite is transferred into the human body by the bite of female Anopheles mosquito. This mosquito is found in humid, swampy areas.

Out of all malarial species the Plasmodium falciparum is the most dangerous.

 

Malarial disease is characterized by

  • Persistent high fever
  • Shaking chills
  • Flu-like symptoms
  • Orthostatic hypotension

If the disease is not treated then Plasmodium falciparum infection results in the obstruction of capillaries which ultimately cause death.

How is Malaria Transmitted?

Malaria is usually transmitted to human by the bite of infected / carrier female mosquito. It can also be transferred from one infected person to another by some carrier, like sharing syringes, infected blood transfusion. It is not a contagious disease.

Life Cycle of malaria Parasite

There are two stages in the life cycle of a malarial parasite.

  • Sexual Life cycle
  • Asexual Life cycle

Malarial parasite completes it life cycle in two hosts;

  • Mosquito (Insect host)
  • Human (Vertebrate host)

Sexual life cycle is completed in mosquito while asexual life cycle is completed in human body.

Mosquito (Insect host)

  • When a female anopheles mosquito bites an infected person than plasmodium male and female gametocytes are ingested into the mosquito body.
  • Inside mosquito body they develop, undergo sexual division and reproduce to form sporozoites.
  • These sporozoites move into the salivary glands of mosquito. From there these are transmitted.

Human (Vertebrate host)

  • When an infected mosquito bites a healthy individual, it injects plasmodium sporozoites into the human blood stream where asexual life cycle of plasmodium starts.
  • Sporozoites then enter into the liver, where they form merozoites (cyst like structures).
  • Merozoites then release into the blood where they attack red blood cells (RBC’s) and use hemoglobin as nutrient.
  • Inside red blood cells RBC’s these merozoites are converted into trophozoites, which multiplies inside the red blood cells.
  • When red blood cells rupture it releases a number of merozoites that attack the other red blood cells and infect them. And the process continues.
  • Some Merozoites are converted into gametocytes.
  • Female mosquito picks up these gametocytes from the infected human body.
  • Then the sexual process starts which is completed in the female body where sporozoites are formed.

Drugs used to prevent malaria are called anti-malarial drugs.

Risk Factors

Risk factor to get malaria infection is high in;

  • People living in areas where disease is common
  • Young children and infants
  • Travelers coming from areas with no malaria
  • Pregnant woman and their baby

Prevention Strategies

Preventing mosquito bites when travelling to areas where the risk of getting malaria is high. It can be done by using;

  • Mosquito repellents
  • Insecticide-treated mosquito Nets
  • Sleeping indoor
  • Indoor insecticide sprays
  • Wearing long sleeve clothing
  • Anti-malarial drugs for travelers

Common Sign and Symptoms

  • High Fever
  • Shaking Chills
  • Sweating
  • Headache
  • Muscle ache
  • Malaise
  • Tiredness
  • Flu-like illness
  • Nausea
  • Vomiting
  • Anemia
  • Jaundice

Complications with Malaria

If Malaria is left untreated then it can be life threatening. The infection becomes very severe causing;

  • Severe jaundice and anemia
  • Kidney failure
  • Mental Confusion
  • Seizures
  • Coma
  • Death

Diagnosis of Malaria

Clinical Diagnosis of Malaria

Clinical diagnosis of malaria is based on Physical findings during examination. These are as follows;

  • Fever
  • Chills
  • Sweats
  • Headaches
  • muscle pains
  • Weakness
  • Abdominal pain
  • nausea and vomiting

The clinical signs are very common with other diseases also, these are nonspecific signs.

In severe cases of infection symptom includes;

  • Confusion
  • Coma
  • Severe anemia
  • Respiratory difficulties

Laboratory Diagnosis

Laboratory diagnosis of malaria includes;

  • Microscopic Diagnostic technique
  • Quantitative buffy coat (QBC) technique
  • Rapid diagnostic tests (RDT’s)
  • Serological tests

 

Microscopic Diagnostic method

Microscopic Diagnostic method includes thin and thick peripheral blood smears. Stained blood smears using Giemsa, Wright’s, or Field’s stains are used to identify the presence of plasmodium and its specie.

  • Thick blood films are used for the screening of presence of malaria parasite
  • Thin blood films are used to confirm the specie.

 

 

QBC technique

QBC method involves the identification of malaria parasite by staining its DNA with fluorescent dyes (acridine orange) in a micro-hematocrit tube using. It is then detected by epi-fluorescent microscopy.

 

Rapid diagnostic tests (RDT’s)

Rapid diagnostic tests (RDT’) are simple, quick, accurate, and cost-effective. These are used to for determining the presence of malaria parasites

Rapid diagnostic tests (RDT’) are all based on the same principle. These tests are used to detect malaria antigen in blood flowing along a membrane containing specific anti-malaria antibodies; they do not require laboratory equipment.

 

Serological tests

Serological tests are used to detect antibodies against malaria parasites. These tests are performed using either indirect immunofluorescence (IFA) or enzyme-linked immunosorbent assay (ELISA).

 

Molecular Diagnosis

Molecular Diagnostic test detects the presence of Parasite nucleic acids by using polymerase chain reaction (PCR). PCR results are often not available quickly.

PCR is mostly used to confirm the species of malaria parasite after the diagnosis has already been established by some other technique.

 

Malaria vaccine: The RTS, S Malaria Vaccine

  • RTS,S (RTS) is the first malaria vaccine.
  • RTS,S was first created in 1987 by scientists working in GSK laboratories. It has shown some good results and efficacy in Phase 3 trial, concluded in 2014.
  • The first malaria vaccine RTS,S (RTS) is launched and piloted in three areas of Africa (Ghana, Kenya, Malawi).
  • It is included in the National Immunization program of these countries.
  • The program is coordinated by WHO in collaboration with Ministry of health of these countries, PATH and GSK (manufacturer of vaccine).
  • The aim of RTS,S vaccine is to trigger the immune system so that it can defend against the initial stages of malaria when the parasite (Plasmodium falciparum) enters the human host’s bloodstream after a mosquito bite. So, the vaccine is designed to prevent the parasite from infecting the liver.
  • There are many ways by which the vaccine prevents the parasite.
  • Malaria Vaccine interfere with the development of many different parts of parasite’s complex life cycle.
  • Vaccine can target the sporozoites after they are injected by the mosquito into the human host body and before they enter the liver.

Treatment

Malaria is a treatable and preventable disease. The main aim of treatment is to eradicate the plasmodium parasite completely from the body, and to prevent the progression of the disease

 

Visit https://www.drugscaps.com/product-category/anti-malarial/ to get your medication at your door step.

Medications

Drugs used to prevent malaria are called anti-malarial drugs. Malaria is treated with prescription drugs including;

  • Chloroquine (LARIAGO)
  • Mefloquine
  • Quinine/Quinidine
  • Pyrimethamine
  • Sulfadoxine
  • Tetracyclines
  • Primaquine
  • Atovaquone
  • Proguanil

 

The most common antimalarial drugs include:

Artemisinin-based combination therapies (ACTs)

ACTs are the first line treatment for malaria. ACTs include;

  • artemether-lumefantrine (Coartem)
  • artesunate-amodiaquine.

Each ACT is a combination of two or more drugs that work against the malaria parasite in different ways.

 

Chloroquine phosphate.

Chloroquine is the preferred treatment for any parasite that is sensitive to the drug. But in many parts of the world, the parasites that cause malaria are resistant to chloroquine, and the drug is no longer an effective treatment.

 

Other common antimalarial drugs include:

  • Atovaquone and proguanil (Malarone)
  • Quinine sulfate (Qualaquin) with doxycycline
  • Mefloquine
  • Primaquine phosphate

 

Visit https://www.drugscaps.com/product-category/anti-malarial/ to get your medication at your door step.

References

  • Richard A. Harvey

Antiprotozoal Drugs In Lippincott’s illustrated reviews of pharmacology. Lippincott Williams & Wilkins, 5th edition, 2012. (page: 445-449)

  • Koda-Kimble et Al.

Antiparasitic drugs In Applied Therapeutics The Clinical Use of Drugs. Lippincott Williams and Wilkins, Inc.  10th Edition 2013 (page: 141-144)

  • Laurence Brunton et al

Chemotherapy of parasitic infection In Goodman & Gilman’s The Pharmacological Basis of Therapeutics. The McGraw Hill Companies, Inc. 11th edition, 2008. (page: 1021-1045)

  • Tangpukdee N, Duangdee C, Wilairatana P, Krudsood S. Malaria diagnosis: a brief review. Korean J Parasitol. 2009;47(2):93–102. doi: 10.3347/kjp.2009.47.2.93.
  • Alonso P, Aponte J, Aide P, et al. Efficacy of the RTS,S/AS02A vaccine against Plasmodium falciparum infection and disease in young African children: randomized controlled trial. The Lancet. 2004;364 (9443):1411-1420. doi: 10.1016/S0140-6736(04)17223-1.
  • Alonso P, Aponte J, Aide P, et al. Safety of the RTS,S/AS02D candidate malaria vaccine in infants living in a highly endemic area of Mozambique: a double blind randomized controlled phase 1/2b trial. The Lancet. 2007;370 (9598): 1543-1551. doi: 10.1016/S0140-6736(07)61542-6.
  • RTS,S Clinical Trials Partnership. Efficacy and safety of RTS,S/AS01 malaria vaccine with or without a booster dose in infants and children in Africa: Final results of a phase 3, individually randomized, controlled trial. The Lancet. 2015;386 (9988): 31-45. doi: 10.1016/S0140-6736(15)60721-8.
  • First malaria vaccine receives positive scientific opinion from EMA [press release]. European Medicines Agency; July 24, 2015. http://bit.ly/1elUa6Z.
  • World Health Organization. Weekly Epidemiological Record. 2016;91(4): 33-52. http://www.who.int/wer.
  • https://www.cdc.gov/malaria/about/disease.html

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