Microbiology Nuts & Bolts
  • Home
  • Basic Concepts
    • What is infection?
    • Normal flora
    • Diagnosing infection
  • Microbiology
    • Basic bacterial identification
    • Interpreting bacteriology results
    • Interpreting serology results
  • Infection Control
    • What is infection control?
    • Universal precautions
    • MRSA
    • Clostridium difficile
  • Clinical Scenarios
    • Respiratory infections
    • Urinary infections
    • GI infections >
      • D&V
      • CDAD
    • CNS infections
    • Skin & bone infections
    • Sepsis
  • Antibiotics
    • Antimicrobial Stewardship
    • How antibiotics work
    • How to choose an antibiotic?
    • Reviewing antibiotics
    • Antibiotic resistance
    • Testing antibiotic resistance
    • Penicillin allergy
    • Theraputic Drug Monitoring
  • Guidelines
  • Lectures & Lecture Notes
    • Medical Students
    • Curriculum for the Foundation Program
    • Foundation Year 1
    • Foundation Year 2
    • Other Lectures
  • The Bug Blog
  • Buy the book...
  • NEW Edition Updates
  • Peer Reviews
  • Our Facebook page
  • Want to know more?
  • Contact

No One is Immune to Malaria

18/2/2014

 
According to the WHO about 3.3 billion people (half of the world's population) are at risk of malaria; globally there are over 200 million cases a year with an estimated 660,000 deaths.

In the UK, there are on average 1,600 cases and 7 deaths per year. It is not particularly common therefore it is easily missed. Any patient/returned traveller who has visited an endemic country (see map) who presents with a fever and flu-like symptoms should have malaria on the differential diagnosis for what might be causing their illness.
malaria map source CDC
Click for larger image
Source: CDC www.cdc.gov/
Just last week we had 5 cases locally! Not a typical week granted, especially as two of our cases had Plasmodium
ovale rather than the typical Plasmodium falciparum, and we had to remind ourselves of the treatment for P. ovale. 

There are 5 species of malaria which can infect humans: 
• Plasmodium falciparum (most common and most deadly)
• Plasmodium vivax (benign)
• Plasmodium malariae (benign)
• Plasmodium ovale (benign)
• Plasmodium knowlesi (rare - only found in some forested areas of South-East Asia)

Clinical 
P. falciparum and P. knowlesi have an incubation period shorter than 1 month and can cause severe disease  (presence of complications such as high parasite load >2%, cerebral malaria, pulmonary oedema, severe anaemia, hypoglycaemia, uraemia and lactic acidosis). The benign malarias (P. ovale along with P. vivax and P. malariae) usually result in a milder disease of a flu-like illness. These species can have an incubation period of longer than 1 month as they can reside in the liver and reactivate.
lifecycle of malaria parasite
Click for larger image
Patients with malaria do not necessarily need admitting into a hospital. However, because severe complications can occur whilst waiting for results to come back from the laboratory, they tend to be admitted for observation until the type of malaria and the parasite load are known.
symptoms of malaria
Laboratory Diagnosis
Many laboratories now use a combination of a malaria antigen test on whole blood samples followed by microscopy of thick and thin blood smears to distinguish the different types of malaria. 

• Antigen tests are good for diagnosing malaria (especially in laboratories that do not see a lot of malaria), but they cannot always distinguish between different species nor do they give a parasite load. They are valuable in laboratories that do not see malaria frequently as they are quick, easy to perform and sensitive. Antigen tests should be used in combination with microscopy.

• Microscopy gives the specific species of malaria and a
parasite load which helps decide on severity and risk of complication. This test requires a high degree of expertise and experience which is difficult for laboratories in the UK to maintain as they do not see enough positive malaria tests.

Treatment
The treatment of malaria depends on the malaria species and the severity of illness. If the species is not known then the patient should be treated as though they have falciparum malaria as this is the most dangerous.
Treatment of falciparum malaria
The treatment of benign malarias, as was the case for our patients, is much simpler and can usually be managed in
the community under a general practitioner. It is aimed at controlling the parasitaemia (the amount of parasite in the blood  stream) and then eradicating the parasite from the hepatocytes (liver cells). P. malariae does not tend to relapse because chronic infection of liver cells is uncommon. 

Treatment of adults is shown in the table below and is based on the British Infection Society Guidelines for the Treatment of Malaria 2007. For the treatment of children seek specialist advice from an Infectious Diseases Consultant and use the Children’s British National Formulary.
Treatment for benign
It is important to remember that no one is immune to malaria, not even those born in endemic countries. Of the patients who died from malaria in the UK, over 60% did not take any prophylaxis whilst travelling to a known endemic country. Ultimately, the best way of managing malaria is to
not catch it in the first place!

Comments are closed.

    RSS Feed

    Blog Author:

    David Garner
    Consultant Microbiologist
    Surrey, UK

    Please DO NOT advertise products and conferences on our website or blog

    Categories

    All
    Antibiotic Resistance
    Antibiotics
    Basic Concepts
    Clinical Scenarios
    Guidelines
    Infection Control
    In The News
    Microbiology

    Archives

    October 2020
    September 2020
    August 2020
    July 2020
    June 2020
    May 2020
    April 2020
    March 2020
    February 2020
    January 2020
    December 2019
    November 2019
    October 2019
    September 2019
    August 2019
    July 2019
    June 2019
    May 2019
    April 2019
    March 2019
    February 2019
    January 2019
    December 2018
    November 2018
    October 2018
    September 2018
    August 2018
    July 2018
    June 2018
    May 2018
    April 2018
    March 2018
    February 2018
    January 2018
    December 2017
    November 2017
    October 2017
    September 2017
    August 2017
    July 2017
    June 2017
    May 2017
    March 2017
    February 2017
    January 2017
    December 2016
    November 2016
    October 2016
    September 2016
    August 2016
    July 2016
    June 2016
    May 2016
    April 2016
    March 2016
    February 2016
    January 2016
    December 2015
    November 2015
    October 2015
    September 2015
    August 2015
    July 2015
    June 2015
    May 2015
    April 2015
    March 2015
    February 2015
    January 2015
    December 2014
    November 2014
    October 2014
    September 2014
    August 2014
    July 2014
    June 2014
    May 2014
    April 2014
    March 2014
    February 2014
    January 2014
    December 2013
    October 2013
    September 2013
    August 2013
    July 2013

    Categories

    All
    Antibiotic Resistance
    Antibiotics
    Basic Concepts
    Clinical Scenarios
    Guidelines
    Infection Control
    In The News
    Microbiology

    RSS Feed

Powered by Create your own unique website with customizable templates.