Malaria
Millennium Development Goal 6
- Reducing the incidence of malaria is part of Millennium Development Goal 6
- This is to be achieved by international collaborative programmes such as :
Malaria Consortium
Malaria Consortium is an organisation dedicated to improving delivery of prevention and treatment to combat malaria and other communicable diseases in Africa and Asia.
The Consortium works with:
- communities,
- health systems,
- government and non-government agencies,
- academic institutions and
- local and international organisations,
to ensure good evidence supports delivery of effective services.
The disease, prevention and treatment
Malaria is a common, preventable and treatable life-threatening disease, caused by plasmodium parasites transmitted by mosquito bites.
Pattern
- Malaria occurs mainly in tropical and subtropical countries
- About half the global population is at risk
- Each year there are globally more than two hundred and fifty million malaria cases a year and around one million deaths.
- Sub-Saharan Africa has the most cases and deaths
- Asia, Latin America and some part of the Middle East and Europe are also affected.
Those particularly at risk are
- young children
- pregnant women
- people with HIV/AIDS
- travellers from non-endemic areas
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Recommended interventions
-
prevention of bites by sleeping under insecticide-treated nets
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indoor spraying of insecticide and environmental management
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case identification and treatment
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intermittent preventative treatment for high risk groups
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Resistance
Resistance of
- parasites to drugs
- mosquitos to insecticides
are threats to malaria treatment and control.
(Malaria vaccination is a future possibility and clinical research trials are making progres)
The illness
Malaria is an acute febrile illness caused by protozoan Plasmodium parasites.
- Plasmodium falciparum predominantly affects Africa
- Plasmodium vivax mainly affects Asia, South and Central America and the Carribbean.
The bite of the female Anopheles mosquito injects the parasites. These develop in the liver and are released into the bloodstream causing illness, from a week to several months after the bite.
First signs of the illness
Mild
- Can mimic other infections with fever, chills, headache and vomiting
Severe :
- Children can present with anaemia, respiratory distress, or cerebral malaria.
- Adults may present with affect multiple organ systems involvement.
Relapsing illness
Some types of Plasmodium can relapse weeks or months after the first infection. Incomplete immunity develops where infection is frequent,
Diagnosis
- is recommended before treatment (because malaria has similar symptoms to other infections, and, without testing, there is over diagnosis by health services).
- is made by
- identifying parasites in the blood using microscopy or
- rapid diagnostic
Treatment
- Start within 24 hours to prevent severe malaria
- Use WHO treatment guidelines
- Refer to country treatment policies to
- identify effective anti-malarials
- reduce drug resistance.
- community-based programmes are needed where there is low access to health services.
Drug resistance
- is a threat to the treatment of malaria
- affects most older anti-malarials
- is starting to affect newer treatments.
- is extensive in South East Asia
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Malaria in high risk groups
Malaria affects the following more severely
- pregnant women
- children under 5 years
- people with HIV/AIDS
- non-immune travellers
Pregnant Women
Malaria increases the risk of
- maternal anaemia
- stillbirth
- spontaneous abortion
- low birth weight
- neonatal death.
Management
- Insecticide treated nets
- Intermittent Preventive Treatment in areas of high malaria transmission in the second and third trimesters of pregnancy
- Effective management of malaria and anaemia.
Infants
- are at high risk from about three months as the immunity from the mother falls
Management
- use insecticide nets
- intermittent full anti-malaria treatment courses as part of the Expanded Programme of Immunisation (usually at ten weeks, fourteen weeks and nine months of age).
In some regions, mass Intermittent Preventive Treatment has been used for school children.
People with HIV infection
- Co-infection with HIV and tuberculosis is common in high prevalence countries. Thus, intensified case finding and infection control are important..
- Use anti-tuberculosis therapy for latent tuberculosis to reduce reactivation
- Treat people with active tuberculosis in the usual way.
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Malaria control
Malaria control depends on disrupting the transmission of the malaria parasite to break its lifecycle.
The most effective approach depends on local conditions.
Variation in
- rainfall
- altitude
- urbanisation
will lead to variation in malaria
- geographically
- seasonal (malaria may be continuous or seasonal)
Climate change is expected to alter the distribution of malaria as a result of changes in rainfall, temperature and humidity and their effects on the distribution of the mosquito and parasite.
Management
Use integrated vector management including
- environmental management of mosquito breeding grounds
- management of water, drainage and sanitation (otherwise there is high urban transmission)
- insecticide spraying
- indoor residual insecticide spraying to reduce survival of mosquitos where there are species which mostly bite and rest indoors.
- long lasting insecticide treated nets (These reduce transmission by 90% when used by the whole population, halving new cases, and reducing child deaths.)
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Malaria advice for travellers
Travellers to areas with endemic malaria are at particular risk as they do not have immunity. Around 300 cases a a year are identified in the UK in returning travellers.
The WHO key ABCD message is:
A. Be Aware of the risk, the incubation period and the main symptoms
B. Avoid being bitten by mosquitoes, especially between dusk and dawn
C. Take antimalarial drugs (Chemoprophylaxis) to suppress infection where appropriate
D. Immediately seek diagnosis and treatment if a fever develops one week or more after entering an area where there is a malaria risk, and up to 3 months after departure.
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