Malaria

Malaria is a protozoal infection by the genus Plasmodium. It is transmitted through the bite of an infected female mosquito belonging to the genus Anopheles. It is characterised by paroxysms of chills, fever and sweating, and may lead to anaemia and splenomegaly.

Malaria parasites comprising 4 species, each one with a different biological pattern may affect man. Plasmodium vivax, Plasmodium falciparum, Plasmodium malariae and Plasmodium ovale. In Zambia, Plasmodium falciparum is the most prevalent.

Clinical features

Diagnosis
• Take a good history and include all the physical examination and make a differential diagnosis.
• Confirm the presence of parasites and complications by laboratory methods

Uncomplicated Malaria

Prodromal symptoms are usually non-specific and are often characterised by intermittent febrile illness. Fever is the most common symptom. Headache, aching joints, back pain, nausea and vomiting and general discomfort usually accompany the fever.

The patient may not present with fever but may have had a recent history of fever. This is due to the natural malaria cycle. A history of fever during the previous two days along with other symptoms of malaria is a critical basis for suspected malaria.

It is equally important to note that fever is a common symptom for other infections besides malaria, such as ear infections, measles and pneumonia. Malaria has been nicknamed "the Great Imitator" because of this. The possibility of other infections, either co-existing with malaria or as the sole cause of fever, should always be borne in mind in arriving at the diagnosis. It is therefore important to carry out a differential diagnosis.

In children, the onset of malaria may be characterized, in the early stages, only by symptoms like poor appetite, fever, restlessness, cough, diarrhoea, malaise and loss of interest in the surroundings.

Severe Malaria

P. falciparum infection in the presence of any life- threatening condition is considered as severe malaria. All life-threatening conditions and the presence of any danger signs in the presence of an acute febrile illness should be considered as possible severe malaria. Some of the danger signs include:

Excessive vomiting
Inability to drink or breastfeed
Extreme weakness
Convulsions
Drowsiness
Loss of consciousness
Abnormal breathing

Severe headache, sleepiness and loss of consciousness are some of the commonest indications of severe malaria. Jaundice is another early sign.

A patient in whom malaria is suspected and is severely ill requires urgent attention and should be referred to an appropriate health facility, where applicable. Severe malaria particularly in pregnant women and children under five should be managed as an emergency.

Other symptoms and signs of severe malaria include:

Convulsions (> 2 episodes within 24 hours)
Coma or altered level of consciousness
Drowsiness/lethargy
Prostration (inability to sit or stand without support)
Respiratory distress
Pulmonary oedema
Shock (cold moist skin, low blood pressure, collapse)
Severe vomiting
Severe anaemia (Hb <5g/dl or HCT <15%)
Haemoglobinuria
Hypoglycaemia (blood glucose <2.2mmol/L or<40mg/%)
Splenomegaly
Hepatomegaly
Abnormal bleeding (spontaneous prolonged bleeding from puncture
sites).

Management

Antimalarial Treatment

For severe (complicated) malaria, Quinine is recommended, however, intravenous Artesunate could be used as an option to Quinine in treatment of severe malaria where available.

Give Artesunate intravenously. If intravenous administration is not possible, Artesunate may be given intramuscularly into the anterior thigh.

Children: Artesunate 2.4 mg/kg BW IV or IM given on admission (time = 0) then at 12 hr and 24 hr, then once a day is the recommended treatment.
Adults: Artesunate 2.4 mg/kg BW IV or IM given on admission (time = 0) then at 12 hr and 24 hr, then once a day is the recommended treatment.

Give 2.4 mg/kg body weight IV or IM stat, repeat after 12 hours and 24 hours, then once daily afterwards. However once patient regains consciousness and can take orally, discontinue parenteral therapy and commence the full course of recommended ACT, such as Artemether + Lumefantrine fixed-dose combination.

Signs and symptoms of uncomplicated malaria

Uncomplicated malaria	Severe and complicated malaria
Fever (<_37.5 ^oC)	Severe anaemia (Hb <5g/dl)
Headache	Jaundice
Sweats and chills	Drowsiness
Body pains	Shock
Acute gastroenteritis	Convulsions
	Respiratory distress
	Unconciousness/ coma
	Change in behaviour
	Hyperparasitaemia
	Prostration, i.e., generalized weakness, inability to stand or walk
	Abnormal bleeding

Treatment

Uncomplicated Malaria

The first line of treatment for malaria is Artemisinin-based combination therapy. For instance:
Artemether 20mg + Lumefantrine 120mg tablets

Artemether + Lumefantrine recommended dosing:

Age (years)	Weight (kg)	Number of tablets	Arthemeter (A) per dose + Lumefantrine (L) per dose 0h, 8h, 24h, 36h, 48h, 60h
<1	<5	Not recommended	Not recommended
1 -5	5-14	1	20mg A + 120mg L
6 -8	15-24	2	40mg A + 240mg L
9 -12	25-34	3	60mg A + 360mg L
Over 12	>35	4	80mg A + 480mg L

Artemether 20mg + Lumefantrine 120mg is not recommended in pregnancy and lactating mothers. Where there is no suitable alternative drug, it should be used.

For those weighing 5kg body weight and below, the drug of choice is Sulphadoxine 500mg + Pyrimethamine 25mg for uncomplicated malaria.

The dosage for Sulphadoxine 500mg + Pyrimethamine 25mg is a single treatment of half a tablet.

Sulphadoxine + Pyrimethamine recommended dosing:

Wt (kg)	Age (years)	Number of Tablets
5-10	2-11 months	0.5
10.1-14	1-2	0.75
14.1-20	3-5	1
20.1-30	6-8	1.5
30.1-40	9-11	2
40.1-50	12-13	2.5
>50	14+	3

For unconscious, persistently vomiting, convulsing or severely ill patients, treat as complicated malaria, resuscitate refer.

Severe Malaria

Children:
By intramuscular injection; Quinine 10mg/kg body weight diluted in saline or water for injection (to a concentration of 60 – 100mg salt/ml), repeated after 4hrs and then 12 hourly. A loading dose is not recommended by this route. By intravenous injection; Quinine loading dose of 20mg/kg body weight diluted in 10ml of 5% or 10% dextrose (or isotonic fluid if hypoglycaemia is excluded) per kg body weight by intravenous infusion over 4 hours. After 12hours maintenance dose of 10mg/kg body weight given over 2 hours, repeated 12 hourly until the patient can swallow, then oral Quinine 10mg/kg body weight 8 hourly to complete a 7-day course of treatment.

Adults:
By intramuscular injection, Quinine 10mg/kg body weight diluted in saline or water for injection (to a concentration of 60 – 100mg salt/ml), repeated after 4hrs and then 12 hourly. A loading dose is not recommended by this route. By intravenous injection; Quinine loading dose of 20mg/kg body weight diluted in 10ml of 5% or 10% dextrose (or isotonic fluid if hypoglycaemia is excluded) per kg body weight by intravenous infusion over 4 hours. After 8 hours maintenance dose of 10mg/kg body weight given over 4 hours, repeated 8 hourly until the patient can swallow or after coma resolution, then oral Quinine 10mg/kg body weight 8 hourly to complete a 7-day course of treatment.

Oral Quinine 300mg tablet dosage schedule:

Age Years	Number of tablets per dose
<1	0.25
1-3	0.5
4-6	0.75
7-11	1
12-15	1.5
15+	2

Quinine is sometimes used in combination with Tetracycline or Clindamycin, Doxycycline in places where there is reduced sensitivity to Quinine. In Zambia, Quinine sensitivity Is still very high and there is no justification for using the combination.

Malaria in Pregnancy

See also Obstetrics Malaria in pregnancy

Intermittent presumptive treatment (IPT) – Sulphadoxine + Pyrimethamine is the drug of choice for prevention of malaria in pregnancy. Sulphadoxine + Pyrimethamine is given after 16 weeks following the last menstrual period (LMP). Two consecutive doses are given at least 4 weeks apart during the second and third trimester. A total of 3 doses should be given during the entire duration of pregnancy.

Individuals who are intolerant to SP should be counselled about personal preventive measures to reduce contact with mosquitoes.

Summary of management of Malaria

Take and record a confirmatory history
Do a confirmatory clinical assessment including body temperature.
Make a differential diagnosis on clinical basis.
Do a lumbar puncture if there is need to exclude meningitis
Prepare a thick and thin blood smear
Do a full blood count
Decide on treatment and method of administration.
Keep treatment, follow-up and referral records. Record treatment failures and adverse events.
Give oral, subcutaneous or intramuscular medications
Decide on the need for referral

Supportive therapy

Monitoring of fluid and electrolyte balance
Correction of fluid and electrolyte imbalance
Correct management of anaemia
Management of hypoglycemia
Management of any other complications

Referred PatientsPatients referred from the community need to have a thorough clinical examination to exclude other causes of fever. Criteria for Referral from the Health Centre to Hospital

The following are criteria for a referral from the Health Centre to Hospital:

Neurological manifestation e.g. convulsions and altered/disturbed consciousness.
Persistent vomiting
Hyperpyrexia (>39 0C).
Hypothermia (< 35.7 0C).
Severe Anaemia.
Jaundice.
Pregnancy with fever
Failure to respond to treatment after 2 days.
Reaction to drugs interfering with normal daily activity e.g. severe rash, severe itch, sulphonamide sensitivity.
Conditions that cannot be managed locally
Rapidly deteriorating condition of the patient.
Conditions that cannot be managed locally

Prevention

Get rid of mosquito breeding sites near residential areas
Use impregnated mosquito nets, repellents and sprays
Give public health education on the dangers of malaria and how to prevent it.

Counselling Points:

Provide health education information on malaria i.e. personal protection measures e.g. bed nets, repellents, general sanitation around the house and in the community, such as reducing breeding sites and clearing of vegetation.
In Children; advise caregiver on the need for growth monitoring, feeding, Vitamin A supplementation and immunisation in children.
Prophylaxis in sickle cell anaemia and post-splenectomy use Pyrimethamine 25mg once weekly.

Zambia has no prophylaxis policy for visitors. Recommendations are provided from their country of origin. Some countries e.g. the United Kingdom are using Mefloquine. Sulphadoxine + Pyrimethamine is not recommended for this purpose.

The use of other drugs like Amodiaquine, Dapsone-Pyramethamine, (maloprim) and Mefloquine for prophylaxis needs further evaluation and is not therefore recommended.