Malaria Information - Dr Neil van Tonder (nbvtond@iafrica.com)

History :
Malaria has been with as since the beginning of time. In Africa, fossils of
mosquitoes up to 30 million years old show that the vector for malaria was
present

Deadly fevers - probably Malaria - have been recorded since the beginning of
the written word ( 6000 - 5500 B.C.)

References can be found in the Vedic writings of 1600 B.C. in India.

Hippocrates described certain aspects of an illness now known as Malaria in
the fifth century B.C.
In the seventh century, the Italians named the disease mal' aria , meaning
bad air, because of its association with the ill smelling vapors from the
swamps near Rome.

There no references to Malaria in the "medical bookes" of the Mayans or
Aztecs. It is likely that European settlers and slavery brought Malaria to
the New World.

Malaria existed in parts of the United States from colonial times to the
1940s. One of the first military expenditures of the Continental Congress,
around 1775, was for $ 300 to buy Quinine to protect Genl. Washington's
troops.

Quinine, a toxic plant alkaloid, made from the bark of the Cinchona tree in
South America, was used for treatment more than 350 years ago.

Identified by French Army physician, Charles Laveran, in Algeria while
viewing blood slides.

Quinine has now been completely synthesized. Its synthetic analogue is
called mefloquine.

Vaccine is still being developed, has not yet proven to reduce deaths.

Facts :
Malaria is a public health problem in 90 countries affecting at least 300
million people.
Tropical Africa accounts for 90% of these cases. Estimates of malaria
mortality vary from 1,5 to 3 million deaths a year.

The Plasmodium genus of protozoal parasites is the causative agent of
malaria. Human malaria is caused by 4 species : P. falciparum, P. malariae,
P. vivax, P. ovale. P. falciparum is the predominant species and the one
that causes the most serious disease. This is also the species that has
given rise to the new drug resistant strains that are emerging.

The Plasmodium parasites are highly specific with female Anopheles
mosquitoes as the vectors and man as the only vertebrate host. The parasites
have a complex life cycle that is split between the host and the vector.

Malaria Statistics in South Africa ( see attached report )

Seasonality of Malaria ( see attached report )

The South African Situation
Incidence assosiated with climatic conditions and influx of migrants from
neighbouring countries.

Chloroquine resistance necessitated continuing changes in chemoprophylaxis.

90 - 95 % of the locally contracted cases are due to P. falciparum.

Prophylaxis against Malaria
1) Precautionary measures against Malaria
Mosquitoes feed between dusk and dawn in doors and outdoors.
- remain indoors
-at night, wear long-sleeved clothing, long trousers and socks
-insect repellent
-stay in well-constracted, well-maintained buildings in the best developed
part of town. ( does this mean rooftop tents are better ?!!! )
- close windows and doors
- mosquito proof net treated with permethrin from time to time and edges
tucked in.
- spray house / tent inside
- use mosquito mats ect.
treat clothes with an insecticide registered for this, permethrin.

2) Taking of anti-malaria drugs
Chloroquine-resistant vs Chloroquine-sensitive areas ( see tabels )

Could still contract Malaria in spite of prophylactic medication. Contact
doctor if any flu-like symptoms start. Tell the doctor of the possibility of
Malaria. He would not look for it if you do not tell him / her !!! Symptoms
of infection can occur up to 6 months after leaving a malaria area !

Recommendations for SA
High risk area : Drugs from October to May
Intermediate risk area : Drugs from October to May only for high risk people
( Children < 5 years, pregnant, Immuno-compromised )
Low risk area : No drugs

Factors influencing the selection of drugs
Patient factors
- Children / infants
- Breast feeding
- Pregnancy / lactation
- Porphyria
- Epilepsy
- Chronic illness : Liver disease may result in drugs becoming toxic.
Patients on cardiac medication can only take certain drugs.
- Sensitivity to Sulph drugs : Persons sensitive for Sulphas, should not
take Fansidar or Maloprim.
-Exposure to sunlight : Exposure for long periods to sunlight can cause
photosensitivity and should use sunscreens.

Environmental factors
- duration of stay : Extended use of chloroquine can cause retinal damage, 6
monthly ophtalmiological check-up recommended
                                  Mefloquine ( Larium ) should not be used
for longer than a year.
                                  Doxycycline should not be used for longer
than 3 months.

 - Type of accommodation : greater risk in tent vs. building
 - Time of year : In southern Africa Malaria is seasonal, although in
certain areas such as Mozambique and the  Zambezi Valley, there is a risk of
contracting the disease throughout the year.

Comments on drugs used for chemoprophylaxis
Seriousness of side-effects should be weighed up against the risk of
contracting malaria.

Chloroquine ( Daramal )
Cheap, without prescription, safe in pregnancy / lactation, safe in
children. Used with caution in patients with epilepsy, cardiac or renal
disease. Usually well tolerated.
Side-effects : headache, nausea / vomiting, diarrhoea, pruritis ( itch ),
skin eruptions and itching of palms, soles, impaired vision
Serious side-effects are rare, but periodic eye examinations are necessary
if used for long periods.

Proguanil ( Paludrine )
Best tolerated, very good safety and can be used in pregnancy and children.
Rarely cause side effects.
Side-effects : Mild gastric intolerance, vomiting, abdominal discomfort,
mouth ulcers, skin reactions, hair loss.

Mefloquine ( Larium )
Should not be used for > 1 year. The following people should not take it :
- Pregnant women or 3 months before conception ( 1/2 life of 42 days )
- Children < 15 kg
- Patients with history of epilepsy or psychiatric disorders
- Cardiac conduction abnormalities
- Depression
- People requiring fine motor control such as pilots, scuba divers,
mountaineers
- Patients on Beta Blockers, Ca Channel Blockers, Digitalis or
Anti-depressant therapy

Side-effects :
- Dizzyness or disturbance of balance
- Gastro-intestinal disturbances
Less frequent effects are :
- Headache, myalgia, feeling of weakness, visual disturbance
- Palpitations, bradycardia, irregular pulse and extrasystoles, AV block
- Hair loss, rash or pruritis
- convulsions
- Psycological changes, eg. depressive mood, confucion, anxiety,
hallucinations, paranoid reactions
- Drop in White blood cells and Platelets

If Mefloquine is used for prophylaxis, Halofantrine should not be used for
treatment since it may lead to potencially fatal prolongation of the QTC
interval ( Heart conduction abnormality )

Doxycycline
Well tolerated
Side-effects : Nausea and vomiting, Photosensitivity, skin reactions,
vaginal candidiasis
Contra-indicated in pregnancy, breastfeeding and children < 8 years as it
can seriously damage tooth development.
Should not be used for longer than 3 months.

Drugs for Standby Treatment
Sulfadoxine-pyrimethamine
Taken as a single dose. Cannot be taken by patients allergic to Sulphas

Quinine
Only if person cannot take Sulfadoxine-pyrimethamine. Should not be used
without medical supervision.
Side-effects :
Mild hearing impairment, tinnitis, headache, nausea, visual disturbances
( up to 70 % of patients ), Arrhythmias, hypoglycemia. Quinine toxicity
could be confused with cerebral malaria.

Halofantrine
Should be taken on an empty stomach. Course could be repeated after 1 week.
Not to be taken if mefloquine was used
Note to be taken in patients with known family history of QTC prolongation.

Important points:
Can contract it, in spite of taking prophylactic medication, up to 6 months
after visiting an area.
Inform your doctor.

Symptoms :
- Fever
- Rigors
- Headaches
- Sweating
- Tiredness
- Myalgia
- Abdominal Pain
- Diarrhoea
- Lost of appetite
- Low blood pressure
- Nausea
- Slight jaundice
- Cough
- Enlarged liver and Spleen