malaria prophylaxis

Possibilities of malaria prophylaxis

In principle, there are two ways of preventing malaria in a risk area of ​​infectious disease: the exposure prophylaxis (Avoidance of mosquito bites) and the medicinal malaria prophylaxis (chemoprophylaxis, precautionary use of malaria drugs). When it is generally spoken of a “malaria prophylaxis”, usually meant the drug malaria prophylaxis. It is generally advisable in countries with a high risk of infection.

In areas with a lower risk of malaria, a so-called Standby therapy suffice: The malaria medicines are only carried for emergencies. If the traveler develops potential malaria symptoms, he can treat himself. If it is indeed malaria, this early self-treatment can significantly improve the prognosis.

The DTG regularly publishes current recommendations on what type of malaria prophylaxis is necessary in which countries.

Note: Basically, you should buy malaria drugs better in Germany. In many malaria areas are deceptively genuine-looking, but ineffective counterfeits of the drugs in circulation. In addition, some health insurance companies reimburse the malaria prophylaxis costs when buying in Germany.

Malaria prophylaxis: avoid mosquito bites

The malaria parasite is transmitted by the sting of the twilight / nocturnal Anopheles mosquito. Therefore, the German Society for Tropical Medicine and International Health (DTG) recommends especially effective mosquito repellent for malaria prophylaxis. For this you should heed the following advice:

• Stay in the evening and at night as possible Mosquito-proof rooms on (rooms with air conditioning and screens in front of the windows and doors).
• Sleep under one mosquito net, Its mesh should be a maximum of 1 to 1.2 millimeters in size. For additional protection you should impregnate the mosquito net with an insecticidal agent (permethrin).
• Wear light, skin-covering clothing (long pants, socks, tops with long sleeves). If possible, impregnate the clothes with an insecticide. In high-risk areas, it may also make sense to wear a large but airy headgear. At the brim you can also attach a mosquito net.
• Apply on uncovered skin Mosquito repellent (repellents) at.

It is best to be protected against Anopheles mosquito bites if you wear impregnated, long, light colored clothing and also apply repellents on the skin.

Mosquito repellent (repellents)

Repellents (repellents) are applied directly to the skin in the form of sprays, ointments or creams. They only protect the area of ​​the skin that has been treated directly with the remedy.

Most repellents indicate how long the protection against insect bites persists after application of the product. Decisive for this is above all the concentration of the active substance. Most of the effectiveness is several hours. This information is only conditionally reliable. If you are in hot tropical areas and sweat a lot, the sweat will wash off the insect repellent much faster. Therefore, in areas where there is a risk of malaria, you should reapply malaria prophylactic repellants earlier than indicated.

Effect and active ingredients of the repellents

Repellents are different from insecticides as they do not kill insects. The substances that are contained in repellents, either deterring the mosquitoes or cover the body odor so that the bloodsuckers can no longer perceive the people. In Germany, various repellents are offered for sale.

Attention: Not all products that are sold in pharmacies or drugstores as repellents are also suitable for protection against the Anopheles mosquito. Therefore, when purchasing, ask specifically for malaria prophylactic repellents.

A very common drug in malaria prophylactic repellents Diethyltoluamide (DEET), It is highly effective and tried and tested for many years. It should not be used during pregnancy, breast-feeding and infants. In small children, it may not be applied over a large area. DEET is not recommended for injured or sensitive skin. Also avoid contact between DEET and plastics (sunglasses, handbag, etc.). These can dissolve through the active ingredient.

Another common repellent agent against malaria mosquitoes is Icaridin, It is less well studied but offers similar protection to DEET. In addition, the risk of side effects is lower (better skin compatibility), the odor pleasant and the contact with plastics no problem. Icaridin may also be used during pregnancy and lactation.

For malaria prophylaxis are also different Plant-based repellents respectively with essential oils Tea tree oil, citronella, etc.). They are considered to be better tolerated by the environment and their own health. However, their duration of action is shorter than that of classical repellents (with DEET or icaridin). In addition, essential oils can irritate the skin / mucous membrane, especially in strong sunlight.

Drug malaria prophylaxis

For the drug malaria prophylaxis (chemoprophylaxis) are the same drugs in question, as they are used for the treatment of malaria. The effect of the preparations is that they either interfere with the metabolism of the pathogens (plasmodia) or prevent the pathogens from multiplying. If the medication is taken preventively in the context of chemoprophylaxis, not the infection itself, but the onset of the disease is prevented.

Tip: Drugs for malaria prophylaxis should preferably be purchased at home. They are also offered for sale abroad. But especially in malaria areas are often deceptively real-looking counterfeits in circulation. They are ineffective and can also harm your health.

The following medications are available for malaria prophylaxis:

• chloroquine: works in principle against all types of malaria pathogens. In some regions, however, the pathogens have become resistant to it, which is why they have to resort to other malaria medications. In areas without chloroquine resistance, however, the active substance can be used for malaria prophylaxis – as well as for emergency self-treatment in cases of suspected malaria (“standby therapy”) and for the medical treatment of malaria.
• Atovaqoun / proguanil: Preparations with a fixed combination of these two agents are suitable for malaria prophylaxis and emergency self-treatment as well as for the treatment of uncomplicated malaria tropica and other malaria forms.
• mefloquine: For malaria prophylaxis, this drug can be used in regions of high malaria risk, where mefloquine-sensitive pathogens are prevalent. Under restrictions, it can also be used there for malaria therapy. For emergency self-treatment, it is recommended only in exceptional cases (pregnant women) – for this use are usually better tolerated alternatives.
• doxycycline: An antibiotic that also works against malaria. It is effective and well tolerated. Therefore, it is recommended in some countries as well as by the World Health Organization (WHO) and the German Society for Tropical Medicine and International Health (DTG) for malaria prophylaxis. In Germany, this use is not officially approved. In justified individual cases, however, a doctor may also prescribe doxycycline for malaria prevention in this country (“off-label”).
• primaquine: This drug is also not approved in Germany for malaria prophylaxis, but can be used in exceptional cases for this (“off label”). More specifically, primaquine is suitable for the prevention of recurrence of malaria tertiana. The drug must be obtained when prescribing from abroad.

Caution: The medicinal malaria prophylaxis does not provide 100% protection against infection. In addition, you should always follow the above tips against mosquito bites (exposure prophylaxis).

All the medicines mentioned are only available on prescription, so only after presentation of a doctor’s prescription in the pharmacy available. Which drug is best suited for malaria prophylaxis in individual cases and how it is dosed and used, should be discussed with the doctor as part of a travel consultation. When choosing a suitable remedy, the doctor will consider the following points in particular:

• holiday destination
• duration of the stay
• Age of the traveler
• possible pregnancy
• possible pre-existing conditions
• possible intake of medication (such as anticoagulants or anti-baby pill)
• any incompatibilities with certain active substances

Depending on the active ingredient, it may take some time before you enter the malaria risk area to start using the medication for malaria prophylaxis. You also have to take the medicine for a while after you return. Premature discontinuation of the medication can lead to a late onset of malaria!

Tip: Discuss the malaria prophylaxis early with your doctor! Then there is enough time to start taking a malaria drug on time and possibly switching to another drug if you can not tolerate this first drug.

Drug malaria prophylaxis: side effects

All medications used for malaria prophylaxis may have side effects. The nature and probability of such undesirable effects depend on the active ingredient:

chloroquine has fewer side effects compared to the other drugs. Moreover, these are usually only light and temporary. Most often, insomnia occurs. In rare cases, the drug causes eye damage with permanent retinal changes. For existing retinal diseases (retinopathies) chloroquine should therefore not be taken. People with psoriasis, muscle diseases (Myasthenia gravis) or severe liver or kidney diseases should also take another drug for malaria prophylaxis.

The active ingredient combination Atovaqoun / proguanil may temporarily cause nausea, indigestion and headache. Other potential side effects include dizziness, palpitations, insomnia, unusual dreams, and depression. Also changes of the oral mucosa and allergic skin reactions are possible. People with chronic kidney disease should not take this combination drug for malaria prophylaxis.

mefloquine On the one hand, it can cause relatively harmless side effects such as nausea, vomiting, diarrhea, abdominal pain and (rarely) allergic skin reactions. On the other hand, there is a risk of serious psycho-vegetative side effects. These include nightmares, acute anxiety, depression, restlessness and confusion. Rarely, epileptic seizures or psychotic symptoms (such as hallucinations) occur. The drug must therefore not be taken in all psychiatric disorders and in many neurological diseases (such as convulsions). Even with certain changes in heart rate (ECG changes) Mefloquin should be avoided or used with great caution.

Attention: If Mefloquin causes psychic / psychotic symptoms (acute anxiety, depression, etc.), it should be stopped.

doxycycline may cause indigestion (such as nausea), elevated liver enzymes and vaginal yeast. In addition, the antibiotic makes the skin more sensitive to UV light, so you should avoid prolonged sunbathing while taking. Doxycycline should not be used in children under the age of eight, pregnant women and nursing women. In certain other cases, it should be taken with caution, such as overweight women of childbearing age.

primaquine should only be taken if someone has been proven not to be deficient in the enzyme glucose-6-phosphate dehydrogenase. In some other cases, it should also not be taken, or at least taken with great caution. This applies, for example, to lupus erythematosus and rheumatoid arthritis. Possible side effects of primaquine include headache and nausea.

Malaria prophylaxis: Standby therapy

The so-called standby therapy allows you to start with the malaria treatment in an emergency on your own. To do this, you carry a malaria medication with you on the trip, which a doctor prescribes individually before you travel. You can take it if:

• You develop symptoms that may be caused by malaria (fevers, etc.), and
• You can not reach a doctor within 14 hours.

The dosing of the standby therapy is based on a treatment plan that your doctor has recommended depending on age, height, weight and risk before departure. If you do not have such a personal intake scheme at hand, you must dose carefully. In children, for example, already much lower levels are effective than in adults. Too high doses are also associated with stronger side effects.

Attention: The standby therapy is intended exclusively for emergencies and does not replace a doctor’s visit! Even if you have already started taking the malaria medication yourself, you should consult a doctor (preferably a tropical medicine specialist) as soon as possible – at the latest after your return to Germany.

Malaria prophylaxis: costs

All medications for malaria prophylaxis and treatment are subject to prescription. In recent years, some funds have begun to reimburse in addition to some travel vaccinations and the cost of drug malaria prophylaxis. Inquire in advance with your cashier, if a cost assumption is possible.

Why is there no malaria vaccine?

So far no malaria vaccine has been developed that could prevent infection with high probability. This is mainly because there are several types of malaria pathogens and these are also divided into different sub-forms. Therefore, it is so difficult to develop a vaccine that works against all known pathogens.

The researchers are still working on a vaccine against malaria. In trial is about the vaccine candidate RTS, S a British pharmaceutical company. It contains a protein of the pathogen of the dangerous malaria tropica (Plasmodium falciparum) as well as a potentiator. The malaria vaccine is designed to prepare the immune system for a possible infection and quickly render the pathogen harmless after penetration. The success rate is not as good as hoped. This vaccine is therefore rather unsuitable as a malaria prophylaxis for travelers. But he could at least reduce the infant mortality from malaria in Africa, some researchers believe.

Thus, until greater progress is achieved in vaccine development, it is particularly important for travelers malaria prophylaxis is to avoid stinging the Anopheles mosquito as much as possible and if necessary take preventive malaria medication!