Treatment and Management of Malaria Parasite

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QUESTION

What are the treatments and management of malaria?

ANSWER

Treatment is actually part of the strategy for managing malaria, so I will come back to that later. The other main ways in which malaria is controlled is through prevention, diagnosis (followed by treatment if necessary) and education.

1) Prevention:

There are a number of ways to prevent malaria. These can be placed into two categories: medication and vector protection.

For medication, there are drugs you can take to prevent the malaria parasite from developing after someone is bitten by an infected mosquito. These drugs are known as “chemoprophylaxis.”

There are several different kinds, such as doxycycline, mefloquine (marketed as Lariam), atovaquone-proguanil (marketed as Malarone) and chloroquine—the type you use depends on the type of malaria present in the area. For example, in much of Africa and India, malaria is resistant to chloroquine, so this cannot be used as a prophylactic. In parts of Thailand, resistance to mefloquine has emerged. However, if the appropriate type of prophylaxis is used, it is very effective against malaria.

The problem is that these drugs have not been tested for long-term use, can be expensive and may have side-effects. Therefore they are of limited use for people who live in areas where malaria is endemic, and are more appropriate for travelers who are in malarial areas for short amounts of time. However, anti-malarial medication may be used in a very specific way for people at particularly high-risk for malaria, such as pregnant women and young children. In these cases, the high-risk individuals receive a dose or series of doses of malaria medication in order to prevent malaria. This form of prevention is known as intermittent preventive therapy (IPT).

Vector prevention involves protecting oneself against getting bitten by mosquitoes. This can involve wearing long-sleeved clothing in the evenings and at night, when malaria mosquitoes are most active, or wearing insect repellent on exposed skin. Indoor residual spraying, whereby repellent and insecticides are sprayed inside the house, can also be used to bring down the number of mosquitoes.

Another very effective technique for preventing malaria is to sleep under a long-lasting insecticide-treated bednet. The mesh acts as a barrier against the mosquitoes, and the insecticide impregnated in the mesh further repels the mosquitoes and prevents them from biting through the mesh.

2) Diagnosis

Diagnosis is considered a crucial step in controlling malaria, since it ensures that people are receiving correct medication, whether for malaria or for another condition which is causing their symptoms. Currently, the most commonly observed form of diagnosis is through microscopy of thick and thin blood films, which can be stained if necessary. These should be read by a qualified technician to determine both the species of malaria infection and the intensity of parasitaemia (number of parasites in the blood).

More recently, other methods for diagnosis have emerged. These include the use of rapid diagnostic tests (RDTs) which utilize a drop of blood applied to a reagent strip which very quickly reacts to show whether the patient is infected with malaria. While considered generally more sensitive than blood films, some RDTs don’t test for all types of malaria parasite, and many require that the reagents be kept cold in order for the test to be effective, which can be a problem in some developing countries.

Perhaps the most sensitive test for malaria is through PCR, which can theoretically detect a single malaria parasite in a drop of blood, and also determine the species. However, measures of infection intensity require an alternative form of PCR, called real-time PCR, which can be technologically challenging. All forms of PCR require a lot of expensive equipment and reagents, trained technicians and take several hours to run.

3) Treatment

Malaria treatment can be determined based on the diagnostic results, as well as other factors, such as:

  • The area where the infection was acquired and its drug-resistance status
  • The clinical status of the patient
  • Any accompanying illness or condition
  • Pregnancy
  • Drug allergies, or other medications taken by the patient

Most uncomplicated (i.e. not severe) cases of P. falciparum can be treated with oral medication, such as artemisinin-based combination therapies (ACTs). Artemisinin is given in combination with another anti-malarial drug in order to prevent resistance from developing in the parasite. Patients who have complicated (severe) P. falciparum malaria or who cannot take oral medications should be given the treatment by continuous intravenous infusion, with quinine recommended by WHO as the first-line treatment.

Other drugs, which are used in some settings, are considered second-line or alternative forms of treatment. These include:

  • chloroquine (very rarely used for P. falciparum, due to widespread resistance)
  • atovaquone-proguanil (Malarone®)
  • mefloquine (Lariam®)
  • quinine
  • quinidine
  • doxycycline (used in combination with quinine)
  • clindamycin (used in combination with quinine)

In addition, primaquine is active against the dormant parasite liver forms (hypnozoites) and prevents relapses, for patients with P. vivax or P. ovale malaria. Primaquine should not be taken by pregnant women or by people who are deficient in G6PD (glucose-6-phosphate dehydrogenase). Patients should not take primaquine until a screening test has excluded G6PD deficiency.

4) Education

Through education, people living in at-risk areas for malaria transmission can learn about ways to prevent the disease (see above), as well as what to do if they suspect they are infected (i.e. seek diagnosis). Similarly, education is important for travellers visiting malarial areas, so they know the best ways in which to avoid being infected.

Malaria Beliefs

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QUESTION

How do beliefs and attitude affect the spread, treatment and prevention of malaria?

ANSWER

Accurate information and knowledge about how malaria is transmitted, diagnosed and treated is crucial to controlling the disease, for the general public living in malarial areas, travelers to these areas and health professionals. For example, many travelers are unaware that their destination is in a malaria transmission zone, so they do not take appropriate preventive precautions. Similarly, many travelers I have met believe that if they have had malaria once, they are immune and cannot get reinfected, so don’t bother protecting themselves from mosquitoes – this is not true, and they are inadvertently putting themselves at great risk.

In terms of endemic areas, the focus is on educating people about day-to-day preventive measures, such as sleeping under long-lasting insecticide treated bednets and indoor residual spraying. Educational campaigns that focus on simple, straightforward ways to prevent malaria are more likely to influence people’s attitudes and lead to better malaria control. Similarly, teaching people to seek accurate diagnosis and then ensuring they have appropriate treatment is an important step.

In some places, people feel they cannot afford to visit a doctor or clinic, or would rather place their trust in a traditional healer or healing herbs; since the most effective medications against malaria are treatments such as artemisinin-based combination therapies, which are available through official health sources such as clinics, believing in traditional medicine can lead to the malaria infection becoming very severe, and even resulting in death. As such, another component to control is making sure that medical services such as clinics are easily accessible even for the poorest people, provide good health care and are affordable.

Malaria Relapse

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QUESTION

Why do I suffer from constant malaria attack? The doctor has prescribed different prescriptions every time I get an attack but its still coming back. What could be the problem?

ANSWER

There are a number of possible answers to your question. First of all, your doctor might not be prescribing the right type of treatment for the type of malaria that you have. The World Health Organisation now recommends that all uncomplicated cases of malaria should be treated with artemisinin-based combination therapies (ACTs), such a Coartem. However, in some places, doctors still prescribe other drugs, such as Fansidar or chloroquine. This can be a problem, as in many areas, the local kinds of malaria have become resistant to these earlier drugs, and so you may not be cleared of the infection. This is called recrudescence—when a malaria infection is not cleared completely from the blood and so symptoms come back once the treatment has stopped.

Alternatively, if there is a longer time interval between your episodes of illness, you may be suffering from relapses. This occurs with two particular types of malaria: Plasmodium vivax and P. ovale. These types of malaria can form liver stages which remain dormant even after the treatment you take kills all the malaria in your blood. Therefore it will appear like you have been cured, but really you still have an infection in the liver.

These liver stages can re-activate and re-enter the blood, causing another episode of malaria symptoms months or even years after the initial infection. If your doctor finds that you are positive for one of these two types of malaria, you should talk to him/her about the possibility of taking primaquine. This drug kills the liver stages of the parasite, but is not appropriate for people with G6DP deficiency, so you should be tested for that first.

Finally, there is the possibility that you are continually being re-infected with malaria. In this case, you should take more preventative precautions. For example, sleep under a long-lasting insecticide-treated bednet, wear long-sleeved clothing (especially at night) and cover exposed skin with insect repellent. All of these measures will help prevent mosquito bites, which transmit malaria. In addition, you could consider indoor residual spraying, which coats the walls inside your house with insecticide to further eliminate the presence of mosquitoes.

Is there Malaria in United Arab Emirates (UAE)?

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QUESTION

Is the UAE malaria free?

ANSWER

Yes—the UAE is not considered a transmission area for malaria. However, other insect-borne diseases can occur in this region, such as West Nile virus, so while in the UAE it is still worth taking preventative measures against insect bites, such as wearing long-sleeved clothing and using insect repellent on exposed skin.

History of Fighting Malaria

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QUESTION

What are some examples of attempts of fighting this disease that happened in the past?

ANSWER

The battle against malaria has been going on, in one form or another, for literally thousands of years. The ancient Chinese mention the symptoms of the disease in a medical scroll as early as 2700 BCE – even more remarkably, a herb called Artemesia has been used in traditional Chinese medicine for more than 2000 years to treat malaria, and compounds extracted from that same herb are the basis for some of the most effective modern medications, known as artemisinin-based combination therapies (ACTs). Indigenous tribes in the Americas also had traditional medicines to treat malaria; having conquered the New World, the Spanish learned of a bark, from the Cinchona tree, which could cure malaria. Quinine, extracted from this same tree bark, is still used today to treat malaria.

However, back then the causes of malaria were not known—it wasn’t until the late 19th century that a more complete understanding of malaria would emerge. The first key development in this process was the observation of the parasites that cause malaria in a patient’s blood, which was first done by Charles Louis Alphonse Laveran in 1880.

A few years later, in 1897, a British army doctor called Ronald Ross discovered that the parasite was transmitted via the bite of infected mosquitoes, of the genus Anopheles. This latter finding allowed for the emergence of the first programmes for malaria control, which focused on vector control, through insecticide use and elimination of water bodies used by the mosquito larvae. An early example of the success of this approach came in the building of the Panama Canal; started in 1906, progress was initially slow, due to the enormous proportion of workers who fell ill from yellow fever and malaria. With vector control, the number of cases plummeted, and the canal was finally opened in 1914.

While prophylactic quinine had also been part of the control strategy during the building of the Panama Canal, it played a much more secondary role to vector control. Using similar strategies, focusing primarily on killing adult mosquitoes through insecticide spraying (mainly DDT), the United States of America successfully eliminated malaria from its shores in the early 1950s. Prior to this, transmission had occurred across most of the south-east of the country.

In the last 50 years, access to early diagnosis and effective treatment have gained a more prominent role among many malaria control strategies, although prevention is still seen as crucial. Many developing countries, where malaria is still rife, have set up national control programmes, which seek to ensure that all communities have access to adequate care and information about malaria prevention.

A key tool in the prevention arsenal has been the long-lasting insecticide treated bednet; sleeping underneath one prevents bites from the mosquitoes that carry malaria, which are most active in the evenings and at night, especially in children and pregnant women, who are among the people most at risk from infection. Bednet distribution has been a major focus of many malaria campaigns, and very successful in many places; in 2008, for example, bednet coverage was estimated at over 80% of the at-risk population in Djibouti, Mali, Ethiopia and Sao Tome and Principe.