Treatment and Management of Malaria Parasite

by

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

by

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.

What happens after you get malaria?

by

QUESTION

What are the after effects of malaria?

ANSWER

In almost all cases, if malaria is diagnosed accurately and treated promptly, patients make a full recovery with no after effects. In some cases of severe malaria, the disease can develop into cerebral malaria, which can result in impaired mental function, loss of consciousness and coma (and, if untreated, even death). Again, if treated promptly, these effects should reverse, but in some cases, some neurological damage remains.

Similarly, children who are affected by malaria while still in the womb or during birth (“congenital” malaria) may experience low birth weight or retarded growth, which can have health implications later in life.

How to Control Malaria

by

QUESTION

Suggestions to control malaria?

ANSWER

This answer is copied from an earlier question asking about strategies for controlling malaria in Africa. The methods below are being used by many health ministries, international agencies and non-governmental organisations to combat malaria all over the world (and not just in Africa).

Currently, malaria control is based on a combination of prevention, education, research and treatment. In more detail:

Prevention: This is arguably one of the keys to sustainably reducing malaria burdens and even eliminating infections. Central to this goal has been the distribution of long-lasting insecticide treated bednets, which prevent people from being bitten by infected mosquitoes while they sleep at night. Unfortunately, some recent research has just been published which suggests that bednets might be contributing to insecticide resistance in mosquitoes, as well as increased rates of malaria in adults due to decreasing natural immunity. As such, it may be that more research is needed in order to determine the most effective and efficient ways of using bednets to prevent malaria infection, particularly in high-risk groups like young children and pregnant women. Another arm of prevention is reducing the number of mosquitoes in an area (called vector control), and thus preventing transmission from occurring at all – this can be achieved through insecticide spraying but also filling in the stagnant pools of water that mosquitoes lay their eggs in. Vector control was highly successful in reducing malaria transmission in the United States and Mediterranean in the years after World War II.

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

Research: Understanding the distribution, factors affecting transmission and the development of new strategies for control and treatment is going to be crucial in the fight against malaria, and particularly in high-burden areas such as Africa. Similarly, scientists are busily looking for new compounds to treat malaria, as well as the ever-elusive malaria vaccine. If such a vaccine could be developed, it would be a huge step forward in the fight against malaria; recently, a study was published which reported the results of the first Phase 3 clinical trial of a malaria vaccine, in African children. The vaccine appeared to confer approximately a 50% level of protection against malaria; while this is a start, it perhaps did not live up to many people’s hopes of a new method for controlling malaria.

Treatment: Hand in hand with treatment comes diagnosis; if a person can have their infection easily, accurately and cheaply diagnosed, then they will be able to access effective treatment more rapidly, thus improving their chances of a swift recovery. As such, countries in Africa are working hard to provide health systems capable of local diagnosis and availability of treatment, so that people don’t have to travel far to have their infections cured.

Taken together, these four strategies are having some success even in the world’s poorest and most malaria-endemic regions, especially in decreasing the number of malaria deaths. Decreasing the overall number of infections will be yet a greater challenge, but one which the world, especially through commitment to the Millenium Development Goals, is dedicated to overcoming.

 

 

How to Prevent Malaria

by

QUESTION

How to prevent malaria?

ANSWER

Despite its wide geographic range and potentially severe consequences, there are actually several effective strategies for controlling malaria, many of which have been successful of reducing the burden of the disease, and especially the number of deaths, in various regions.

The first step towards control is prevention. This has largely been achieved through the distribution of long-lasting insecticide treated bednets, which prevent people from being bitten by infected mosquitoes as they sleep at night. While this has drastically reduced the number of cases of malaria in some settings, and particularly in certain high risk groups such as children under five and pregnant women, some worrying new data just was published which suggested that in high transmission zones, bednets may actually exacerbate re-infection rates for older children and adults, and lead to insecticide resistance in mosquitoes. As such, while bednets clearly are still a key prevention strategy, their effect should be closely monitored.

Secondly, there is diagnosis and treatment. These go hand in hand, as they usually require the availability of health services or health professionals. If malaria infections are rapidly and accurately diagnosed, appropriate treatment can be swiftly given, preventing the progression of the disease and allowing the patient to recover. Appropriate administration of medication, as well as adherence to the full course of the drugs, can also help to prevent drug-resistance from emerging.

Finally, there are on-going research initiatives looking to find new ways to tackle malaria. For example, many scientists are involved in the search for a malaria vaccine, which, if safe, effective, and sufficiently cheap, could transform the way we think about fighting malaria. Similarly, due to the unfortunate circumstance of ever-increasing drug-resistance, particularly in Plasmodium falciparum, new types of medication are constantly being tested and trialled. The combination of all these efforts has managed to reduce the mortality of malaria greatly over the past few years; the aim now, espoused by organisations such as Malaria No More, is to get to a point where deaths from malaria are eliminated by the year 2015.

 

History of Fighting Malaria

by

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.

Malaria Month

by

QUESTION

What is the national month for malaria?

ANSWER

I’m not exactly sure I understand your question. If you are asking if there is a specific month when malaria is the worst, that depends on where you are. Malaria transmission is highly seasonal, because the mosquitoes that transmit the disease require pools of standing water in order to reproduce. Therefore in many places, transmission is highest during the rainy or wet season.

However, if you mean if there is a specific month dedicated to raising awareness about malaria and control, then the answer is yes, at least for certain countries. India, for example, has declared each June between 2005 and 2012 to be “Anti-malaria Month,” when a big push is made nation-wide to educate people about preventing malaria, implement early diagnosis and treatment and organise vector control efforts. June was selected as it is the month before the start of the monsoon season, when malaria transmission increases due to the heavy rains.

Symptoms of Malaria

by

QUESTION

What are the symptoms of malaria?

ANSWER

The symptoms of malaria include fever and flu-like illness, including shaking chills, headache, muscle aches, and tiredness. Nausea, vomiting, and diarrhea may also occur. Malaria may cause anemia and jaundice (yellow coloring of the skin and eyes) because of the loss of red blood cells. Infection with one type of malaria, Plasmodium falciparum, if not promptly treated, may cause kidney failure, seizures, mental confusion, coma, and death. Since the early symptoms of malaria are very similar to many other conditions, including flu and the common cold, if you live in a malaria area it is important not to ignore these symptoms but to seek medical help and have a blood test to check for malaria early on. 

Malaria Schizonts

by

QUESTION:

What is the difference between schizont of Plasmodium vivax and P. falciparum?

ANSWER:

P. falciparum schizonts tend to fill up to about two-thirds of the host red blood cell, and contain 8-24 merozoites (see image below for development of schizont). However, schizonts of P. falciparum are rarely seen in peripheral blood; instead, multiple, smaller rings are the usual diagnostic sign. Characteristic crescent-shaped gametocytes may also be observed, though usually later on in infection.

 

falciparum schizont CDC

The stages of maturation of a Plasmodium falciparum schizont. Image courtesy of CDC (www.dpd.cdc.gov)

P. vivax schizonts are large and fill up the entirety of the red blood cell with 12-24 merozoites, each containing visible chromatin and cytoplasm (see below). Their size and shape can differentiate them from the more compact P. ovale and P. malariae schizonts, though separating the former can sometimes be difficult.

vivax schizont CDC

The stages of maturation of a Plasmodium vivax schizont. Image courtesy of CDC (www.dpd.cdc.gov)

Malaria and stomach pains

by

QUESTION:

Will malaria cause severe stomach pain?

ANSWER:

In some cases, yes, malaria can cause stomach cramps and pain. It also often causes nausea and vomiting. It is important to seek medical attention if you think you have symptoms of malaria; a quick and accurate diagnosis will lead to effective and efficient treatment, which improves chances of a rapid recovery.