Malaria in Pakistan

QUESTION

4 years ago I traveled to FATA Pakistan and in every year in the month of August I caught malaria. Last few days I feel much Headache and fever in the evening and go to doctor. He diagnosed malarial parasites in blood and has advised me take tab artem ds 2 BD for three days after complete the course I feel same headache fever with shivering. Please recommend something.

ANSWER

I am not sure which malaria treatment you have taken—was it just artemisinin, or a combination drug which also included another anti-malarial? The latter type is what is recommended by the World Health Organization (WHO); treatments only containing artemisinin are very effective short term, but can sometimes leave a few parasites alive at the end of the course, which not only may result in a recurrence of symptoms (known as recrudescence) but is very bad in terms of leading to drug resistance in the malaria parasite. However, it is also possible that you are merely experiencing some slight side effects to the medication you took; often these mild side effects are very similar to the symptoms of malaria! If you don’t feel better in a few days, it might be worth visiting the doctor again to check that you don’t still have malaria parasites in your blood.

Antimalarial Drugs During pPregnancy

QUESTION

What is the safest antimalarial drug to be used by a pregnant woman in her second trimester?

ANSWER

With regards to treating malaria, intravenous artesunate (or quinine, if artesunate is not available) should be used for the treatment of severe/complicated Plasmodium falciparum malaria. Signs of severe and/or complicated malaria include impaired consciousness, organ failure, abnormal bleeding, hypoglycemia, severe anemia and/or inability to ingest medication orally. Treatment for uncomplicated malaria (where the above signs are absent) in pregnant women is usually chloroquine for P. vivax, P. ovale, P. knowlesi and P. malariae, as well as for P. falciparum if there are no reports of this parasite being resistant to chloroquine in the area. In places where P. falciparum is resistant to chloroquine, quinine and clindamycin should be used to treat this parasite in pregnant women.

As for preventative anti-malarials (chemoprophylaxis), if a pregnant woman is travelling to an area where only P. vivax, P. ovale, P. knowlesi, P. malariae or chloroquine-sensitive P. falciparum is transmitted, then she should take chloroquine to prevent malaria. In areas where P. falciparum is resistant to chloroquine, mefloquine is also suitable during pregnancy. Note that in some areas of south-east Asia, there are areas where P. falciparum is resistant to mefloquine, which may prevent its suitability as a prophylactic in this region. Preventing malaria during pregnancy is crucial, since the mother, particularly if it is her first baby, is especially vulnerable to the parasite. Moreover, malaria can have a negative impact on the fetus.

How is Malaria Prevented?

QUESTION

What are the methods to prevent malaria?

ANSWER

Malaria prevention consists of a combination of mosquito avoidance measures and chemoprophylaxis. Although very efficacious, none of the recommended interventions are 100% effective.

Mosquito Avoidance Measures

  • Because of the nocturnal feeding habits of Anopheles mosquitoes, malaria transmission occurs primarily between dusk and dawn.
  • Contact with mosquitoes can be reduced by remaining in well-screened areas, using mosquito bed nets (preferably insecticide-treated nets), using a pyrethroid-containing flying-insect spray in living and sleeping areas during evening and nighttime hours, and wearing clothes that cover most of the body.
  • All travelers should use an effective mosquito repellent.
  • The most effective repellent against a wide range of vectors is DEET (N,N-diethylmetatoluamide), an ingredient in many commercially available insect repellents. The actual concentration of DEET varies widely among repellents. DEET formulations as high as 50% are recommended for both adults and children older than 2 months of age (see the Protection Against Mosquitoes, Ticks, and Other Insects and Arthropods section later in this chapter). DEET should be applied to the exposed parts of the skin when mosquitoes are likely to be present.
  • In addition to using a topical insect repellent, a permethrin-containing product may be applied to bed nets and clothing for additional protection against mosquitoes.

Chemoprophylaxis

  • All currently recommended primary chemoprophylaxis regimens involve taking a medicine before travel, during travel, and for a period of time after leaving the malaria endemic area. Beginning the drug before travel allows the antimalarial agent to be in the blood before the traveler is exposed to malaria parasites.
  • Presumptive antirelapse therapy (also known as terminal prophylaxis) uses a medication towards the end of the exposure period (or immediately thereafter) to prevent relapses or delayed-onset clinical presentations of malaria caused by hypnozoites (dormant liver stages) of P. vivax or P. ovale. Because most malarious areas of the world (except the Caribbean) have at least one species of relapsing malaria, travelers to these areas have some risk for acquiring either P. vivax or P. ovale, although the actual risk for an individual traveler is difficult to define. Presumptive anti-relapse therapy is generally indicated only for persons who have had prolonged exposure in malaria-endemic areas (e.g., missionaries, volunteers).
  • In choosing an appropriate chemoprophylactic regimen before travel, the traveler and the health-care provider should consider several factors. The travel itinerary should be reviewed in detail and compared with the information on where malaria transmission occurs within a given country (see the Malaria Risk Information and Prophylaxis, by Country, section later in this chapter) to determine whether the traveler will actually be traveling in a part of the country where malaria occurs and if significant antimalarial drug resistance has been reported in that location.
  • The resistance of P. falciparum to chloroquine has been confirmed in all areas with P. falciparum malaria except the Caribbean, Central America west of the Panama Canal, and some countries in the Middle East. In addition, resistance to sulfadoxine–pyrimethamine (e.g., Fansidar) is widespread in the Amazon River Basin area of South America, much of Southeast Asia, other parts of Asia, and in large parts of Africa. Resistance to mefloquine has been confirmed on the borders of Thailand with Burma (Myanmar) and Cambodia, in the western provinces of Cambodia, in the eastern states of Burma (Myanmar), on the border between Burma and China, along the borders of Laos and Burma, and the adjacent parts of the Thailand–Cambodia border, as well as in southern Vietnam.
  • Additional factors to consider are the patient’s other medical conditions, medications being taken (to assess potential drug–drug interactions), the cost of the medicines, and the potential side effects.
      The medications recommended for chemoprophylaxis of malaria may also be available at overseas destinations. However, combinations of these medications and additional drugs that are not recommended may be commonly prescribed and used in other countries. Travelers should be strongly discouraged from obtaining chemoprophylactic medications while abroad. The quality of these products is not known, and they may not be protective and may be dangerous. These medications may have been produced by substandard manufacturing practices, may be counterfeit, or may contain contaminants. Additional information on this topic can be found in an FDA document

Purchasing Medications Outside the United States

    .

 

How is Malaria Treated

QUESTION

how is malaria treated?

ANSWER

Malaria can be a severe, potentially fatal disease (especially when caused by Plasmodium falciparum) and treatment should be initiated as soon as possible.

Patients who have severe P. falciparum malaria or who cannot take oral medications should be given the treatment by continuous intravenous infusion.

Most drugs used in treatment are active against the parasite forms in the blood (the form that causes disease) and include:

  • chloroquine
  • atovaquone-proguanil (Malarone®)
  • artemether-lumefantrine (Coartem®)
  • mefloquine (Lariam®)
  • quinine
  • quinidine
  • doxycycline (used in combination with quinine)
  • clindamycin (used in combination with quinine)
  • artesunate (not licensed for use in the United States, but available through the CDC malaria hotline)

In addition, primaquine is active against the dormant parasite liver forms (hypnozoites) and prevents relapses. 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.

How to treat a patient with malaria depends on:

  • The type (species) of the infecting parasite
  • 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

If you have or suspect you have malaria, you should contact your doctor immediately.

Dormant Malaria

QUESTION

I was bitten by mosquitoes many years ago and I was wondering can the symptoms lie dormant for as long as 40 years? The reason I am asking is that every summer I am ill with several of these symptoms. I do not have a good immune system.

ANSWER

There are a couple of types of malaria, namely Plasmodium vivax and Plasmodium ovale, which can lie dormant for many years, and often cause relapses at regular intervals.

Next time you suffer from these symptoms, you should go to your doctor and have a blood test to check for malaria; while you are experiencing symptoms, if you have malaria, the parasites will be visible in your blood.

Once positively diagnosed, your doctor can provide you with treatment. If you do have malaria, you will need one medication to clear the infection from your blood (which kind depends on where you were when you got those mosquito bites; malaria has become resistant to certain types of medication in some areas), plus another type of medication to kill the dormant forms which are responsible for the yearly relapses. This latter medication is called primaquine, and is not recommended for people with G6DP deficiency, so you should be tested for this prior to taking the medication.

Having said all of that, it is very important to get the blood test if you suspect you have malaria, because the symptoms of malaria are very general (fever, chills, nausea, aches) and can be mistaken for many other illnesses. If your blood test is negative for malaria, then you should talk to your doctor about other possible infections.

Drug-Resistant Malaria Threatens Effort to Control Disease

A team of researchers from the United States and Thailand says the growing number of cases of drug-resistant malaria being reported in Thailand and neighboring countries threatens the worldwide campaign to control and eliminate the mosquito-borne disease. The malaria parasite in the region is becoming resistant to the first-line malaria therapy – artemisinin combination treatment – and experts say there is a real danger of the resistant strain moving to Africa, where malaria is widespread.

“The biggest fear is the resistance will spread across Southeast Asia and then spill over into Africa, where the vast majority of the 700,000 deaths a year [from malaria] occur. Historically, we have seen that when resistance to chloroquine [another anti-malaria drug] spread, there was an increase in mortality due to malaria. This is a very, very urgent situation,” said Tim Anderson, of the Texas Biomedical Research Institute, who spoke to us via Skype.

Anderson was part of the team that found evidence of growing resistance to artemesinin therapy for malaria in the border regions of Thailand and Burma, which they fear can spread westward across south east Asia and into Africa. The researchers are calling for immediate steps to control the spread of the resistant malaria parasite.

The number of malaria deaths dropped in the last few years because of the artemisinin combination treatment, and Anderson predicts that mortality figures will rebound if the drug loses its efficacy.

“We are seeing that the drug kills the parasite 100-fold less well than it used to. That doesn’t mean that the parasites are not killed, so we can still cure patients. But the concern is that the number of patients who are NOT cured will rise. We currently estimate that about 30 percent of the patients are not cured with artemisinin,” said Anderson.

“I have to say that I am not actually all that surprised. Every time we have developed a new drug, the parasite has figured out a way to get around it,” said Dr. David Kaslow, the director of the PATH Malaria Vaccine Initiative – an international nonprofit organization committed to developing a malaria vaccine.

“The good news is that the first-ever malaria vaccine is on the horizon,” said Kaslow.

The malaria vaccine could be available by 2015, Kaslow said. But it will be just one more weapon against malaria, and the problem of resistance to artemisinin is real.

“It is a piece of a larger control and – hopefully, some day – elimination and eradication program. We have to use a variety of tools – [including] bed nets, indoor residual spraying, and preventive therapy,” said Kaslow.

Experts say drug-resistant strains of malaria likely will continue to emerge. The solution, they believe, is to support the development of new drugs and new therapies to fight the disease.

Source: VOA News

Malaria Prevention

QUESTION

What are the ways in which you can prevent yourself from being infected with malaria?

ANSWER

Malaria prevention consists of a combination of mosquito avoidance measures (since malaria is transmitted by infected mosquitoes) and chemoprophylaxis (medication to prevent the establishment of malaria in your body, if you do get bitten). Although very efficacious, none of the recommended interventions are 100% effective.

Mosquito Avoidance Measures

  • Because of the nocturnal feeding habits of Anopheles mosquitoes, malaria transmission occurs primarily between dusk and dawn.
  • Contact with mosquitoes can be reduced by remaining in well-screened areas, using mosquito bed nets (preferably insecticide-treated nets), using a pyrethroid-containing flying-insect spray in living and sleeping areas during evening and nighttime hours, and wearing clothes that cover most of the body.
  • All travelers should use an effective mosquito repellent.
  • The most effective repellent against a wide range of vectors is DEET (N,N-diethylmetatoluamide), an ingredient in many commercially available insect repellents. The actual concentration of DEET varies widely among repellents. DEET formulations as high as 50% are recommended for both adults and children older than 2 months of age (see the Protection Against Mosquitoes, Ticks, and Other Insects and Arthropods section later in this chapter). DEET should be applied to the exposed parts of the skin when mosquitoes are likely to be present.
  • In addition to using a topical insect repellent, a permethrin-containing product may be applied to bed nets and clothing for additional protection against mosquitoes.

Chemoprophylaxis

      • All currently recommended primary chemoprophylaxis regimens involve taking a medicine before travel, during travel, and for a period of time after leaving the malaria endemic area. Beginning the drug before travel allows the antimalarial agent to be in the blood before the traveler is exposed to malaria parasites.
      • Presumptive antirelapse therapy (also known as terminal prophylaxis) uses a medication towards the end of the exposure period (or immediately thereafter) to prevent relapses or delayed-onset clinical presentations of malaria caused by hypnozoites (dormant liver stages) of P. vivax or P. ovale. Because most malarious areas of the world (except the Caribbean) have at least one species of relapsing malaria, travelers to these areas have some risk for acquiring either P. vivax or P. ovale, although the actual risk for an individual traveler is difficult to define. Presumptive anti-relapse therapy is generally indicated only for persons who have had prolonged exposure in malaria-endemic areas (e.g., missionaries, volunteers).
      • In choosing an appropriate chemoprophylactic regimen before travel, the traveler and the health-care provider should consider several factors. The travel itinerary should be reviewed in detail and compared with the information on where malaria transmission occurs within a given country to determine whether the traveler will actually be traveling in a part of the country where malaria occurs and if significant antimalarial drug resistance has been reported in that location.
      • The resistance of P. falciparum to chloroquine has been confirmed in all areas with P. falciparum malaria except the Caribbean, Central America west of the Panama Canal, and some countries in the Middle East. In addition, resistance to sulfadoxine–pyrimethamine (e.g., Fansidar) is widespread in the Amazon River Basin area of South America, much of Southeast Asia, other parts of Asia, and in large parts of Africa. Resistance to mefloquine has been confirmed on the borders of Thailand with Burma (Myanmar) and Cambodia, in the western provinces of Cambodia, in the eastern states of Burma (Myanmar), on the border between Burma and China, along the borders of Laos and Burma, and the adjacent parts of the Thailand–Cambodia border, as well as in southern Vietnam.
      • Additional factors to consider are the patient’s other medical conditions, medications being taken (to assess potential drug–drug interactions), the cost of the medicines, and the potential side effects.

The medications recommended for chemoprophylaxis of malaria may also be available at overseas destinations. However, combinations of these medications and additional drugs that are not recommended may be commonly prescribed and used in other countries. Travelers should be strongly discouraged from obtaining chemoprophylactic medications while abroad. The quality of these products is not known, and they may not be protective and may be dangerous. These medications may have been produced by substandard manufacturing practices, may be counterfeit, or may contain contaminants. Additional information on this topic can be found in an FDA document

Purchasing Medications Outside the United States.

Resistance to Malaria Treatments Seriously Compromises Efforts to Eliminate Malaria

Scientists have found new evidence that resistance to the front-line treatments for malaria is increasing.

They have confirmed that resistant strains of the malaria parasite on the border between Thailand and Burma, 500 miles (800km) away from previous sites.

Researchers say that the rise of resistance means the effort to eliminate malaria is "seriously compromised".

The details have been published in The Lancet medical journal.

[Read more…]

Antimalarial Drug Therapeutic Life

QUESTION

Why do some antimalarial drugs have long therapeutic life while others have short therapeutic lives?

ANSWER

Different anti-malarial drugs target slightly different aspects of the malaria Plasmodium parasite, and so are made with different chemical structures.

The differences in therapeutic life across different malaria drugs has to do with the specific pharmacokinetic properties of the chemical compounds from which the drugs are made. Even drugs designed around the same principal chemical compound can persist for different amounts of time in the human body, depending on the other chemicals with which the active compound is bound. The length of time it takes for a chemical compound to halve in concentration, or for its pharmacological effect to reduce by half, in the human blood stream is known as its “half life.”

For example, the common anti-malarial drug chloroquine has a half life of about 10 days, and is based on a chemical compound called 4-aminoquinoline. However, another drug also based on 4-aminoquinoline, called amodioquine, has a half life of only 10 hours.

Proguanil (combined with atovaquone in the drug Malarone) is dihydrofolate reductase inhibitor with a half life of about 16 hours, while mefloquine (sold as Lariam), is made from quinoline methanol and has a half life ranging from 10-40 days. These differences in length of therapeutic action also affect the efficacy of the compounds against malaria at various stages in its progression, and can also be implicated in the propensity to resistance developing to the drug in the malaria parasite.

Malaria Vaccine

QUESTION:

Why is a vaccine against malaria seen as the main hope for the future?

ANSWER:

This answer is courtesy of a medical doctor assisting us with answering your questions.

A vaccine is seen as the great hope for the future because the malaria parasite has an extraordinary talent for developing resistance very rapidly against each class of drug that is introduced into the arsenal against it.  This is accomplished by various mechanisms, such as concentrating and pumping the drug back outside its outer membrane, mutation of drug binding sites rendering the drug molecules incapable of attaching to or entering the cell in order to do its work and alteration of other enzymes within the cell to change the pH  (acidity), again rendering certain drugs ineffective, even if they do get in (among other mechanisms!). That said, the development of an effective vaccine has been difficult due to changing surface proteins against which these vaccines are being developed.  In order to work, the vaccine has to be developed targeting highly “conserved” outer proteins which do not undergo genetic mutation frequently…ie, not so much of a moving target.