Fighting Malaria with Oil and Fungus

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Mosquitoes transmit the parasite, Plasmodium, that causes malaria, one the deadliest diseases on Earth. Recent research could turn the tables on the mosquitoes by using fungal parasites to kill them before they can do any damage.

800px-Larve_de_moustique Some species of fungus feed on the mosquitoes before they even develop into their flying stage. Mosquitoes live in the water before turning into buzzing blood suckers. By using the fungus to kill off mosquito larvae in the water, the insects never get a chance to infect anyone with malaria.

via Discovery News.

Malaria Countries and Map

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Geographic Distribution of Malaria Around the World

Where malaria is found depends mainly on climatic factors such as temperature, humidity, and rainfalls. Malaria is transmitted in tropical and subtropical areas, where:

  • Anopheles mosquitoes can survive and multiply
  • Malaria parasites can complete their growth cycle in the mosquitoes (“extrinsic incubation period”).

Temperature is particularly critical. For example, at temperatures below 20°C (68°F), Plasmodium falciparum (which causes severe malaria) cannot complete its growth cycle in the Anopheles mosquito, and thus cannot be transmitted. [Read more…]

Malaria Prevention

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Photo by Matthew Naythons, MD

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. [Read more…]

Malaria Treatment

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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.

Source: Centers for Disease Control (CDC)

Professor Working on Malaria Vaccine that Will Inoculate Mosquitos When They Bite People

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The same menace that spreads malaria – the mosquito bite – could help wipe out the deadly disease, according to researchers working on a new vaccine at Tulane University.

The PATH Malaria Vaccine Initiative(MVI), established in 1999 through a grant from the Bill & Melinda Gates Foundation, announced today a collaboration with Tulane University School of Public Health and Tropical Medicine and India’s Gennova Biopharmaceuticals Ltd. to produce and test a novel vaccine that aims to inoculate mosquitoes when they bite people. [Read more…]

Malaria Prevention and Control

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Malaria Prevention

Prevention of malaria can aim at either:

  • preventing infection, by avoiding bites by parasite-carrying mosquitoes, or
  • preventing disease, by using antimalarial drugs prophylactically. The drugs do not prevent initial infection through a mosquito bite, but they prevent the development of malaria parasites in the blood, which are the forms that cause disease. This type of prevention is also called “suppression.” [Read more…]

Travel Information

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Malaria, a common and life-threatening disease, is a risk in tropical and subtropical areas of over 100 countries. An estimated 30,000 international travelers fall ill with the disease annually. Fever occurring in a traveller one week or more after entering a malaria risk area, and up to 3 months after departure, is a medical emergency that should be investigated urgently. Prompt diagnosis and correct treatment of malaria can mean the difference between life and death.

The ABCD’s of Malaria Protection

  • A: Awareness—Be aware of the Risk, the Incubation Period, and the Main Symptoms of malaria.
  • B: Bites—Avoid being bitten by mosquitos—especially between dusk and dawn.
  • C: Chemoprophylaxis—Take antimalarial drugs (chemoprophylaxis) to suppress infection where appropriate. (More information on antimalarial drugs).
  • D: Diagnosis—Immediately seek diagnosis and treatment if a fever develops one week or more after entering an area where there is malaria risk, and up to 3 months after departure.

Malaria in travellers can usually be prevented. All travellers to malarious regions should follow the ABCD principles listed above.

 

This information is intended for travelers who reside in the United States. Travelers from other countries may find this information helpful; however, because malaria prevention recommendations and the availability of antimalarial drugs vary, travelers from other countries should consult health care providers in their respective countries.

On this Page:

Countries with Malaria Risk

Travelers to sub-Saharan Africa have the greatest risk of both getting malaria and dying from their infection. However, all travelers to countries with malaria risk may get this potentially deadly disease.

Malaria is transmitted in

  • large areas of Central and South America
  • the island of Hispaniola (includes Haiti and the Dominican Republic)
  • Africa
  • Asia (including the Indian subcontinent, Southeast Asia and the Middle East)
  • Eastern Europe
  • and the South Pacific

What Determines Your Individual Risk

If you are traveling outside of the United States, Canada, and Western Europe, you may be at risk for malaria. All visitors to malaria risk areas are at risk of getting malaria; however, many factors determine the risk to an individual traveler. Even in the same locale, these factors can vary widely over time. From year to year, conditions such as amount of rainfall, the number of mosquitoes, and the number of infected persons in the area will change and may produce a different level of risk than previously seen.

Factors that determine a traveler’s risk include:

  • Unaware of malaria risk areas
    Many U.S. travelers, their healthcare providers, and tour companies may be unaware that their travel itinerary includes malaria risk areas.
  • Amount of malaria in the area to be visited
    Most malaria transmission occurs in rural areas, although malaria occurs in urban areas in many countries. Low altitudes with warm temperatures allow for larger populations of infective mosquitoes. Transmission is generally higher in Africa south of the Sahara than in most other areas of the world; in 2002, 73% of imported malaria cases among U.S. and foreign civilians occurred in persons who traveled to Africa.
  • Time of the year
    Seasons with more rainfall and higher temperatures will have more malaria transmission than colder, drier seasons. However, in most tropical and semi-tropical countries, transmission may occur even during cooler months or periods of less rainfall.
  • Type (species) of malaria parasite present in the area
    While all species of malaria parasites can make a person feel very ill, Plasmodium falciparum causes severe, potentially fatal malaria. Persons who travel to areas where P. falciparum malaria is present should be extra careful to take their antimalarial drug and to prevent mosquito bites.
  • Nighttime exposure to mosquito bites
    Because the mosquito that transmits malaria bites at night, travelers who are frequently out of doors between dusk and dawn will be at greater risk for malaria.
  • Preventive measures taken by travelers
    Individual measures, such as taking an effective antimalarial drug and preventing mosquito bites, are the most important factors in minimizing risk. While other risk factors may be difficult to change or avoid, travelers can greatly reduce their risk of malaria by following recommended travel precautions.
  • Immunity or lack of immunity to malaria
    Because malaria was eliminated from the United States in the late 1940s, most residents have never developed resistance (immunity) to the disease. Malaria infection in a non-immune person can quickly result in a severe and life-threatening illness.

In addition, many healthcare providers and laboratories in the United States rarely see cases of malaria and may be unfamiliar with the diagnosis and treatment of the disease, and this can delay effective treatment.

How to Protect Yourself

Know the Facts About Malaria

Every year, millions of United States residents travel to countries where malaria is present; about 800 cases of malaria are diagnosed in these returning travelers each year. From 1985-2002, 78 U.S. travelers died from malaria.

Persons who are traveling to malaria risk areas can almost always prevent this potentially deadly disease if they correctly take an effective antimalarial drug and follow measures to prevent mosquito bites.

Know the Symptoms

Despite these protective measures, travelers may become infected with malaria. Malaria symptoms can include:

  • fever
  • chills
  • headache
  • flu-like symptoms
  • muscle aches
  • fatigue
  • low blood cell counts (anemia)
  • yellowing of the skin and whites of the eye (jaundice)

If not promptly treated, infection with Plasmodium falciparum, the most harmful malaria parasite, may cause coma, kidney failure, and death.

When Symptoms Appear, Seek Immediate Medical Attention
Malaria is always a serious disease and may be a deadly illness. Travelers who become ill with a fever or flu-like illness either while traveling in a malaria-risk area or after returning home (for up to 1 year) should seek immediate medical attention and should tell the physician their travel history.

Additional Information Resources:

  • The CDC Travelers’ Health website provides information on protecting the health of international travelers, including detailed country-specific malaria prevention information plus recommendations for vaccinations (there is no malaria vaccine), food and water precautions, and safety information.
  • Preventing Malaria in Travelers ((PDF brochure, Size: 280 KB/8 pages

Counterfeit (“fake”) Drugs

In some countries (including those with malaria risk), drugs may be sold that are counterfeit (“fake”) or substandard (not made according to United States standards). Such drugs may not be effective. Purchase your antimalarial drugs before traveling overseas!

Source: World Health Organization (WHO); Centers for Disease Control (CDC)

A Research Agenda for Malaria Eradication: Vector Control

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Abstract: Different challenges are presented by the variety of malaria transmission environments present in the world today. In each setting, improved control for reduction of morbidity is a necessary first step towards the long-range goal of malaria eradication and a priority for regions where the disease burden is high.

For many geographic areas where transmission rates are low to moderate, sustained and well-managed application of currently available tools may be sufficient to achieve local elimination. The research needs for these areas will be to sustain and perhaps improve the effectiveness of currently available tools. For other low-to-moderate transmission regions, notably areas where the vectors exhibit behaviours such as outdoor feeding and resting that are not well targeted by current strategies, new interventions that target predictable features of the biology/ecologies of the local vectors will be required. [Read more…]

A Research Agenda for Malaria Eradication: Drugs

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Abstract: Antimalarial drugs will be essential tools at all stages of malaria elimination along the path towards eradication, including the early control or “attack” phase to drive down transmission and the later stages of maintaining interruption of transmission, preventing reintroduction of malaria, and eliminating the last residual foci of infection.Drugs will continue to be used to treat acute malaria illness and prevent complications in vulnerable groups, but better drugs are needed for elimination-specific indications such as mass treatment, curing asymptomatic infections, curing relapsing liver stages, and preventing transmission. [Read more…]

A Research Agenda for Malaria Eradication: Vaccines

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Abstract: Vaccines could be a crucial component of efforts to eradicate malaria. Current attempts to develop malaria vaccines are primarily focused on Plasmodium falciparum and are directed towards reducing morbidity and mortality. Continued support for these efforts is essential, but if malaria vaccines are to be used as part of a repertoire of tools for elimination or eradication of malaria, they will need to have an impact on malaria transmission.

We introduce the concept of “vaccines that interrupt malaria transmission” (VIMT), which includes not only “classical” transmission-blocking vaccines that target the sexual and mosquito stages but also pre-erythrocytic and asexual stage vaccines that have an effect on transmission. VIMT may also include vaccines that target the vector to disrupt parasite development in the mosquito. Importantly, if eradication is to be achieved, malaria vaccine development efforts will need to target other malaria parasite species, especially Plasmodium vivax, where novel therapeutic vaccines against hypnozoites or preventive vaccines with effect against multiple stages could have enormous impact. A target product profile (TPP) for VIMT is proposed and a research agenda to address current knowledge gaps and develop tools necessary for design and development of VIMT is presented.

Citation: The malERA Consultative Group on Vaccines (2011) A Research Agenda for Malaria Eradication: Vaccines. PLoS Med 8(1): e1000398. doi:10.1371/journal.pmed.1000398
Published: January 25, 2011

Funding: malERA received a grant from the Bill & Melinda Gates Foundation. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Competing interests: No competing interests: PLA, CC, VM, AS, DW. GB is the Chair of MALVAC, Chair of the USAID Malaria Vaccine Development Program Scientific Consultants Group, a member of the Board of Roll Back Malaria, and the APMEN Advisory Board. RB is an employee of Glaxo SmithKline (GSK) and owns GSK stock. GSK is developing malaria vaccines. At the time of the malERA meetings, RB was employed by the Bill & Melinda Gates Foundation. CL states that the PATH Malaria Vaccine Initiative has partnerships with several commercial entities developing malaria vaccines. Each partnership has defined access conditions.

Abbreviations: TBV, transmission-blocking vaccine; TPP, target product profile; VIMT, vaccines that interrupt malaria transmission

Copyright: © 2011 The malERA Consultative Group on Vaccines. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

More information:
A Research Agenda for Malaria Eradication: Vaccines (PDF)