Dhaka, Bangladesh
Malaria updates and prevention

Malaria updates and prevention

Malaria affects 500 million people worldwide and kills at least 2 million per year. Over one million Africans die of Malaria yearly (mostly children). 30,000 Europeans and North Americans are affected. Sometimes Malaria may be easy to recognize, but it can also sometimes be difficult to diagnose. In travelers, over 1300 cases are reported each year with most of these having used no chemoprophylaxis. It is important to stress to travelers the importance of Malaria precautions if they are going to countries where it is present. Malaria Parasites Malaria is caused by a parasite transmitted by certain species of mosquitoes. Plasmodium falciparum, vivax, oval, or malaria are the four different species. The mosquito contracts the Malaria parasite when biting an infected person; a gamocyte form enters the mosquito and breeds internally creating oocytes and then sporocites. These then travel to the salivary glands of the mosquito, which will be passed to people with the next bite. These sporocites can penetrate the liver of an infected human within 45 minutes. Within 9-16 days the sporocites differentiate into merozites, which invade red blood cells and liver cells. Blood cells will then rupture releasing gametocytes and merozites, which cause the cycle of fevers and chills in the human host. Mosquitoes carrying Malaria Anopheles mosquitoes are responsible for the transmission of Malaria. Anopheles mosquitoes are sometimes identifiable by the way they bite (head downward when biting), as compared with Culex mosquitoes (stand parallel when biting). Female mosquitoes of the Anopheles type bite at night or twilight. Urbanization may create areas where mosquitoes may breed close to people (stagnant water). Mosquitoes don't travel more than two miles from where they are bred. Weird exceptions are airport Malaria, acquired by passengers being bitten by mosquitoes indoors during stopovers. Wind could also blow mosquitoes further away. Only female mosquitoes drain blood. Males survive off of nectars and fluids. Symptoms Sometimes Malaria may be easy to recognize, but it can also sometimes be difficult to diagnose. Symptoms of Malaria may be very subtle like flu like attacks, fever and chills, which may lead to multi- organ failure and death. It is important to note that Malaria medication /will lessen symptoms of Malaria but will not guarantee immunity. Malaria /hemoprophylaxis helps prevent life threatening Malaria that will kill people before they are able to seek medical attention. Any symptoms should be investigated with a thick and thin malarial smear. This can still lead to misdiagnosis, as a smear may not "catch" parasites on microscopic analysis. If Malaria is suspected, one normal smear does not rule it out. It is generally assumed that any returning traveler with fever has Malaria until proven otherwise. Many other infectious diseases may also manifest themselves with flu-like symptoms but Malaria is the one diagnosis not to miss. Many other mosquitoes co-exist with the Anopheles mosquito-Aedes aegypti, Culex, Haemogogus, Sabethes, and Masonia, which cause other diseases like Yellow fever, Filariasis, viral Encephalitis, Dengue and other hemorrhagic fevers. Other insects (Tse-Tse flies, black flies, deerflies, sand flies, lice, ticks and mites) cause a variety of illnesses many of which have no known vaccine or medication to prevent illness as well as no good treatment. General recommendations are to avoid all insect bites similarly as to malarial mosquitoes. The A, B, C and D approach to Prevention of Malaria: This new way of emphasizing the risk for travelers simplifies the issues important for Malaria prevention. A is for Awareness. All travelers going to areas of risk should be informed. B is for Bite Avoidance, which involves behavior as well as chemical and barrier methods. C is for Compliance with Medication. It is not enough to just prescribe the correct medication but also stress the importance of taking the medication correctly. Practitioners must be prepared to discuss the pros and cons of different choices so that clients will actually take the medication they receive. D is for (prompt) Diagnosis. Travelers returning from a malarious area must be assessed correctly for the possibility of Malaria Assessing Risk Using the traveler's itinerary, which includes geographic areas visited, types of accommodation (resort, camping), duration of stay, season (rainy, dry or recent human disasters), and elevation will help practitioners make the decision in what type of malarial medication to recommend. Medications should be compatible with the patient's medical conditions and other medications. There are several malarial maps published by the CDC (www.cdc.gov/travel/) and other organizations that list malarious areas of the world. This information is constantly being reassessed and updated. Prevention of Bites Malarial prevention is best accomplished by avoiding being bitten. Wear long sleeved shirts and long pants. Uses insect repellent, sleep under a mosquito net, use mosquito coils, don't sleep on the ground, and check for ticks and insect bites daily. Be knowledgeable of the signs and symptoms of the disease you may likely encounter where you are traveling. DEET works well as a skin protectant. Permethroid insecticides on clothing and tents dissuade biting insects. Chemoprophylaxis for the Prevention of Malaria Taking an antimalarial drug before, after, and during exposure to malarious areas should be understood not to completely protect the traveler from Malaria. The purpose of antimalarial chemoprophylaxis is to prevent life-threatening Malaria from killing or dehabilitating a traveler. It is always implied that fever in a traveler to a malarious area is Malaria until proven otherwise and swift steps to accurately diagnose and treat must be taken. Antimalarials buy time and in many cases do prevent infections. All malarial medications have some side effects as well. Types of medication to prevent malaria (chemoprophylaxis) include: Chloroquine (Aralen): This medication is cheap and well tolerated but has a bitter taste. It can upset the stomach and blur vision. There are many areas of the world where the strains of Malaria are resistant to Chloroquine. The adult dose is 500mg once weekly of Chloroquine phosphate. Previously, Chloroquine was dispensed as either a salt or base but currently the Chloroquine phosphate notation is easily understood. Chloroquine comes as 250mg strength tablets so that travelers must take 2 tablets once per week, on the same day. Some suggest taking it on Monday using the pneumonic "Malaria Mondays" to make it easier to remember to take on the proper day. For those having stomach upset, Chloroquine may also be taken as 250mg twice weekly. The children's dose is 8.3mg/kg once per week. Children may take fractions of an adult tablet if this is convenient; otherwise send the prescription to a Compounding Pharmacist who will be able to dispense an irregular dose with precision. Medication is started one week prior to travel, and is taken weekly during, and for four weeks after the trip. Chloroquine is very safe but it can aggravate inactive psoriasis. It is safe for pregnant women to take. Chloroquine with proguanil was previously used for pregnant women going to Chloroquine resistant areas, but this regiment is no longer used. Mefloquine (Larium): Mefloquine is moderately expensive but it can be used in Chloroquine resistant areas although there are now Mefloquine resistant areas also. An estimated 25-40% of people experience mild self limited side effects including stomach upset, strange dreams, mood changes, insomnia and headaches. However, these side effects are generally well tolerated so that the medication schedule is not interrupted and is properly finished. Approximately 5% of people have more significant adverse effects including anxiety, depression, nightmares, paranoia, and dizziness, which may cause them to seek medical attention and discontinue the drug. Severe side effects occur in 1 in 10,000-13,000 people and may include seizures and psychosis. If adverse effects will occur, they will normally manifest themselves after 3 doses of Mefloquine. If a person is unsure about how they would react to Mefloquine they may be given a loading dose of Mefloquine 250mg daily for 3 days. If they do not experience any problems at this loading dose they will be unlikely to have any future problems from taking Mefloquine. The normal Mefloquine dose for prevention is 250 mg taken weekly, starting one week prior to departure, during the trip and for four weeks after the trip. Mefloquine is considered a category C drug for pregnant women in their second and third trimesters and a Category IIIB drug for the first trimester. Mefloquine is the only drug available to pregnant women traveling to Chloroquine resistant areas. It should also be emphasized that Malaria is often more severe in pregnant women. Mefloquine in children The adult dose is prorated according to weight (kg): 5-14 kg 1/8th adult tablet; 15-19 kg ¼ adult tablet; 20-30kg ½ adult tablet; 31-45kg ¾ adult tablet; 0.45kg one adult tablet weekly. Children generally tolerate Mefloquine well having less adverse effects than adults do. Doxycycline : Doxycycline is effective against all Malaria strains and is used in areas where Mefloquine resistance exists. The dose is one daily pill started 1-2 days before exposure and continued during the trip and until 4 weeks post travel. Side effects include stomach irritation and photosensitivity. Doxycycline is well tolerated but can cause Candida yeast infections in women. Those taking it are more prone to sun photosensitivity. Rarely patients experience esophageal ulcers. It is recommended to take Doxycycline while in an upright position with fluids and food and avoid lying down right after taking the pill. It is not used in children or pregnant women because it can discolour developing teeth. It may be used in children 9 years and older and the dose is 2mg/kg each day. Malarone (Atoraquine/ Proquinil) : Malarone is new, but it is expensive. It has fewer side effects than other antimalarials but can cause nausea and vomiting. Patients also have reported the occurrence of mouth ulcers from Malarone. This drug may be started 2 days before the trip. It is taken daily and then discontinued 7 days after the trip. It is discontinued sooner because it is effective at killing Malaria in the liver. So, there is no need to take this medication as long as 4 weeks as with Mefloquine, Chloroquine or Doxycycline. Malarone is not approved for pregnant women. Children's dosing is according to weight: Children 1-20kg 1 Pediatric tablet; 21-30kg 2 pediatric tablets; 31-40kg 3 pediatric tablets; and >40kg 4 pediatric tablets or one adult tablet. Other treatments are possible and some are under investigation. Self treat Malaria Self-treatment Malaria kits are available. Many travelers like the idea of doing self-testing and then consequently treating themselves. However, large doses of Malaria drugs in a sick person are not without side effects. Self-treatment is not recommended. Instead preventative measures are best with medication to prevent Malaria and to seek immediate medical attention if ill. 90% of travelers with Malaria do not become ill until after they return home. This illusion of good health may foster urban myths among travelers that Malaria is not a significant risk, which lead to laxity of mosquito precautions. Taking medications to prevent Malaria is not a perfect solution but is still the overall best way to prevent Malaria. All of the Malaria medications have some type of side effects but the benefits they confer of preventing Malaria far outweigh these effects. Information on Malaria for Patients: General: Malaria is an infection caused by a parasite that is transmitted through the bite of an infected mosquito. Malaria enters the body through the blood stream. Once in the blood stream parasites travel to the liver and destroy red blood cells. Other complications include anemia caused by blood cell destruction, and the clumping of blood cells which may cause brain and kidney damage. Signs & Symptoms Headaches Shakes and chills caused by fever Fatigue Rapid breathing Nausea Extremes sweating with a drop in temperature Prevention Prevention is best accomplished by avoiding being bitten. The best ways to do this are: wearing long sleeved shirts and long pants; using insect repellent; sleeping under a mosquito net; using mosquito coils; not sleeping on the ground; and checking for ticks and insect bites daily. Be knowledgeable of the signs and symptoms of the diseases you may likely encounter where you are traveling. Use anti-malarial drugs Use mosquito netting while in mosquito infested areas Avoid crowded or unsanitary conditions Wear long pants and long sleeved shirts.

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