WORLD MALARIA DAY 2016

WORLD MALARIA DAY 2016

Malaria is a serious and sometimes fatal disease caused by a parasite that commonly infects a

certain type of mosquito which feeds on humans. People who get malaria are typically very sick with

high fevers, shaking chills, and flu-like illness. Although malaria can be a deadly disease, illness and

death from malaria can usually be prevented.

Malaria is generally caused by a parasite Plasmodium falciparium and transmitted by female

anopheles mosquito.

Malaria Worldwide

3.2 billion People live in areas at risk of malaria transmission in 106 countries and territories.The

disease is widespread in the tropical and subtropical regions that exist in a broad band around the

equator. This includes much of Sub-Saharan Africa, Asia, and Latin America. In 2015, there were 214

million cases of malaria worldwide. This resulted in an estimated 438,000 deaths, 90% of which occurred

in Africa.

Two important currently used antimalarial drugs are derived from plants whose medicinal values had

been noted for centuries: artemisinin from the Qinghaosu plant (Artemisia annua, China, 4th century)

and quinine from the cinchona tree (Cinchona spp., South America, 17th century).

This map shows an approximation of the parts of the world where malaria transmission occurs. For

more detailed information about the occurrence of malaria transmission in specific countries, please

use the interactive Malaria Map Application.

SYMPTOMS

Malaria_Symptoms

Uncomplicated Malaria

The classical (but rarely observed) malaria attack lasts 6-10 hours. It consists of

 a cold stage (sensation of cold, shivering)

 a hot stage (fever, headaches, vomiting; seizures in young children)

 And finally a sweating stage (sweats, return to normal temperature, tiredness).

More commonly, the patient presents with a combination of the following symptoms:

 Fever

 Chill

 Sweats

 Headaches

 Nausea and vomiting

 Body aches

 General malaise

In countries where cases of malaria are infrequent, these symptoms may be attributed to influenza, a

cold, or other common infections, especially if malaria is not suspected. Conversely, in countries

where malaria is frequent, residents often recognize the symptoms as malaria and treat themselves

without seeking diagnostic confirmation ("presumptive treatment").

Physical findings may include:

 Elevated temperatures

 Perspiration

 Weakness

 Enlarged spleen

 Mild jaundice

 Enlargement of the liver

 Increased respiratory rate

Diagnosis of malaria depends on the demonstration of parasites in the blood, usually by microscopy.

Additional laboratory findings may include mild anemia, mild decrease in blood platelets

(thrombocytopenia), elevation of bilirubin, and elevation of aminotransferases.

Severe Malaria

Severe malaria occurs when infections are complicated by serious organ failures or abnormalities in

the patient's blood or metabolism. The manifestations of severe malaria include

 Cerebral malaria, with abnormal behavior, impairment of consciousness, seizures, coma, or other

neurologic abnormalities

 Severe anemia due to hemolysis (destruction of the red blood cells)

 Hemoglobinuria (hemoglobin in the urine) due to hemolysis

 Acute respiratory distress syndrome (ARDS), an inflammatory reaction in the lungs that inhibits

oxygen exchange, which may occur even after the parasite counts have decreased in response to

treatment

 Abnormalities in blood coagulation

 Low blood pressure caused by cardiovascular collapse

 Acute kidney failure

 Hyperparasitemia, where more than 5% of the red blood cells are infected by malaria parasites

 Metabolic acidosis (excessive acidity in the blood and tissue fluids), often in association with

hypoglycemia

 Hypoglycemia (low blood glucose). Hypoglycemia may also occur in pregnant women with

uncomplicated malaria, or after treatment with quinine.

Severe malaria is a medical emergency and should be treated urgently and aggressively.

Malaria Relapses

In P. vivax and P. ovale infections, patients having recovered from the first episode of illness may

suffer several additional attacks ("relapses") after months or even years without symptoms.

Relapses occur because P. vivax and P. ovale have dormant liver stage parasites. Treatment to

reduce the chance of such relapses is available and should follow treatment of the first attack.

Anopheles_stephensi

Prevention

An Anopheles stephensi mosquito shortly after obtaining blood from a human (the droplet of blood is

expelled as a surplus). This mosquito is a vector of malaria, and mosquito control is an effective way of

reducing its incidence.

Methods used to prevent malaria include medications, mosquito elimination and the prevention

of bites. The presence of malaria in an area requires a combination of high human population

density, high anopheles mosquito population density and high rates of transmission from humans

to mosquitoes and from mosquitoes to humans.

Vector control refers to methods used to decrease malaria by reducing the levels of transmission

by mosquitoes. For individual protection, the most effective insect repellents are based on DEET

or picaridin. Insecticide-treated mosquito nets (ITNs) and indoor residual spraying (IRS) have

been shown to be highly effective in preventing malaria among children in areas where malaria

is common. Prompt treatment of confirmed cases with artemisinin-based combination therapies

(ACTs) may also reduce transmission.

Walls where indoor residual spraying of DDT has been applied. The mosquitoes remain on the wall until

they fall down dead on the floor.

A mosquito net in use.

Mosquito nets help keep mosquitoes away from people and reduce infection rates and

transmission of malaria. Nets are not a perfect barrier and are often treated with an insecticide

designed to kill the mosquito before it has time to find a way past the net. Insecticide-treated nets

are estimated to be twice as effective as untreated nets and offer greater than 70% protection

compared with no net.

Indoor residual spraying is the spraying of insecticides on the walls inside a home. After

feeding, many mosquitoes rest on a nearby surface while digesting the bloodmeal, so if the walls

of houses have been coated with insecticides, the resting mosquitoes can be killed before they

can bite another person and transfer the malaria parasite.

There are a number of other methods to reduce mosquito bites and slow the spread of malaria.

Efforts to decrease mosquito larva by decreasing the availability of open water in which they

develop or by adding substances to decrease their development is effective in some locations.

Electronic mosquito repellent devices which make very high frequency sounds that are supposed

to keep female mosquitoes away, do not have supporting evidence.

Other methods

Community participation and health education strategies promoting awareness of malaria and the

importance of control measures have been successfully used to reduce the incidence of malaria in

some areas of the developing world. Recognizing the disease in the early stages can stop the

disease from becoming fatal. Education can also inform people to cover over areas of stagnant,

still water, such as water tanks that are ideal breeding grounds for the parasite and mosquito, thus

cutting down the risk of the transmission between people. This is generally used in urban areas

where there are large centers of population in a confined space and transmission would be most

likely in these areas. Intermittent preventive therapy is another intervention that has been used

successfully to control malaria in pregnant women and infants, and in preschool children where

transmission is seasonal.

TREATMENT

There are a number of drugs that can help prevent or interrupt malaria in travelers to places

where infection is common. Many of these drugs are also used in treatment. Chloroquine may be

used where chloroquine-resistant parasites are not common. In places where Plasmodium is

resistant to one or more medications, three medications—mefloquine (Lariam), doxycycline

(available generically), or the combination of atovaquone and proguanil hydrochloride

(Malarone)—are frequently used when prophylaxis(prevention) is needed. Doxycycline and the

atovaquone plus proguanil combination are the best tolerated.

Simple or uncomplicated malaria may be treated with oral medications. The most effective

treatment for P. falciparum infection is the use of artemisinins in combination with other

antimalarials (known as artemisinin-combination therapy, or ACT), which decreases resistance

to any single drug component. These additional antimalarials include: amodiaquine,

lumefantrine, mefloquine or sulfadoxine/pyrimethamine. Another recommended combination is

dihydroartemisinin and piperaquine. ACT is about 90% effective when used to treat

uncomplicated malaria. To treat malaria during pregnancy, the WHO recommends the use of

quinine plus clindamycin early in the pregnancy (1st trimester), and ACT in later stages (2nd

and 3rd trimesters). In the 2000s (decade), malaria with partial resistance to artemisins emerged

in Southeast Asia. Infection with P. vivax, P. ovale or P. malariae usually do not require

hospitalization. Treatment of P. vivax requires both treatment of blood stages (with chloroquine

or ACT) and clearance of liver forms with primaquine.

Severe and complicated malaria are almost always caused by infection with P. falciparum. The

other species usually cause only febrile disease. Severe and complicated malaria are medical

emergencies since mortality rates are high (10% to 50%). Cerebral malaria is the form of severe

and complicated malaria with the worst neurological symptoms. Recommended treatment for

severe malaria is the intravenous use of antimalarial drugs. For severe malaria, parenteral

artesunate was superior to quinine in both children and adults. In another systematic review,

artemisinin derivatives (artemether and arteether) were as efficacious as quinine in the treatment

of cerebral malaria in children. Treatment of severe malaria involves supportive measures that

are best done in a critical care unit. This includes the management of high fevers and the seizures

that may result from it. It also includes monitoring for poor breathing effort, low blood sugar,

and low blood potassium.

Resistance

Drug resistance poses a growing problem in 21st-century malaria treatment. Resistance is now

common against all classes of antimalarial drugs apart from artemisinins. Treatment of resistant

strains became increasingly dependent on this class of drugs. The cost of artemisinins limits their

use in the developing world. Malaria strains found on the Cambodia–Thailand border are

resistant to combination therapies that include artemisinins, and may therefore be untreatable.

Exposure of the parasite population to artemisinin monotherapies in subtherapeutic doses for

over 30 years and the availability of substandard artemisinins likely drove the selection of the

resistant phenotype.

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