Prepared by:Frankie Deo C. Detosil

WHAT IS MALARIA• A vector-borne infectious disease caused by protozoan

parasites. • The term MALARIA originates from MEDIEVAL ITALIAN: MALA

ARIA – “BAD AIR”; and the disease was formerly called ague or marsh fever due to its association with swamps.

• It is widespread in tropical and subtropical regions, including parts of the Americas, Asia, and Africa.

• Historical records suggest malaria has infected humans since the beginning of mankind.

• It has been infected humans for over 50,000 years, and may have been a human pathogen for the entire history of our species.

1880 A French army doctor

working in the military hospital of Constantine Algeria named Charles Louise Alphonse Laveran observed parasites for the first time, inside the red blood cells of people suffering from malaria. He therefore proposed that malaria was caused by this protozoan, the first time protozoa were identified as causing disease.

1884 Ettore Marchiafava and

Angelo Celli, while studying wet blood smears from malarious patients with the new oil-immersion lens, looked at unstained blood and saw an active amoeboid ring in the red blood cells. They then published this finding and named it Plasmodium.

A year later Carlos Finlay, a Cuban

doctor treating patients with yellow fever in Havana, first suggested that mosquitoes were transmitting disease to and from humans.

1898 It was Britain's Sir

Ronald Ross working in India who finally proved in 1898 that malaria is transmitted by mosquitoes

ETIOLOGY

• Malaria is caused by protozoan parasites of the genus Plasmodium (phylum apicomplexa).

• There are several species of Plasmodium Parasites but only four of them are significant to the cause of malaria diseases to humans. Some of these are in to animals. Like birds,reptiles, monkeys, chimpanzees, and rodents.

PLASMODIUM VIVAX

PLASMODIUM MALARIAE

PLASMODIUM OVALE

PLASMODIUM FALCIPARUM

• P. Vivax is the most common cause of infection, responsible for about 80% of all malaria cases.

• However, P. Falciparum is the most important cause of disease, and responsible for about 15% of infections and 90% of deaths.

The Parasite’s primary hosts and transmission vectors are female mosquitoes of the Anopheles genus.

The disease is transmitted to humans when an infected Anopheles mosquito bites a person and injects the malaria parasites (sporozoites) into the blood.

Mosquito injects the infective plasmodial sporozoites.

Sporozoites enter the liver cells, and transform into merozoites which penetrate RBC.

Once in RBC, merozoites reproduce rapidly, producing many more merozoites, which burst out of the RBC & penetrate new cells.

Some of these merozoites form male & female gametocytes, which can be picked up by another mosquito.

Inside the gut of the mosquito, gametocytes will fertilize creating zygote.

The zygote then develops into an oocyst and ruptures to release thousands of sporozoites.

Ready for another cycle.

Only female mosquitoes feed on blood, thus males do not transmit the disease. The females of the Anopheles genus of mosquito prefer to feed at night. They usually start searching for a meal at dusk, and will continue throughout the night until taking a meal.

Malaria parasites can also be transmitted by blood transfusion, although this is rare.

SIGNS & SYMPTOMS

The symptoms characteristic of malaria include flu-like illness with fever, chills, muscle aches, joint pain (athralgia), vomiting, anemia caused by hemolysis, hemoglobinuria, convulsions, and headache.

The classical symptom of malaria is cyclical occurrence of sudden coldness followed by rigor and then fever and sweating lasting four to six hours, occurring every two days in P. vivax and P. ovale infections, while every three for P. malariae. P. falciparum can have recurrent fever every 36-48 hours or a less pronounced and almost continuous fever.

People with severe P. falciparum malaria can develop bleeding problems, shock, liver or kidney failure, central nervous system problems, coma, and can die from the infection or its complications.

Cerebral malaria (coma, or altered mental status or seizures) can occur with severe P. falciparum infection. It is lethal if not treated quickly; even with treatment, about 15%-20% die.

INCUBATION PERIOD

The period between the mosquito bite and the onset of the malarial illness is usually one to three weeks (seven to 21 days). This initial time period is highly variable as reports suggest that the range of incubation periods may range from four days to one year.

The usual incubation period may be increased when a person has taken an inadequate course of malaria prevention medications.

Certain types of malaria (P. vivax and P. ovale) parasites can also take much longer, as long as eight to 10 months, to cause symptoms. These parasites remain dormant (inactive or hibernating) in the liver cells during this time. Unfortunately, some of these dormant parasites can remain even after a patient recovers from malaria, so the patient can get sick again. This situation is termed relapsing malaria.

TREATMENT Malaria can be a severe, potentially fatal disease

(especially when caused by P. Falciparum) and treatment should be initiated as soon as possible.

The Word Health Organization recommends that those in endemic areas, treatment should be started within 24 hours after the first symptoms appear. Treatment of patients with uncomplicated malaria can be conducted on an ambulatory basis (without hospitalization) but patients with severe malaria should be hospitalized if possible.

In areas where malaria is not endemic, all patients with malaria (uncomplicated or severe) should be kept under clinical observation if possible.

Drug Treatment The first effective treatment for malaria

was the bark of cinchona tree, which contains QUININE. It was first used by the inhabitants of Peru, where these trees mainly grow.

Today, there are several antimalarial drugs available for treatment:

Chloroquine sulfadoxine-pyrimethamine (Fansidar®) mefloquine (Lariam®) atovaquone-proguanil (Malarone®) quinine doxycycline artemisin derivatives primaquine

But, drug treatment of malaria is not always easy. You have to consider some factors in treating different conditions of patients having malaria.

1. The infecting species of Plasmodium parasites. Different species of Plasmodium parasites may vary in

treating patients.2. The clinical situation of the patient.

Mild malaria can be treated with oral medication. Severe malaria (having one or more symptoms of either

coma, severe anemia, renal failure, shock, etc.) requires intravenous (IV) drug treatment and fluids.

Malaria may pose a serious threat to a pregnant women and her pregnancy. Infection may be more severe than those women who are not pregnant.

3. The drug susceptibility of the infecting parasites. Determined by the geographic area where the infection

was acquired. Different areas of the world have malaria types that

are resistant to certain medications. Correct drug must be prescribed by the doctor who is

familiar with malaria treatment protocol.

There are three main factors in determining treatment

PUBLIC HEALTH PREVENTIONMALARIA CONTROL

The goal of malaria control in malaria-endemic countries is to reduce as much as possible the health impact of malaria on a population, using the resources available, and taking into account other health priorities.

Malaria control does not aim to eliminate malaria totally. Complete elimination of the malaria parasite (and thus the disease) would constitute eradication. While eradication is more desirable, it is not currently a realistic goal for most of the countries where malaria is endemic.

Malaria control is carried out through the following interventions, which are often combined:

Case Management (diagnosis and treatment) of patients suffering from malaria. Persons who are sick should be treated promptly

and correctly. It eliminates an essential component of the cycle (the parasite) and thus interrupts the transmission cycle.

WHO recommends that anyone suspected of having malaria should receive diagnosis and treatment with an effective drug within 24 hours of the onset of symptoms.

Prevention of Infection through vector control. Infection is prevented when malaria-carrying

Anopheles mosquitoes are prevented from biting humans.

Vector control aims to reduce contacts between mosquitoes and humans.

Some vector control measures like (destruction of larval breeding sites, insecticide spraying inside houses) may require organized teams and resources that are not always available.

Insecticide-treated bed nets could also be an alternative in vector control and personal protection. It could be conducted by the community themselves and become a major intervention in malaria control.

Prevention of Disease by administration of antimalarial drugs to particularly vulnerable population groups such as pregnant women and infants. Administration of antimalarial drugs to

vulnerable population groups does not prevent infection, which happens through mosquito bites. But drugs can prevent disease by eliminating the parasites that are in the blood, which are the forms that cause disease.

Pregnant women are the vulnerable group most frequently targeted. They may receive, for example, "intermittent preventive treatment" (IPT) with antimalarial drugs given most often at antenatal consultations during the second and third trimesters of pregnancy.

MALARIA IN THE PHILIPPINES

The Philippines is one of the Southeast Asian countries plagued with malaria. Although the country does not contribute significantly to the global mortality attributed to malaria, the disease remains to be a major cause of “healthy days of life lost” (HDLL) in the endemic areas of the country. Malaria affects the socioeconomic well-being of the affected population, and the different socioeconomic activities affect transmission, prevention, and control of the disease. Thus, this situation not only generates an enormous economic, social and health burden to these people per se, but also poses a huge and persistent challenge to the health deliverers of the Malaria Control Program.

PHILIPPINE SCENARIO

MALARIA AS A HEALTH PROBLEM It is the eighth leading cause of morbidity in the

Philippines. (HIS 2000) According to DOH Secretary Reynaldo Duque, “an

average of three Filipinos die daily due to malaria despite the government’s intensified efforts to control the occurrence of the ailment”.

Malaria has become a health threat. Although malaria endemicity is now generally moderate

to low, the disease continues to be a major impediment to human and economic development in areas where it persists

This disease is still endemic in 65 of the 79 provinces in the country, and around 10 million people who live in these areas are at risk of getting the disease.

Morbidity trend suggest that there might be a cause and effect relationship between the activities which aim to eradicate malaria and its incidence

There is a decreasing number of deaths caused by malaria

Chloroquine, the cheapest medicine against malaria is losing its effectiveness

Malaria as a Health Services Problem It poses challenges of access to health care for prompt

and effective treatment There are shortages of antimalarial drug supplies,

especially in peripheral health centers The disease still costs the Philippine economy to spend

over Php 100 million in order to sustain control efforts Failures in treatment still occur despite the

preventability of malaria. Causes of Malaria Treatment Failure in the Philippines

Drug resistance Non-compliance of patients in the treatment regimen Deficient drug absorption Self-medication Resorting to herbal remedies Seeking help when the disease is severe (Malaria is

fatal only when it is seen in its later stages.)

Epidemiology of malaria is complex, due to Variety of ecological conditions observed in different

island groups Occurrence of more than one vector species

Malaria Control Program of the Department of Health

For 2007, The Department of Health has developed a malaria control program as a measure to help eradicate the spread of the disease. Some of the program strategies are:

1. Early diagnosis of the disease and prompt treatment.This was achieved through:

diagnostic centers which serve as cites of microscopy manning by a RDT (Rapid Diagnostic Test) trained

personnel promotion of the existence of diagnostic

centers                           

2. Controlling the spread of mosquitoes This was achieved through:

giving out insecticide-treated mosquito nets indoor spraying which targets houses and not only

communities 

3. Implementation of community-based malaria control This was achieved through:

social mobilization education sessions

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