Malaria

Welcome to PT 635 Pathophysiology of Complex Patient Problems This is a wiki created by and for the students in the School of Physical Therapy at Bellarmine University in Louisville KY. Please do not edit unless you are involved in this project, but please come back in the near future to check out new information!!

Original Editors - Students from Bellarmine University's Pathophysiology of Complex Patient Problems project.

Lead Editors - Your name will be added here if you are a lead editor on this page.  Read more.

Definition/Description

Malaria is a parasitic infection caused by the bite of a female Anopheles mosquito.¹ The infection can result from any one of five parasites from the Plasmodium group including Plasmodium flaciparum (P. flaciparum), Plasmodium vivax (P. vivax), Plasmodium ovale (P. ovale), Plasmodium malariae (P. malariae), and Plasmodium knowlesi (P. knowlesi). Malaria causes fever, chills, malaise, headaches, and myalgia and can result in death if not treated appropriately.¹ The disease is most prevalent in Sub Suhahran Africa and Southeast Asia.¹ It has been eliminated from the United States, but is still one of the most common causes of fever in travelers that have returned from the aforementioned areas.¹

Prevalence

An estimated 500 million cases of Malaria occur each year, with 1-2 million deaths.²  About 90 % of these deaths occur in Sub-Saharan Africa.⁶ Severe Malaria (caused by P. falciparum) has a mortality rate of about 15-20%.¹ About 1,500 cases are diagnosed within United States every year.⁴ An estimated 50% of the world’s population, about 3.3 billion people, are at risk for Malaria.⁶ The following areas are most commonly affected by malaria : Africa, India, Pakistan, Southeast Asia, Paupa New Guinea, Haiti, and parts of South America.² 109 countries and territories are affected worldwide and the disease is most prevelant in area of tropical climate, as the Anopheles mosquito is able to live in areas with warm temperatures.⁶ Transmission of Malaria has been eliminated from the U.S., Puerto Rico, Jamaica, Chile, Israel, Lebanon, North Korea, and Europe. However, Anopheles mosquitos are found throughout the world, except for Antarctica.  As a result, the disease can be re-introduced into any country.

Characteristics/Clinical Presentation

The person infected with Malaria will not present with symptoms until about 7 days to 4 weeks after he or she has been bitten.⁶ However, symptoms may not occur until up to 6 months to 1 year after the bite.² The bite of a female Anopheles mosquito produces infection and consequent death to erythrocytes, or red blood cells, (see the Plasmodium life cycle in “causes” for more information) which causes hemolysis, anemia, and tissue hypoxia.² Symptoms could include fever, chills, malaise, headaches, and myalgia. Cough, abdominal pain, and diarrhea may also occur, but are less likely.¹ 

Infection by the P. Falciparum parasite produces the most severe form of Malaria and is the most life-threatening.⁴ When diagnosed with Malaria, the patient is classified as either severe (complicated) or uncomplicated. The criteria for diagnosis of severe Malaria is listed in the “diagnosis” section. If infected by P. vivax or P. ovale, the patient may experience relapsing Malaria in which the infection can lie dormant in the body for up to 4 years.⁴

Associated Co-morbidities

Co-morbidities caused by severe Malaria (P. flaciparum) could include cerebral malaria, hypoglycemia, severe anemia, pulmonary edema, respiratory failure, renal failure, and metabolic acidosis.¹ Below is a description of each, and an explanation of the pathophisiology as it relates to Malaria.

Cerebral Malaria: This form of Malaria can only be caused by P. Flaciparum.² It is characterized by “the intense sequestration of parasites in the cerebral microvasculature.³” In other words, the parasite invades the blood vessels of the brain and disallow blood to circulate as it normally would.  Furthermore, oxygen and glucose supply to the brain is compromised because of improper amounts of blood flow.³ Cerebral Malaria causes over 80% of the casualties caused by Malaria.² Symptoms of cerebral Malaria include seizures, stupor and focal neurological symptoms.²

Hypoglycemia: In children, hypoglycemia is caused by the inability of the liver to make new forms of glucose (hepatic gluconeogenesis) because the hepatocytes (liver cells) have been infected.³ In adults, hypoglycemia is caused by increased amounts of insulin in cells which is a result of stimulation of the islet cells in the pancreas which are responsible for some insulin production.³

Anemia: Loss of red blood cells results not only from phagocytic removal of infected erythrocytes, but also removal of uninfected erythtrocytes.³ The bone marrow, which is responsible for blood cell production,is defected in the Malaria infected individual and the result is a decreased level of erythroprotein production and an increased level of phagocytic activity within red blood cells.³

Pulmonary Edema and Respiratory Failure: Inflammatory cytokines (substances that carry signals between cells) are produced in the lungs in response to erythrocyte sequestration (microvascular obstruction).³ As a result, capillary permeability is increased which can produce pulmonary edema, dyspnea, hypoxia, or acute respiratory distress syndrome.³

Metabolic Acidosis: Lack of oxygen to the tissues produces acidosis (High H+ concentration and low pH). The effects of anemia, microvascular obstruction, and hypovolemia (reduced perfusion of the tissues) can cause this lack of oxygen.³

Medications

add text here

Diagnostic Tests/Lab Tests/Lab Values

add text here

Causes

add text here

Systemic Involvement

add text here

Medical Management (current best evidence)

add text here

Physical Therapy Management (current best evidence)

add text here

Alternative/Holistic Management (current best evidence)

add text here

Differential Diagnosis

add text here

Case Reports

add links to case studies here (case studies should be added on new pages using the case study template)

Resources

add appropriate resources here

Recent Related Research (from Pubmed)

see tutorial on Adding PubMed Feed

References

see adding references tutorial.