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Malicious MALARIA

"A child dying from malaria every 30 seconds is completely unacceptable when we have effective and affordable ways to help children and adults avoid infection."

-Dr. Carol Bellamy, Executive Director, UNICEF

Title: Malicious Malaria
Author: Emily Lewis & Charlotte Didlake
Date: 20 May 2010

Half of the world's population (3.3 billion people) live in at-risk areas for Malaria, in 109 different countries. Malaria's initial symptoms are similar to flu symptoms and diagnosis is difficult. Symptoms include fever, shivering, pain in joints, and headache. Malaria is most effectively diagnosed by a blood exam and it is curable if detected early. These symptoms disappear quickly after the parasite is killed. Malaria is caused by a Protozoan Apicomplex intercellular blood parasite. The parasite Plasmodium is a zoonose that is hosted in the female anopheline mosquito. The mosquito is Plasmodium's definite host and the vector carrier. There are four different types of Plasmodium: P. falciparum, P. vivax, P. ovale, and P. malaria. The most common, and the deadliest form of Plasmodium is P. falciparum. The parasite can be transmitted, not only through vectors, but also specific direct and indirect methods. Yet, Malaria is typically transmitted through the life cycle of Plasmodium where the female anopheline mosquito is the definite host allowing the parasite to reproduce sexually. It is then transmitted to the human, or intermediate host, where it continues to reproduce asexually.

Due to Emily's summer travels to Guatemala and Charlotte's hopes of traveling to Haiti in the near future, both Emily and Charlotte were interested in the types of disease they could possibly encounter, specifically malaria. We were shocked to learn that a child dies every thirty seconds due to Malaria (CDC, 2009). We do not think twice about traveling to these malaria infected countries due to preventative medication and our access to advanced health care. Our research made us aware, however, of how malaria is spread and why it is a huge problem in under-developed countries and in countries with hot and moist climates that attract large mosquito populations.

  • Impact/Distribution

Malaria is responsible for three thousand deaths every day. This means that more than one million people each year lose their life because of this disease. According to the World Health Organization (WHO), between 300 and 500 million people are infected. Most of these people are young children in sub-Saharan Africa (CDC, 2009).

Malaria is a serious crisis worldwide. We do not often think of its profound effects because we live in the United States (a low-risk area). "About 1,500 cases of malaria are diagnosed in the United States each year. The vast majority of [these] cases...are in travelers and immigrants returning from countries where malaria transmission occurs" (CDC, 2009). Below is a map showing Malaria endemic countries, where transmission is mostly confined to Africa, Asia, and Latin America.

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  • Symptoms/Diagnosis

Clinical Diagnosis:

The first symptoms of Malaria include fever, chills, sweats, headaches, muscle pains, nausea, vomiting, elevated temperature, perspiration, and fatigue. The problem with these symptoms are that they are nonspecific. Malaria caused by Plasmodium falciparum is severe and has more significant symptoms: confusion, coma, neurologic focal signs, severe anemia, and respiratory difficulties (CDC, 2009).

Microscopic Diagnosis:

A drop of the patient's blood is spread on a microscopic slide. The stain used in this analysis to identify parasites in the blood is usually Giemsa. This is the most common confirmation of Malaria diagnosis. RDTS, or Rapid Diagnostic Tests, "detect antigens derived from malaria parasites" (CDC, 2009). They provide results in two to fifteen minutes, however, they are not always accurate and are expensive. RDTs are a time saver, but follow up with microscopic diagnosis is required. On June 13, 2007, the FDA approved the first RDT for use in the U.S. by hospitals and clinical labs.

Malaria is curable if detected early. The main cause of malaria deaths in the United States is the delay of diagnosis and treatment. It is difficult to diagnose Malaria in the United States because health-care providers may not consider the disease as a potential diagnosis in a risk-free area. They need to obtain and consider the patient's travel history, or the proper blood tests will not be ordered. Likewise, lab workers may not notice the malaria parasite when examining blood smears unless they are looking for it (CDC, 2009). There are anti-malarial drugs, including Chloroquine (both a preventative and a treatment). Interestingly, people who live in malaria-endemic countries can develop gradual immunity to the disease. The parasites may be evident in a person due to infection, but they may not show evidence of the illness (CDC, 2009).

  • How Malaria is Transmitted

Malaria is a systemic infection caused by the protozoan parasite Plasmodium. There are four different forms of the Plasmodium parasite (Microbiologybytes, 2009):

  1. P. falciparum

  2. P. vivax

  3. P. ovale

  4. P. malariae

These affecting agents are transmitted through the biological transmission of the female anopheline mosquito, which is Malaria's arthropod vector (Tortora, 412). Although Malaria is mainly transmitted from the saliva of the female anopheline mosquito, Malaria can also be transmitted through direct contact of an infected persons' blood with the blood of an unaffected person (Tortora, 410). Another way of transmitting Malaria is through indirect contact by unsterilized syringes that was used on an affected person which is common among drug addicts (Tortora, 410).

  • Life Cycle of the Anopheline Mosquito

In the female anopheline, Plasmodium matures by sexual reproduction where it enters the salivary glands of the mosquito. When the mosquito bites its human victim it will pass the Plasmodium sporozoite, which is the infective stage of the Plasmodium parasite, to the human. There, the sporozoites travel to the liver of the human and undergo schizogony in the liver. Schizogony is where the cell participates in multiple fission and the nucleus partakes in multiple divisions before the cell divides. (Mikolajczak, 1501). Schizogony produces thousands of merozoites are released into the bloodstream and they have the ability to enter and infect red blood cells. At this point, the merozoites inside the red blood cells are known as trophozoites because they are in the metabolically active stage of their life cycle. Trophozoites produce and release more merozoites upon rupture of the red blood cell. (Mikolajczak, 1503). The merozoites continue to infect red blood cells, reproducing asexually within the human, but some develop into male or female gametocytes. These gametocytes cannot do any more damage to the human, but if both male and female gametocytes are picked up by an anopheline mosquito they will reproduce sexually in the intestines of the mosquito. Then the gametocytes will form a zygote, resulting in the production of sporozoites, which will travel to the salivary glands of the mosquito. The cycle will restart. The mosquito is the host to the Plasmodium parasite during the sexual reproductive stage. The mosquito is the definite host and the human is the intermediate host because is carries the parasite during asexual reproduction (Mikolajczak, 1499-1506).

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Andrade, B. "Towards a Precise Test for Malaria Diagnosis in the Brazilian Amazon: Comparison among Field Microscopy, a Rapid Diagnostic Test, Nested PCR, and a Computational Expert System Based on Artificial Neural Networks." Malaria Journal. 6 May 2010. Web. 18 May 2010. <http://www.malariajournal.com/content/9/1/117>.

"Computer Vision for Microscopy Diagnosis of Malaria." Malaria Journal, 13 July 2009. Web. 20 May 2010. <http://www.malariajournal.com/content/8/1/153>.

"Malaria." Centers for Disease Control and Prevention. 8 Feb. 2010. Web. 17 May 2010. <http://www.cdc.gov/malaria/>.

"Malaria." MicrobiologyBytes. Ed. Dr Alan Cann. 8 Apr. 2009. Web. 19 Apr 2010. <http://www.microbiologybytes.com/introduction/Malaria.html>.

Mikolajczak, Sebastian A., and Stefan H. I. Kappe. "A Clash to Conquer; the Malaria Parasite Liver Infection". Molecular Biology 62.6 (2006): 1499-1506. Biological Abstracts 1969-Present. EBSCO. Web. 20 May 2010.

Tortora, Gerard J., Berdell R. Funke, and Christine L. Case. Microbiology: an Introduction. San Francisco: Pearson Benjamin Cummings, 2007. Print