Question

malaria parasites after entering the human body reaches the

Answer 1

IPMalaria is one of the most common infectious parasitic diseases in the world. About 500 million clinical cases of malaria arise each year, resulting in more than 1 million deaths; most deaths due to malaria are of infants and children.

These parasites are originated in Africa and have infected humans for over 50,000 years. In the fifth century B.C., Hippocrates first described certain aspects of an illness which is now known to be the characteristics of malaria. However, it was not until 1880, when the epidemiologic breakthrough came when Charles Lavern, a French army surgeon in Algeria, observed and described the exflagellated gamete of malaria parasites in the red blood cells of man. Ten years later, it was thought that malaria was transmitted by mosquitoes. Sir Ronald Ross supported this theory when he observed developing plasmodia in the intestine of mosquitoes. Malaria contributed many major problems not only in the past; it remains to be one of the world’s most concerned infectious diseases.

In recent days, malaria is most prevalent in tropical developing countries, mainly due to the local weather conditions which often allow transmission to occur year round and also an efficient mosquito vector that assures high transmission. About 60% of the cases of malaria and 80% of the malaria deaths occur in Africa south of the Sahara. In the United States, approximately 2000 malaria cases occur each year, majority of the cases occur among people who have traveled to areas with ongoing malaria transmission. Although malaria is not a serious problem in the United States, the threat is increasing as malaria parasites become resistant to drugs. In 2005, there was an outbreak of malaria in US Army rangers returning from Afghanistan; a total of 38 cases of malaria were identified among the 725 men in the army.

Malaria is caused by intraerytrocytic protozoa of the genus Plasmodium which is a one-celled parasite. More than 100 different species of plasmodium exist and they produce malaria in many types of animals. Of these, four species of Plasmodium infects human which include P. falciparum, P. vivax, P. ovale, or P. malariae; however, only malaria caused by Plasmodium falciparum is potentially life-threatening. The parasite is spread to people by the female Anopheles mosquito, which is fed on human blood. Human body is the reservoir of malaria; after a person gets malaria from the bite of an infected mosquito, the mosquito injects immature form of Plasmodium parasites into the host’s body; travel through the person’s bloodstream to the liver and grow into mature form; the mature form of parasites then enter the bloodstream again and attack the red blood cells, where they multiply quickly. The number of parasites increases until the red blood cells burst, releasing thousands of parasites into the person’s bloodstream. Then the parasites continue to attack other red blood cells, and symptoms start to develop as the cycle of infection continues. The disease can spread when a mosquito bite an infected person and carry the parasites and re-infect other people via biting. Malaria can also be transmitted through blood transfusions from infected people or needle sharing for intravenous drug. Malaria infection either causes the patient to die or the parasite is defeated by the immune system or medications. However, in most cases, the body’s immune system can control malaria. The symptoms of malaria are similar to those of the common flu such as headache, vomiting, nausea, fatigue, body pains etc; and these flu-like symptoms undergo three stages: chills, fever and sweating. The cyclic pattern of malaria symptoms is due to the life cycle of malaria parasites as they develop, reproduce, and are released from the red blood cells and liver cells in the human body.

Answer 2

Answer:

Liver and then RBCs

• are the correct option