Question

Plasmodium falciparum

a. in host: location sample type

b. transmission

c. vector

d. disease caused

e. symptoms

f. geographic distribution

g. diagnostic stage

Answer 1

Plasmodium falciparum is a unicellular protozoan parasite of that causes malaria.

a) Humans are the intermediate host in which asexual reproduction occurs. Female anopheles mosquitos are the definitive host in which sexual reproduction occurs. Within the human host, P. falciparum is found mostly within mature erythrocytes in nutritionally complex environment of the blood stream an metabolism of these blood stage parasite has diverged significantly from the eukaryotes such as yeast.

b) Transmission of P. falciparum occurs between human and the Female anopheles mosquito. Mosquito vectors pass malaria from host to host. The parasite can infect the mosquitoes through the intake of human blood or a human may be infected by the mosquito's injection of human saliva. Transfusion of blood from infected persons and use of contaminated needles and syringes are other potential modes of transmission. Transmission of P. falciparum malaria parasite requires formation and development of gametocytes, yet all but the most mature of these sexual parasite forms are absent from the blood circulation. It also be transmitted through - an organ transplant and a transfusion.

C) Malaria is caused by plasmodium parasites. The parasites are spread to people through the bites of the infected female anopheles mosquitoes called malaria vectors. only female mosquitoes are infected with plasmodium, since only they feed on the blood of vertebrate hosts. The malarial parasite, P. falciparum increases the frequency of multiple feeding of its mosquito vector, anopheles gambiae.

d) Malaria is a life threatening disease caused by P. falciparum and it is the most dangerous form. Those who contract this form of malaria have a high risk of death. An infected mother can also pass the disease to her baby at the birth. This known as congenital malaria.

e) The symptoms of malaria typically develop within 10 days to 4 weeks following the infection. In some cases symptoms may not develope for several months. *Common symptoms of malaria include:

Shaking chills that can range from moderate to severe, high fever, profuse sweating, headache, nausea, vomiting, abdominal pain, diarrhea, anemia, muscle pain, convulsions, coma and bloody stools.

f) P. falciparum is the predominant species in the word. It has wide global distribution, being found in South america, Asia and Africa, but is less frequent than P. falciparum in terms of association with cases of infection. Malaria can occur in the main urbal areas of Africa and, to a lesser extent India. There is usually less risk at altitudes above 1500 m, although in favourable climatic conditions the disease can occur at altitudes upto almost 3000 m.

P. falciparum - Geographic distribution occurs in tropical and subtropical areas of C. & S. America, Africa and S. E. Asia.

g) P. falciparum assumes several different forms during its life cycle. The human infective stage are sporozoites from the salivary gland of a mosquito. The sporozoites grow and multiply in the liver to become merozoites. In the mosquito gametocytes undergo sexual reproduction to a zygote, which turns into ookinete. Diagnosis of malaria can be difficult. Involves clinical diagnosis, microscopic diagnosis, antigen detection, molecular diagnosis, serology and drug resistance.

Malarial parasite can be identified by examining under the microscope a drop of the patients blood, spread out as a blood smear on microscope slide. Prior to examination the specimen is stained to give tge parasites a distinctive appearance.