Parasitology 1

Question 1

What is Symbiosis?

Answer 1

Symbiosis refers to a long-term relationship between two or more organisms living closely together.

Question 2

What are the different types of parasitic relationships?

Answer 2

• Ectoparasites: Live on the surface of the host.
• Endoparasites: Live within the host’s body.
• Permanent (obligate) parasites: Cannot live without the host.
• Facultative parasites: Can survive without the host if alternative food sources are available.
• Pathogenic parasites: Cause disease in the host.
• Non-Pathogenic parasites: Usually harmless, obtaining food and protection without causing harm.
• Opportunistic parasites: Cause mild disease in healthy individuals but severe disease in immuno-deficient hosts.

Question 3

How are hosts classified in parasitology?

Answer 3

• Definitive host: The host for the adult stage of a parasite.
• Intermediate host: The host for the sexually immature or larval stage of a parasite.
• Animal reservoir host: Acts as sources of infection to the definitive host.
• Accidental (Incidental) host: Not the target host, and life cycles cannot be completed.
• Paratenic host: Harbors the parasite until it reaches the definitive host without any development.

Question 4

What is the difference between an epidemic and a pandemic?

Answer 4

An epidemic refers to the rapid spread of a disease within a specific region, while a pandemic is the worldwide spread of a disease, usually a new one.

Question 5

Name the four species of Plasmodium that cause malaria in humans.

Answer 5

Plasmodium falciparum
Plasmodium vivax
Plasmodium malariae
Plasmodium ovale

Question 6

What are the general symptoms of malaria?

Answer 6

Symptoms include malaise, headache, fever, chills, sweats, myalgia, abdominal pain, vomiting, mild watery diarrhea, anemia, mild jaundice, splenomegaly, pulmonary symptoms (in children), and convulsions (in children).

Question 7

What is severe falciparum malaria, and why is it dangerous?

Answer 7

Severe falciparum malaria has a high risk of mortality and manifests with syndromes like severe anemia, severe respiratory distress, and coma. It is the most dangerous form of malaria due to its complications and high mortality rate.

Question 8

What are Rapid Diagnostic Tests (RDT) used for in malaria diagnosis?

Answer 8

RDTs detect specific antigens produced by malaria parasites, offering quick results (15-30 minutes) and are especially useful in remote areas with limited access to microscopy.

Question 9

What is the role of mosquito bed nets in malaria prevention?

Answer 9

Mosquito bed nets help prevent mosquito bites, reducing the risk of malaria in endemic areas.

Question 10

What are some of the challenges in the treatment and prevention of malaria?

Answer 10

Challenges include drug side effects, drug failure, resistance, and the limited efficacy of the current malaria vaccine (about 50%).

Question 11

How are parasites and hosts classified?

Answer 11

Parasites are classified based on their relationship with the host, while hosts are classified based on the parasite’s stage of development within them (definitive, intermediate, etc.).

Question 12

How are the species of malaria distributed geographically?

Answer 12

• Plasmodium falciparum: Commonest in Africa, causing most malarial deaths.
• Plasmodium vivax: Widespread in tropical regions, especially Asia.
• Plasmodium malariae: Can persist in blood for long periods without symptoms.
• Plasmodium ovale: Rare, generally found in West Africa.

Question 13

What are the advantages and disadvantages of diagnostic techniques in Plasmodium detection?

Answer 13

• Microscopy: Accurate and detailed but requires expertise and proper equipment.
• Rapid Diagnostic Tests (RDTs): Quick and easy, useful in remote areas, but may not always distinguish between species.