Parasitolgy

Question 1

Identify the three main groups of parasites that infect humans

Answer 1

1. protozoa
2. helminths
3. ectoparasites (live on surface of body)

Question 2

Understand the geographic distributions of parasitic infections and the determinants of that distribution

Answer 2

• leishmania common in Asian distribution
• Chugs disease common in Latin America (endemic)
• faecal/oral routes: sanitation, food regulation, access to clean water
• government hygiene regulations for food and housing
• personal sanitation habits
• life cycles of parasites / intermediate hosts/ complex vector transmission
• availability of effective treatments
• amastagotes (from asexual repro in host cells) => triptomastogotes

Question 3

Define parasite

Answer 3

organism that lives and survives on host organism at the expense/detriment of host

Question 4

Discuss protozoa

Answer 4

• can survive outside humans but become parasitic
• can reproduce in human hosts = infection development
• fecal / oral routes of infection/transmitted
• existing in blood/tissues could be transported by arthropod vector eg: mosquitos)

Question 5

State the classification of protozoa

Answer 5

• amoeba = travel slowly / pseudopodia pushes out allowing motility
• flagellates = uses flagellum for motility
• ciliates = outer cilia allowing travel through GI tract
• sporozoa = adult state not motile (eg: plasmodium => malaria)

Question 6

Describe some medically relevant parasitic infections

Answer 6

• entamoeba histolytica = invasion and death of mucosal tissue / invasion of intestinal tract amoebic dysentry
• guardia lamblia
• trichomonsas viaginalis (STI)
  -cryptosporidium = causes diarrhoea

Question 7

Describe helminths and their classification

Answer 7

infectious eggs hatch worms
- roundworm (nematodes)
- flukes (trematodes)
- tapeworms (cestodes)
visible under naked eye in adulthood