1. Infestation, hyperinfestation and diseases Dr
Infestation, hyperinfestation and diseases Dr. Md Fazlul Haque Assistant Professor Dept. of Zoology Rajshahi University

2. Infestation
Infestation refers to the invasion by larger and complex parasites than microbes
The term infestation is also used to describe invasion of living places by pests

3. Infestation
In infestation parasites usually live and reproduce on external surface of host body.

4. Infestation
Infestation can happen both in living organisms and non- living objects.

5. Infection
Infection refers to the invasion by microorganisms like viruses, protozoa and bacteria.

6. Infection
In infection parasites usually enter the internal body tissues and then multiply disrupting the normal functionality of the cell.
Tuberculosis

7. Infection
Infection can happen only in living organisms.

8. Hyperinfestation
Hyperinfestation refers to invasion by thousands or millions of larger and complex parasites resulting in severe form of diseases. eg. Crusted scabies.
Sarcoptes scabiei

9. Hyperinfestation
Crusted scabies is a more severe form of scabies with a hyperinfestation of lots of scabies mites.
Sarcoptes scabiei

10. Hyperinfestation
It can be very extensive and can, if severe, lead to serious secondary bacterial skin infections.
Crusted scabies mainly occurs in people who have a poor immune system (immunocompromised).
Sarcoptes scabiei

11. Disease Measles a disorder of structure or function in an organism,
especially one that produces specific signs or symptoms or
that affects a specific location and
is not simply a direct result of physical injury.
Measles

12. Parasitic disease Measles Scurvy Chickenpox
A parasitic disease is a disease caused or transmitted by a parasite.
The parasitic disease usually are designate by generic names of the parasites ending with -iasis or –osis.
e.g., Schistosoma infection is called as schistosomiasis
Measles
Scurvy
Chickenpox

13. Pathogenesis
Pathogenesis is the manner of development of a disease, or
the biological mechanisms that lead to the diseased state.
Pathogenesis of the parasitic diseases is a dynamic process and depends on the complex interaction of a variety of host and parasitic factors.
Pathogenesis of TB

14. Host factors
Nutritional status of the host, whether malnutrition or under nutrition.

15. Host factors
Immune response to a specific parasitic infection. eg. Antibody mediated enhancement for dengue

16. Host factors AIDS patient
Immune status of the host whether there is immuno- suppression or not.
AIDS patient

17. Host factors Pregnancy
The presence or absence of the co-existing disease or other physiological conditions such as pregnancy.
Pregnancy

18. Host factors
The age at the time of infection.

19. Parasitic factors The parasitic factors include:
Site of the attachment of the parasite and the size of the parasite.
Number of invading parasites (infection size)
Parasite strain (pathogenic or non-pathogenic)
Growth, development and multiplication ability of parasites inside the host body
Type of their metabolic products for affecting host body.

20. How parasites can cause disease
Trauma by parasite
Invasion and destruction of host cell by parasite

21. How parasites can cause disease
Inflammatory reaction to parasites or their product

22. How parasites can cause disease
Toxin production by parasites, eg toxin produced by bacterium Clostridium tetani

23. How parasites can cause disease
Allergic manifestation