Introduction Flashcards
What do parasites cause?
Chronic infections
What is a parasitism?
A type of symbiosis in which one species benefits and the other is harmed
What pathogens cause acute infections?
Viruses
Bacteria
Fungi
What are 3 types if symbiotic relationships?
Commensal
Mutualism
Parasitic
What are the stages of infectious disease?
Incubation period
Prodomal period
Illness
Convalescence
What is the incubation period?
Time between infection and occurrence of first symptoms
What happens in the prodomal period
Mild symptoms
What happens in the illness stage?
Most severe stage when symptoms are most evident
What happens in the stage of convalescence?
Body gradually returns to its bitmap state
What does clinical picture depend upon?
Infecting dose Age of host Gender of host Host genetics Host nutritional status Co infection with other pathogens
How can pathogens enter our body?
Oral transmission Intra uterine Skin contact Inhalation Direct inoculation Injections Insect bites Sexual transmission
Can protists multiply within the body?
Yes
What is disease severity dependant on in protists?
How quickly they multiply
What is disease severity dependant upon in helminths?
Number of infectious stages acquired by host over time
Can helminths multiply within the body?
No
What are the factors of pathogenesis?
Number of pathogenic organisms present
Virulence if the organism
The host and degree of resistance
What is pathogenesis?
Production and development of disease
What does incidence measure?
Number of new cases of infection occurring in a population in w defined period of time
What does prevalence measure?
Total number of infected individuals in a population
In developing countries what are main causes of death?
Infectious disease eg. HIV and respiratory infections
What does DALY (disability adjusted life year) measure?
Indication of overall burden of disease
What is morbidity?
Ill heath associated with disease
How is DALY calculated?
YLL+YLD
Years of life lost+Years of life lost to living with a disability
What are limitations of DALY?
Only measures direct health loss
Don’t consider economic impacts
Don’t account for direct cost of treatments
Doesn’t consider social stigma
