What is the causative agent of HIV/AIDS?
HIV (human immunodeficiency virus)
List three methods of reducing malaria transmission
reduce number of mosquitos, reduce chances of being biten, use drugs to prevent Plasmodium infecting humans
What is the incubation period of HIV?
a few weeks
Why was the WHO unable to eradicate malaria in the past?
Plasmodium became resistant to drugs
Describe a technique to eliminate mosquitoes
spraying living areas insecticides, draining bodies of water, spreading oil over bodies of water
What is a social factor that contributes to the spread of TB?
poor housing conditions
An example of a non-infectious disease is
cardiovascular disease
What are the methods of transmission of Vibrio cholerae?
food-borne, water borne
Name the primary site of action of TB pathogen
the lungs
How does penicillin work?
prevents bacteria from making normal cell walls resulting in osmotic lysis
Why was the eradication program against malaria unsuccessful?
Plasmodium developed resistance to drugs, Anopheles mosquitos became resistant to DDT and other insecticides
Outline process of malaria transmission after a human is biten by an infected mosquito
infective stages of parasite enter bloodstream and travel to liver cells--> leave liver cells and enter RBCs parasite's gametes mature and reproduce
How can cholera be prevented?
sewage treatment and chlorination of drinking water
Why is it difficult to prevent the spread of cholera?
infrastructure in developing countries insufficient, humanitarian crises, raw sewage used to irrigate crops
How is cholera treated?
oral rehydration therapy
Infectious diseases are diseases caused by organisms known as
pathogens
How is TB prevented?
contact tracing and treatment, vaccination with the BCG vaccine
Give one reason why the body's immune system finds it difficult to recognise HIV
it changes its surface proteins
Name the insect vector of malaria
female Anopheles mosquito (uses the protein in blood to develop eggs)
What are the main symptoms of cholera?
severe diarrhoea, dehydration
What is the site of action of HIV?
T helper lymphocytes
Mycobacterium bovis is the form of TB transmitted to humans by contact with
cattle
What are antibiotics?
substances produced by microorganisms that destroy other microorganisms or inhibit their growth
smallpox is the first and only virus to be
eradicated
Name three examples of how HIV can be transmitted
unprotected sexual intercourse, blood donation (untested), sharing of needles (IV drug users) , mother to child (birth, across the placenta, breast feeding)
Stocking ponds with fish that feed on mosquito larvae is an example of what type of control measure?
biological
Why don't antibiotics affect viruses
viruses dont have the same sites of action as bacteria (protein coat v. cell wall, simple with few organelles, use metabolism of host, live inside host cells)
What does MDR-TB stand for?
multiple-drug-resistant forms of TB
Malaria is caused by four species of Plasmodium. What type of organism is plasmodium?
protoctisst
How is HIV diagnosed?
Testing blood for antibodies produced against HIV
Streptomycin, an antibiotic, is now less effective at treating TB worldwide. Why?
There is an increase in the number of people with drug resistant infections
What causes drug-resistance in bacteria?
mutation of bacterial DNA
People who spread a pathogen even though they do not have the disease
carrier
Name the four species of Plasmodium that can transmit malaria
falciparum, malariae, ovale, vivax
Name the enzyme secreted by young bacterial cells as they grow to allow them to stretch
autolysins
How can cholera be controlled?
WHO monitoring, access to ORT, use of antibiotics in severe causes
What causes antibiotic resistance?
mutations in bacteria (by chance) ex. production of penicillinase)
How can ABR be prevented? (name three)
limit use of antibiotics to essential conditions, educate patients to take the full course, limit use in livestock, hold back anitbiotics of last resort
How long could it take an untreated person to develop AIDS from HIV?
10 years
How can transmission of TB to humans from cattle be prevented?
Pasteurise all milk, routine testing of cattle for TB and destroying any who are positive, ensuring meat is properly cooked
Name a site of action of Plasmodium
red blood cells
How can the spread of HIV be stopped?
public health measures
How can malaria be prevented?
reduce the number of mosquitoes
What happens to people continually re-infected by different strains of malaria
They become immune
Outline the process of malaria transmission which occurs within the mosquito
mosquito takes blood meal, male and female gametes of parasite fuse in mosquito and produce 1000's of parasites-->enter salivary glands and spread by bite
What is the name for a type of medication that we take to prevent getting infected with a disease?
prophylaxic
How is HIV transmitted?
direct exchange of bodily fluids
Name a social factor that contributes to the spreading of malaria
migration of people due to war
How can HIV be controlled?
contact tracing, screening blood donations, needle-exchange programs, public health measures such as testing at-risk populations and education, anti-retro drugs
Name the pathogen that causes tuberculosis
Mycobacterium tuberculosis
What is the causative agent (pathogen) responsible for cholera
Vibrio cholerae
Name the inflexible material that makes up the bacterial cell wall of bacteria cells
peptidogylcan (murein)
Where is malaria found?
tropics and subtropics (endemic in 106 countries!)
Besides the mosquito vector, how can malaria be transmitted person to person?
blood transfusion, sharing unsterile needles, across the placenta mother to child
How is resistance passed from one generation to another?
vertically gene transmission (all offspring have advantaeous trait) or horizontal gene transmission (transfer of plasmids through conjugation- pass species)
Name the causative agents (2) of tuberculosis
Mycobacterium tuberculosis, Mycobacterium bovis
Why is preventing the spread of HIV difficult?
long latent stage and where infected people have no symptoms
How is TB transmitted?
air borne droplets, undercooked meat and unpasterised milk