Infectious diseases Flashcards
What is an infectious disease?
A disease caused by a pathogen, is transmissible, and reduces the effectiveness of the organism’s functions
What is the difference between incidence and prevalence?
Incidence is the number of new cases over a certain period, while prevalence is the total number of people with the disease at any given time.
Name the vector for malaria.
Female Anopheles mosquito.
How is cholera transmitted?
Through the faecal-oral route, often via contaminated water or food.
Why is it difficult to create a vaccine for malaria?
Plasmodium is a eukaryote, its antigens differ in different life stages, and it is an intracellular parasite with antigenic concealment.
What causes AIDS and how does it affect the body?
AIDS is caused by HIV, which destroys T-helper cells, weakening the immune system and allowing opportunistic infections.
How does penicillin kill bacteria?
Penicillin prevents the synthesis of cross-links in bacterial cell walls, leading to wall weakness and eventual bursting.
What are antibiotics and how do they work?
Antibiotics kill or stop the growth of bacteria without harming the host. They may interfere with cell walls, proteins, enzymes, DNA, or protein synthesis.
Why don’t antibiotics work against viruses?
Viruses lack the cellular structures that antibiotics target, such as cell walls or organelles.
What are some steps to reduce antibiotic resistance?
- complete the full course of antibiotics
- avoid using them for viral infections
- rotate antibiotics
- don’t sell without a prescription.
Why is malaria difficult to control?
There is no vaccine, Plasmodium has different life stages with varying antigens, and there is drug and insecticide resistance.
What is a pandemic?
A pandemic is a worldwide increase in the number of cases of a particular disease.
How is tuberculosis (TB) transmitted?
TB is transmitted through aerosol droplets from an infected person or by consuming contaminated meat or milk.
How is malaria controlled?
- draining stagnant water
- spraying insecticide
- using bed nets
- screening blood before transfusions.
How is HIV transmitted?
- through sexual contact
- infected blood
- sharing needles
- from mother to child during birth or breastfeeding.
What is reverse transcriptase?
An enzyme used by retroviruses like HIV to convert viral RNA into DNA in the host cell.
How does HIV affect the immune system?
HIV destroys T-helper cells, weakening the immune response and leading to opportunistic infections.
What is antibiotic resistance, and how does it occur?
Resistance occurs when bacteria mutate, survive antibiotic treatments, and pass on the resistant genes to offspring.
What is the consequence of antibiotic resistance?
- Increased human illness
- higher treatment costs
- longer treatments
- fewer effective antibiotics.
