Microbes and World Health

Question 1

What is Endemic

Answer 1

Always present at a low frequency in a population (common cold)

Question 2

What is an epidemic?

Answer 2

Larger than normal frequency of infection, rapid and direct human-human transmission

Question 3

What is a pandemic

Answer 3

an epidemic that occurs over a wide geographic area

Question 4

What is prevalence

Answer 4

total number of active cases ( how many people in a population have it)

Question 5

What is incidence

Answer 5

number of new cases

Question 6

what is morbidity

Answer 6

having an illness

Question 7

what is mortality

Answer 7

death from an illness

Question 8

How to stop an epidemic in its tracts? (5 steps)

Answer 8

1) track diseases through systematic surveillance or syndromic surveillance
2) identify an outbreak of an emerging or known disease
3) track down patient zero. index case and identify close contacts
4) for emerging diseases, determine disease etiology (cause of disease, method of transmission and infection)
5) develop effective intervention and treatments

Question 9

Why are disease statistics important

Answer 9

-understanding an individual’s risk of contracting an illness based on population-level trends is key to targeting our prevention efforts

Question 9

What are the three strategies to prevent and treat HIV?

Answer 9

1) decrease viral loads through treatment of infected individuals -> lower rates of transmission
2) destigmatization + easily available HIV testing + sexual education -> lower rates of transmission
3) pre-exposure prophylaxis -> lower rates of transmission

Question 9

What are the three categories of drugs?

Answer 9

1) nucleoside analogs that inhibit reverse transcriptase-AZT are one example of this class. These analogs can be added to a growing chain but prevent the addition of the next base
2) nucleoside reverse transcriptase inhibitors. These compounds interact directly with the enzyme and alter the catalytic site
3) protease inhibitors. These bind to and block the activity of the HIV protease preventing the processing of the polyproteins (cannot produce viral coats cannot leave cell to infect another)

3)

Question 10

What is the most effective therapy for HIV?

Answer 10

cocktail of several different drugs: typically a protease inhibitor and two nucleoside analogs (block replication at multiple levels)

Question 11

What is PrEP

Answer 11

-medication that reduces the risk of contracting HIV
-Two approved daily oral medications, 1 approved weekly shot
-some side effects (headache, nausea, loss of appetite) are common; less common side effects include kidney and liver damage
-PrEP is not PEP (post-exposure prophylaxis) which is used after known exposure PrEP is used before known exposure

Question 12

Why are vaccines for HIV a difficult problem

Answer 12

-live attenuated virus could integrate in to host cell’s DNA and cause disease
-HIV has a high mutation rate and it is difficult to make a vaccine against all clades
-mRNA vaccine technology is limited by how much mRNA you can have in a single vaccine
-there have been 250 HIV vaccine trials

Question 13

What was the most successful HIV vaccine trial

Answer 13

HIV frontier phase III vaccine trials in South Africa

Question 14

What are neglected tropical diseases

Answer 14

share features that allow them to persist in conditions of poverty, where they cluster and frequently overlap

Question 15

What is the basics of Dengue (NEglected tropical diseases)

Answer 15

-the most common mosquito-borne viral disease of humans
-half of the world’s population lives in areas where dengue viruses can be transmitted
-transmitted by the Aedes aegytpi mosquito, there are four distinct, but closely related, viruses that cause dengue
-immunity to one serotype confers only partial and transient protection against subsequent infection by the other three

Question 16

What are the symptoms of dengue

Answer 16

-infants and young children have a rash
-older children and adults w/ out risk factors have a mild fever or the classical incapacitating disease with abrupt onset and high fever, severe headache, pain behind the eyes, muscle and joint pains, and rash

Question 17

What are the symptoms of Dengue haemorrhagic fever (dengue complications)

Answer 17

-potentially deadly complication with high fever and haemorrhagic phenomena
-severe cases have circulatory failure and death

Question 18

What is treatment for Dengue

Answer 18

-no specific treatment
-maintenance of the circulating fluid volume (lots of IV fluids)
for less severe cases, treatment focuses on pain and fever management

Question 19

What is the prevention of dengue

Answer 19

–until 2022 the only method of controlling or preventing dengue and DHF was to combat the vector mosquitoes
-vector control is implemented using environmental management and chemical methods
vaccine was approved in 2022: only approved for those with previous dengue infection in areas where dengue is endemic