Infetous Diseases

Question 1

Cholera pathogen

Answer 1

Vibrio cholerae

Which is a type of bacteria

Question 2

Malaria pathogen

Answer 2

Four species of plasmodium

Which is a type of protoctis

Question 3

Tuberculosis pathogen

Answer 3

Mycobacterium tuberculosis

Which is a type of bacteria

Question 4

HIV pathogen

Answer 4

The HIV virus

Question 5

Measles pathogen

Answer 5

A species of Morbillivirus

Which is a type of virus

Question 6

Smallpox virus

Answer 6

Variola virus

Question 7

Definition of disease

Answer 7

An illness or disorder of the body or mind that leads to poor health. Each disease is associated with a set of signs and symptoms

Question 8

How is cholera transmitted

Answer 8

The infected person passes out the bacteria in their faeces, the unifected person eats contaminated food or drinks contaminated water

Question 9

Differences between infectious and non infectious diseases

Answer 9

Infectious disease are caused by a pathogen. Non-infectious diseases include long term degenerative diseases such as lung cancer and genetic diseases such as sickle cell anaemia

Question 10

Preventing and controlling cholera

Answer 10

Not necessarily fatal. Important that fluid loss equals fluid intake. Would be prevented with clean water and sewage treatment. Countries in dept do not have the financial resources to do this. Using human sewage to irrigate vegetables is a common cause of the disease. Common after natural disaster when drainage has been broken.

Question 11

Why is the vaccine for cholera ineffective

Answer 11

There are multiple strains

Question 12

How is malaria transmitted

Answer 12

When a female anopheles mosquito bites an infected person then bites a non-infected person and transmits the parasite into the persons blood stream. Can also be transmitted during blood transfusion

Question 13

Where are most cases of malaria

Answer 13

Anopheles mosquitos live in the tropics. Countries may not have the money to eradicate mosquitos

Question 14

Immunity against malaria

Answer 14

People can gain immunity to malaria, meaning it’s very dangerous when it spreads to places where it is not endemic. Especially areas where it only occurs during the rainy season.

Question 15

Preventing malaria

Answer 15

Oil can be spread over water making it impossible for mosquito larvae to breath. Marshes can be drained. People covering their body at dusk when the mosquitos are most active. Sleeping under mosquito nets and wearing insect repellent

Question 16

Treating malaria

Answer 16

There are anti-malaria drugs but some plasmodium are now resistant.

Question 17

Worldwide control of malaria

Answer 17

In the 1950s the WHO tried to eradicate it but were unsuccessful because the plasmodium became resistant to the drugs. The program was unpopular as people lost immunity.

Question 18

Worldwide concern over malaria

Answer 18

An increase in drug resistant forms of plasmodium. An increase in the number of cases caused by p.falciparum which causes the most severe type. Difficult to develop vaccines. Increase in cases due to climate change

Question 19

How is HIV transmitted

Answer 19

During sexual intercours, from mother to baby through the placenta, through breast milk, due to the sharing of needles and blood transfusions

Question 20

Factors in preventing HIV

Answer 20

Slow to show symptoms so hard to know you have it. More likely to get it if you are promiscuous or use intravenous drugs. There is no cure. Countries are reluctant to have widespread testing as it infringes on personal freedom. In Africa it is not restricted to easily identified groups such as prostitutes so it is harder to test

Question 21

How to prevent HIV

Answer 21

Education. Using condoms. Needle exchange programs where old needles are exchanged for new ones. Contact tracing where you tell the people who the person has had sex with that they should get tested. Blood collected from donors is tested and heat treated to kill viruses.

Question 22

Transmitting TB

Answer 22

When an infected person breaths out droplets containing the parasite and an unifected person breaths it in. So is prevalent in over crowded and poor areas. More likely to get it if your immunity is low due to malnutrition or HIV. Can occur in in unpasteurised milk or in beef

Question 23

Factors in treating TB

Answer 23

Some strains of TB are resistant to antibiotics. As it is a long course of drugs, some people stop taking he drugs when they feel better but before the course ends. The bacteria will then spread throughout the body increasing the likelihood of a mutation arising. The WHO promotes a scheme where DOTS involves health workers ensuring the patients have taken their medication.

Question 24

Preventing TB

Answer 24

Contact tracing. There is a vaccine but its effectiveness decreases with age. Cattle are checked for TB and milk is pasteurised.

Question 25

Transmission of measles

Answer 25

When an infected person breaths out droplets with the pathogen in which an uninfected person breaths in.

Question 26

Facts about measles

Answer 26

Spreads in overcrowded conditions where it is unsanitary and there is a high birth rate. Is very contagious. Infects mainly malnourished infants suffering from vitamin A deficiency.

Question 27

What is an antibiotic?

Answer 27

A drug that kills or stops the growth of bacteria without harming the cells of the infected person.

Question 28

How does penicillin work?

Answer 28

When a bacterial cell is growing it secretes the enzyme autolysins, which makes little holes in the cell wall. These holes allow the wall to stretch so the peptidoglycan chains can link them together. However, penicillin stops theses chains from linking up, but the autolysins keeps on making more holes. Water enters by osmosis and the cell eventually bursts.

Question 29

Why do antibiotics not affect viruses or human cells?

Answer 29

Viruses and human cells do not have a cell walls, viruses also do not have a cytoplasm

Question 30

How does antibiotic resistance arise?

Answer 30

When a gene within the bacterial genome changes to give rise to a nucleotide sequence which is not affected by antibiotics. When someone does not fulfill their cause of penicillin some of the bacteria survive and a mutation may occur giving resistance. The more we misuse antibiotics the greater selection pressure we place.

Question 31

How can resistance be transmitted

Answer 31

It can be done vertically, when a resistant bacteria reproduces asexually to produce 2 daughter cells with a copy of the plasmid coding for resistance. Horizontal transmission can occur during conjugation, when a tube forms between the 2 bacteria allowing for the movement of DNA.

Question 32

Consequences of antibiotic resistance

Answer 32

Can increase the risk of death, are associated with longer stays in hospital and complications. Can spread to different species of bacteria and some species may become resistant to multiple types of antibiotics.

Question 33

Steps which can be taken to reduce the impact of antibiotic resistance

Answer 33

Only prescribing antibiotics when appropriate so not for a viral infection. Reducing the number of countries where antibiotics are available without a prescription. Using antibiotics which are specific to that infection. Making sure the patient completes their curse of treatment. Avoiding using it in farming to prevent rather then cure.

Question 34

Why is cholera common after a natural disaster

Answer 34

Damage to sewers, so mixing of drinking water and sewage. Contaminated water supplies cannot be treated. Peoples immune system is weakened due to malnutrition

Question 35

What is an auto-immune disease

Answer 35

The failure to distinguish self and non-self (antigens)