Infectous Diseases Flashcards

1
Q

Define ‘pathogenic’

A

If a microorganism is pathogenic it is a disease-causing Microbes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Explain these microbial relationships and give an example of each.

Commensal:

Mutualistic:

Parasitic:

Opportunistic:

A

Commensal:
A symbiotic relationship b/w organisms whereby one benefits and the other is unaffected .

eg; Microbes on your skin.

Mutualistic:
A symbiotic relationship b/w organisms, whereby both benefit

eg; E. coli make vitamin K for humans.

Parasitic:
A symbiotic relationship b/w organisms whereby one benefits at the other’s expense

eg; Head lice

Opportunistic:
A symbiotic relationship
b/w organisms which is initially commensal /
mutualistic then becomes parasitic.

eg; Candida

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Describe the difference between ‘Pasteur’ and ‘Bechamp’ theories.

A

Pasteur’s germ theory of disease was that all germs are bad and cause disease. Therefore we should be kiiling them off. Hence pasturisation

Bechamp’s theory is that germs are opportunistic in nature and live with us symbiotically. To promote health we should not be killing them but instead improving our terrain (diet, exercise) so that germs do not have the opportunity to harm us.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

List TWO differences between ‘gram-negative’ and ‘gram-positive’ bacteria.

A

Bacteria have two types of cell wall

gram positive
* Thick mesh like cell wall
* stains purple with Grams method
* Wall made of peptidoglycan

gram negative.
* Thinner cell wall layer
* stains pink with Grams method
* Wall has an additional outer lipid-rich membrane

Exotoxins are gram-positive and negative

Endotoxins are gram-negative only

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

‘Bacteria are prokaryotic cells with a simple structure, nucleus and membrane bound organelles’

True or False - discuss

A

True - Bacteria are Prokaryotic cells

False - The DNA is not in the nucleus. The control centre of bacteria is a single loop of DNA.

Bacteria are simple structures to allow for very fast division.

Bacteria reproduce through binary fission which is a rapid form of cell division that allows bacteria to reproduce in high numbers at a rapid rate.

For example, e. Coli can divide in as little as 20 minutes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe TWO key differences between ‘exotoxins’ and ‘endotoxins’.

A

EXOTOXINS
* Gram-positive and negative bacteria
* Released by a living microbe
* Very toxic, protein toxins
* Have a variety of effects on bodily functions
* Eg: Diptheria, e.coli

ENDOTOXINS
* Gram-negative bacteria only
* Released from cell wall after organism death
* Usually less toxic
* Stimulate inflammatory cascade and and often cause fever / malaise
* Eg: Salmonella

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Name ONE method by which bacteria reproduce.

A

Asexual Binary fission

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

With regards to resident and transient microflora, list:

a. TWO body locations where microflora is present

b. TWO body locations where microflora is absent

A

a. TWO body locations where microflora is present
1. Small and large intestine
2. Mouth
3. Vagina and perineum
4. Nasal Cavity
5. Skin

b. TWO body locations where microflora is absent
There are parts of the body that should be sterile and therefore bacteria in these locations is potentially dangerous.

  1. Blood
  2. Lungs
  3. Bladder and Kidneys
  4. Ovaries; fallopian tubes; uterus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Describe how microflora organisms can become pathogenic.

A

Organisms within the microflora can become pathogenic if the local
environment changes or if the immune system becomes compromised
(opportunistic).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Explain how broad-spectrum antibiotics affect microflora in the body.

A

Broad spectrum antibiotics possess no specificity for the bacteria they kill and instead can have devastating effects on the body’s microflora because they are indiscriminate and wide ranging.

Often used because there is not enough time or money to test further and refine choice of microorganism to target.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

List TWO adverse effects of broad-spectrum antibiotics.

A

Broad spectrum antibiotics possess no specificity for the bacteria they kill and lead to
* Microflora damage
* Antibiotic resistance
* Impaired immunity
* Candida overgrowth (yeast) due to loss of friendly flora
* Diarrhoea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Describe the structure of a virus.

A
  • A virus is not a cell but rather consists of either a strand of RNA or DNA which is enclosed in a hard protein shell called a capsid.
  • Each capsid is unique for each virus.
  • Viruses are the smallest microbes and are too small to be seen with light microscopy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Name TWO DNA viral pathologies.

A
  1. Varicella Zoster - chicken pox and shingles
  2. Herpes
  3. Smallpox
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Describe how viruses reproduce.

A
  • Viruses are unique because they are only able to multiply inside the cells of other living things.
  • They reproduce by injecting their RNA or DNA strand into a living host cell and use the host cell’s apparatus for reproduction.
  • They are specific about which cells they infect
  • When the virus binds with a cell it only allows entry of the genetic material. The capsid remains outside.
  • A virus will generally burst a host cell as it leaves it
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Describe FOUR ways in which viruses make it difficult for the body to identify and destroy.

A
  1. They hide inside the host cells (can be latent).
  2. They do not have a metabolism of their own — hence anti-microbial agents cannot be targeted towards enzymes.
  3. They do not have many structures of their own.
  4. Able to mutate — this allows them to change their surface antigens and avoid host immune response.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Explain the following terms:

a. Viral lysis
b. Viral budding
c. Latent stage

A

a. Viral lysis
Virus particles burst out of the host cell into the extracellular space, resulting in the death of the host cell.

b. Viral budding
Process by which a virus exits a cell and acquires an envelope (outer membrane) of its own from the host cell membrane and usually leads to cell death. Used in viruses which need an envelope; e.g. HIV.

c. Latent stage
Stage of infection where the disease is present but hidden and inactive. Viruses can remain in a latent stage for years; e.g. herpes simplex.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Fungal growth usually results from 3 forms of fungi.

What are they and how do they promote growth?

A

a. Yeasts
*Single celled fungus thateproduce through budding
* eg: Candida Albicans

b. Dermatophytes
* Fungi causing skin disease.
* They obtain nutrients from keratin in skin (no living tissue is invaded) and colonise in the stratum corneum.
* It’s the only fungus dependent on humans
* e.g. ringworm or tinea.

c. Moulds:
* Multi-cellular fungi.
* Reproduce by means of tiny spores
* Some moulds cause disease, others are involved in production of various foods and antibiotics;
* e.g. aspergillus and penicillium.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

List FOUR factors that promote growth of fungi in the body.

A

Warmth
Acidity
Rich Nutrition
Moisture

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

List TWO ways in which fungi reproduce.

A

Asexual reproduction
Occurs via budding (extension of the Hyphae) containing chromatin that eventually detach and develop into an independent organism.

Sexual reproduction
This is less common and occurs by fungal spores

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

-

Name ONE example of a protozoa.

A

Helminths – Parasitic Worms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Define the following terms:

a. Epidemic
b. Pandemic
c. Endemic

A

a. Epidemic – Infections in large groups

b. Pandemic – Worldwide infections

c. Endemic – Infections restricted to an area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Define the following infection sources:

Reservoir
Carrier
Vector
Host

A

Reservoir
Location where the pathogen exists, reproduces and spreads to new hosts

Carrier
Infected individuals who are asymptomatic
Eg: A human with HIV, who can transmit the virus to another healthy individual

Vector
Intermediate carrier, transporting pathogens from reservoir to host.
eg: Mosquitos carry malaria

The main difference between vector and carrier is that a vector does not show any symptoms of the disease whereas a carrier is an infected organism capable of transmitting the disease-causing microorganisms to a healthy individual.

Host
An infected person or animal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Explain what is meant by ‘nosocomial’.

A

Infection acquired from a medical setting (hospital or care facility);
e.g. surgical site, UTIs, pneumonia, ulcers.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Describe in detail the FOUR stages of infection.

A
  1. Incubation period: the time between the initial exposure to the infecting Organism and the appearance of the first signs of symptoms it produces
  2. Prodomal period: This is the interval from the non specific symptoms such as malaise and fever fatigue to more specific acute symptoms related to that particular infecting agent.
  3. Acute period: this is when the quantity of pathogen peaks and this associated with very pronounced symptoms specific to the disease
  4. Chronic Infection: infection with insidious or slow onset of long duration.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

List FOUR ways in which a host can provide resistance against microbes.

A

First Line: Inate
* Active skin and mucous membranes
* Body secretions - stomach acid, tears etc

Second Line: Inate
* Phagocytosis
* Interferon production
* Effective inflammatory response

Third Line - Adaptive
* Effective inflammatory response
* Effective immune system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

List FOUR ways in which a microbe displays ‘virulence’ against a host.

A
  • Production of invasive and destructive enzymes
  • Production of endo or exo toxins
  • Spore formation
  • Entry of a large number of organisms but formed colonies
  • Presence of bacterial capsule and Pillai
  • Ability to mutate Eg; MRSA, HIV
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

State THREE methods to reduce the spread of infection.

A
  1. Reduce the reservoir.
  2. Stop droplet transmission — covering the mouth (not with the hand).
  3. Block the method of transmission - hand washing, gloves, condoms
  4. Kill the organism.
  5. Sterilisation.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Explain how the following ‘infection control’ processes work:

a. Sterilisation

b. Pasteurisation

A

a. Sterilisation

All microorganisms and their spores are destroyed. There are two methods:

Hot air - 30 minutes of 180°C
Steaming - 20 minutes at 120°C

b. Pasteurisation

71.7°C for 15 to 25 seconds. It will kill most pathogenic microbes but not their spores

Note: Disinfectants and antiseptics will destroy/ reduce the number of organisms but not their spores

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

With regards to natural anti-microbials, name TWO examples for each of the following:

a. Anti-bacterial

b. Anti-fungal

c. Anti-viral

d. Anti-parasitic

A

a. Anti-bacterial
* Oregano.
* Grapefruit seed extract.
* Colloidal silver.

b. Anti-fungal
* Oregano
* Garlic
* Cinnamon.
* Berberine.

c. Anti-viral
* Elderberry
* Olive leaf.
* St John’s Wort
* Lemon balm (Herpes simplex).

d. Anti-parasitic
* Garlic.
* Berberine.
* Goldenseal.
* Oregano.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Explain briefly how ‘sepsis’ develops in the body.

A

It occurs when the pathogen has infected the blood. It arises when the body’s response to the infection causes injury to the body’s own organs, potentially leading to multi-organ failure.

Symptoms include lethargy, nausea, vomiting, abdominal pain, diarrhoea, coughing, etc.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

List TWO groups of individuals at higher risk of developing sepsis.

A
  • Elderly populations [over 75]
  • The very young
  • Alcoholics
  • Diabetics
  • Chemotherapy patients
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Using definitions, describe the difference between ‘cellulitis’ and ‘erysipelas’.

A

Both are bacterial skin infections

Cellulitis is a bacterial skin infection creating inflammation of dermal and subcutaneous layers.

Erysipelas is a more superficial bacterial skin infection of the dermis and upper subcutaneous layer, producing a well-defined edge.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

List ONE bacterial cause of cellulitis.

A

Staphylococcus Aureus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Name TWO characteristic signs / symptoms of cellulitis.

A

Very red inflamed skin
Fever
Malaise

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Miss X displays the following signs and symptoms. Which pathology do you suspect?

‘Pustules with round oozing patches and golden yellow crusts that grow larger daily. Mostly affects hands and face or in skin folds’.

A

Impetigo

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Explain why an immune-compromised patient is at increased risk of oral candidiasis.

A

It is a superficial fungal yeast infection of the mucous tissue.

It often presents after broad spectrum antibiotics or in immune compromised patients because the skin and mucous membranes are not able to provide as good a physical barrier with support of the CD4 cells.

CD4 cells are T-Helper cells and T-Regulatory Cells (I think)

37
Q

Name the organism that cause cold sores

A

Herpes simplex virus type 1

38
Q

List TWO causes / triggers of genital candidiasis.

A

Although you would expect it to be so, it is not sex related.

As with oral candidia it relates to immune comprise that reduces the effectiveness of physical barriers, namely mucous tissue.

Triggers include
antibiotic treatment;
Diabetes mellitus;
Pregnancy;
Immune system disorders

39
Q

Describe TWO characteristic signs/symptoms of genital candidiasis.

A

Vagina/genital itch, discomfort or irritation

Thick, clumpy discharge (cottage cheese effect)

40
Q

Describe the rash associated with Lyme disease.

A

It looks a bit like something you would use for target practise - a circle within a circle within a circle.

A circular pink or red rash at the site of the tick attachment that radiates from the bite, usually over 5 centimetres in diameter

41
Q

Name the bacterial cause of ‘diphtheria’.

A

Corynebacterium diphtheriae (gram-positive) transmitted by droplet.

42
Q

Describe the appearance of the tonsils in diphtheria.

A

A grey membrane grows across the tonsils/ pharynx or nose.

43
Q

Explain how complications develop in diphtheria.

A

Exotoxins from the bacteria cause endothelial necrosis by inhibiting protein synthesis.

This can cause myocarditis and paralyse the diaphragm.

Ultimately the grey membrane that is produced from necrotic cells can block the Airways

44
Q

Briefly describe the pathophysiology of scarlet fever (HINT — think bacteria).

A

Scarlet fever is an infectious disease resulting from exotoxins released by streptococci pyogenes bacteria.

Streptococci pyogenes secrete haemolytic enzymes and exotoxins. It is the damage to capillaries this causes which leads to the red rash.

45
Q

Describe briefly the difference between a rash associated with ‘scarlet fever’ and ‘meningitis’.

A

Meningitis is non blanching meaning it is still there when you put pressure on it.
In scarlet fever the rash blanches under pressure

46
Q

Describe the appearance of the tongue in scarlet fever.

A

The first two days you have a white tongue with red papillae (look like little red dots).

After this it looks more raw and red

47
Q

Name ONE cranial nerve where the herpes simplex virus (Type I) remains dormant.

A

Trigeminal Nerve

48
Q

Describe the appearance of lesions associated with cold sores.

A

Painful fluid lesions around the mouth that scab and then heal.

Prior to the lesions it often begins as a tingling on the lip as the virus travels down the nerve

49
Q

Using definitions, compare ‘chickenpox’ and ‘shingles’.

A

Both are infectious viral diseases caused by the varicella zoster virus.

Chicken pox is a highly infectious viral disease caused by the varicella zoster virus.
- Vesicular eruptions on the skin appear over three to five days mostly on the head, neck, and trunk.
- It is very itchy.

Shingles are also an infection by the varicella zoster virus but it is following a chickenpox infection.
- For one to two days before the rash emerges you will see burning/ itching/ tingling.
- Then eruptive phase, producing skin lesions similar to chicken pox and,
- causing severe dermatomal pain, altered sensation and vesicular rash in the affected dermatome

50
Q

Describe the distribution of lesions / rash in ‘chickenpox’ and ‘shingles’.

A

Chicken pox: mostly on the head, neck and trunk

Shingles: in the location that the infected nerve relates to on the dermatome. Commonly it is the thoracic nerve or trigeminal nerve so therefore affecting the thoracic region or the head and face.

51
Q

List ONE serious complication of chickenpox.

A
  1. Infection because of scratching
  2. Encephalitis
  3. Viral pneumonia
52
Q

Using definitions, compare ‘whooping cough’ and ‘tuberculosis’.

A

Whooping Cough Vs TB
* Both Bacterial
Bordetella Pertussis Vs pus producing Mycobacterium tuberculosis
* Cough with whoop on greathing in Vs chronic Cough + more systemic symptoms
* Cough Vs lungs and other organs
* Lasts 3-6 weeks Vs can attack straight away or lay dormant

TB is a chronic granulomatis disease where bacteria can replicate within the macrophages and spread to nearby lymph nodes, leading to the formation of small granulomas, which are clusters of immune cells that wall off the bacteria.
* If these clusters are not eliminated by the immune system they become active immediately, later or remain dormant

53
Q

List ONE bacterial cause of whooping cough.

A

Bordetella Pertussis

One way to remember it is to associate the “Bordetella” part with the name of the bacteriologist who discovered it, Jules Bordet. The “pertussis” part is derived from Latin, meaning “intense cough.”

54
Q

Describe the cough associated with whooping cough.

A

A desperate attempt to breathe in creates a whooping sound. The cough does not respond to usual cough medication and gets worse over three to six weeks, presenting in the form of attacks

55
Q

Describe briefly the pathophysiology of tuberculosis.

A

Granulomas are the hallmark of TB infection.

  1. TB is primarily transmitted through the air when the infected person coughs, sneezes or speaks, releasing tiny droplets containing the bacteria.
  2. When inhaled the bacteria enters the lungs and replicates within the macrophages and spreading to nearby lymph nodes.
  3. This leads to the formation of small granulomas which are clusters of immune cells that wall off the bacteria.
  4. The immune system may be able to contain the infection in which case the bacteria remains dormant but if the immune system is weak or becomes weak it can progress to active TB.
  5. The granulomas breakdown, releasing the bacteria into the lungs and potentially spreading to the other areas such as CNS, lymph, circulation, genitourinary, bones, joints and skin.

The granuloma is the body’s attempt to contain the bacteria and prevent the spread. However they can also contribute to tissue damage and inflammation

56
Q

List ONE bacterial cause of tuberculosis.

A

Mycobacterium tuberculosis

57
Q

List TWO signs and / or symptoms more characteristic of tuberculosis.

A

Fever
Chronic cough,
Purulent/ bloody sputum
Night sweats
Severe malaise.
Weight loss, anorexia

58
Q

Describe ‘Koplik spots’ seen in measles.

A

Small grey spots on oral mucosa opposite molar teeth

These occur in the first phase along with non specific cold symptoms such as a cough, runny nose, red eyes and fever.

Phase two is known as the eruptive phase and that is when we see the rash

59
Q

Name TWO glands affected by the mumps virus.

A

Parotid glands - the pair of salivary glands that sit in front of the ears. Usually starts with one and moves to the other.

Other salivary glands

60
Q

List ONE complication of mumps.

A

Make sterility caused by testicular inflammation – in 30% of cases

61
Q

Name ONE major complication of the ‘rubella’ virus.

A

Abnormal foetal development [birth defects]

Can cause miscarriage and foetal death

62
Q

Describe any TWO signs and / or symptoms associated with viral hepatitis in the following stages:

a. Pre-icteric stage

b. Icteric stage

A

Hepatitis is an acute viral infection of the liver

a. Pre-icteric stage - malaise and diarrhoea

b. Icteric stage - jaundice, pale stools, dark urine, pruritic skin, enlarged liver, impaired blood clotting

63
Q

List ONE serious complication of viral hepatitis.

A

Chronic liver disease - 85% of hep C becomes chronic

64
Q

Name THREE viruses that can cause hepatitis.

A

Hepatitis virus types A, B, C, D and E.

65
Q

Name which area of the brain is affected by the ‘polio virus’.

A

The polio virus targets anterior horn cells of the CNS (motor) and has no cure

66
Q

Describe in detail the pathophysiology of Human Immunodeficiency Viral (HIV) infection.

A

Entry
* HIV binds to CD4 receptors which are found on T helper cells and macrophages
* The viral envelope and cell membrane fuse and the viral RNA enters the cell

Replication
* Viral RNA is converted by an enzyme called reverse transcriptase into viral DNA
* Using integrase it integrates into the host cell DNA
* The viral DNA forces the host cell to produce viral DNA and proteins

Spread:
* Viral RNA and proteins are synthesised in the host cell cytoplasm and assembled into a new virus articles that bud off.

Immune system:
* Action leads to the gradual depletion of CD4 and T helper cells, impairing the immune systems ability to mount an effective response to pathogen leading to increased susceptibility to infections and other complications

67
Q

Name the T-cell affected by HIV.

A

T-Helper Cells

68
Q

Discuss the following statement:

HIV is transmitted by casual contact’

A

This statement is false. HIV is not transmitted by casual contact such as toilet seats or sharing eating utensils. The HIV virus is fragile and easily destroyed outside the body so only active for a short time outside of the body.

HIV is primarily transmitted through blood and semen and there is a low risk with saliva and vaginal secretions.

69
Q

Explain why a pregnant woman infected with HIV would choose to:

a. Have a caesarean section

b. Not breastfeed her baby

A

a. Have a caesarean section

There is an increased risk of transmission during birth because it can be transmitted through blood and birth is a bloody business!

b. Not breastfeed her baby

The risk is not known but there may be a risk of transmission through breastfeeding

70
Q

Explain why diagnostic tests for HIV antibodies are often inaccurate in the first 2 weeks to 6 months of HIV infection.

A

There is a delay in the appearance of HIV antibodies from anything between two weeks to six months. Therefore during this window tests are inaccurate

71
Q

List TWO signs / symptoms of HIV progression:

a. 1‒6 weeks post infection

b. Late stage

A

a. 1‒6 weeks post infection

  • 50% of people are symptomatic
  • Flu/glandular fever like … sore throat, fever, malaise, muscle/joint pain, rash, swollen lymph nodes
  • Negative antibody tests likely but viral RNA an P24 core protein high

b. Late stage
* huge reduction CD4 count and rise in viral load
* severely impaired immune function
* opportunistic infections can cause disease
* AIDS diagnosis based on T helper cell count (less than 14%) and presence of opportunistic infections such a pneumonia, TB, Candida, some cancers, Herpes zoster

72
Q

Name FOUR opportunistic infections which may occur with HIV infection.

A
  • Current pneumonia
  • active TB
  • candida - oral and vaginal
  • lymphoma
  • herpes Zoster
  • Herpes simplex
73
Q

Describe ONE key difference between ‘HIV’ and ‘AIDS’ (Acquired Immune Deficiency Syndrome).

A

HIV

Immunodeficiency virus that attacks white blood cells.

Directly transmissible

AIDS

Develops from HIV and describes later stages of HIV when the immune system is severely impaired.

Not transmissible.

74
Q

Define dysentery.

A

An infection of the intestines that causes diarrhoea containing blood and/or mucus

75
Q

List ONE characteristic sign and / or symptom of dysentery.

A
  • Diarrhoea with mucus and blood
  • Cramping and possible nausea/vomiting
76
Q

Name the infective organism that causes malaria

A

Plasmodium Species – a protozoa

77
Q

Describe in detail how malarial infection develops in the human body.

A

There are three stages in the malaria life cycle: mosquito, human liver, erhtrocyte stage

Mosquito: Infected female mosquito bites the human.

Human Liver:
Plasmodium parasites taken up by the liver where they proliferate and mature (and some varieties lie dormant for up to a year)

Erythrocytes:
* Spread to the erythrocytes and proliferate further.
* Symptoms such as fever begin
* Infected cells burst and spread infection

Mosquito:
Protozoan gamettes are formed and taken up by mosquito during a blood meal

78
Q

Describe the fever associated with malaria.

A

Cyclical fever attacks depending on the type of malaria.

Chills/shivering &raquo_space;> then fever for several hours &raquo_space;> followed by extreme sweating&raquo_space;> and then chills/shivering.

79
Q

List TWO key signs of malaria AND explain why they develop.

A

Splenomegaly
Hepatomegaly
Jaundice

All of these occur because of excessive haemolysis.

80
Q

Using definitions compare ‘chlamydia’ with ‘gonorrhoea’.

A

Both are very common sexually transmitted bacterial infections that can lead to pelvic inflammatory disease and subsequent risk of infertility.

Chlamydia is caused by the Chlamydia Trachomatis bacteria.Gonorrhoea is caused by Neisseria Gonorrhoea bacteria.

81
Q

Describe TWO signs and / or symptoms in a male affected by chlamydia.

A

A male affected by chlamydia may have
* a milky white or yellow discharge from the penis
* epididymitis - Epidydimis is a tube that is attached to each of the testicles. Sperm cells move from the testicles into the epididymis, where they finish maturing and are stored.
* dysuria
but in 50% of cases it is asymptomatic.

For females it is 80% is asymptomatic and one sign would be yellow vaginal discharge

82
Q

List ONE complication of chlamydia.

A

Inflammatory disease that can lead to infertility

83
Q

Describe THREE keys signs and / or symptoms of gonorrhoea in a female.

A

Female affected by gonorrhoea might have a yellow vaginal discharge, dysuria, irregular vaginal bleeding, lower abdominal pain and pain during sex. In 50% of cases they will be asymptomatic.

90% of males will be symptomatic and have yellow penile discharge and disurea

84
Q

Name the specific virus that causes genital herpes.

A

Herpes simplex virus - mostly type 2. Type 1 tends to be oral herpes

85
Q

Describe the lesions associated with genital herpes Vs Genital Warts

A

Genital Herpes: Initially painful vesicles and then shallow ulcers

Genital warts: Flat lesions on the vagina, cervix, penis

86
Q

State ONE way in which ‘syphilis’ is transmitted.

A

Enters the body via damaged skin or mucous membranes. Examples of this could be through sexual contact or pregnancy if the bacteria cross the placenta

87
Q

Name the specific virus that causes genital warts.

A

Human Papillomavirus (HPV)

88
Q

Name one sexually transmitted disease that is caused by

(a) bacterium

(b) Virus:

A

(a) bacterium

  • Gonorrhoea – Neisseria Gonorrhoea
  • Chlamydia – Chlamydia Trachomatis
  • Syphilis – Treponema Pallidum

(b) Virus:
* Genital warts – Human Papillomavirus (HPV)
* Genital Herpes - Herpes Simples Virus – Type 11