Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

path + micro > Health, Safety and you > Flashcards

Health, Safety and you Flashcards

1
Q

what are types of pathogens

A

extracellular , bacteria , fungi , parasites , protozoa - examples = streptoccus , pneumoniae , clostridium tentane , tyrapsoma bruchi- disesses oenumonai , teneantus , sleeping sickness

intracellular bacteria , parasites mycobacterium leprae , plasmodium flaicpraum - leporasy malaria

viruses (intracellular) variola , influenza , Hiv

smallpox flu aids

parasitic worms extracellular acaris schistoma , acaris schisomitasis

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

what is the relative size of medically important micro-organisms

A

adult tapeworms , some protozoan are visible with the naked eye 2 micrometers

bacteria and mycoplasma and rickesettsia can be seen with a light microscope

chyalimida bacteria , viruses and prions can be seen with an electron microscope

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

what is entry into the body by injection know as

A

Entry into the body by injection is known as the parenteral route of inoculation, and distinguishes this route of entry from all other routes e.g. oral or via a wound

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

what are the different transmission routes of microorgansisms

A

Soil – worms/some bacteria - eg Ascaris lumbricoides; Cl. tetani

Animals/insects – e.g. rabies virus; Plasmodium spp. (malaria)

Food/water – e.g. Enterobacteria; hepatitis A virus; vCJD

Faecal-oral – e.g. Enterobacteria; hepatitis A; noroviruses

Aerosol – e.g. B. pertussis (whooping cough); measles & influenza viruses

Direct contact – e.g. sexual; e.g. HIV infection; some herpesviruses

Transplacental – e.g. rubella virus; Zika virus?

Iatrogenic – e.g. blood; hepatitis B and C; HIV

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

how are diseases transmitted via non human sources

A

dogs infected with rabies virus

Rabies is a vaccine-preventable viral disease which occurs in more than 150 countries and territories
Dogs are the main source of human rabies deaths, contributing up to 99% of all rabies transmissions to humans
Rabies elimination is feasible through vaccination of dogs and prevention of dog bites
Infection causes tens of thousands of deaths every year, mainly in Asia and Africa
40% of people bitten by suspect rabid animals are children under 15 years of age
Immediate, thorough wound washing with soap and water after contact with a suspect rabid animal is crucial and can save lives’

Insects

The female Anopheles mosquito and the malaria protozoan - Plasmodium falciparum

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

how are miccorganissm transmitted in healthcare settings

A

Transmission of micro-organisms in a healthcare setting can be:

  1. through cross-infection (patient to patient), either directly or indirectly
  2. from patient to healthcare worker

from healthcare worker to patient

PERCUTANEOUS – injuries through needles and other sharps, human bites and human scratches.
MUCOCUTANEOUS – exposures to the mucous membranes of the eyes and mouth.

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

what are fomites

A

Fomites are objects or things e.g. a cup or the surface of a table or a bedsheet.

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

what are nosomial infections

A

Nosocomial infections are infections occurring in hospitals.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

give examples of contaminated sources that may result in transmission of microorganisms between humans

A

Mucosal secretions and saliva
Fluids from vesicles or other open lesions
Faeces, vomit and urine
Fomites
Pus
Blood

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

how do respiratory tract infections spread

A

respiratory tract infections spread via mucosal secretions

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

what protective procedures in healthcare settings stop the transmission of microoganisms

A

Preventing micro-organism transmission and spread in the healthcare setting:
. Handwashing and good general hygienic procedures

  1. Use of appropriate protective clothing
  2. Appropriate and effective sterilisation of instruments
  3. Education and awareness
  4. Immunisation, where available
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what bacteria are problem microorganisms in healthcare settings

A

bacteria

Staphylococcus aureus/MRSA

Pseudomonas aeruginosa

Streptococcus pyogenes

Clostridioides difficile

Klebsiella sp.

Bordetella pertussis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what viruses are problem micoorgansism in healthcare settings

A

HIV (blood-borne)

Hepatitis B and C (blood-borne)

Herpes simplex virus (HSV) type 1 (from infected lesion fluids)

Noroviruses (from infected faeces or vomit)

Adenoviruses (from infected body fluids)

Ebola viruses (from all infected body fluids)

Coronavirus (respiratory)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what viruses are problem micoorgansism in healthcare settings

A

HIV (blood-borne)

Hepatitis B and C (blood-borne)

Herpes simplex virus (HSV) type 1 (from infected lesion fluids)

Noroviruses (from infected faeces or vomit)

Adenoviruses (from infected body fluids)

Ebola viruses (from all infected body fluids)

Coronavirus (respiratory)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is dangerous about mrsa

A

About 30% of people carriers without symptoms
In healthcare settings, S. aureus infections can be serious or fatal (bacteraemia or sepsis, pneumonia, endocarditis, bone infections)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is clostridiodes difficile

A

Causes diarrhoea and colitis
Most infections happen after a course of antibiotics
Symptoms: severe diarrhoea including loose, water stools, frequent bowel movements for several days/fever/stomach tenderness or pain/nausea

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

what is kelbsiella sp

A

Gram-negative bacteria
Cause pneumonia, bloodstream infections, wound or surgical site infections, and meningitis
Normally found in the human intestines (not causing disease)/faeces
Patients at risk – on ventilators or catheters/on long course of antibiotics
Healthy individuals are usually not at risk

18
Q

what is Pseudomonas aeruginosa

A

Pseudomonas aeruginosa is a gram-negative, rod-shaped bacterium commonly found in soil, water, and vegetation. It is an opportunistic pathogen that can cause infections in humans, particularly in people with weakened immune systems,

Seriousinfections usually to people in the hospital and/or with weakened immune systems
Infections of the blood, pneumonia, and infections following surgery can lead to severe illness and death in these people
Healthy individuals can also develop mild illnesses - ear infections, especially in children and skin rashes after exposure to contaminated swimming pools
Eye infections have occasionally been reported in persons using extended-wear contact lenses
Can be spread on the hands of healthcare workers or by equipment that gets contaminated and is not properly cleaned

19
Q

what is group a strep

A

Acute infections may take the form of pharyngitis, scarlet fever (rash), impetigo, cellulitis, or erysipelas
Invasive infections can result in necrotizing fasciitis, myositis and streptococcal toxic shock syndrome
Highly contagious/spreads through airborne droplets when someone with the infection coughs or sneezes, or through shared food or drinks

20
Q

what is (Bordetella pertussis) – Saliva

A

Pertussis is a highly contagious disease of the respiratory tract
Many children who contract pertussis have coughing spells that last four to eight weeks
The disease is most dangerous in infants and spreads easily from person to person, mainly through droplets produced by coughing or sneezing.
The first symptoms generally appear 7–10 days after infection, and include mild fever, runny nose, and cough, which in typical cases gradually develops into a paroxysmal cough followed by whooping (hence the common name of whooping cough).
In the youngest infants, the paroxysms may be followed by periods of apnoea.
Pneumonia is a relatively common complication; seizures and encephalopathy occur more rarely. Untreated patients may be contagious for three weeks or more following onset of the cough. Pertussis can be prevented by immunization.

21
Q

how is hiv 1 spread

A

Spread from contaminated needles, blood or blood-products, the main problem for hospitals

Virus has been isolated from human blood, semen, vaginal secretions, saliva, tears and breast milk. Commonest routes of transmission are via blood, semen and vaginal secretions

Contact with saliva is not a route of infection, and there is no evidence for transmission by an airborne route or via food, water, fomites or insects

Skin or mucous membranes must be broken for HIV-1 to infect

22
Q

what are the risks for the transmission of hiv 1

A

Blood transfusions and Factor VIII – 3-5% of all infections
Rate of transmission from infected blood by transfusion – 90%
————————–wh————————————————————————
Intravenous drug abuse – 5-10% of all infections
Rate of transmission from needle stick – 0.5% per episode
————————————————————————————————–
Sexual intercourse – 80% of all infections
Rate of transmission following vaginal intercourse – 0.1% per episode
Rate of transmission following anal intercourse – 1.0% per episode
(Risk of transmission is higher to the passive {receptive} partner)
(Concurrent STD enhances the above risks by 10-fold)
————————————————————————————————–
Perinatal infection – 10% of all infections
Rate of transmission from mother to infant – 12% - 40%
(via transplacental, intrapartum, blood, genital secretions, breast milk)

23
Q

what virus causes aids

A

hiv

hiv enters host cell

viral rna

rna dna hybrid

viral proteins

24
Q

what are the stages of hiv 1 replication

A

Attachment to host cell receptor

Viral core with ssRNA and reverse transcriptase (RT) enzyme released into the host cell cytoplasm

RT enzyme converts viral ssRNA into viral dsDNA

Viral dsDNA enters host cell nucleus and is incorporated into the host cell genome through activity of viral integrase enzyme

Integrated viral dsDNA (termed ‘provirus’) remains latent in host cell genome until cell is activated by a foreign protein

25
Q

what is the natural history of hiv infection

A

HIV is a chronic infection with ongoing viral replication

Progressive decline in CD4+ T-lymphocyte count. Below 200 cells/ml, the individual is defined as having Acquired Immunodeficiency Syndrome (AIDS), and is at risk of opportunistic infections

On average it takes 10 years to progress to AIDS in an untreated person but there is wide individual variation

The major determinant of the rate of progression to AIDS is the amount of HIV virus particles in the bloodstream

26
Q

what is the pathogenesis of hiv infection

A

Acute infection with spread to lymphoid tissue

Virus present in CD4+ helper T lymphocytes and macrophages in both a latent (hidden) and a replicative form

Control of the infection by the immune defences, particularly via cytotoxic T lymphocytes (CD8+ cells)

Loss of immune control with time, virus escape by genetic variability

Loss of greater numbers of helper T lymphocytes through virus and host cell destruction

Development of AIDS and the appearance of opportunist infections

26
Q

what is the pathogenesis of hiv infection

A

Acute infection with spread to lymphoid tissue

Virus present in CD4+ helper T lymphocytes and macrophages in both a latent (hidden) and a replicative form

Control of the infection by the immune defences, particularly via cytotoxic T lymphocytes (CD8+ cells)

Loss of immune control with time, virus escape by genetic variability

Loss of greater numbers of helper T lymphocytes through virus and host cell destruction

Development of AIDS and the appearance of opportunist infections

27
Q

what are opportunistic infections in aids patients

A

Bacterial skin infections

Seborrhoeic dermatitis
Folliculitis (both caused by Staphylococcus aureus)

Fungal skin infections
Candidiasis

Viral skin infections
Zoster/Shingles
Herpes simplex virus
Warts

28
Q

what procedures need to be taken following accidental exposure to hiv 1

A

The nature and extent of the exposure is assessed immediately by an informed clinician

Treatment with appropriate anti-HIV drugs should be commenced immediately

Usually a combination of drugs is used, including reverse transcriptase inhibitors and protease inhibitors

29
Q

what are the major hepatitis viruses

A

hepatitis b virus - hbv - long incubation period , some antigenic variation , carrier state , dna

hepatitis c virus (ccv) - long incubation period much antigenic variation , carrier site , rna

hepatitis a virus - hav - short incubation period , little antigenic variation , no carrier state, rna

30
Q

what are clinical and biochemical features of hepatitis

A

symptoms

Anorexia
Malaise
Nausea
Aches in back and limbs

signs
- jaundice
enlarged liver
enlarged spleen
slightly raised temperature
pale stools
blood in urine

characterised by raised biliburnin and liver transaminase levels in serum

31
Q

what are at risk groups of hepatitis b and c viruses

A

drug addicts -
inidivduals with lymph proliferative disorders
individuals on immune suppressive therapy
users of blood or blood products on a regular basis
individuals in ‘‘at risk’’ occupations

32
Q

what events occur following hepatitis b virus infection in a unvaccinated person

A

25% acute hepatitis disease
99% full recovery
75% transient subclinical disease
infection with hepatitis b virus

10% have chronic liver disease and of that 10 percent
10-30% of cirrhosis of liver
70-90% are healthy carriers and have primary heptaoceullular carcinoma

33
Q

what is the prevalence of hepatitis c virus

A

There are about 1 x 106 new Hepatitis C virus infections worldwide per annum

There are 6 HCV genotypes and about 80 subtypes within the six genotypes

HCV persists in 70-80% of infections

Diagnosis and screening is by an ELISA test for viral antibody, but HCV infection is difficult to recognise in its early stages

34
Q

what is the prevalence of hepatitis c virus

A

There are about 1 x 106 new Hepatitis C virus infections worldwide per annum

There are 6 HCV genotypes and about 80 subtypes within the six genotypes

HCV persists in 70-80% of infections

Diagnosis and screening is by an ELISA test for viral antibody, but HCV infection is difficult to recognise in its early stages

35
Q

how is heptatis b controlled

A

HEPATITIS B
Screening of blood and blood products
Hygienic measures (contaminated needles, tattoos, sexual contact)
Vaccination against HBV – the subunit HBsAg preparation

36
Q

how is hepatitis c controlled

A

HEPATITIS C
Screening of blood and blood products
Hygienic measures (contaminated needles, tattoos, sexual contact)
No vaccine against HCV yet available!

37
Q

how is hepatitis a controlled

A

HEPATITIS A
Hygienic measures (faecal-oral spread)
Common vehicle outbreaks (contaminated water/food)
Inactivated, whole virus vaccine

38
Q

what is ulcerating herpes simplex virus

A

(hsv1)

lesions around mouth (cold sores) and on finger

spread through fluids from ulcers open lesions , hsv2 sexual contact

39
Q

what is norovirus spread from

A

spred from faces and vomit

40
Q

how is adenovirus conjuctivits

A

spread from eye and oral secretions
Transmission through contact with infected upper respiratory droplets, fomites, contaminated swimming pool
Often associated with an infection of the upper respiratory tract, common cold or sore throat
Watery discharge, variable itch

41
Q

Ebola virus

A

Ebola is a severe haemorrhagic disease caused by negative sense ssRNA viruses of the genus Ebolavirus in the family Filoviridae

Filovirus particles form twisted filaments of 80nm diameter, with a genome that codes for 8 proteins

Infection of humans is probably via fruit bats. In some ‘at risk’ countries the sale of fruit bats for culinary purposes is now banned

All bodily fluids are infectious; full body protective clothing must be worn by medical and ancillary staff dealing with patients and samples

Early symptoms include fever, diarrhoea, vomiting; later, there is renal failure, shock and terminal haemorrhagic fever. The case fatality rate in the recent outbreak was 61%

path + micro (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions