Infectology exam 3/3

Definition of HAI. HAI risk factors. The most common HAIclinical syndromes (syndrome, brief description).

HAI- Hospital acquired infection. Infection acquired during care at the hospital, not present at admission. Between 48h after admission and 30 days after procedure.

Risk factor
Age, immunosuppression, chronic diseases, malnutrition.
Invasive devices/procedures,
Prolonged stay, poor hygiene,

clinical syndromes:
Catheter-associated UTI/Skin/Soft tissue infection: E.Coli, Candida
Central Line-associated bloodstream infection: staphylococci, S.aureis, Candida
Ventilator-associated/hospital acquired Pneumonia: Pneumonia >48h after intubation
Surgical site infection
Clostridoides difficile infection.

Gr- agents in HAI – ESBL+, KPE+, Acinetobacter baumannii, Pseudomonas aeruginosa (clinical presentation, diagnosis, treatment).

SHORT ANSWER!!!! DONT NEED TO REMEMBER EVERYTHING

ESBL+
clinical presentation: UTI,Sepsis, pneumonia
(catheter-associated bloodstream infections, hospital acquired pneumonia, intra abdominal infections)
diagnosis: Blood/urine/respiratory/wound culture, antibiotic susceptibility testing (AST)
treatment: Carbapenems, Ceftazidime/avibactam

KPE+
clinical presentation: Multidrug resistant UTI,Sepsis, pneumonia
(Severe HAI, sepsis, ventilator acsociated pneumonia, intra abdominal infection.)
Diagnosis: AST Carbapenems resistant culture,
treatment: Ceftazidime/avibactam

Acinetobacter baumannii
clinical presentation: ventilator-associated pneumonia, Wound infection (Bloodstream/wound/trauma/catheter/intra abdominal infections)
diagnosis: Blood/urine/respiratory/wound culture, AST Carbapenems resistant culture,
treatment: High dose ampicillin/Sulbactam

Pseudomonas aeruginosa
clinical presentation: Opportunistic, Hospital aqured pneumonia, UTI, (Bacteremia, Wound infection)
diagnosis: Blood/urine/respiratory/wound culture, AST to identify phenotype
treatment: Ceftazidime/avibactam

MRSA, clinical picture, diagnosis, treatment, prevention.

Methicillin resistant stahylococcus aureus

clinical picture:
Skin infection
Pneumonia
sepsis
Community acquired or healthhcare associated

diagnosis:
Blood/urine/respiratory/wound culture
AST
PCR

treatment:
Drainage
Remove infected device
Antibiotics: Vancomycin

prevention:
Hygiene and protective equipment
Cover lesions
isolation

Ways of transmission of hospital-acquired infection, preventive measures (isolation, screening, transmission prevention, antibiotic management). Personal protective equipment.

Transmission
Direct/indirect Contact (touching, using same objects)
Droplet: Respiratory droplets
Airborn: small particles traveling long distances
Enviormental: contaminated food/water
Vector born: rare

preventive measures:
isolation:
screening: screening on admission for high risk organisms, targeted screening in outbreak situations, Pre operative screening
transmission prevention: : Hand hygine, cleaning/disinfection, education
antibiotic management: opitmal dose/type/duration, narrow spectrum

Nosocomial sepsis, screening scales, diagnosis and treatment.

Hospital aquired sepsis,

Screening scales:
Quick SOFA: Bedside screening of risks, RR/BP/mental status
SOFA score: in hospital confirming organ dysfunction, RR/platelets/bilirubin/BP/Creatinine
SIRS criteria: Temp/HR/RR/WBC
NEWS/MEWS early warning score: National early warning score, RR/O2/Temp/HP/BP

diagnosis
Infection >48h after hospitalisation
SOFA score
Blood/urine/respiratory/wound culture
CBC: high CRP, WBC, anemia, creainine

treatment.
Immediate management within 1h
Oxygen,BP, antibiotics (first broud then narrow)

Hospital and ventilator-associated pneumonia, diagnosis, treatment.

Diagnosis
Sympoms: fever, purulent sputum, cough, crackles
Infiltrate on Xray, CT
↑ CRP, leukocytosis
Sputum culture

treatment
Antibiotics: vancomycin
Supportive: Oxygen, ventilator, fluids, airway suction

Vascular catheter-related infection, diagnosis, treatment.

diagnosis
Symptoms: fever, sepsis, erythema, hypotension
blood culture, Catheter tip culture
Leukocytosis, ↑ CRP

treatment
Remove catheter
Antibiotics vancomycin

Catheter-associated urinary tract infection, diagnosis, treatment.

Diagnosis
Symptoms: fever, pain, delirium, sepsis
Urinanalysis, urine culture

treatmnet
remove catheter
antibiotics: vancomycin

Describe the objectives of epidemiological surveillance of infectious diseases.

continois systemic collection, analysis, interpretation and dissemination of health data.

Main objectives:
Early detection of cases and outbreaks
Monitoring disease trends over time
Guiding public health interbentions
Informing clinical and resouce planning
Identifying risk factors and sources of infection
monitoring animicrobal resitance
Evaluating effectivness of prevention and conrol programs
Supporting communication and public awareness

Explain the rationale and relevance of the One Health approach.

Rationale:
Most infectious diseases originate in animals
Antiicrobal resistance is driven in all sectors
Enviorment stress increases disease emergence
Globalization accelerates pathogen spread

Relevance:
Early detection and control of outbreaks
More effective prevention
Strengthening anti-microbial resistance containment
Protecting food safety and security
Enhancing climate and ecosystem resilience
Improves Policy, collaboration, and resource efficiency

Explain the reasons and criteria for using the infectious disease case definitions.

• Standardizes diagnosis across clinicians and hospitals

• Ensures uniform surveillance and reporting

• Allows comparison of disease data between regions/time periods

• Helps detect outbreaks early

• Guides inclusion/exclusion in epidemiological studies

• Improves public health decision-making (vaccination, control measures)

• Reduces diagnostic variability between laboratories/physicians

What is bioterrorism? Briefly describe the current actualities and dangers in the world.

deliberate release or use of biological agents (bacteria, viruses, toxins) to cause disease or death in humans, animals, or plants,

biotechnology and synthetic biology could allow malicious actors to create or enhance pathogens

geoplolitical tension- warfare

What are the most dangerous toxins, viruses, and microorganisms in the context of bioterrorism? Please list the Group A biological agents of the CDC ABC classification.

Botulinum toxin
Variola virus, Eboa virus
Bacilllus anthracis, yersinia pestis

CDC Group A Biological Agents = high mortality, easy to spread
Anthrax, plague, botulinum toxin
Smallpox, hemorrhagic fever (ebola)

What signs could indicate a bioterrorism attack?

Sudden increase in cases of rare disease

patients with uncommon symptoms

cluster of high morality
clutsers of illness
unusual resistance patterna

in a known terrosit active area

What should government institutions and epidemiologists do to detect a bioterrorism threat and attack in time?

enhacen surveillance

strenghten laboratory capacity

improve communication and reporting

enhacne training and preparedness

invest in reseasech and development

internaltional collaboration

Please briefly describe the main aspects of the actions of health care professionals in the event of a bioterrorism threat and attack.

Recognitionand diagnosis

immediate reporting

patient management and infection control

specimen collection and laboratory responce

public health educatin/communication

Describe what is meant by sensitivity and specificity of methods.

Sensitivity:

• Ability of a test to correctly identify diseased individuals

• Measures true positive rate

• High sensitivity → few false negatives

Specificity:

• Ability of a test to correctly identify non-diseased individuals

• Measures true negative rate

• High specificity → few false positives

Name the modifiable factors of the pre-analytical stage that affect the testing results.

Modifiable factors:
Patient preparation: fasting, time of day, exercise, medicatin
Sample collection: Techinque, Site, timing
Collection container:
Sample handling and transport
sample identification

Laboratory diagnosis algorithm of HIV infection.

Initia screening: HIV-1/2 antigen–antibody test,
if possitive repeat as confirmation test

NAT: PCR for RNA

Viral hepatitis (HAV, HBV, HCV) laboratory diagnostic screening tests.

Igm: acute infection
IgG+IgM: total antibodies, past infection/vaccination
Surgace antigen: Current infection
Suface antibody: past infection/vaccination
Core antibody: past or ongoing infection
DNA/quantitative PCR: acite infection, viral load

HAV
Anti-HAV IgM
Anti-HAV total (IgG+IgM)

HBV
HBsAG (surface antigen)
Anti-HBs (surface antibody)
Anti-HBc total (Core antibody)
IgM Anti-HBc
HBV DNA/quantitative PCR

HCV
Anti-HCV Antibody
HCV RNA (qualitative/quantitative PCR)

Laboratory diagnosis and differential diagnosis of acute viral gastroenterocolitis.

NAAT/PCR: high sensativity and specificity. Tells multiple viruses/bacteria/paracites apart

Enzyme immunoassays (EIAs): Rapid antigen detection for rotavirus/enteric adenovirus. Quick and cheap

Electron microscopy: most for research

Differential diagnosis
Bacterial gastroenteritis: salmonella, shigella, E.coli
Parasitic infection: Cryptosporidum parvum, giardia lablia
non infectious causes: Inflammatory bowel disease, allergies, irritable bowel syndrome

Laboratory diagnostic tests for cardiovascular diseases.

Cardiac biomarkers:
Troponin (myocardial infarction)
Creatine Kinase-MB
Natriuretic peptides BNP
C- reative proteins

Lipid profile
Blood glucose, HbA1c
Coagulation profile
Electrolytes

ECG
Echocardiography
Coronary CT/MRI/PET

Diabetes: laboratory diagnostic tests.

Fasting plasma glucose
oral glucose tolerance test
glucated hemoglobin HbA1c
Plasma glucose
C peptide
Urine albumin to creatinine ratio

Laboratory diagnosis of diseases of the skin and its derivatives.

Microscopy, & Culture
Fungal infection: skin/hair/nail parts,
BActerial infection: wound swab
Parasitic infection: mites, eggs, fece

Histopathology & microscopy of skin biopsy

PCR: Pathogens from skin lesions, viruses, bacteria

Serology:Detects antibodies

Objectives of medicine laboratory quality controls, internal and external quality controls.

Objective:
Maintain Accuracy, precision, reliability, Compliance,
Idetify errors and cause improvment

Internal quality control
Procedures performed inside laboatory daily to monitor
Control of material
detects immediate errors
Routune calibration, maintenacnce, and monitoring of instruments

External Quality Control
External agency sends proficiency testing samples, compares result to other laboratories.
Provides objective, retrospective assessment of accuarcy and performance
Identifies systematic errors, validate methods and ensure harmonization.

Risk groups of biological agents.

based on their pathogenicity, mode of transmission, and the availability of preventive measures.

Risk group 1:
minimal risk to individuals, not assosciated with disease in healthy adults

Risk group 2:
Can cause disease but unlikely serious hazard to aboratory workers. Effective treatment and prevention. Staphylococcus/hepatitis A

Risk group 3:
Cause serious/lethal disease though inhalation. Significant risk to laboratory workers. Often have effective treatment and prevention. Tuberculosis

Risk group 4:
Likely to cause life threatening disease, high risk of transmission. No treatments. Ebola