Emerging Infections Flashcards
What are new pathogens?
Includes new species and new strains of existing species
e.g. SARS-CoV, H1N1 influenza (pandemic strain)
What are emerging infections?
New pathogens Re-emerging infections drug resistant Nosocomial Zoonotic bioweapons
What are re-emerging infections?
Have experienced increased incidence following a period of recession or control of infection in a given area
e.g. Poliomyelitis or malaria
What are some examples of re-emerging infections?
MRSA, VRSA Multidrug resistant tuberculosis HIV Influenza A N. gonorrhoea
What is the definition of outbreak?
A sudden unexpected increase in disease incidence
What is the definition of epidemic?
A greater prevalence of disease in a population/community than is generally expected in that population at a given time
What is the definition of pandemic?
A greater worldwide prevalence of disease than expected at a given time
What is the definition of endemic?
refers to a pathogen having a steady prevalence in a given population, area, or community
What are nosocomial infections?
An infection acquired by a patient admitted to hospital/health care facility for a reason other than the infection
Infection was not present or incubating in the patient before admittance
signs of infection may appear after discharge
Often opportunistic
What are factors associated with incidence of nosocomial infections?
Increased prevalence of pathogen and close contact in hospital setting
decreased immune status in infected population
emergence of antibiotic-resistant strains of pathogen
surgery or devices
What are some examples of nosocomial infections?
S. aureus MRSA/VRSA Candida albicans C. difficile UTI Hospital acquired pneumonia Surgical site infection Viruses
What are Zoonotic infection?
An infection that is transmitted to a human from another species
May or may not be contagious
e.g rabies
What are factors associated with incidence of zoonotic infections?
Increased prevalence of vector in changing climates, increased interactions
Increased prevalence of pathogen in developing areas, loss of natural habitat
Human activity - increased transportation, dmas, deforestation
Complex interactions between environment, vector, and host (7 generations)
What are the at risk groups for zoonotic infections?
Occupational risk (butchers, farmers etc)
Activity (camping, swimming)
Animal scratches/bites (rabies, arboviruses)
What are some examples of zoonotic infections?
* You should be able to define the vector for a disease for the final
Flavivirus Rabies SARS CoV Influenza A Yersinia pestis Plasmodium falciparum
What is the machupo virus spread by?
Bolivian hemorrhagic fever
Large vesper mouse, machupo virus harmless persistent infection in bush mice
DDT leads to shortage to cats = more mice = mice invade human dwellings
What are bioweapons?
May involve pathogens with limited or no current prevalence
Historic and contemporary usage: smallpox, anthrax
What are category B criteria for bioweapons?
Are moderately easy to disseminate
result in moderate morbidity rates and low mortality rates
require specific enhancements of CDCs diagnositc capacity and enhanced disease surveillance
What are category C bioweapons?
easily available
easy to produce and disseminate
high mortality and high morbidity
What are device associated infections?
Are generally nosocomial
Are associated with a number of opportunistic pathogens
includes catheters, shunts, prostheses
plastic devices are prone to colonization by bacteria, biofilm formation
Symptoms related to site of infection, sepsis always a risk
What are the symptoms related to intravasular catheters?
Pain, inflammation, erythema, purulent discharge at exit site, low-grade fever
Diagnosis via analysis of exit site swab
What are the symptoms related to ambulatory peritoneal dialysis catheters?
Pain, inflammation, erythema, purulent d/c
Peritonitis w/ abdominal pain, fever, nausea, vomiting
Tachychardia, increased WBC in dialysis fluid
Diagnosis via analysis of exit site swab or dialysis fluid
What are the symptoms of a urinary catheter infection?
flank pain, pressure or spasm near the bladder, hematuria, cloudy urine, fever
Diagnosis via urinalysis via catheter
- Any bacterial numbers are considered significant when sample is taken via catheter
- No introduction of bacteria from the urinary tract
What are the symptoms of prosthetic joint infection?
*Important because joints can only be replaced so many times, preventative antibiotics
Joint/bone pain, tenderness, inflammation, fever
Loosing of prosthetic joint, low grade bacteremia
Chronic infection - requires removal of the prosthesis
Diagnosis via analysis of joint aspirate: Culture, stain, PCR (pathogen associated gene), CRP, erythrocyte sedimentation rate, elevated leukocytes, sinus tract formation
What are the symptoms of CSF shunt infection?
Symptoms appear months to years after surgery
Ventriculoatrial (VA) shunt infections - fever, tachycardia, rigors, rash, arthralgia, anemia, myalgia
Ventriculoperitoneal (VP) shunt - vomiting, headache, visual disturbance, abdominal distension
What benefits do the use of microbes have for a host?
Increase immune capacity
Compete with pathogenic organisms/microbes
Target pathogenic organisms/microbes
What are preventative/therapeutic approaches of microbiology?
Probiotics
Prebiotics
Synbiotics
What are emerging therapeutic microbiology approaches?
Bacteriophage
Fecal transplantation
What are probiotics used for?
Gastrointestinal disorders
Genito-urinary tract infections
Skin
What is the function of host microbiome?
Provides a delicate balance between health and disease
- use of probiotics long term immune stimulation, good or bad?
- proinflammatory treatments vs. anti-inflammatory treatments indications and CIs
What are prebiotics/synbiotics?
Are nonliving non digestible factors that contribute to the growth of probiotics
What is phage therapy?
Using bacteriophages as antibiotics
