Infections of the Cardiovascular System

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Questions and Answers

What is the term for the presence of bacteria in the blood determined by growth in a blood culture?

Pseudobacteremia

Bacteremia (correct)

Viremia

Septicemia

What is Pseudobacteremia primarily caused by?

Direct introduction of microbes into the bloodstream

Infection requiring therapy

True positive blood cultures

Contamination during blood sample collection (correct)

Which classification would a bacteremia of unknown origin fall under?

Bacteremia of Unknown Origin (correct)

Pseudobacteremia

Primary Bacteremia

Secondary Bacteremia

Which outcome of bacteremia can lead to meningitis, osteomyelitis, or endocarditis?

Establishment of distant foci of infection Signup and view all the answers

What is the definition of septicemia?

Acute illness due to microbial proliferation in blood Signup and view all the answers

What criteria were introduced in 2016 to define sepsis?

Documented source of infection plus an acute rise in SOFA points Signup and view all the answers

Which term refers to swollen lymph nodes due to infection?

Buboes Signup and view all the answers

What does the term lymphangitis refer to?

Visible red streaks in inflamed lymph vessels Signup and view all the answers

Which condition does not require therapy, except in certain clinical situations?

Pseudobacteremia Signup and view all the answers

What does the name 'chikungunya' mean in the Kimakonde language?

To become contorted Signup and view all the answers

What is the primary vector responsible for the transmission of chikungunya?

Aedes spp Signup and view all the answers

Which of the following is NOT a common symptom of chikungunya?

Skin peeling Signup and view all the answers

What is the typical onset period for symptoms after the bite of an infected mosquito?

4 to 8 days Signup and view all the answers

What is the most dangerous form of anthrax?

Pulmonary anthrax Signup and view all the answers

What has been a significant risk factor for chikungunya outbreaks?

Proximity of mosquito breeding sites to human habitation Signup and view all the answers

In which year was chikungunya transmission first reported in Europe?

2007 Signup and view all the answers

How is pulmonary anthrax primarily transmitted?

Inhalation of spores from contaminated animal products Signup and view all the answers

What is the initial manifestation of pulmonary anthrax?

Influenza-like symptoms Signup and view all the answers

What is the mortality rate of untreated pulmonary anthrax?

Almost 100% Signup and view all the answers

Which of the following is a presumptive diagnostic method for pulmonary anthrax?

Gram stain and fluorescent-antibody stain Signup and view all the answers

What is the drug of choice for nonbioterrorist anthrax treatment?

Penicillin Signup and view all the answers

What is the primary prevention method for anthrax in humans?

Vaccination Signup and view all the answers

Raxibacumab functions as what type of treatment against anthrax?

Monoclonal antibody therapy Signup and view all the answers

How many injections are required for the anthrax vaccination series for humans?

6 injections over 18 months Signup and view all the answers

Which antibiotic is recommended for postexposure prophylaxis against anthrax?

Ciprofloxacin Signup and view all the answers

What is required for a diagnosis of probable dengue?

Suspect dengue with laboratory test Signup and view all the answers

Which of the following laboratory tests can confirm a dengue diagnosis?

Nucleic Acid Amplification Test-Loop Mediated Amplification Assay (NAAT-LAMP) Signup and view all the answers

What is the primary purpose of the tourniquet test in dengue evaluation?

To check for capillary fragility Signup and view all the answers

What is the management recommendation for hydration in dengue patients?

Provide ORS and fruit juices, avoiding plain water Signup and view all the answers

Which of the following serological results indicates a past dengue infection?

NS1 (-); IgM (-); IgG (+) Signup and view all the answers

What is a characteristic sign associated with dengue hemorrhagic fever when using the tourniquet test?

20 or more petechiae per square inch Signup and view all the answers

What type of medication is strictly advised against in dengue management?

Aspirin Signup and view all the answers

The dengue vaccine is recommended specifically for which group of individuals?

Those aged 9-45 years with prior dengue infection Signup and view all the answers

Which cytokine-related theory involves immunity complications from secondary dengue infections?

Antibody Dependent Enhancement Theory Signup and view all the answers

What is the primary recommended method for disposal of infected animal carcasses?

Incineration or burial in deep pits Signup and view all the answers

Which animal groups are considered reservoir hosts for Francisella tularensis?

Lagomorphs and terrestrial rodents Signup and view all the answers

What is a common vector for the transmission of Tularemia?

Mosquito Signup and view all the answers

What is a characteristic of Francisella tularensis?

Aerobic and non-spore forming Signup and view all the answers

Which of the following antibiotics is considered the drug of choice for treating Tularemia?

Streptomycin Signup and view all the answers

What is one of the significant clinical manifestations of Tularemia?

Widened mediastinum on CXR Signup and view all the answers

What is the primary characteristic of Leptospira interrogans?

Coiled, flexible spirochete Signup and view all the answers

What is a significant virulence mechanism of Leptospira interrogans?

Reduction of phagocytosis Signup and view all the answers

What is the optimal growth requirement for Francisella tularensis in culture media?

Amino acid cysteine Signup and view all the answers

What preventive measure can help avoid infection from Francisella tularensis?

Wearing gloves and protective clothing Signup and view all the answers

Study Notes

Cardiovascular and Lymphatic System Infections

Buboes are swollen lymph nodes.
Lymphangitis is inflammation of lymph vessels, appearing as red streaks under the skin, running from the site of infection.
Bacteremia is the presence of bacteria in the blood, detected by blood culture.
- Sources include a focus of infection like pneumonia or urinary tract infection, and physical introduction like trauma, catheter insertion or dental prophylaxis.
- Outcomes of bacteremia include transient and inconsequential, establishment of distant foci of infection, and progression to sepsis.
Pseudobacteremia is a positive blood culture due to contamination of blood samples during phlebotomy, resulting in a false-positive result. Coagulase-negative staphylococci is a common contaminant.
Septicemia is the proliferation of microbes in the blood, causing acute illness.
Sepsis is defined by either the 1991 or 2003 guidelines, or by the 2016 criteria.
- The 1991/2003 guidelines define it as a suspected or documented source of infection PLUS systemic inflammatory response syndrome (SIRS) caused by a focus of infection releasing inflammatory mediators into circulation.
- The 2016 criteria define it as a suspected or documented source of infection PLUS an acute increase in >2 Sepsis-Related Organ Failure Assessment (SOFA) points.
Inhalation Anthrax is the most dangerous form of anthrax, referred to as "Woolsorter's Disease". It is caused by inhaling spores from contaminated animal products.
- Macrophages ingest spores, which germinate, leading to sepsis and death within 24 hours if untreated.
- Symptoms mimic influenza-like illness, progressing to severe fatal pneumonia.
- The mortality rate is almost 100% without antibiotics.
Francisella tularensis was first isolated in 1911 during an outbreak among ground squirrels in Tulare County, California. The disease is known as Tularemia or Rabbit Fever.
- The organism is a small, aerobic, gram-negative coccobacillus, non-motile and non-spore forming.
- The organism is an obligate intracellular pathogen, requiring host cell invasion for multiplication and disease causation.
- Reservoir animals include lagomorphs (rabbits and hares), terrestrial rodents (voles and meadow mice), and aquatic rodents (muskrats and beavers).
- Vectors include ticks, fleas, deer flies, and mosquitoes.
- Transmission occurs through arthropod bites, direct exposure to contaminated materials (skin, mouth, lungs, eyes), and there is no documented person-to-person transmission.
Leptospira interrogans is found worldwide, particularly in the subtropics and tropics.
- Rodents, specifically their kidneys, serve as a reservoir for the organism.
- The organism is a tightly coiled, thin, flexible spirochete, 6-20 micra in length and 0.1 micron in diameter, with one or both ends hooked.
- The organism is an obligate aerobe, oxidase (+), and catalase (+).
- It is stained by silver stain.
Dengue Fever is a viral disease transmitted by mosquitoes.
- The virus circulates in a sylvatic cycle between forest-dwelling Aedes species mosquitos and nonhuman primates.
- Sporadic human cases occur with infrequent large human outbreaks.
- The disease is spread by a vector: Aedes mosquitos.
- Symptoms include fever, severe joint pain, muscle pain, headache, nausea, fatigue, and rash.
- Treatment focuses on relieving symptoms.
- The proximity of mosquito breeding sites to human habitation poses a significant risk factor.
- In recent decades, the mosquito vectors have spread to Europe and the Americas.
- The first documented transmission in Europe was in 2007 during a localized outbreak in northeastern Italy.
Chikungunya Fever is a viral disease spread by mosquitos (Aedes aegypti and Aedes albopictus).
- Symptoms include high fever, severe onset joint pain, headache, muscle pain, and rash.
- The illness typically develops between four and eight days after the bite of an infected mosquito, but it can range from two to twelve days.
- Treatment focuses on symptom relief.
- There is no cure for the disease.
- The virus shares some clinical features with dengue, causing misdiagnosis in areas where dengue is common.
Original Antigenic Sin Theory explains why dengue infection can be more severe in subsequent infections with different viral strains.
- Once an individual is infected with a dengue virus, their immune system develops antibodies specifically targeted to that particular strain.
- Upon reinfection with a different strain, these antibodies, despite being specific to the first infection, can bind to the new strain but fail to effectively neutralize it.
- This binding action can enhance the virus's ability to infect cells, potentially leading to a more severe clinical presentation known as dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS).
Antibody-Dependent Enhancement Theory explains why subsequent dengue infections may be more severe.
- When the body encounters a dengue virus for the first time, it creates antibodies specific to that particular strain.
- These antibodies can persist in the blood, but if a person is subsequently infected with a different dengue strain, the existing antibodies might not fully neutralize the new virus.
- Instead, these preexisting antibodies might enhance the virus's ability to infect cells, leading to a more severe dengue infection.
The Tourniquet Test is used to check for capillary fragility.
- Inflating a blood pressure cuff to a point midway between systolic and diastolic pressures for five minutes.
- A positive result is defined as 10 or more petechiae per square inch; 20 or more petechiae is suggestive of DHF.
- Obese individuals and those in profound shock may yield false negative results.
NS1 antigen testing is a rapid diagnostic test for dengue.
- The test detects the NS1 protein, which is produced by the dengue virus during the acute phase of infection.
- Testing is usually done in the emergency room.
- The results are typically available quickly.
Dengue Fever Management focuses on relieving symptoms and preventing complications.
- Anti-pyretics like paracetamol and TSB are used to reduce fever, but NSAIDs, aspirin, and steroids are strictly avoided.
- Hydration is crucial, with oral rehydration fluids (ORS), fruit juices (not plain water), and intravenous fluids (isotonic crystalloids or volume expanders if needed).
- Blood transfusions may be required, including full blood (FWB) or packed red blood cells (PRBC), fresh frozen plasma (FFP), and platelets (only for patients taking antiplatelets; platelet concentrates can worsen congestion).
Dengue Vaccinations are available in some countries but have certain limitations.
- The World Health Organization recommends vaccination for individuals aged 9-45 years old with a three-dose series (0-6-12 months).
- Vaccination is recommended only for individuals with a prior dengue infection.
- Individuals who have never been infected with dengue are at an increased risk for developing severe dengue disease if they receive the vaccine.
Chikungunya Case Management primarily focuses on providing symptomatic relief.
- The symptoms can be incapacitating, leading to a period of disability, and complications are possible in rare instances.
- There remains no cure for the disease.

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Description

This quiz covers key concepts related to infections affecting the cardiovascular and lymphatic systems, including conditions like bacteremia, sepsis, and lymphangitis. Explore terms such as buboes and septicemia to deepen your understanding of how these infections manifest and their possible outcomes.