case study 6

What part of the United States is endemic for RMSF?

the Appalachian region (North Carolina, Kentucky)

Arrange the following statements in the order that best describes the sequence of events involved in the replication of influenza.

from left to right in order: -hemagglutinin -influenza enter the host cell -nucleic acid enters the host -influenza protein synthesized -influenza nucleic acid is packaged -influenza particle bud from cell

Which of the following are symptoms of influenza infection? Select all that apply.

headache muscle pain fever

What disease does Paul suspect Ron might have contracted?

Rocky Mountain spotted fever

Which of the following statements regarding antigenic shift are true? Select all that apply.

-Antigenic shift results in a major change in the genetic composition of the virus. -Viral strains resulting from antigenic shift contain RNA segments from different species. -Little immunity to virus strains resulting from antigenic shift exists in the population.

What are some of the current challenges to production of the influenza vaccine? Select all that apply.

-In order to yield a vaccine, the virus must be produced in eggs. -The virus undergoes antigenic changes on a regular basis.

An indirect immunofluorescence assay is described as the CDC "gold standard serological test" for RMSF. Keeping in mind the principles behind indirect fluorescent-antibody (indirect FA) testing, which of the following characteristics contributes to its choice as the gold standard? Select all that apply.

-Indirect FA is more sensitive than direct immunofluorescent testing. -Indirect FA will detect R. rickettsii-specific antibodies present in the patient's serum. -Indirect FA uses an antibody that reacts with any human antibody. -Indirect FA is rapid, sensitive, and specific.

The IV regimen administered by Ron's doctors is consistent with the CDC's recommendation that doxycycline be administered when RMSF is suspected. Apply your knowledge of RMSF to choose the most likely reasons behind this recommendation. Select all that apply.

-The symptoms of RMSF are similar to those of several other infections, making definitive diagnosis difficult. -Most tests that can definitively identify R. rickettsii are not very effective early in infection. -A delay in treatment can lead to complications that include respiratory, cardiac, and renal failure. -Without prompt treatment, RMSF can have a mortality rate as high as 20%.

Predict which of the following are reasonable outcomes of the cytokine storm during the 1918 flu pandemic. Select all that apply.

-an excessive inflammatory response leading to extensive tissue damage -increased fluid in the lungs and labored breathing

Predict which of the following would be outcomes of treatment with Tamiflu. Select all that apply.

-overall decrease in the replication rate of influenza -a decrease in the release of viral particles from the cell -an increase in the ability of the immune system to combat the infection

Apply your knowledge of bacterial pathogenesis and the symptoms of RMSF to predict the order of events that occur during RMSF.

1. tick bites transmit 2.R.rickettsii travels throughout the body 3.R.rickettsii invades endothelial cell 4.R.rickettsii multiplies 5blood begins to escape from vessel 6.symptom

Rickettsia rickettsii is a gram-negative, obligate intracellular pathogen. Which of the following statements about the R. rickettsii life cycle is FALSE?

After entering a host, R. rickettsii multiplies to levels high enough to successfully invade cells and establish an infection.

Which of the following is a characteristic of biological transmission from Dermacentor to a human host?

R. rickettsii is transmitted to the human host during a bite, when tick saliva enters the wound.

Drag each one of the labels onto the figure to identify the function of each structure.

from left top to bottom: -assists -protects -recognizes -contain antigenic On the right side: -contains the viral genetic