Chapter 61: Encephalitis Flashcards
Which action will the public health nurse take to reduce the incidence of epidemic encephalitis in a community?
a. Teach about prophylactic antibiotics after exposure to encephalitis.
b. Encourage the use of effective insect repellent during mosquito season.
c. Remind patients that most cases of viral encephalitis can be cared for at home.
d. Arrange to screen school-age children for West Nile virus during the school year.
b. Encourage the use of effective insect repellent during mosquito season.
Rationale: Mosquitoes and ticks usually spread epidemic encephalitis. Use of insect repellent is effective in reducing risk. Encephalitis frequently requires that the patient be hospitalized in an intensive care unit during the initial stages. Antibiotic prophylaxis is not used to prevent encephalitis because most encephalitis is viral. West Nile virus is most common in adults over age 50 during the summer and early fall.
A nurse is caring for a patient who has been diagnosed with encephalitis caused by the herpes simplex virus (HSV). Which of the following is the most important nursing intervention for this patient?
A) Administering antipyretic medications as prescribed
B) Monitoring the patient’s level of consciousness frequently
C) Encouraging fluid intake to maintain hydration
D) Performing passive range-of-motion exercises daily
B) Monitoring the patient’s level of consciousness frequently
Rationale: HSV encephalitis can lead to significant neurological deterioration. Monitoring the patient’s level of consciousness (LOC) is critical in detecting any changes in neurological status early, which can indicate worsening of the condition. This allows for prompt intervention to prevent further complications. While antipyretics, hydration, and range-of-motion exercises are important, the priority in encephalitis is monitoring neurological function.
Which of the following statements by a nurse is most accurate when educating a patient about the risk factors for encephalitis?
A) “Encephalitis is commonly caused by bacteria rather than viruses.”
B) “Only individuals who live in rural areas are at risk for mosquito-borne encephalitis.”
C) “The herpes simplex virus (HSV) is a common cause of nonepidemic encephalitis.”
D) “Vaccination against chickenpox completely prevents encephalitis.”
C) “The herpes simplex virus (HSV) is a common cause of nonepidemic encephalitis.”
Rationale: HSV is the most common cause of nonepidemic viral encephalitis. While encephalitis can be caused by bacteria, viruses are the more common culprits. Additionally, mosquito-borne encephalitis can occur in various areas, not just rural ones, and vaccination against chickenpox does not guarantee prevention of encephalitis as it is a complication of the infection.
A patient with encephalitis caused by West Nile virus is admitted to the hospital. What is the most likely route of transmission of the West Nile virus in this patient?
A) Airborne droplets
B) Direct contact with infected blood
C) Mosquito bite
D) Contaminated food or water
C) Mosquito bite
Rationale: West Nile virus is typically transmitted to humans through the bite of an infected mosquito. Mosquitoes serve as the vector for this virus, which is most common in certain geographic areas during specific seasons. The other options are not routes of transmission for West Nile virus.
A patient with acquired immunodeficiency syndrome (AIDS) is diagnosed with cytomegalovirus (CMV) encephalitis. The nurse should understand that this condition is primarily associated with which of the following?
A) A tick-borne illness
B) A complication of chickenpox
C) Seasonal outbreaks of viral infections
D) Immunocompromised status
D) Immunocompromised status
Rationale: Cytomegalovirus encephalitis is most commonly seen in patients with compromised immune systems, such as those with AIDS. The immunocompromised state predisposes individuals to infections like CMV, which can affect the brain. This is not typically related to tick-borne illnesses, chickenpox, or seasonal outbreaks.
Which of the following viruses is commonly associated with epidemic encephalitis transmitted by mosquitoes and ticks?
A) West Nile virus
B) Herpes simplex virus (HSV)
C) Measles virus
D) Varicella-zoster virus
A) West Nile virus
Rationale: Rationale: West Nile virus, along with other mosquito-borne viruses like St. Louis and Eastern equine encephalitis, is an example of epidemic encephalitis transmitted by mosquitoes and ticks. HSV causes nonepidemic encephalitis, while measles and varicella-zoster viruses are more commonly associated with other complications, not epidemic encephalitis.
A nurse is providing discharge instructions for a patient with encephalitis caused by La Crosse virus. The nurse should include which of the following information in the teaching plan?
A) “Avoid exposure to mosquitoes by using insect repellent and wearing long sleeves.”
B) “You should receive an antiviral medication to prevent future outbreaks.”
C) “You can resume normal activities immediately once you feel better.”
D) “A yearly flu vaccination will protect you from encephalitis caused by viruses.”
A) “Avoid exposure to mosquitoes by using insect repellent and wearing long sleeves.”
Rationale: La Crosse virus is transmitted by mosquito bites, so the patient should be advised to avoid mosquito exposure through protective measures, such as using insect repellent and wearing long sleeves. There is no antiviral medication to prevent future outbreaks of this viral encephalitis, and vaccination for the flu does not protect against this virus. The patient should also be encouraged to rest and avoid overexertion until fully recovered.
A patient presents with fever, headache, nausea, and vomiting. On day 3, the patient develops confusion and slight hemiparesis. The nurse suspects encephalitis. Which of the following diagnostic tests should be prioritized for confirming the diagnosis?
A) Blood glucose level
B) Polymerase chain reaction (PCR) test for HSV or West Nile
C) Complete blood count (CBC)
D) Electroencephalogram (EEG)
B) Polymerase chain reaction (PCR) test for HSV or West Nile
Rationale: The PCR test for HSV or West Nile virus is critical for early diagnosis of viral encephalitis. This test is specific for detecting the presence of viral RNA, which is essential in diagnosing viral causes of encephalitis, particularly in patients with neurologic symptoms. A CBC, blood glucose level, and EEG may help assess other conditions, but the PCR test is the most directly useful for diagnosing encephalitis.
Which of the following clinical manifestations is commonly seen in patients with encephalitis caused by herpes simplex virus (HSV)?
A) Hemiparesis and tremors
B) Increased intracranial pressure and altered respiratory pattern
C) Seizures and personality changes
D) Nausea and vomiting without CNS involvement
C) Seizures and personality changes
Rationale: HSV encephalitis often presents with seizures, personality changes, and other neurological signs such as confusion or hemiparesis. While increased intracranial pressure and respiratory changes may occur in severe cases, they are not as commonly seen as seizures and personality changes in HSV-related encephalitis.
A nurse is caring for a patient with encephalitis who presents with confusion, amnesia, and difficulty speaking. The patient’s MRI results show no significant findings. What is the most appropriate next step in diagnosing the type of encephalitis?
A) Conduct a lumbar puncture to assess cerebrospinal fluid (CSF)
B) Obtain a complete blood count (CBC)
C) Perform a CT scan of the chest
D) Administer antiviral medications immediately
A) Conduct a lumbar puncture to assess cerebrospinal fluid (CSF)
Rationale: A lumbar puncture to analyze cerebrospinal fluid (CSF) is crucial for diagnosing viral encephalitis, as CSF analysis can reveal elevated white blood cells, protein, and glucose changes, which are indicative of inflammation caused by viral infections. MRI may not show early or subtle changes, making CSF analysis a better next step.
Which of the following statements is most accurate regarding the diagnostic process for West Nile virus encephalitis?
A) Blood cultures are the most sensitive diagnostic test.
B) A brain biopsy is required for confirmation.
C) MRI is the best method for detecting West Nile virus.
D) The best test for diagnosing West Nile virus is a blood test that detects viral RNA.
D) The best test for diagnosing West Nile virus is a blood test that detects viral RNA.
Rationale: A blood test detecting viral RNA is the most accurate diagnostic test for West Nile virus. PCR testing for West Nile viral RNA provides early detection and can confirm the diagnosis. Other diagnostic methods such as cultures or brain biopsy are not as specific for this virus.
A patient with encephalitis caused by La Crosse virus presents with mild confusion and memory impairment. What is the nurse’s priority when caring for this patient?
A) Ensuring the patient is isolated from other patients
B) Administering an intravenous antibiotic
C) Encouraging fluid intake to prevent dehydration
D) Frequent monitoring of neurological status
D) Frequent monitoring of neurological status
Rationale: In encephalitis, changes in neurological status can occur rapidly, so it is essential to monitor the patient frequently for any deterioration, such as increasing confusion or signs of worsening neurological deficits. Isolating the patient, administering antibiotics, and encouraging fluid intake are also important but do not take precedence over neurological monitoring.
Which of the following is a common early clinical manifestation of encephalitis?
A) Fever and headache
B) Seizures and hemiparesis
C) Numbness and tingling in the extremities
D) Slurred speech and dysphagia
A) Fever and headache
Rationale: The early signs of encephalitis typically include nonspecific symptoms such as fever, headache, nausea, and vomiting. Neurological symptoms such as seizures, hemiparesis, and changes in speech usually develop after the initial onset of these nonspecific symptoms.
A 60-year-old patient with encephalitis caused by West Nile virus presents with confusion and altered mental status. The nurse recognizes that the patient is at higher risk for poor outcomes due to which of the following factors?
A) Younger age
B) Presence of a viral rash
C) Age over 50 years
D) Elevated blood pressure
C) Age over 50 years
Rationale: Adults over the age of 50 are at a higher risk for severe complications and poor outcomes from West Nile virus encephalitis. Older adults may have a weaker immune response, leading to more severe manifestations of the disease. Age is a significant risk factor, while a rash, elevated blood pressure, and younger age do not correlate with worse outcomes.
Which diagnostic test is most likely to show early evidence of herpes simplex virus (HSV) encephalitis?
A) MRI scan of the brain
B) Polymerase chain reaction (PCR) test on cerebrospinal fluid (CSF)
C) Complete blood count (CBC)
D) Arterial blood gas (ABG) analysis
B) Polymerase chain reaction (PCR) test on cerebrospinal fluid (CSF)
Rationale: The PCR test on CSF is the most sensitive and specific test for detecting HSV encephalitis. Early detection through PCR can guide appropriate antiviral treatment. MRI may show changes in the brain, but it is not as useful as PCR for diagnosing HSV encephalitis early in the course of the disease.
