A 61-year-old man was bitten by a mosquito and subsequently developed the symptoms of encephalitis. On admission to the hospital a serum specimen, the acute sample, was drawn. The patient recovered and one month later another serum sample, the convalescent specimen, was drawn. Complement fixation tests using his serum and West Nile virus were performed. The acute phase serum gave a titer of 1:8 and the convalescent serum gave a titer of 1:4. What is the most likely conclusion that can be drawn from these observations?
A. The data are inconclusive
B. The patient probably did not have West Nile virus encephalitis
C. The patient probably had West Nile virus encephalitis
D. The patient probably has a complement deficiency
Answer:B
A 61-year-old man was bitten by a mosquito and subsequently developed the symptoms of encephalitis. On admission to the hospital a serum specimen, the acute sample, was drawn. The patient recovered and one month later another serum sample, the convalescent specimen, was drawn. Complement fixation tests using his serum and West Nile virus were performed. The acute phase serum gave a titer of 1:8 and the convalescent serum gave a titer of 1:4. What is the most likely conclusion that can be drawn from these observations?
A. The data are inconclusive B. The patient probably did not have West Nile virus encephalitis C. The patient probably had West Nile virus encephalitis D. The patient probably has a complement deficiency