This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacteriology, Subject name: Microbiology
[{'content': 'A VDRL reactive mother gave bih to an infant. All of the following would help in determining the risk of transmission to the infant, Except \nSelect and explain. \nA. TPHA test on the serum sample of the mother, B. TPHA test on the serum sample of the infant, C. VDRL on the paired serum sample of the infant and mother, D. Time interval between the treatment of the mother and her delivery', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Positive TPHA mother is responsible for transmission of infection to the infant In infants, no test (even TPHA) can show the difference between asymptomatic infected and noninfected. VDRL -- detect antibody titer raised in both infants and mother suggests the transmission 4 weeks before delivery treatment should be completed so time interval is the impoant factor. Ref: Ananthanarayana textbook of Microbiology 9th edition Pgno : 374', 'role': 'assistant'}]