{"data":{"id":"us/21-cfr-866.3940","jurisdiction":"us","citation":"21 CFR 866.3940","heading":"West Nile virus serological reagents.","body":"(a) Identification. West Nile virus serological reagents are devices that consist of antigens and antisera for the detection of anti-West Nile virus IgM antibodies, in human serum, from individuals who have signs and symptoms consistent with viral meningitis/encephalitis. The detection aids in the clinical laboratory diagnosis of viral meningitis/encephalitis caused by West Nile virus.\n(b) Classification. Class II (special controls). The special control is FDA's guidance entitled “Class II Special Controls Guidance Document: Serological Reagents for the Laboratory Diagnosis of West Nile Virus.” See § 866.1(e) for the availability of this guidance document.","path":["Title 21—Food and Drugs","CHAPTER I—FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES","SUBCHAPTER H—MEDICAL DEVICES","PART 866—IMMUNOLOGY AND MICROBIOLOGY DEVICES","Subpart D—Serological Reagents"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-21.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:24:47Z","sha256":"24ee9b556bfc80c115128a5d59766f2dbea4810428a5fe6f686ce68d5b044fb4","source_id":"us-cfr","stale":true,"prev":"us/21-cfr-866.3935","next":"us/21-cfr-866.3945"},"notice":"GroundRules: Original legal text. Not legal advice."}