The Centers for Disease Control (hereafter referred to as CDC) announced today (the 11th) that on August 6, 2026, a new first domestic confirmed case of typhoid for this year was reported. The typhoid case was sampled by the treating hospital (accredited laboratory) in late July, and because Salmonella Typhi was detected in the specimen, it was reported and automatically confirmed by the system. Since this case was the first domestic case of the year, the CDC performed whole‑genome sequencing of the strain for epidemiological monitoring, confirming that the strain was a “non‑typhoidal Salmonella.” According to the “Quality Assurance Requirements for Infectious Disease Testing Laboratories,” the accredited laboratory was asked to correct the report, and on August 10 the case was excluded as typhoid. Additionally, regarding this laboratory quality‑control non‑conformance event, the CDC recorded and analyzed the causes and implemented necessary corrective and preventive measures.
The CDC pointed out that the issue was caused by human interpretation errors in the serum agglutination test during the testing process. Typhoid bacteria and other specific bacterial pathogens can have a chance of cross‑reaction in a single serum agglutination test; weak agglutination particles can be misinterpreted due to insufficient operator experience, decreased reagent potency, or improper timing, leading to false‑positive results. The CDC has required the accredited typhoid testing institutions to, after confirming the biochemical characteristics of Salmonella Typhi according to the testing procedures, implement a “dual‑verification” mechanism for any positive serum agglutination result, and to verify each piece of test data before releasing the test result.
The CDC stated that during the patient’s hospitalization, physicians evaluated and treated the case according to clinical expertise, and the patient recovered and was discharged on August 5. According to the CDC’s Typhoid Prevention and Control Manual, a confirmed typhoid case can be released from follow‑up management after three consecutive negative stool tests. The patient was originally scheduled for the first stool collection on August 19, but since the typhoid infection was ruled out on August 10, the collection was unnecessary and no follow‑up management is required.
Source: Centers for Disease Control
Data compiled: Surveillance Office
