Laboratory and Clinical Diagnosis of Patients Reporting Multiple Notifiable Diseases

Laboratory and Clinical Diagnosis of Patients Reporting Multiple Notifiable Diseases

In Taiwan, clinicians frequently report multiple notifiable diseases for a single case to have each of the diseases tested. The clinical and public health implications and the optimal laboratory diagnostic algorithm for these cases are not known. Cases reporting more than three notifiable diseases through National Notifiable Diseases Surveillance System (NNDSS) during January-June, 2009 were included. Their characteristics were collected from NNDSS and medical chart review. Diagnostic algorithms were designed. Cost-savings and diagnostic yield were calculated. During the study period, 623 cases have reported more than three notifiable diseases. The most commonly reported diseases were scrub typhus (92.3%), Q fever (88.6%), endemic typhus (77.8%), leptospirosis (47.6%) and dengue fever (15.6%). The most common combination of diseases were scrub typhus, Q fever, and endemic typhus (34.5%). Of the 551 cases with medical chart review, 111 (20.1%) were diagnosed with a notifiable disease; while 118 (21.4%) had a definite clinical diagnosis other than notifiable disease. The most common clinical syndromes were fever and rash (18.1%), abnormal liver function and jaundice (14.3%) and pneumonia/acute respiratory distress syndrome (12.5%). Cost-saving diagnostic algorithms based on patient characteristics, test positive rate or diagnostic method showed limited effect. Because of the similarity in clinical presentation and the lack of diagnostic capability in most hospitals, it is expected that clinicians will continue to report multiple notifiable diseases. Public health authorities should re-evaluate the purpose and means of surveillance.