Rate of Congenital Toxoplasmosis in Large Integrated Health Care Setting, California, USA, 1998–2012

Courcol RJ. First isolation of Clostridium amygdalinum from a patient with chronic osteitis. Post traumatic bone and/or joint limb infections due to Clostridium spp. Pre-emptive treatment for Clostridium tet-ani: importance of early recognition and treatment in the community. BMJ Case et al. An unusual case of chronic relapsing tetanus associated with mandibular osteomyelitis. To the Editor: Although congenital toxoplasmosis occurs throughout the United States, little information is available about the rates of diagnosed illness in most of the nation, including California. Infection usually occurs by ingestion of undercooked meat and unwashed fruits and vegetables or exposure to soil or water contaminated with cat feces. Congenital transmission can occur when a woman is infected with Toxoplasma gondii during, or just before, pregnancy. Approximately 91% of women of childbearing age in the United States are susceptible to T. gondii infection (1). The United States has a low prevalence of T. gon-dii infection compared with many areas of the world (2). Severe congenital toxoplasmosis can result in hydro-cephalus, retinochoroiditis that affects vision, microcephalus, seizures, hepa-tosplenomegaly, icterus, psychomotor retardation, and other sequelae (3). Infants with congenital toxoplasmosis are most often asymptomatic at birth; however, when severe symptoms occur , they are usually recognized and the condition diagnosed by the time the child is 2 years of age (3). Our goal was to determine the rate of clinically identified cases of congenital toxoplasmosis in children from birth to 2 years of age within the Northern California Kaiser Perman-ente Medical Care Program (KPNC) during a 15-year period. KPNC is a group health plan that provides care for >3.2 million residents of northern California. The KPNC membership represents ≈30% of the insured population in the region and is demographically similar to the residents of the counties served except that the very poor and very wealthy are underrep-resented (4). We studied live births and infants during 1998–2012, the most recent 15-year period for which records were available and considered complete. We identified potential cases from KPNC electronic medical record databases and confirmed them by reviewing electronic and paper records. The system documents outside services, identified by the corresponding diagnostic codes or laboratory test codes. Eligible case-patients were infants, defined as <24 months of age, at the time of meeting any potential case criterion. We identified all births in which ICD-9-CM diagnostic codes for the mother or the infant included the following: 130-130.9 (toxoplasmosis), 771.2a (a special KPNC subset …