An enhanced surveillance program for adult T-cell leukemia in central Brooklyn

The Brooklyn Adult T-cell Leukemia/Lymphoma (ATL) study was developed to estimate the incidence of the human T-cell lymphotropic virus type I (HTLV-I)-associated ATL in the Crown Heights/Bedford Stuyvesant community. This central Brooklyn black community is an area which has already been shown in earlier reports to be endemic for HTLV-I-associated ATL. Surveillance has been conducted at seven area hospitals that serve this community, with surveillance already completed at five hospitals. Potential study subjects who are 20 years or older are identified by the review of admission records, discharge summaries, pathology and clinical chemistry reports, or physician referrals. Diagnoses of leukemia or lymphoma, or the presence of leukocytosis or hypercalcemia are used as criteria to identify the subjects. Participating subjects give a sample of blood for the determination of HTLV-I infection by serologic tests. At the time of enrollment, subjects provide demographic information including age, sex and birthplace. After one year of surveillance at five hospitals (39.5% of inpatient beds in the catchment), we have identified 12 cases of HTLV-I-associated ATL. The mean age of the ATL patients was 50 years, with patients being predominantly female (83.3%) and often Caribbean immigrants (83.3%). Interestingly, 42% of our cases were identified solely by findings of hypercalcemia from clinical chemistry reports. The remaining ATL cases were identified by physician referral. This enhanced surveillance program that uses both clinical and laboratory criteria for ATL case ascertainment can serve as a prototype for similar surveillance in other areas endemic for HTLV-I-associated ATL--an important effort because of the strong potential for disease prevention.