Human visceral leishmaniasis (HVL), caused by Leishmania infantum is mainly observed as sporadic cases in Turkey and dogs are considered as the main reservoir of the disease. The incidence of visceral leishmaniasis among members of households where a HVL infection has already been diagnosed was studied in clusters around the diagnosed cases in different regions in Turkey. A total of 47 serum samples collected from the households of 11 proven visceral leishmaniasis patients were screened for anti-Leishmania antibodies by indirect immunofluorescent antibody test (IFAT). Three and one such household members belonging to the different families were found to be seropositive and borderline, respectively. Diagnosis was confirmed with the presence of amastigotes in bone marrow aspiration samples in all seropositives while the borderline case with slight and indefinitive symptoms of VL was followed only serologically at 3-month intervals and improved spontaneously in I year. Household members of individuals with previously confirmed visceral leishmaniasis were found to have higher frequency of the disease suggesting the household members should be included in the risk group for visceral leishmaniasis and serological screening should be performed for the detection of possible infection. (c) 2005 Elsevier Ireland Ltd. All rights reserved.