PRZEGL EPIDEMIOL 2013; 67: 29 - 33 Problems of infections © National Institute of Public Health – National Institute of Hygiene Dorota Samojłowicz 1 , Aleksandra Borowska-Solonynko 1 , Elżbieta Gołąb 2 PREVALEnCE OF TOXOPLASMA GONDII PARASITE InFECTIOn AMOnG PEOPLE WHO DIED DUE TO SUDDEn DEATH In THE CAPITAL CITY OF WARSAW AnD ITS VICInITY 1 Department of Forensic Medicine of Medical University of Warsaw, Poland 2 Department of Medical Parasitology, National Institute of Public Health – National Institute of Hygiene, Warsaw, Poland ABSTRACT BACGROUnD. It has recently been shown that the behavioural effects resulting from latent T. gondii infection in immunocompetent people could pose as a threat to their welfare. AIM. The aim of the study was to evaluate the prevalence of T. gondii infection in a group of people who died suddenly in Warsaw and its vicinity. MATERIAL AnD METHODS The studied group (n=169 people) included 42 road traffic accident victims who were driving a vehicle (bicycle (n=6), a motorbike (n=3), a motorcycle (n=13), a car (n=20)) prior to sudden death and 41 people whose death resulted from suicide. Blood samples were collected post-mortem and examined for the presence of T. gondii, IgG antibodies and ethyl alcohol. RESULTS. Of the 169 people tested, T. gondii IgG antibodies were found in the serum of 93 (55%) of which 25 (59.5%) were drivers and 26 (63.4%) people who died as a result of suicide. With respect to the prevalence of T. gondii infection no statistically significant differences were found between the study (61.4%) and control group (49.4%); (p=0.09). A statistically significant result was recorded in the 38-58 age group between suicide and control groups (71.4% vs. 44.4%; p<0.05). Positive test results for the presence of ethyl alcohol in the blood were reported among 49.7% of the studied population: 25.7% among drivers, 67.6% among suicides and 51.8% in the control group. To a statisctically siginificant degree, IgG T. gondii antibodies were found to occur more frequently in people with positive blood alcohol test results among suicides (72% vs. 50%; p<0.05) and among the control group (60% vs. 40%; p<0.05) than in their equivalents with negative test results. COnCLUSIOnS. Our work confirmed the usefulness of serologically testing samples collected post-mortem for epidemiological purposes. The small size of the study group made it impossible to evaluate the potential associations between exposure to T. gondii infection and the probability of sudden death. The significance of Toxoplasma gondii infection as a risk factor for self-destructive behaviour merits further study. Key words: Toxoplasma gondii, toxoplasmosis, post mortem serological testing, suicide, traffic accidents. INTRODUCTION Infection with Toxoplasma gondii is common in the human population. The percentage of population infected is estimated to vary from 30% to 60%, depend- ing on the region of the world (1,2). In its latent form, the infection persists until the infected person dies and is usually asymptomatic in nature. Until recently, T. gondii was considered to pose as a threat to the health of patients with heavy immunosuppresion and in immu- nonaive pregnant women, as an agent of the congenital infection. However, the results of studies carried out initially on animal models and later also on people, seem to indicate that the consequences of T. gondii infection can also appear in people with a properly functioning immune system. Infection among immu- nocompetent people are connected with the particular preference of the parasite to form cysts in the brain. It has been found that chronic T. gondii infection may lead to lack of concentration, prolongation of reaction time, decreased reflexes and feeling of fear (3-6). These features may lead to behaviours that threaten the health