Knowledge of the prevalence of human Toxoplasma gondii infection is required in the Republic of Korea. In this study, we surveyed the seroprevalence of T. gondii infection and analyzed the risk factors associated with seropositivity among residents in 2 administrative districts; Seoul and the island of Jeju-do, which have contrasting epidemiologic characteristics. Sera and blood collected from 2,150 residents (1,114 in Seoul and 1,036 in Jeju-do) were checked for IgG antibody titers using ELISA and for the T. gondii B1 gene using PCR. In addition, participants completed a questionnaire that solicited information on gender, age, occupation, eating habits, history of contact with animals, and travel abroad. The T. gondii B1 gene was not detected in all residents examined. However, ELISA showed 8.0% (89 of 1,114 sera) positive for IgG antibodies against T. gondii in Seoul and 11.3% (117 of 1,036 sera) in Jeju-do. In both districts, the positive rates were higher in males than in females, and those 40-79 years of age showed higher rates than other ages. In Seoul, residents older than 70 years of age showed the highest positive rate, 14.9%, whereas in Jeju-do the highest prevalence, 15.6%, was in those in their sixties. The higher seropositive rate in Jeju-do than in Seoul may be related to eating habits and occupations. The present results and a review of related literature are indicative of an increased seroprevalence of T. gondii in Korea in recent years.

A 58-year old housewife consulted us about 1 cm sized, dark-brownish, bean-like mass which was dropped spontaneously from indurated skin lesion on her abdomen. The mass was identified morphologically as an engorged female Ixodes nipponensis. Nine days earlier, she had an excursion collecting edible sprouts of wild grass. Spontaneous retreat has been unusual in clinical tick bites in Korea. Fourteen cases of tick bite described in the Korean literature were reviewed briefly in relation to Lyme borreliosis.

Total of 216 animals conserved in Seoul Grand Park were examined on the antibody titers of Toxoplasma by the indirect latex agglutination test, 20 out of 131 cases (15.3%) in mammals, 2 out of 75 cases (2.7%) in birds, and none in reptiles, according to species, 15 out of 68 species (22.1%) in mammals, 2 out of 36 species (5.6%) in birds showed positive antibody titers when the titers of 1:32 or higher were regarded as positive. In mammals, it appeared as positive in 2 out of 6 cases (1 out of 3 species ) in marsupials, 1 out of 15 cases (1 out of 11 species) in primates, 1 out of 1 case in bats, 6 out of 13 cases (5 out of 10 species) in carnivores, 1 in 12 cases (1 species out of 3) in odd-toed ungulates, 9 out of 80 cases (6 species out of 38) in even-toed ungulates, and none in rodents and in whales. In birds, 1 out of 21 cases (1 out of 7 species) in gallinaceous birds and 1 out of 6 (5 species ) in parrots appeared to have the positive antibody titers of Toxoplasma. And, none of reptiles showed positive. Frequencies of positive antibody titers were high in 1: 64, 9 cases in mammals followed by 1: 32, 6 cases, 1: 128, 3 cases, and 1: 256, 2 cases, respectively. Two positive cases in birds appeared to be 1: 64.

The cello-tape anal swab specimens from 936 primary school children in Seoul, 308 primary school children in a rural area and 92 children in Nanjido, were examined for Enterobius vermicularis eggs. Out of 936 specimens from a primary school in Seoul, E. vermicularis eggs were detected in 114 specimens, the egg detection rate being 12.2 percent. In 308 specimens from a primary school in a rural area, 77 (25.0 percent) were positive for E. vermicularis eggs. Among 92 specimens from Nanjido children in Seoul, egg positive rate of E. vermicularis was 28.3 percent. The egg detection rate of primary school children in Seoul was significantly lower than that of primary school children in a rural area and of Nanjido children. The egg detection rate in boys was lower than that of girls. As the age of children increased, the egg detection rate decreased.

Dendritic cells have been known as a member of strong innate immune cells against infectious organelles. In this study, we evaluated the cytokine expression of splenic dendritic cells in chronic mouse toxoplasmosis by tissue cyst-forming Me49 strain and demonstrated the distribution of lymphoid dendritic cells by fluorescence-activated cell sorter (FACS). Pro-inflammatory cytokines, such as IL-1α, IL-1β, IL-6, and IL-10 increased rapidly at week 1 post-infection (PI) and peaked at week 3 PI. Serum IL-10 level followed the similar patterns. FACS analysis showed that the number of CD8α+/CD11c+ splenic dendritic cells increased at week 1 and peaked at week 3 PI. In conclusion, mouse splenic dendritic cells showed early and rapid cytokine changes and may have important protective roles in early phases of murine toxoplasmosis.