Congenital toxoplasmosis

Parasitic infections and medical expenses according to Health Insurance Review Assessment claims data in South Korea, 2011-2018

Introduction

In South Korea, Health Insurance Review and Assessment claims data contain comprehensive information on healthcare services for almost the entire population. The present study used claims data on parasitic diseases from 2011 to 2018, and associated medical expenses to investigate infection trends associated with endemic parasitic diseases in South Korea, including those not monitored by Korea Centers for Disease Control and Prevention.

Methods

Basic data regarding each parasitic disease were curated from the Healthcare Bigdata Hub (http://opendata.hira.or.kr). Ten endemic parasitic diseases, three pandemic protozoan diseases, and three ectoparasitic diseases were evaluated between 2011 and 2018. Data on each parasitic disease included the number of patients of each sex, age range within 5 years, province, and total medical expenses. Heatmap and principal component analysis were performed to visualize the incidence pattern of parasitic diseases by provinces.

Results

Clonorchiasis and pinworm infections decreased remarkably from 6,097 and 4,018 infections in 2011 to 3,008 and 1,988 infections in 2018, respectively. Other endemic parasitic diseases mostly declined or remained steady over the 8-year period, except for anisakiasis, which doubled from 409 in 2011 to 818 in 2018. Provinces close to North Korea had a higher frequency of claims for Plasmodium vivax infection. The highest rate of clonorchiasis was in Gyeongsangnam-do, while that of anisakiasis was in southern Korea. Jeju province had the highest number of claims for cysticercosis, anisakiasis, pinworm infection, and soil-transmitted helminth infections. The total medical expense for anisakiasis was 65 million Korean won (57,000 US$) in 2011, rising to 237 million Korean won (206,000 US$) in 2018. The medical expense for trichomoniasis was 6,063 million won and for scabies was 1,669 million won in 2018. Since the claims data include only data reported by healthcare providers, some discrepancies might have occurred.

Conclusion

Our findings provide the basis for a health policy to reduce further infections and medical expense.

Proteomic analysis of Toxoplasma gondii KI-1 tachyzoites

We studied on the proteomic characteristics of Toxoplasma gondii KI-1 tachyzoites which were originally isolated from a Korean patient, and compared with those of the well-known virulent RH strain using 2-dimensional electrophoresis (2-DE), mass spectrometry, and quantitative real-time PCR. Two-dimensional separation of the total proteins isolated from KI-1 tachyzoites revealed up to 150 spots, of which 121 were consistent with those of RH tachyzoites. Of the remaining 29 spots, 14 showed greater than 5-fold difference in density between the KI-1 and RH tachyzoites at a pH of 5.0-8.0. Among the 14 spots, 5 from the KI-1 isolate and 7 from the RH strain were identified using MALDI-TOF mass spectrometry and database searches. The spots from the KI-1 tachyzoites were dense granule proteins (GRA 2, 3, 6, and 7), hypoxanthine-guanine-xanthine phosphoribosyltransferase (HGRPTase), and uracil phosphoribosyltransferase (UPRTase). The spots from the RH strain were surface antigen 1 (SAG 1), L-lactate dehydrogenase (LDH), actin, chorismate synthase, peroximal catalase, hexokinase, bifunctional dihydrofolate reductase-thymidylate synthase (DHTR-TS), and nucleoside-triphosphatases (NTPases). Quantitative real-time PCR supported our mass spectrometric results by showing the elevated expression of the genes encoding GRA 2, 3, and 6 and UPRTase in the KI-1 tachyzoites and those encoding GRA 7, SAG 1, NTPase, and chorismate synthase in the RH tachyzoites. These observations demonstrate that the protein compositions of KI-1 and RH tachyzoites are similar but differential protein expression is involved in virulence.

Laboratory passage and characterization of an isolate of Toxoplasma gondii from an ocular patient in Korea

Toxoplasma gondii tachyzoites were isolated from the blood of an ocular patient, and have been successfully passaged in the laboratory, for over a year, by peritoneal inoculation in mice. The isolated parasite was designated the Korean Isolate-1 (KI-1) and its characteristics were compared with those of the RH strain, a wellknown virulent strain originating from a child who suffered from encephalitis. The morphology, pathogenicity, infectivity and cell culture characteristics of the KI-1 were similar to those of the RH strain. Both RH and KI-1 antigens were detected by an anti-T. gondii monoclonal antibody (mAb), Tg563, against the major surface protein SAG1 (30 kDa), whereas no reaction was observed against an anti-Neospora caninum mAb, 12B4. The KI-1 was confirmed as an isolate of T. gondii. A long-term laboratory maintenance and characterization of a local T. gondii isolate is reported for the first time in the Republic of Korea.

[Chemotherapeutic efficacy of trimethoprim-sulfamethoxazole (Bactrim) in experimental murine toxoplasmosis]

The chemotherapeutic efficacy of trimethoprim-sulfamethoxazole (Bactrim) in mice experimentally infected with Toxoplasma gondii was evaluated. The average survival days and survival rate of mice infected intraperitoneally with 1 x 10(5) trophozoites and treated with Bactrim were compared with those of untreated group. The hematologic findings of blood samples of experimental mice were observed for comparison of side effects between Bactrim and pyrimethamine (Daraprim), the latter of which has been one of the favorable drugs for the treatment of toxoplasmosis. The results are summarized as follows: Bactrim showed a strong evidence of potent anti-Toxoplasma activity. The survival rate of mice administered with 24 mg of Bactrim per mouse per day for 7 days, was 83.3 percent, and the rate was increased to 100 percent in mice administered with two-fold concentrated dose of the drug. The average numbers of white blood cells (W.B.C.) in the mouse groups treated with Bactrim or Daraprim were more increased than those only infected with T. gondi. The mice treated with Daraprim, however, showed remarkably decreased numbers of W.B.C. as compared with those treated with Bactrim. The average numbers of red blood cells (R.B.C.) and platelets both in the drug-treated and untreated T. gondii-infected mice were decreased as compared with normal mice. The numbers of R.B.C. in Daraprim-treated mice, however, were more decreased than in Bactrim-treated mice. The average levels of hemoglobin both in the drug-treated and untreated T. gondii-infected mice were decreased, compared with normal mice. But there was no difference in the levels of hemoglobin between Bactrim- and Daraprim-treated groups. In conclusion, trimethoprim-sulfamethoxazole (Bactrim) was proven to be effective and safe for the treatment of murine toxoplasmosis. The efficacy was comparable with pyrimethamine (Daraprim), but bone marrow depression was less severe with Bactrim treatment.