Animals ; China ; Humans ; Research ; Toxoplasmosis ; diagnosis ; epidemiology ; etiology ; therapy

OBJECTIVEIn order to accumulate experiences for improving the efficiency in serological tests, the present study on mixed testing of serum samples was performed by taking the serological test of trichinellosis and toxoplasmosis as the examples, and had proved the effects on cost-effectiveness of seroepidemiological survey of parasitic disease with method of mixed-samples test.

METHODSAccording to the binomial distribution principle, to develop an approach to the feasibility of mixed testing of serum samples, and to work on a cost-effectiveness analysis of one-by-one testing and mixed testing using hygienic economic analysis method was performed. For serological test of trichinellosis and toxoplasmosis, 3 kinds of mixed testing methods, namely 3 serum sample mixture, 5 serum sample mixture and 10 serum sample mixture, were performed.

RESULTSThe results showed that all the 3 kinds of mixed tests of trichinellosis and toxoplasmosis showing positive result if only 1 weak positive serum sample were mixed with. When the serum samples being mixed were all negative ones, then among the 24 groups tested with each kind of negative serum sample mixture of trichinellosis (3 serum samples, 5 serum samples and 10 serum samples), they all showed negative. However, among the 12 groups tested with 2 kinds of negative serum mixture of toxoplasmosis (3 serum samples and 5 serum samples), all showed negative while among the 18 groups tested with the 10 serum sample mixture, 16 groups showed negative and 2 were positive. The mixed testing of trichinellosis and toxoplasmosis showed that the efficiency of mixed testing was related to the serological positive rate of the parasitic diseases to be examined. When serological positive rate was 10%, the efficiency of mixed testing was higher in 4 serum sample group. When serological positive rate was 1%, the efficiency of mixed testing was higher in 10 serum sample group and when serological positive rate was 0.1%, the in crease of the size of mixed serum samples could decrease the number of testing, but the prerequisite was that there must be one positive sample, so that the positivity for all the mixed tests could be detected. If mixed testing were performed on all negative samples, no positivity could be detected.

CONCLUSIONThe result of cost-effectiveness analysis demonstrated that for seroepidemiological survey of parasitic diseases, the cost for mixed testing was low, especially when the serological positive rate was expected low (< or = 1%, thus the mixed testing could save a large amount of the cost.

Cost-Benefit Analysis ; Data Collection ; Humans ; Seroepidemiologic Studies ; Specimen Handling ; Toxoplasmosis ; diagnosis ; epidemiology ; Trichinellosis ; diagnosis ; epidemiology

The increasing prevalence of Toxoplasma gondii infection in the human population in the Republic of Korea (= Korea) is due to various reasons such as an increase in meat consumption. However, the importance of cats in transmitting T. gondii infection through oocysts to humans has seldom been assessed. A total of 300 fecal samples of stray cats captured around Seoul from June to August 2013 were examined for T. gondii B1 gene (indicating the presence of oocysts) using nested-PCR. Fourteen (4.7%) of 300 cats examined were positive for B1 gene. Female cats (7.5%) showed a higher prevalence than male cats (1.4%). Cats younger than 3 months (5.5%) showed a higher prevalence than cats (1.5%) older than 3 months. For laboratory passage of the positive samples, the fecal suspension (0.2 ml) of B1 gene positive cats was orally inoculated into experimental mice. Brain tissues of the mice were obtained after 40 days and examined for the presence of tissue cysts. Two isolates were successfully passaged (designated KNIH-1 and KNIH-2) and were molecularly analyzed using the SAG5D and SAG5E gene sequences. The SAG5D and SAG5E gene sequences showed high homologies with the ME49 strain (less virulent strain). The results indicated the importance of stray cats in transmitting T. gondii to humans in Korea, as revealed by detection of B1 gene in fecal samples. T. gondii isolates from cats were successfully passaged in the laboratory for the first time in Korea.
Animals ; Cat Diseases/diagnosis/epidemiology/*parasitology ; Cats ; Feces/*parasitology ; Female ; Genotype ; Humans ; Male ; Mice ; Protozoan Proteins/genetics ; Seoul/epidemiology ; Toxoplasma/genetics/*isolation & purification ; Toxoplasmosis/epidemiology/parasitology/transmission ; Toxoplasmosis, Animal/diagnosis/epidemiology/*parasitology

This cross sectional study was conducted in the city of Taiz, Yemen, during the period from August 2006 to August 2007 in order to investigate the seroprevalence and incidence of toxoplasmosis among apparently healthy children (AHC) and visually and/or hearing disabled children (DC). The seroprevalence was 16.0% among AHC compared to 32.5% among DC. The effect of gender was clear as the seroprevalence rate was significantly higher among females (18.3 and 43.8% for AHC and DC, respectively) than males (13.8 and 25% for AHC and DC, respectively). The seroprevalence was proportionally increased with the age, and the highest rates (20.9 and 53.0%) were reported among the oldest age group (> 10-14 years) for AHC and DC groups, respectively. The incidence rate was also higher (4.2%) in DC group compared to AHC group (2.4%) during 1 year period. These data indicate that the seroprevalence and incidence of toxoplasmosis are significantly higher in DC group than those of AHC group. We need to check further relationship between toxoplasmosis and visual and/or hearing disability.
Adolescent ; Age Factors ; Animals ; Child ; Child, Preschool ; Cross-Sectional Studies ; Disabled Children ; Female ; *Hearing Impaired Persons ; Humans ; Incidence ; Infant ; Male ; Seroepidemiologic Studies ; Sex Factors ; Toxoplasma/*isolation & purification ; Toxoplasmosis/diagnosis/*epidemiology ; Urban Population ; *Visually Impaired Persons ; Yemen/epidemiology

Toxoplasma gondii is an apicomplexan parasite with a broad host range of most warm-blooded mammals including humans, of which one-thirds of the human population has been infected worldwide which can cause congenital defects, abortion, and neonatal complications. Here, we developed a rapid diagnostic test (RDT) for T. gondii infection. Antigenic N-terminal half of the major surface antigen (SAG1) was linked with intrinsically unstructured domain (IUD) of dense granule protein 2 (GRA2). The recombinant GST-GRA2-SAG1A protein was successfully expressed and purified as 51 kDa of molecular weight. Furthermore, antigenicity and solubility of the rGST-GRA2-SAG1A protein were significantly increased. The overall specificity and sensitivity of GST-GRA2-SAG1A loaded RDT (TgRDT) were estimated as 100% and 97.1% by comparing with ELISA result which uses T. gondii whole cell lysates as the antigen. The TgRDT tested with Uganda people sera for field trial and showed 31.9% of seroprevalence against T. gondii antibody. The TgRDT is proved to be a kit for rapid and easy to use with high accuracy, which would be a suitable serodiagnostic tool for toxoplasmosis.
Adolescent ; Adult ; Amino Acid Sequence ; Antibodies, Protozoan/*blood ; Antigens, Protozoan/genetics/*immunology ; Child ; Child, Preschool ; Female ; Humans ; Infant ; Male ; Molecular Sequence Data ; Protozoan Proteins/genetics/*immunology ; Recombinant Fusion Proteins ; Reproducibility of Results ; Republic of Korea/epidemiology ; Sensitivity and Specificity ; Serologic Tests ; Time Factors ; Toxoplasma/genetics/*immunology/isolation & purification ; Toxoplasmosis/*diagnosis/epidemiology/parasitology ; Uganda/epidemiology ; Young Adult

This study aimed to determine the status of common parasitic disease in Korea in 2019. Twelve parasitic diseases were selected: toxocariasis, anisakiasis, paragonimiasis, sparganosis, cysticercosis, toxoplasmosis, clonorchiasis, enterobiasis, trichuriasis, trichomoniasis, cryptosporidiosis, and malaria. Their biology, epidemiology, pathogenesis, symptoms and signs, diagnosis, treatment, and prognosis were evaluated. Of the parasitic diseases, toxocariasis was the most prevalent according to serological results. Anisakiasis should be considered when acute gastrointestinal symptoms occur with a recent past history of raw seafood ingestion. Paragonimiasis, sparganosis, and cysticercosis can be diagnosed using an enzyme-linked immunosorbent assay; thus, enzyme-linked immunosorbent assay needs to be performed for suspected cases. Toxoplasmosis and cryptosporidiosis are opportunistic infections. The symptoms and signs are aggravated under immunocompromised conditions. Although the egg positivity rate of Clonorchis sinensis is higher than that of other intestinal parasitic diseases, encountering patients with complaints of symptoms caused by clonorchiasis is rare because the worm burden is low. Trichomoniasis is usually managed by gynecologists; therefore, it should be included in the differential diagnoses of vaginal diseases. The annual number of malaria cases has decreased, although it remains at approximately 500 cases per year. Malaria should be suspected when symptoms such as intermittent fever, headache, and splenomegaly are noted especially when the patients reside near demilitarized zones. Although the prevalence and number of reported cases of parasitic diseases have decreased in Korea, we should consider parasitic diseases in the list of differential diagnoses.
Animals ; Anisakiasis ; Biology ; Clonorchiasis ; Clonorchis sinensis ; Cryptosporidiosis ; Cysticercosis ; Diagnosis ; Diagnosis, Differential ; Eating ; Enterobiasis ; Enzyme-Linked Immunosorbent Assay ; Epidemiology ; Fever ; Headache ; Humans ; Korea ; Malaria ; Opportunistic Infections ; Ovum ; Paragonimiasis ; Parasitic Diseases ; Prevalence ; Prognosis ; Republic of Korea ; Seafood ; Sparganosis ; Splenomegaly ; Toxocariasis ; Toxoplasmosis ; Trichuriasis ; Vaginal Diseases