Comparative study of paired serum and cerebrospinal fluid samples from neurocysticercosis patients for the detection of specific antibody to <i>Taenia solium</i> immunodiagnostic antigen

Neurocysticercosis(NCC) is an important disease in central nervous system caused by infectionwith <i>Taenia solium </i>metacestodes. Inaddition to clinical findings and the imaging analysis, the results ofimmunological tests are informative to diagnose NCC. To compare the usefulnessof serum and cerebrospinal fluid (CSF) samples for antibody detection test,paired serum and CSF samples from NCC and other neurological disease patientswere examined by an enzyme-linked immunosorbent assay with low-molecular-weightantigens purified from <i>T. solium</i> cystfluid in a blinded fashion. Sensitivities of both serum and CSF samples were25.0% in inactive NCC cases (n = 4) and 90.9% in active NCC cases (n = 33) and specificitiesof serum and CSF were 100% and 95.8%, respectively. By the combination of serumand CSF samples, sensitivity for active NCC cases became 100%. There was nodifference in the test performance between serum and CSF samples. Based onthese results, we suggest the detection of specific antibodies in serum for thediagnosis of active NCC because of an easy collection of it. However, in caseof the antibody test negative, CSF should be used to confirm NCC and to ruleout other medical disorders of central nerve system. For diagnosis of suspectedinactive NCC cases, antibody detection test using either serum or CSF has alimited diagnostic value and cannot be recommended.

Comparative Study of Paired Serum and Cerebrospinal Fluid Samples from Neurocysticercosis Patients for the Detection of Specific Antibody to <i>Taenia solium</i> Immunodiagnostic Antigen

Neurocysticercosis (NCC) is an important disease of the central nervous system caused by infection with <i>Taenia solium</i> metacestodes. In addition to the clinical findings and the imaging analysis, the results of immunological tests are informative for the diagnosis of NCC. To compare the usefulness of serum and cerebrospinal fluid (CSF) samples for antibody detection, paired serum and CSF samples from patients with NCC and other neurological diseases were examined by an enzyme-linked immunosorbent assay with low-molecular-weight antigens purified from <i>T. solium</i> cyst fluid in a blinded fashion. The sensitivity of both serum and CSF samples was 25.0% in inactive NCC cases (n = 4) and 90.9% in active NCC cases (n = 33), and the specificity of serum and CSF was 100% and 95.8%, respectively. When the serum and CSF samples were combined, the sensitivity in active NCC cases became 100%. There was no difference in test performance between serum and CSF samples. Based on these results, we recommend the detection of specific antibodies in serum for the diagnosis of active NCC because of the ease of collection. When the antibody test is negative, however, CSF should be used to confirm NCC and to rule out other medical disorders of the central nervous system. Antibody detection test using only serum or CSF has a limited diagnostic value and cannot be recommended for the diagnosis of suspected inactive NCC cases.

Recent Situation of Taeniasis in Mongolia (2002-2012)

Epidemiological situation of taeniasis in Mongolia was assessed based on mitochondrial DNA identification of the parasite species. Multiplex PCR was used on a total of 194 proglottid specimens of Taenia species and copro-PCR and loop-mediated isothermal amplification (LAMP) assays were utilized for detection of copro-DNA of 37 fecal samples from taeniasis patients submitted to the Mongolian National Center for Communicable Diseases (NCCD) from 2002 to 2012. In addition, 4 out of 44 calcified cysts in beef kept in formalin since 2003 were evaluated for histopathological confirmation of cattle cysticercosis. All proglottid specimens and stool samples were confirmed to be Taenia saginata by multiplex PCR and by copro-PCR and LAMP, respectively. Cysts collected from cattle were morphologically confirmed to be metacestodes of Taenia species. T. saginata taeniasis was identified from almost all ages from a 2-year-old boy up to a 88-year-old woman and most prominently in 15-29 age group (37%, 74/198) followed by 30-44 age group (34.8%, 69/198 ) from 15 of Mongolia's 21 provinces, while cattle cysticerci were found from 12 provinces. The highest proportion of taeniasis patients was in Ulaanbaatar, the capital of Mongolia.

Serological and Molecular Characteristics of the First Korean Case of Echinococcus multilocularis

In December 2011, we reported an autochthonous case of Echinococcus multilocularis infection in a 42-year-old woman in Korea. The diagnosis was based on histopathological findings of the surgically resected liver cyst. In the present study, we evaluated the serological and molecular characteristics of this Korean E. multilocularis case. The patient's serum strongly reacted with affinity-purified native Em18 and recombinant Em18 antigens (specific for E. multilocularis) but negative for recombinant antigen B8/1 (reactive for Echinococcus granulosus). In immunoaffinity chromatography, the serum also strongly reacted with E. multilocularis and only weakly positive for E. granulosus. We determined the whole nucleotide sequence of cox1 (1,608 bp) using the paraffin-embedded cystic tissue which was compared with E. multilocularis isolates from China, Japan, Kazakhstan, Austria, France, and Slovakia. The Korean case showed 99.8-99.9% similarity with isolates from Asia (the highest similarity with an isolate from Sichuan, China), whereas the similarity with European isolates ranged from 99.5 to 99.6%.

Current Situation of Taeniasis and Cysticercosis in Indonesia

Three human taeniid species, <I>Taenia solium, Taenia saginata</I> and <I>Taenia asiatica</I> are distributed in Indonesia. A field survey conducted in Bali from 2002 to 2006 showed that the prevalence of taeniasis was highly variable among four districts (1.1-27.5%), and only two cysticercosis cases due to <I>T. solium</I> infection were detected. All tapeworms (n = 66) expelled from 66 tapeworm carriers were confirmed to be <I>T. saginata</I> by mitochondrial DNA analysis. A total prevalence of 13.0% (19⁄146) for <I>T. solium</I> taeniasis was found in Jayawijaya District, Papua (Irian Jaya). It included 14 of 88 (15.9%) in 1999 and 5 of 58 (8.6%) in 2001, while the seroprevalence of cysticercosis in humans by sub-district in Papua ranged from 0.0% in a non-endemic area to 48.5% in an endemic area from 1996 to 2005. The seroprevalence of cysticercosis in pigs and dogs in Jayawijaya ranged from 8.5% to 70.4% (1998-1999) and 4.9% to 33.3% (2000-2002), respectively. A 2003-2006 survey of 371 local people in Samosir island, north Sumatra revealed 6 of 240 (2.5%) to be infected with <I>T. asiatica</I>; 2 of 58 (3.4%) and 4 of 182 (2.2%) cases were detected in 2003 and 2005, respectively. This brief review summarizes the present situation of taeniasis and cysticercosis, the distribution of three human taeniid species, and the risk factors⁄transmission aspects of these tapeworm infections in Bali, Papua, and north Sumatra regions of Indonesia.

Significance of Molecular Diagnosis using Histopathological Specimens in Cestode Zoonoses

Cestode zoonosis cases confirmed by PCR-based mitochondrial DNA analysis were investigated. The cestodiosis included taeniasis, cysticercosis, alveolar echinococcosis, cystic echinococcosis, sparganosis mansoni, diphyllobothriasis and diplogonoporiasis. DNA samples were extracted from the ethanol-fixed, formalin-fixed, paraffin-embedded sections, HE-stained, and the PAS- or acetocarmine-stained samples submitted for histopathology. For PCR-based analysis, cytochrome <I>c</I> oxidase subunit 1 and⁄or cytochrome <I>b</I> genes were amplified by multiplex PCR or conventional PCR coupled with DNA sequencing. Although DNA molecules were degraded in most formalin-fixed samples, smaller gene fragments were successfully amplified and the species causing cestodiosis could be identified by DNA sequence analysis of the amplicons. This review describes cestode zoonosis cases in which mitochondrial DNA analysis was useful not only for routine and retrospective diagnosis, but also for genetic polymorphism analysis and molecular identification of the species associated with pathogenicity. The significance of molecular diagnosis using histopathological specimens for cestode zoonoses is also discussed.