One of the most well-characterized tests for diagnosing neurocysticercosis (NCC) is the enzyme-linked immunoelectrotransfer blot (EITB) assay developed at the CDC, which uses lentil lectin-bound glycoproteins (LLGP) extracted from Taenia solium cysticerci. Although the test is very reliable, the purification process for the LLGP antigens has been difficult to transfer to other laboratories because of the need for expensive equipment and technical expertise. To develop a simpler assay, we previously purified and cloned the diagnostic glycoproteins in the LLGP fraction. In this study, we evaluated three representative recombinant or synthetic antigens from the LLGP fraction, individually and in different combinations, using an immunoblot assay (recombinant EITB). Using a panel of 249 confirmed NCC-positive and 401 negative blood serum samples, the sensitivity of the recombinant EITB assay was determined to be 99% and the specificity was 99% for diagnosing NCC. We also tested a panel of 239 confirmed NCC-positive serum samples in Lima, Peru, and found similar results. Overall, our data show that the performance characteristics of the recombinant EITB assay are comparable to those of the LLGP-EITB assay. This new recombinant-and synthetic antigen-based assay is sustainable and can be easily transferred to other laboratories in the United States and throughout the world.T he diagnosis of neurocysticercosis (NCC), a condition caused by the larvae Taenia solium, is reliably established using results from both imaging and serological tests. The guidelines proposed for making a diagnosis of presumptive NCC (1, 2) define cases as definitive, probable, or possible based on computed tomography (CT) or magnetic resonance imaging (MRI) findings, exposure risk, and serological results. These guidelines specifically define the lentil lectin-bound glycoprotein enzyme-linked immunoelectrotransfer blot assay (LLGP-EITB) as the serological reference standard for diagnosing NCC (3).The LLGP-EITB assay is an immunoblot method that detects antibodies to one or more of seven lentil lectin-bound glycoproteins, which are present in the soluble fraction of an extract of T. solium cysts. In patients with multiple enhancing intracranial lesions, the LLGP-EITB assay is 100% specific and 95% sensitive using blood serum or cerebrospinal fluid (CSF) samples (3-6). The original study that described and evaluated the LLGP-EITB assay was performed using serum samples from biopsy-proven cases of NCC, most with multiple lesions, as detected by skeletal radiographs, and reported a sensitivity of 98% and a specificity of 100% (3). Continued monitoring of the test performance compared with clinical findings using newer imaging techniques, such as CT and MRI, revealed that the sensitivity of the assay was lower, between 50 to 80%, in cases with a single lesion or calcified cysts (6-10). The specificity of the LLGP-EITB assay has been remarkable at essentially 100%, with only rare anecdotal reports of falsepositive results (11)(12)(13).Although the LLGP-...

Taeniasis/cysticercosis caused by Taenia solium is a frequent parasitic infection of the human brain in most of the world. Rapid and simple screening tools to identify taeniasis and cysticercosis cases are needed for control programs, mostly to identify tapeworm carriers which are the source of infection and need to be treated, or as tools for point-of-care case detection or confirmation. These screening assays should be affordable, reliable, rapid, and easy to perform. Immunochromatographic tests meet these criteria. To demonstrate proof of principle, we developed and evaluated two magnetic immunochromatographic tests (MICTs) for detection of human Taenia solium taeniasis antibodies (ES33-MICT) and neurocysticercosis antibodies (T24-MICT). These assays detected stage-specific antibodies by using two recombinant proteins, rES33 for detection of taeniasis antibodies and rT24H for detection of cysticercosis antibodies. The sensitivity and specificity of the ES33-MICT to detect taeniasis infections were 94.5% and 96%, respectively, and those of the T24-MICT to detect cases of human cysticercosis with two or more viable brain cysts were 93.9% and 98.9%, respectively. These data provide proof of principle that the ES33-and T24-MICTs provide rapid and suitable methods to identify individuals with taeniasis and cysticercosis.

One of the best-characterized tests for the diagnosis of neurocysticercosis is the enzyme-linked immunoelectrotransfer blot assay, developed at the CDC, which uses lentil lectin-purified glycoproteins (LLGPs) extracted from Taenia solium cysticerci. The purification of the LLGP antigens has been difficult to standardize, and the polyacrylamide gel system used for the immunoblot assay is not easily transferable to other laboratories. In this study, we developed a multiantigen printing immunoassay (MAPIA) to compare the performance of multiple recombinant Taenia solium proteins with the potential for the detection of cysticercosis and taeniasis. We prepared MAPIA strips using six cysticercosis and two taeniasis diagnostic proteins and compared the performance of the proteins with sera collected from defined cysticercosis and taeniasis cases. Of the six cysticercosis antigens, rT24H performed well in detecting cases with two or more viable cysts in the brain (sensitivity and specificity, 97% and 99.4%, respectively); the use of a combination of cysticercosis antigens did not improve the sensitivity of the test and decreased the specificity. None of the antigens could differentiate the different clinical presentations of cysticercosis. Both of the taeniasis antigens (rES33 and rES38) had the same sensitivity of 99.4% and specificities of 93.9% and 94.5%, respectively. Some crossreactivity against rES33 and rES38 was found, especially with sera from cases infected with Schistosoma mansoni. We conclude that MAPIA is a simple and effective tool that may be used to compare antibody responses to different cysticercosis and taeniasis antigens and, in this case, may be useful for the rapid detection of T. solium cases.Excellent laboratory methods with high specificities and sensitivities for the immunodiagnosis of neurocysticercosis and taeniasis exist. The enzyme immunoelectrotransfer blot (EITB) for cysticercosis is accepted as the "gold standard" assay for the serological identification of cysticercosis (16,19). Unfortunately, the test employs complex native proteins in immunoblot assay formats, and therefore, the tests are not easily adaptable to field use. Over the last 10 years we systematically purified and cloned the diagnostic glycoproteins expressed in the lentil lectin glycoprotein fraction. We found that the seven diagnostic proteins are members of three antigenic protein families: the GP50, GP24, and 8-kDa families. The recombinant proteins or synthetic peptides identified in the first-generation assays are available for further comparative analysis.Many of these recombinant proteins (rGP50 and rT24H, used for the diagnosis of cysticercosis, and rES38 and rES33, used for the diagnosis of taeniasis) and synthetic peptides (sTsRS1, sTS18var1, sTSRS2var1, and sTS14, used for the diagnosis of cysticercosis) have been evaluated by EITB or enzyme-linked immunosorbent assay (ELISA) and have performed well (3, 7-9, 11, 18). Unfortunately, the development of diagnostic methods that use all of these proteins will be exp...

Abstract. Diagnosis of Taenia solium cysticercosis is an important component in the control and elimination of cysticercosis and taeniasis. New detection assays using recombinant and synthetic antigens originating from the lentil lectinpurified glycoproteins (LLGPs) of T. solium cysticerci were developed in a QuickELISA™ format. We analyzed a panel of 474 serum samples composed of 108 serum samples from donors with two or more viable cysts, 252 serum samples from persons with other parasitic infections, and 114 serum samples from persons with no documented illnesses. The sensitivities and specificities of T24H QuickELISA™, GP50 QuickELISA™, and Ts18var1 QuickELISA™ were 96.3% and 99.2%, 93.5% and 98.6%, and 89.8% and 96.4%, respectively, for detecting cases with multiple, viable cysts. T 24H QuickELISA™ performs best among the three assays, and has sensitivity and specificity values comparable to those of the LLGP enzyme-linked immunosorbent blot. The QuickELISA™ are simple, rapid quantitative methods for detecting antibodies specific for T. solium cysticerci antigens.

In August 2000, the Ohio Department of Health requested assistance to investigate a cryptosporidiosis outbreak with more than 700 clinical case-patients. An epidemiologic and environmental investigation was conducted. Stool specimens, pool water, and sand filter samples were analyzed. A community-based case-control study showed that the main risk factor was swimming in pool A (odds ratio [OR] = 42, 95% confidence interval [CI] = 12.3-144.9). This was supported by results of polymerase chain reaction (PCR) analysis, which showed the presence of both the human and bovine genotypes of Cryptosporidium parvum in case-patients and samples from the filter of pool A. A pool-based case-control study indicated that the highest risk was related to exposure to pool water via the mouth (OR = 5.1, 95% CI = 2.1-12.5) or to pool sprinklers (OR = 2.5, 95% CI = 1.3-4.7). Fecal accidents at the pool were documented. Records indicated that the pool met local health regulations. The outbreak, caused by co-infection with two C. parvum genotypes (human and bovine), underscores the need for concerted action to improve public health policies for recreational water facilities and enhanced education regarding the potential for disease transmission through pools.

We evaluated three diagnostic antigens (recombinant GP50, recombinant T24H, and synthetic Ts18var1) for cysticercosis and found that all three performed well in detecting cysticercosis in humans and pigs in several assay formats. These antigens were adapted to a new antibody detection format (QuickELISA). With one single incubation step which involves all reactants except the enzyme substrate, the QuickELISA is particularly suited for automation. We formatted the QuickELISA for the Triturus EIA analyzer for testing large numbers of samples. We found that in QuickELISA formats rGP50 and rT24H have better sensitivity and specificity than sTs18var1 for detecting porcine cysticercosis.