Cysticercosis Antibodies Research Articles

Evaluating the modulation of peripheral immune profile in people living with HIV and (Neuro)cysticercosis.

The parasitic infection caused by Taenia solium represents a significant public health concern in developing countries. Larval invasion of body tissues leads to cysticercosis (CC), while central nervous system (CNS) involvement results in neurocysticercosis (NCC). Both conditions exhibit diverse clinical manifestations, and the potential impact of concomitant HIV infection especially prevalent in sub-Saharan Africa on peripheral and CNS immune responses remains poorly understood. This study aimed to identify the potential impact of HIV coinfection in CC and NCC patients. A nested study within a cross-sectional analysis in two Tanzanian regions was performed and 234 participants (110 HIV+ and 124 HIV-) were tested for cysticercosis antibodies, antigens, CD4 counts and serum Th1 and Th2 cytokines via multiplex bead-based immunoassay. 127 cysticercosis seropositive individuals underwent cranial computed tomography (CCT) and clinical symptoms were assessed. Multiple regression analyses were performed to identify factors associated with cytokine modulation due to HIV in CC and NCC patients. Serologically, 18.8% tested positive for cysticercosis antibodies, with no significant difference HIV+ and HIV+. A significantly higher rate of cysticercosis antigen positivity was found in HIV+ individuals (43.6%) compared to HIV- (28.2%) (p = 0.016). CCT scans revealed that overall 10.3% had active brain cysts (NCC+). Our study found no significant changes in the overall cytokine profiles between HIV+ and HIV- participants coinfected CC and NCC, except for IL-5 which was elevated in HIV+ individuals with cysticercosis. Furthermore, HIV infection in general was associated with increased levels of pro-and some anti-inflammatory cytokines e.g. TNF-α, IL-8, and IFN-γ. However, based on the interaction analyses, no cytokine changes were observed due to HIV in CC or NCC patients. In conclusion, while HIV infection itself significantly modulates levels of key cytokines such as TNF-α, IL-8, and IFN-γ, it does not modulate any cytokine changes due to CC or NCC. This underscores the dominant influence of HIV on the immune system and highlights the importance of effective antiretroviral therapy in managing immune responses in individuals coinfected with HIV and CC/NCC.

Clinical Implications for the Comprehensive Interpretation of Radiologic and Immunodiagnostic Tests in Patients Suspected of Parasitic Hepatic Cyst, a Rare Case in Korea

Cystic echinococcosis (CE) is a representative neglected tropical disease (NTD) with increased morbidity and mortality but is ignored and overlooked in developed countries. Serological and radiographic findings are helpful in distinguishing these parasites; however, conflicting results of these can make it difficult to diagnose if medical knowledge of hepatic parasitic disease, including the etiology, features of imaging, and immunodiagnostic test, is not acquired. We report the case of a male patient with dyspepsia and right epigastric pain who had positive results for cysticercosis antibodies on immunodiagnostic examination. Abdominal ultrasonography revealed two huge communicating cystic lesions measuring 8-11 cm. Further evaluations for cysticercosis of the brain (neurocysticercosis) and eyes (intraocular cysticercosis) were unremarkable throughout the brain imaging test and fundus examination. A laparoscopic right hemi-hepatectomy was performed for diagnosis and treatment. On histopathological examination, diverse stages of Echinococcus granulosus were identified. Albendazole was administered postoperatively, and the patient was also followed up. We should be aware of the etiologies that have been prevalent in parasite infection thought to be the cause of hepatic cysts. Moreover, we make an effort to ascertain the patient's nationality, past travel experiences, and immediate environment, including any animals and pets. We present the case of a patient who was worried about the possibility of liver invasion of cysticercus due to the positivity of the cysticercosis antibody and was ultimately diagnosed with CE.

A CORRELATION OF NEUROCYSTICERCOSIS AND IGG4 ANTIBODIES

TOPIC: Critical Care TYPE: Fellow Case Reports INTRODUCTION: In endemic regions, 30% of patients presenting with epilepsy, have evidence of neurocysticercosis. In the US, between the years of 2003 and 2012, there were more than 18,000 hospitalizations for neurocysticercosis. A study done in 2002 showed that IgG4 was found in the sera of patients with cerebral cysticercosis 97.8% of the time. Reliance on immunological assays holds importance due to the lower costs in comparison to imaging studies in impoverished areas. This case presentation follows a patient with a ring-enhancing brain lesion, positive cysticercosis antibodies, and positive IgG4 cells on tissue biopsy. CASE PRESENTATION: A 56-year-old male with a past medical history of hypertension, recent head injury and no other risk factors, presented for evaluation of syncope. Before the syncopal episode, the patient was seen by the primary physician for sustained injury to his head with complaints of recurrent fevers, headache, and blurred vision. The patient was prescribed steroids and antibiotics but did not feel any improvement and ended having a syncopal episode with a brief loss of consciousness. Magnetic resonance imaging of the brain with contrast showed a 17mm right mid corona radiata/mid-lateral ventricle peripherally enhancing mass with surrounding white matter edema and centralized restricted diffusion. Patient was admitted to the intensive care unit and treated with antibiotics, steroids, and antiepileptics. Stereotactic brain biopsy showed brain parenchyma with mildly increased cellularity consisting primarily of glial cells suggestive of reactive tissue. All labs and immunological studies were negative except for positive Cysticercosis IgG Antibody. Computed tomography of the abdomen and pelvis was positive for a 3 cm low-density lesion in the right lobe of the liver for which biopsy showed rare CMV inclusions in infected cells on a background of storiform fibrosis and lymphoplasmacytic inflammation with numerous IgG4 positive cells. The patient was started on albendazole and over the course of a few days, symptoms significantly improved. DISCUSSION: Brain biopsy showed only reactive tissue, hence to ensure no other primary lesion is present, further imaging tests were ordered which led to the revelation of the liver lesion and the biopsy was pathognomonic for IGG4 related disease, however, due to a lack of other necessary diagnostic criteria (serum IgG4 above 135 and histopathology showing IGG4 positive cells greater than 40%), the conclusion was not reached. However, due to the ring-enhancing lesion and positive cysticercosis IgG antibody, neurocysticercosis was higher on the differential as IgG4 is the most commonly found antibody in serum or CSF. CONCLUSIONS: Our findings of a correlation between neurocysticercosis and IgG4, strengthen the promise of a better immunodiagnostic tool thereby fighting the issues of accessibility and cost-effectiveness for endemic areas. REFERENCE #1: O'Neal SE, Flecker RH. Hospitalization frequency and charges for neurocysticercosis, United States, 2003-2012. Emerg Infect Dis. 2015 Jun;21(6):969–76. REFERENCE #2: Huang B, Li G, Jia F, Liu F, Ge L, Li W, et al. Determination of specific IgG4 for diagnosis and therapeutic evaluation of cerebral cysticercosis. Chin Med J (Engl). 2002 Apr;115(4):580–3. REFERENCE #3: Legatowicz-Koprowska M. IgG4-related disease: why is it so important? Cent-Eur J Immunol. 2018;43(2):204–8. DISCLOSURES: No relevant relationships by Rahul Dadhwal, source=Web Response no disclosure on file for Lauren Howard; No relevant relationships by Alamgir Khan, source=Web Response No relevant relationships by Katrina Rathjen, source=Web Response No relevant relationships by Salim Surani, source=Web Response

Operational characteristics of an antibody detecting point of care test for Taenia solium infections in a community and hospital setting

BackgroundDiagnostic test evaluation includes measures of performance and assessment of operational characteristics. The latter focuses on end-user understanding of instructions to perform the test, ease of use, test turnaround time and ease of result interpretation. This study aimed to assess user comprehension of training for and ease of use of a Taenia solium point of care test (TS POC) evaluated in a community and hospital setting in Zambia and Tanzania, respectively.MethodsThe TS POC is a three-step in-house-produced rapid diagnostic test (RDT) for the simultaneous detection of taeniosis (TST) and cysticercosis (TSCC) antibodies. Data collected by administering questionnaires to 29 end-users and from the main evaluation database was analyzed quantitatively.ResultsEnd-users (28/29, 97%) perceived that the training they received for performing the test was sufficient. They performed 4080 tests, of which 80 were invalid. The community-based study and TST tests had higher invalid rates. The overall result interpretation was within the acceptable range of RDTs with an overall disagreement between readers of 3.3%. The Kappa coefficient of agreement was 85 and 82% for TSCC and TST, respectively. There was more disagreement among readers in the community-based study.ConclusionEnd-users rated the TS POC kit moderate in terms of ease of use citing long test turnaround time and difficulties in using the blood transfer device. Overall, the operational performance of the TS POC kit and end-users was within the established acceptable performance range.

Detection of Porcine Cysticercosis in Meat Juice Samples from Infected Pigs.

Seroprevalence of porcine cysticercosis has been generally studied using enzyme-linked immunosorbent assays (ELISA) detecting either antigens or antibodies in sera. However, serum is not always readily available. The objective of this study was to assess the diagnostic potential of meat juice in detecting porcine cysticercosis using a cysticercosis antibody ELISA. Sera and meat juice samples from 13 different organs/tissues were collected from nine pigs naturally infected with cysticercosis and from six uninfected pigs reared under hygienic conditions. The sensitivity of the cysticercosis antibody ELISA in detecting porcine cysticercosis in meat juice samples was compared to that in serum samples from the same pigs. Using sera, cysticercosis was detected in all nine pigs harbouring cysticerci, but not in those reared under hygienic conditions. The sensitivity of the ELISA was highest in meat juice extracted from the diaphragm (100%), heart (89%) and neck muscle (78%) of the nine infected pigs, whereas it varied between 0 and 44% in the other samples. To the best of our knowledge, this is the first study for T. solium cysticercosis serology to use meat juice. Our results show that meat juice from pig carcass organs or muscles is a promising diagnostic specimen for the detection of porcine cysticercosis. More studies including a large sample size of pigs with varying degrees of cysticercosis infection are needed to further prove this concept.

High prevalence of taeniasis and Taenia solium cysticercosis in children in western Sichuan, China

Data in China on human Taenia infections, including Taenia solium cysticercosis, is largely lacking. We aimed to determine the prevalence of taeniasis with all three human Taenia species as well as T. solium cysticercosis in primary school-aged children in minority areas of western Sichuan, China. During April 2016 to December 2017, we did a cross-sectional study in five western Sichuan Province primary schools in Liangshan (3 schools), Ganzi (1 school) and Aba (1 school) prefectures. Diagnosis of taeniasis was made by stool microscopy for presence of Taenia eggs, as well as recovery of taeniid tapeworms or proglottids by medicinal treatment followed by species identification using multiplex PCR. Diagnosis of T. solium cysticercosis was made serologically using an ELISA with low-molecular-weight antigens purified from T. solium cyst fluid to detect specific IgG antibodies. A total of 1672 children were screened for taeniasis and 1639 were evaluated for cysticercosis antibodies. Overall prevalence of taeniasis was 7.5% but was as high as 15.6% at one school site (e.g., Shuiluo). Of the three known human Taenia species, adult T. solium tapeworms were detected in 42 children from four of the five schools (all three schools in Liangshan and one in Aba), giving a prevalence of T. solium taeniasis of 2.5% (95% confidence interval 0–6.7%). Cysticercosis antibody seropositivity by school varied from 2.3% to 15.6% (overall 7.5%). T. solium taeniasis carriers were more likely to have cysticercosis antibodies than children without T. solium taeniasis (43.6% vs 6.6%). Schools with higher prevalences of T. solium taeniasis were more likely to have children with human cysticercosis IgG antibodies. This study shows a high prevalence of taeniasis and T. solium cysticercosis in primary school-aged children in minority areas of western Sichuan, suggesting an urgent necessity for school-based disease control.

Prevalence and risk factors for Taenia solium cysticercosis in school-aged children: A school based study in western Sichuan, People's Republic of China.

BackgroundTaenia solium cysticercosis affects millions of impoverished people worldwide and can cause neurocysticercosis, an infection of the central nervous system which is potentially fatal. Children may represent an especially vulnerable population to neurocysticercosis, due to the risk of cognitive impairment during formative school years. While previous epidemiologic studies have suggested high prevalence in rural China, the prevalence in children as well as risk factors and impact of disease in low-resource areas remain poorly characterized.Methodology/Principal findingsUtilizing school based sampling, we conducted a cross-sectional study, administering a questionnaire and collecting blood for T. solium cysticercosis antibodies in 2867 fifth and sixth grade students across 27 schools in west Sichuan. We used mixed-effects logistic regression models controlling for school-level clustering to study associations between risk factors and to characterize factors influencing the administration of deworming medication. Overall prevalence of cysticercosis antibodies was 6%, but prevalence was significantly higher in three schools which all had prevalences of 15% or higher. Students from households owning pigs (adjusted odds ratio [OR] 1.81, 95% CI 1.08–3.03), from households reporting feeding their pigs human feces (adjusted OR 1.49, 95% CI 1.03–2.16), and self-reporting worms in their feces (adjusted OR 1.85, 95% CI 1.18–2.91) were more likely to have cysticercosis IgG antibodies. Students attending high prevalence schools were more likely to come from households allowing pigs to freely forage for food (OR 2.26, 95% CI 1.72–2.98) and lacking a toilet (OR 1.84, 95% CI 1.38–2.46). Children who were boarding at school were less likely to have received treatment for gastrointestinal worms (adjusted OR 0.58, 95% CI 0.42–0.80).Conclusions/SignificanceOur study indicates high prevalences of cysticercosis antibodies in young school aged children in rural China. While further studies to assess potential for school-based transmission are needed, school-based disease control may be an important intervention to ensure the health of vulnerable pediatric populations in T. solium endemic areas.

Next generation sequencing based pathogen analysis in a patient with neurocysticercosis: a case report

BackgroundAccurate and early diagnosis of neurocysticercosis (NCC) remains a challenge due to the heterogeneity of its clinical, immunological and imaging characteristics. The presence of cysticercus DNA in cerebrospinal fluid (CSF) of NCC patients has been previously detected via conventional PCR assays. To the best of our knowledge, the use of CSF Next-Generation Sequencing (NGS) based pathogen analysis in patients with NCC infection has never been reported.Case presentationThis study reports the clinical, imaging, and immunological features of a patient initially presenting with several months of headache who further developed a pure sensory stroke. NGS was used to detect the pathogen, and her CSF demonstrated the presence of Taenia solium-DNA. This finding was confirmed by a positive reaction to CSF cysticercosis antibodies. After antiparasitic treatment, secondary CSF NGS revealed the DNA index have dropped considerably compared to the initial NGS readings.ConclusionsNGS is a promising tool for the early and accurate diagnosis of central nervous system (CNS) infection, especially in the setting of atypical clinical manifestations. Further studies are required to evaluate the persistence of DNA in the CSF of patients.

Low sensitivity and frequent cross-reactions in commercially available antibody detection ELISA assays for Taenia solium cysticercosis.

To evaluate the diagnostic performance of two commercially available ELISA kits, Novalisa® and Ridascreen® , for the detection of antibodies to Taenia solium, compared to serological diagnosis of neurocysticercosis (NCC) by LLGP-EITB (electro-immunotransfer blot assay using lentil-lectin purified glycoprotein antigens). Archive serum samples from patients with viable NCC (n = 45) or resolved, calcified NCC (n = 45), as well as sera from patients with other cestode parasites (hymenolepiasis, n = 45 and cystic hydatid disease, n = 45), were evaluated for cysticercosis antibody detection using two ELISA kits, Novalisa® and Ridascreen® . All NCC samples had previously tested positive, and all samples from heterologous infections were negative on LLGP-EITB for cysticercosis. Positive rates were calculated by kit and sample group and compared between the two kits. Compared to LLGP-EITB, the sensitivity of both ELISA assays to detect specific antibodies in patients with viable NCC was low (44.4% and 22.2%), and for calcified NCC, it was only 6.7% and 4.5%. Sera from patients with cystic hydatid disease were highly cross-reactive in both ELISA assays (38/45, 84.4%; and 25/45, 55.6%). Sera from patients with hymenolepiasis cross-reacted in five cases in one of the assays (11.1%) and in only one sample with the second assay (2.2%). The performance of Novalisa® and Ridascreen® was poor. Antibody ELISA detection cannot be recommended for the diagnosis of neurocysticercosis.

High prevalence of Taenia solium taeniasis and cysticercosis in Tibetan schoolchildren in western Sichuan, China: a cross-sectional study

BackgroundCysticercosis, an infection caused by the larval stage of Taenia solium, is a serious but neglected disease in developing countries. Information about the prevalence of taeniasis, the gastrointestinal infestation with the adult tapeworm, and cysticercosis is lacking in China. In the current study, we aimed to understand the prevalence of T solium taeniasis and cysticercosis in children in a Tibetan region of western Sichuan. MethodsA cross-sectional study was conducted through cluster sampling in two Tibetan primary schools of Muli County, Liangshan Prefecture, in 2016. Sample collection in two schools was carried out in April and September, respectively, whereas treatment of taeniasis carriers was performed in December. Each student was questioned about a history of segment expulsion within the previous year by showing a segment photo, and also provided faecal and blood samples. All faecal samples were examined for presence of Taenia spp eggs by direct smear, and serum samples were tested for specific IgG antibodies to T solium cysticercus using an ELISA based on low-molecular-weight antigens of T solium cyst fluids. Treatment with pumpkin seeds combined with areca nut extract was provided to confirmed (stool-positive for Taenia spp eggs by microscopy) and suspected taeniasis carriers (reporting a history of segment expulsion within the previous year). All collected tapeworms following treatment were subject to morphology examination and genotyping by multiplex PCR. χ2 test was used to compare the infection rate of T solium taeniasis and seroprevalence in different groups of students. Significance was set at p≤0·05. Informed consent was obtained and Institutional Review Board approval was received. FindingsA total of 636 students (mean sampling coverage 90%) were involved in the study, with a median age of 11 years (range 5–15). The overall prevalence of taeniasis due to all three endemic Taenia species (T solium, T saginata, and T asiatica) was 10·4% (95% CI 7·9–12·9). The prevalence of T solium taeniasis was 6·1% (95% CI 4·2–8·0). Eight (23%) of 35 T solium taeniasis carriers expelled multiple tapeworms (range 2–11), including concurrent infection with other Taenia species. The prevalence of T solium cysticercosis IgG antibodies was 12·9% (95% CI 10·4–15·4) in 619 tested students. Of 32 students with T solium taeniasis, 13 (41%) were seropositive, compared with 12% (63/529) in the group of students without T solium taeniasis (p<0·0001). When analysed separately, the two schools had similar T solium taeniasis prevalence and cysticercosis antibody seroprevalence. InterpretationThe current study suggests that the prevalence of T solium taeniasis and cysticercosis is high in schoolchildren in Tibetan rural areas of western Sichuan. Further studies to better understand transmission patterns and risk factors in poor-resource rural areas of western China are needed to aid further eradication efforts. FundingGlobal Development and Poverty Initiative at Stanford University, Sichuan Provincial Department of Finance, and Science and Technology Department of Sichuan Province (2014SZ0151).

Seizures, cysticercosis and rural-to-urban migration: the PERU MIGRANT study.

To examine the prevalence of seizures, epilepsy and seropositivity to cysticercosis in rural villagers (cysticercosis-endemic setting), rural-to-urban migrants into a non-endemic urban shanty town and urban inhabitants of the same non-endemic shanty town. Three Peruvian populations (n=985) originally recruited into a study about chronic diseases and migration were studied. These groups included rural inhabitants from an endemic region (n=200), long-term rural-to-urban migrants (n=589) and individuals living in the same urban setting (n=196). Seizure disorders were detected by a survey, and a neurologist examined positive respondents. Serum samples from 981/985 individuals were processed for cysticercosis antibodies on immunoblot. Epilepsy prevalence (per 1000 people) was 15.3 in the urban group, 35.6 in migrants and 25 in rural inhabitants. A gradient in cysticercosis antibody seroprevalence was observed: urban 2%, migrant 13.5% and rural group 18% (P<0.05). A similarly increasing pattern of higher seroprevalence was observed among migrants by age at migration. In rural villagers, there was strong evidence of an association between positive serology and having seizures (P=0.011) but such an association was not observed in long-term migrants or in urban residents. In the entire study population, compared with seronegative participants, those with strong antibody reactions (≥4 antibody bands) were more likely to have epilepsy (P<0.001). It is not only international migration that affects cysticercosis endemicity; internal migration can also affect patterns of endemicity within an endemic country. The neurological consequences of cysticercosis infection likely outlast the antibody response for years after rural-to-urban migration.

Added Value of Antigen ELISA in the Diagnosis of Neurocysticercosis in Resource Poor Settings

BackgroundNeurocysticercosis (NCC) is the most common cause of acquired epilepsy in Taenia solium endemic areas, primarily situated in low-income countries. Diagnosis is largely based upon the “Del Brutto diagnostic criteria” using the definitive/probable/no NCC diagnosis approach. Neuroimaging and specific T. solium cysticercosis antibody detection results are at the mainstay of this diagnosis, while antigen detection in serum has never been included. This study aimed at evaluating the addition of antigen detection as a major diagnostic criterion, especially in areas where neuroimaging is absent.MethodsThe B158/B60 monoclonal antibody-based enzyme-linked immunosorbent assay (ELISA) for the detection of circulating cysticercus antigen was carried out retrospectively on serum samples collected during a hospital-based study from 83 people with epilepsy (PWE) in an endemic area.ResultsThe addition of antigen results as a major criterion allowed the correct diagnosis of definitive NCC in 10 out of 17 patients as opposed to 0/17 without antigen results in the absence of neuroimaging. A sensitivity of 100% and a specificity of 84% were determined for the diagnosis of active NCC using antigen ELISA. While the use of a higher cutoff improves the specificity of the test to 96%, it decreases its sensitivity to 83%.ConclusionsIn areas where neuroimaging is absent, NCC diagnosis according to the existing criteria is problematic. Taking into account its limitations for diagnosis of inactive NCC, antigen detection can be of added value for diagnosing NCC in PWE by supporting diagnostic and treatment decisions. Therefore, we recommend a revision of the “Del Brutto diagnostic criteria” for use in resource poor areas and suggest the inclusion of serum antigen detection as a major criterion.

Verifying Elimination Programs with a Special Emphasis on Cysticercosis Endpoints and Postelimination Surveillance

Methods are needed for determining program endpoints or postprogram surveillance for any elimination program. Cysticercosis has the necessary effective strategies and diagnostic tools for establishing an elimination program; however, tools to verify program endpoints have not been determined. Using a statistical approach, the present study proposed that taeniasis and porcine cysticercosis antibody assays could be used to determine with a high statistical confidence whether an area is free of disease. Confidence would be improved by using secondary tests such as the taeniasis coproantigen assay and necropsy of the sentinel pigs.

Human and porcine Taenia solium infections in Mozambique: identifying research priorities.

The objective of this paper is to critically review and summarize available scientific and lay literature, and ongoing studies on human and porcine cysticercosis in Mozambique to identify knowledge gaps and direct immediate and long-term research efforts. Data on the spatial distribution and prevalence of the disease in human and swine populations are scarce and fragmented. Human serological studies have shown that 15-21% of apparently healthy adults were positive for cysticercosis antibodies or antigen, while in neuropsychiatric patients seroprevalence was as high as 51%. Slaughterhouse records indicate a countrywide occurrence of porcine cysticercosis, while studies have shown that 10-35% of pigs tested were seropositive for cysticercosis antibodies or antigen. Current research in Mozambique includes studies on the epidemiology, molecular biology, diagnosis and control of the disease. Future research efforts should be directed at better understanding the epidemiology of the disease in Mozambique, particularly risk factors for its occurrence and spread in human and swine populations, documenting the socio-economic impact of the disease, identifying critical control points and evaluating the feasibility and epidemiological impact of control measures and development of local level diagnostic tools for use in humans and swine.

Development and Evaluation of a Magnetic Immunochromatographic Test To Detect Taenia solium , Which Causes Taeniasis and Neurocysticercosis in Humans

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.

TAENIASIS AND CYSTICERCOSIS IN HOUSEMAIDS WORKING IN AFFLUENT NEIGHBORHOODS IN LIMA, PERU

Taenia solium taeniasis/cysticercosis is endemic in most developing countries, where it is an important cause of epileptic seizures and other neurologic symptoms. In industrialized countries, cysticercosis results from travel or immigration of tapeworm carriers from endemic areas. In both endemic and nonendemic countries, housemaids commonly immigrate from cysticercosis-endemic areas and can transmit the infection if they carry the adult tapeworm. Between July 2001 and July 2002, 1,178 housemaids (961 of them work in the top five most affluent districts of Lima, a metropolis of 8 million inhabitants considered nonendemic for cysticercosis) were evaluated for serum antibodies to Taenia solium and stool microscopy for taeniasis and cysticercosis. The serosurvey revealed a prevalence of cysticercosis-specific antibodies of 14.6% (95% CI: 12.6-16.6%), and stool microscopy detected 12 T. solium tapeworm carriers, for a prevalence of taeniasis of 1.2% (95% CI: 0.6-1.8%). A nonrandom sample of 26 seropositive housemaids was examined by brain CT and 50% of them had brain lesions compatible with neurocysticercosis, mainly calcifications. From the families who used a tapeworm-carrier housemaid, cysticercosis antibodies were detected in 6 (23%) of 26 persons who agreed to participate. One seropositive member of the employer families was symptomatic for seizures and had brain calcifications. The prevalence of tapeworm infections in this housemaid group is similar to levels in endemic areas, constituting a source of neurocysticercosis infection.

Purification of larval Taenia solium antigens by isoelectric focusing

By preparative isoelectric focusing in a rotating ampholine column, crude cystic membrane (M) or fluid (F) antigens of larval Taenia solium were each separated into 20 fractions. M fractions were less specific and sensitive than F fractions in detecting cysticercosis antibodies in pig serum. Among the F fractions, F 15 showed the best potential to serve as a screening antigen. It contained 18 polypeptides, with pI 5.3–8.2 and a specific epitope of 25 kDa which was detected by immunoblotting. Although F 15 showed slight cross-reactions with heterologous antisera in double-antibody IgG enzyme-linked immunosorbent assays (ELISA), it yielded the highest absorbance values when tested against homologous antisera. The antigen was used to screen sera samples from 4870 pigs slaughtered in Hong Kong and five other Chinese cities for cysticercosis antibodies by double-antibody ELISA, Falcon Assay Screening Test (FAST)–ELISA and enhanced chemiluminescent immunoassay. The results varied significantly between assays. However, the samples collected from Shenzhen yielded the highest positive rates. Enhanced chemiluminescent immunoassay based on camera-luminometry was found suitable for use under field conditions.

Seroprevalence of cysticercosis in an Orthodox Jewish community.

Neurocysticercosis cases were identified in 1991 in an Orthodox Jewish community. Transmission was linked to tapeworm-infected immigrant housekeepers from countries where Taenia solium is endemic. To evaluate the extent of and risks for locally acquired cysticercosis, a seroprevalence survey was conducted in 9% of the households in this community. Cysticercosis antibodies were detected in 23 (1.3%) of 1,789 persons from 612 families. All 23 seropositive persons were asymptomatic, and no intracerebral lesions were found for the 21 seropositive persons who underwent brain imaging. Seropositivity was associated with female sex (relative risk [RR] = 2.45, P = 0.049), hiring a domestic worker for child care duties (RR = 3.79, P = 0.05), and with employees from Central America (RR = 2.70, P = 0.0001). Exposure to T. solium in this community is unexpectedly high. Widespread employment of domestic workers from endemic regions and high employee turnover contributes to exposure risk.

Epidemiological investigation of Taenia solium taeniasis and cysticercosis in a rural village of Michoacan State, Mexico

We performed a survey for taeniasis and cysticercosis among persons living in a Mexican village where Taenia solium infection in pigs was known to be enzootic. A standardized questionnaire was administered in all 577 households to obtain medical histories and information on demographic and environmental factors and on risk factors associated with transmission of infection. Serum and/or stool specimens were obtained from 1005 volunteers and examined for cysticercosis antibodies and intestinal parasites. Faecal examination of 828 participants revealed infection by Taenia sp. in 2 (0·2%). Three additional cases of taeniasis were detected in individuals who evacuated proglottids after treatment with praziquantel. Of 1005 human serum specimens, 49 (4·9%) were positive in the cysticercosis immunoblot assay. Seropositivity increased with age and reached a peak in subjects aged 46–55 years ( P < 0·05). A history of seizures was significantly associated with seropositivity ( P < 0·05); approximately 25% of persons with such histories were seropositive. Histories of headache, dizziness, trembling, blurred vision, and vomiting were also significantly associated with positive immunoblot assays. This study has demonstrated previously undiagnosed morbidity associated with T. solium neurocysticercosis and identified community behavioural and environmental practices that must be modified to prevent continued transmission of cysticercosis and taeniasis.

Clinical Evaluation of the Cysticercosis Enzyme-Linked Immunoelectrotransfer Blot in Patients with Neurocysticercosis

During the 3 years that the enzyme-linked immunoelectrotransfer blot (EITB) assay for the diagnosis of human cysticercosis has been in use at the Centers for Disease Control, 50 patients with both pathologically confirmed neurocysticercosis and computed tomographic (CT) or magnetic resonance imaging (MRI) scan results were identified. Of 32 patients with two or more lesions, 94% had detectable antibodies by EITB compared with 28% of 18 patients with single lesions. Patients with only calcified cysts (single or multiple) were less likely to have EITB-positive results than were those with noncalcified, enhancing lesions. Antibody was detectable more frequently in serum than in cerebrospinal fluid, regardless of the number or apparent condition of the cysts. These findings confirm that the EITB assay for cysticercosis antibodies is highly sensitive in patients with multiple, enhancing intracranial lesions but is less sensitive in patients with single lesions and in those with calcified lesions.