Last data update: Mar 25, 2024. (Total: 45740 publications since 2009)
Records 1-30 (of 132 Records) |
Query Trace: Blot V [original query] |
---|
Multiantigen print immunoassay (MAPIA) for the diagnosis of neurocysticercosis: a single-center diagnostic optimization and accuracy study in Lima, Peru
Toribio L , Guzman C , Noazin S , Zimic-Sheen A , Zimic M , Gonzales I , Saavedra H , Pretell EJ , Bustos JA , Handali S , García HH . J Clin Microbiol 2023 61 (12) e0076023 Neurocysticercosis (NCC) is the most common helminthic infection of the human central nervous system. The antibody detection assay of choice is the enzyme-linked immunoelectrotransfer blot assay using lentil-lectin purified parasite antigens (LLGP-EITB, Western blot), an immunoassay with exceptional performance in clinical samples. However, its use is mainly restricted to a few research laboratories because the assay is labor-intensive and requires sophisticated equipment, expertise, and large amounts of parasite material for preparation of reagents. We report a new immunoprint assay (MAPIA) that overcomes most of these barriers. We initially compared the performance of five different antigen combinations in a subset of defined samples in the MAPIA format. After selecting the best-performing assay format (a combination of rGP50 + rT24H + sTs14 antigens), 148 archived serum samples were tested, including 40 from individuals with parenchymal NCC, 40 with subarachnoid NCC, and 68 healthy controls with no evidence of neurologic disease. MAPIA using three antigens (rGP50 + rT24H + sTs14) was highly sensitive and specific for detecting antibodies in NCC. It detected 39 out of 40 (97.5%) parenchymal NCC cases and 40/40 (100%) subarachnoid cases and was negative in 67 out of 68 (98.53%) negative samples. MAPIA using three recombinant and synthetic antigens is a simple and economical tool with a performance equivalent to the LLGP-EITB assay for the detection of specific antibodies to NCC. The MAPIA overcomes existing barriers to adoption of the EITG LLGP and is a candidate for worldwide use. |
Prevalence of epilepsy, human cysticercosis, and porcine cysticercosis in western Kenya
Diaz MM , Sokhi D , Noh J , Ngugi AK , Minja FJ , Reddi P , Fevre EM , Meyer ACL . Am J Trop Med Hyg 2022 106 (5) 1450-1455 Cysticercosis is the leading cause of acquired epilepsy worldwide and has been shown to be highly prevalent in pig populations in western Kenya. We conducted a community-based door-to-door survey in a region of western Kenya with a high proportion of pig-keeping households. Persons with epilepsy (PWE) were determined using a screening questionnaire followed by a neurologist evaluation. Cysticercosis serum apDia antigen ELISAs and Western blot for LLGP and rT24h antigen were performed on all PWE and 2% of screen-negative patients. All PWE or people with positive apDia underwent contrast-enhanced brain computed tomography (CT). Of a sample of 810 village residents, 660 (81%) were present in the homestead, of whom 648 (98%) participated. Of these, 17 were confirmed to have lifetime epilepsy, an estimated crude prevalence of 2.6%. No humans with (N = 17) or without (N = 12) epilepsy had serological evidence of cysticercosis infection. Fourteen PWE and one individual with borderline positive apDia antigen ELISA underwent brain CT; none had radiographic findings consistent with neurocysticercosis. Nearly 30% of households kept pigs, with 69% always tethered in both wet and dry seasons. More than 8% (6/72) of pigs had palpable lingual cysts; these pigs all originated from homesteads with latrines, one-third of which were free-ranging at least some of the time. Epilepsy prevalence in our study was greater than the national prevalence, but we found no individuals with epilepsy attributable to cysticercosis. Additional studies are required to identify causes of epilepsy, human and porcine cysticercosis, the role of spatial clustering, and protective factors like host-pathogen immunity. |
Performance evaluation of the Asante Rapid Recency Assay for verification of HIV diagnosis and detection of recent HIV-1 infections: implications for epidemic control
Yufenyuy EL , Detorio M , Dobbs T , Patel HK , Jackson K , Shanmugam Vedapuri , Parekh BS . PLoS Glob Public Health 2022 2 (4) e0000316 We previously described development of a rapid test for recent infection (RTRI) that can diagnose HIV infection and detect HIV-1 recent infections in a single device. This technology was transferred to a commercial partner as Asante Rapid Recency Assay (ARRA). We evaluated performance of the ARRA kits in the laboratory using a well-characterized panel of specimens. The plasma specimen panel (N=1500) included HIV-1 (N=570), HIV-2 (N=10), and HIV-negatives (N=920) representing multiple subtypes and geographic locations. Reference diagnostic data were generated using the Bio-Rad HIV-1-2-O EIA/Western blot algorithm with further serotyping performed using the Multispot HIV-1/2 assay. The LAg-Avidity EIA was used to generate reference data on recent and long-term infection for HIV-1 positive specimens at a normalized optical density (ODn) cutoff of 2.0 corresponding to a mean duration of about 6 months. All specimens were tested with ARRA according to the manufacturer's recommendations. Test strips were also read for line intensities using a reader and results were correlated with visual interpretation. ARRA's positive verification line (PVL) correctly classified 575 of 580 HIV-positive and 910 of 920 negative specimens resulting in a sensitivity of 99.1% (95% CI: 98.0-99.6) and specificity of 98.9% (95% CI: 98.1-99.4), respectively. The reader-based classification was similar for PVL with sensitivity of 99.3% (576/580) and specificity of 98.8% (909/920). ARRA's long-term line (LTL) classified 109 of 565 HIV-1 specimens as recent and 456 as long-term compared to 98 as recent and 467 as long-term (LT) by LAg-Avidity EIA (cutoff ODn=2.0), suggesting a mean duration of recent infection (MDRI) close to 6 months. Agreement of ARRA with LAg recent cases was 81.6% (80/98) and LT cases was 93.8% (438/467), with an overall agreement of 91.7% (kappa=0.72). The reader (cutoff 2.9) classified 109/566 specimens as recent infections compared to 99 by the LAg-Avidity EIA for recency agreement of 81.8% (81/99), LT agreement of 9% (439/467) with overall agreement of 91.9% (kappa=0.72). The agreement between visual interpretation and strip reader was 99.9% (95% CI: 99.6-99.9) for the PVL and 98.1% (95% CI: 96.6-98.9) for the LTL. ARRA performed well with HIV diagnostic sensitivity >99% and specificity >98%. Its ability to identify recent infections is comparable to the LA-Avidity EIA corresponding to an MDRI of about 6 months. This point-of-care assay has implications for real-time surveillance of new infections among newly diagnosed individuals for targeted prevention and interrupting ongoing transmission thus accelerating epidemic control. |
Improved diagnosis of viable parenchymal neurocysticercosis by combining antibody banding patterns on enzyme-linked immunoelectrotransfer blot (EITB) with antigen ELISA assay
Arroyo G , Bustos JA , Lescano AG , Gonzales I , Saavedra H , Pretell EJ , Castillo Y , Perez E , Handali S , Noh J , Dorny P , Gilman RH , O'Neal S , Gonzalez A , Garcia H . J Clin Microbiol 2021 60 (2) Jcm0155021 The diagnosis of NCC depends on neuroimaging and serological confirmation. While antibody detection by enzyme-linked immunoelectrotransfer blot (EITB) fails to predict viable NCC, EITB banding patterns provide information about the host's infection course. Adding antigen ELISA results on EITB banding patterns may improve their ability to predict or rule out of viable NCC. We assessed whether combining EITB banding patterns with Ag-ELISA improves discrimination of viable infection in imaging-confirmed parenchymal NCC. EITB banding patterns were grouped into classes using latent class analysis. True-positive and false-negative Ag-ELISA results in each class were compared using Fisher's exact test. Four classes were identified: 1 (EITB-negative or positive to GP50 alone [GP50 antigen family]), 2 (positive to GP42-39 and GP24 [T24/42 family], with or without GP50), 3 and 4 (positive to GP50, GP42-39 and GP24, and reacting to bands in the 8-kDa family). Most cases in classes 3 and 4 had viable NCC (82% and 88%) compared to classes 2 and 1 (53% and 5%). Adding positive Ag-ELISA results to class 2 predicted all viable NCC cases (22/22 [100%]), whereas 11/40 patients (27.5%) Ag-ELISA negative had viable NCC (P < 0.001). Only 1/4 patients (25%) Ag-ELISA positive in class 1 had viable NCC, whereas 1/36 patients (2.8%) Ag-ELISA negative had viable NCC (P = 0.192). In classes 3 and 4, adding Ag-ELISA was not contributory. Combining Ag-ELISA with EITB banding patterns improves discrimination of viable from non-viable NCC, particularly for class-2 responses. Together, these complement neuroimaging more appropriately for the diagnosis of viable NCC. |
Evaluation of an Antibody Detecting Point of Care Test for Diagnosis of Taenia solium Cysticercosis in a Zambian Rural Community: A Prospective Diagnostic Accuracy Study
Mubanga C , Van Damme I , Trevisan C , Schmidt V , Phiri IK , Zulu G , Noh J , Handali S , Mambo R , Chembensofu M , Masuku M , Reynders D , Jansen F , Bottieau E , Magnussen P , Winkler AS , Dorny P , Mwape KE , Gabriël S . Diagnostics (Basel) 2021 11 (11) The lack of cheap, easy-to-use, rapid diagnostic tests has led to the development of several rapid diagnostic tests for cysticercosis. The new prototype two-strip, Taenia solium point of care test (TS POC) detects antibodies against taeniosis (TS POC T) and cysticercosis (TS POC CC). This study evaluated the diagnostic performance of the TS POC CC in the Sinda district in eastern Zambia. A sample of 1254 participants was recruited and tested with the TS POC. Out of the 1249 participants with a valid TS POC result, 177 (14%) tested positive while 1072 (86%) tested negative. All individuals with a positive TS POC and a subset of negative TS POC participants were selected for serum sampling, and were subjected to the recombinant glycoprotein T24H enzyme-linked immunoelectrotransfer blot (rT24H EITB) and the serum B60/158 (serum Ag) enzyme-linked immunosorbent assay (Ag ELISA). Performance characteristics were estimated using a Bayesian approach with probabilistic constraints. Based on 255 complete cases, the estimated sensitivity and specificity of the TS POC CC test were 35% (95% CI: 14-63%) and 87% (95% CI: 83-90%), respectively. The diagnostic performance needs to be improved, possibly by titrating antigen and other reagents' concentration in the strip to produce a performance similar to existing cysticercosis tests such as the rT24H EITB. |
Challenges encountered when evaluating an antibody-detecting point-of-care test for taeniosis in an endemic community in Zambia: A prospective diagnostic accuracy study
Mubanga C , Trevisan C , Van Damme I , Schmidt V , Phiri IK , Zulu G , Noh J , Handali S , Mambo R , Chembensofu M , Masuku M , Reynders D , Jansen F , Bottieau E , Magnussen P , Winkler AS , Dorny P , Mwape KE , Gabriel S . Diagnostics (Basel) 2021 11 (11) Taenia solium taeniosis diagnosis is challenging because current tests perform sub-optimally and/or are expensive, require sophisticated equipment, infrastructure and trained manpower, and therefore are not community deployable. A recently-developed, multi-strip, T. solium point-of-care test (TS POC) for simultaneous detection of tapeworm (TS POC T) and cysticercus (TS POC CC) human antibodies was evaluated for diagnostic accuracy on consecutively recruited community participants in Sinda district, Zambia. All participants were tested using the TS POC test. All test-positives and 20% of the test-negative participants were invited to give a blood and stool sample for reference testing. Three different reference tests were used for taeniosis diagnosis: recombinant rES33 enzyme-linked immunoelectrotransfer blot (rES33 EITB), copro PCR and copro Ag ELISA. Bayesian analysis with probabilistic constraints was used to estimate sensitivity and specificity. In total, 1254 participants were tested with the TS POC test, of whom 13 tested positive using the TS POC T. Based on 161 participants with complete data, the estimated sensitivity and specificity for the TS POC T test were 38% (95% CI: 5–93%) and 99% (95% CI: 98–100%), respectively. The challenge of highly variable inter-assay performance is highlighted. We recommend either increasing the sensitivity or redesigning the test. © 2021 by the authors. Licensee MDPI, Basel, Switzerland. |
Purification of native histidine-rich protein 2 (nHRP2) from Plasmodium falciparum culture supernatant, infected RBCs, and parasite lysate.
Singh B , McCaffery JN , Kong A , Ah Y , Wilson S , Chatterjee S , Tomar D , Aidoo M , Udhayakumar V , Rogier E . Malar J 2021 20 (1) 405 BACKGROUND: Despite the widespread use of histidine-rich protein 2 (HRP2)-based rapid diagnostic tests (RDTs), purified native HRP2 antigen is not standardly used in research applications or assessment of RDTs used in the field. METHODS: This report describes the purification of native HRP2 (nHRP2) from the HB3 Plasmodium falciparum culture strain. As this culture strain lacks pfhrp3 from its genome, it is an excellent source of HRP2 protein only and does not produce the closely-related HRP3. The nHRP2 protein was isolated from culture supernatant, infected red blood cells (iRBCs), and whole parasite lysate using nickel-metal chelate chromatography. Biochemical characterization of nHRP2 from HB3 culture was conducted by SDS-PAGE and western blotting, and nHRP2 was assayed by RDT, ELISA, and bead-based immunoassay. RESULTS: Purified nHRP2 was identified by SDS-PAGE and western blot as a - 60 kDa protein that bound anti-HRP-2 monoclonal antibodies. Mouse anti-HRP2 monoclonal antibody was found to produce high optical density readings between dilutions of 1:100 and 1:3,200 by ELISA with assay signal observed up to a 1:200,000 dilution. nHRP2 yield from HB3 culture by bead-based immunoassay revealed that both culture supernatant and iRBC lysate were practical sources of large quantities of this antigen, producing a total yield of 292.4 µg of nHRP2 from two pooled culture preparations. Assessment of nHRP2 recognition by RDTs revealed that Carestart Pf HRP2 and HRP2/pLDH RDTs detected purified nHRP2 when applied at concentrations between 20.6 and 2060 ng/mL, performing within a log-fold dilution of commercially-available recombinant HRP2. The band intensity observed for the nHRP2 dilutions was equivalent to that observed for P. falciparum culture strain dilutions of 3D7 and US06 F Nigeria XII between 12.5 and 1000 parasites/µL. CONCLUSIONS: Purified nHRP2 could be a valuable reagent for laboratory applications as well as assessment of new and existing RDTs prior to their use in clinical settings. These results establish that it is possible to extract microgram quantities of the native HRP2 antigen from HB3 culture and that this purified protein is well recognized by existing monoclonal antibody lines and RDTs. |
Taskforce report on the diagnosis and clinical management of COVID-19 associated pulmonary aspergillosis.
Verweij PE , Brüggemann RJM , Azoulay E , Bassetti M , Blot S , Buil JB , Calandra T , Chiller T , Clancy CJ , Cornely OA , Depuydt P , Koehler P , Lagrou K , de Lange D , Lass-Flörl C , Lewis RE , Lortholary O , Liu PL , Maertens J , Nguyen MH , Patterson TF , Rijnders BJA , Rodriguez A , Rogers TR , Schouten JA , Wauters J , van de Veerdonk FL , Martin-Loeches I . Intensive Care Med 2021 47 (8) 1-16 PURPOSE: Invasive pulmonary aspergillosis (IPA) is increasingly reported in patients with severe coronavirus disease 2019 (COVID-19) admitted to the intensive care unit (ICU). Diagnosis and management of COVID-19 associated pulmonary aspergillosis (CAPA) are challenging and our aim was to develop practical guidance. METHODS: A group of 28 international experts reviewed current insights in the epidemiology, diagnosis and management of CAPA and developed recommendations using GRADE methodology. RESULTS: The prevalence of CAPA varied between 0 and 33%, which may be partly due to variable case definitions, but likely represents true variation. Bronchoscopy and bronchoalveolar lavage (BAL) remain the cornerstone of CAPA diagnosis, allowing for diagnosis of invasive Aspergillus tracheobronchitis and collection of the best validated specimen for Aspergillus diagnostics. Most patients diagnosed with CAPA lack traditional host factors, but pre-existing structural lung disease and immunomodulating therapy may predispose to CAPA risk. Computed tomography seems to be of limited value to rule CAPA in or out, and serum biomarkers are negative in 85% of patients. As the mortality of CAPA is around 50%, antifungal therapy is recommended for BAL positive patients, but the decision to treat depends on the patients' clinical condition and the institutional incidence of CAPA. We recommend against routinely stopping concomitant corticosteroid or IL-6 blocking therapy in CAPA patients. CONCLUSION: CAPA is a complex disease involving a continuum of respiratory colonization, tissue invasion and angioinvasive disease. Knowledge gaps including true epidemiology, optimal diagnostic work-up, management strategies and role of host-directed therapy require further study. |
Development of rSs-NIE-1 and rSs-IR Recombinant Antigen-Based Immunoblot for Detection of Antibody to Strongyloides stercoralis
de Souza JN , Langford I , Wang Y , Soares NM , Handali S . Am J Trop Med Hyg 2021 104 (6) 2038-2041 Strongyloides stercoralis is a soil-transmitted nematode that can cause life-threatening conditions in immunocompromised persons. In the United States, strongyloidiasis should be considered mainly in immigrants, refugees, or travelers. The confirmatory laboratory diagnosis is usually performed by detecting larvae from the stool, duodenal material, and sputum. In persons who are immunocompromised with severe strongyloidiasis, adult worms and eggs can be detected from duodenal material. For serological diagnosis, most assays use crude antigens to detect anti-S. stercoralis IgG. Recently, recombinant proteins such as rSs-NIE-1 and rSs-IR have been used to detect IgG antibodies. We used rSs-NIE-1 and rSs-IR recombinant antigens to develop a biplex Western blot assay to detect the IgG4 antibody in individuals with strongyloidiasis. The sensitivities of rSs-NIE-1 and rSs-IR were 97.4% and 90.8%, respectively, whereas the specificities were 97.6% and 98%, respectively. In conclusion, the biplex rSs-NIE-1 and rSs-IR immunoblot performs well in detecting IgG4 antibody in S. stercoralis-infected persons. |
Broadly neutralizing HIV-1 antibody reactivity in HIV tests: implications for diagnostics
Smith T , Masciotra S , Luo W , Sullivan V , Switzer WM , Johnson JA , Heneine W . AIDS 2021 35 (10) 1561-1565 OBJECTIVE: Passive immunization with broadly neutralizing antibodies (bNAbs) is under evaluation for HIV prevention. BNAbs target gp120 or gp41, two HIV envelope antigens commonly present in diagnostic tests. Depending on bNAb type and dose administered to humans, serum levels can reach ∼1 mg/mL and wane over several weeks to months. We investigated the reactivity of bNAbs in HIV serological tests to inform diagnostic testing practices for persons treated with these products. DESIGN METHODS: The anti-gp120 bNAbs VRCO1, PGT121, PGT145, 3BNC117, 10-1074, and N6 and anti-gp41 bNAbs 10E8 and 10E8v4 were tested with the laboratory-based Bio-Rad Ag/Ab Combo assay, the point-of-care single-use Determine Combo, OraQuick, Reveal G4, SureCheck, Uni-Gold, INSTI and DPP HIV 1/2 assays, and the supplemental Geenius and HIV-1 Western blot assays. RESULTS: At 1 mg/mL, all bNAbs were nonreactive in four screening tests. OraQuick, SureCheck, Reveal G4, and INSTI detected at least two bNAbs each; SureCheck exhibited reactivity to six bNAbs. Geenius was HIV-1 indeterminate (gp160+) with all bNAbs except PGT121, which was HIV antibody-negative. HIV-1 Western blot was indeterminate (gp41+/gp160+) with 10E8 and 10E8v4 and negative with the remaining bNAbs. There was no correlation between the test antigen construct(s) and bNAb reactivity. CONCLUSION: We identified a laboratory-based Ag/Ab EIA and three single-use rapid HIV tests that are nonreactive against a panel of bNAbs supporting some diagnostic tests can distinguish HIV-1 infection events among persons receiving bNAb immunoprophylaxis. Evaluation of HIV diagnostic tests prior to clinical use may identify suitable serologic assays for persons administered bNAbs. |
Human T-cell lymphotropic virus type 1 transmission dynamics in rural villages in the democratic republic of the congo with high nonhuman primate exposure.
Halbrook M , Gadoth A , Shankar A , Zheng H , Campbell EM , Hoff NA , Muyembe JJ , Wemakoy EO , Rimoin AW , Switzer WM . PLoS Negl Trop Dis 2021 15 (1) e0008923 The Democratic Republic of the Congo (DRC) has a history of nonhuman primate (NHP) consumption and exposure to simian retroviruses yet little is known about the extent of zoonotic simian retroviral infections in DRC. We examined the prevalence of human T-lymphotropic viruses (HTLV), a retrovirus group of simian origin, in a large population of persons with frequent NHP exposures and a history of simian foamy virus infection. We screened plasma from 3,051 persons living in rural villages in central DRC using HTLV EIA and western blot (WB). PCR amplification of HTLV tax and LTR sequences from buffy coat DNA was used to confirm infection and to measure proviral loads (pVLs). We used phylogenetic analyses of LTR sequences to infer evolutionary histories and potential transmission clusters. Questionnaire data was analyzed in conjunction with serological and molecular data. A relatively high proportion of the study population (5.4%, n = 165) were WB seropositive: 128 HTLV-1-like, 3 HTLV-2-like, and 34 HTLV-positive but untypeable profiles. 85 persons had HTLV indeterminate WB profiles. HTLV seroreactivity was higher in females, wives, heads of households, and increased with age. HTLV-1 LTR sequences from 109 persons clustered strongly with HTLV-1 and STLV-1 subtype B from humans and simians from DRC, with most sequences more closely related to STLV-1 from Allenopithecus nigroviridis (Allen's swamp monkey). While 18 potential transmission clusters were identified, most were in different households, villages, and health zones. Three HTLV-1-infected persons were co-infected with simian foamy virus. The mean and median percentage of HTLV-1 pVLs were 5.72% and 1.53%, respectively, but were not associated with age, NHP exposure, village, or gender. We document high HTLV prevalence in DRC likely originating from STLV-1. We demonstrate regional spread of HTLV-1 in DRC with pVLs reported to be associated with HTLV disease, supporting local and national public health measures to prevent spread and morbidity. |
Borrelia burgdorferi and Borrelia miyamotoi seroprevalence in California blood donors.
Brummitt SI , Kjemtrup AM , Harvey DJ , Petersen JM , Sexton C , Replogle A , Packham AE , Bloch EM , Barbour AG , Krause PJ , Green V , Smith WA . PLoS One 2020 15 (12) e0243950 The western blacklegged tick, Ixodes pacificus, an important vector in the western United States of two zoonotic spirochetes: Borrelia burgdorferi (also called Borreliella burgdorferi), causing Lyme disease, and Borrelia miyamotoi, causing a relapsing fever-type illness. Human cases of Lyme disease are well-documented in California, with increased risk in the north coastal areas and western slopes of the Sierra Nevada range. Despite the established presence of B. miyamotoi in the human-biting I. pacificus tick in California, clinical cases with this spirochete have not been well studied. To assess exposure to B. burgdorferi and B. miyamotoi in California, and to address the hypothesis that B. miyamotoi exposure in humans is similar in geographic range to B. burgdorferi, 1,700 blood donor sera from California were tested for antibodies to both pathogens. Sampling was from high endemic and low endemic counties for Lyme disease in California. All sera were screened using the C6 ELISA. All C6 positive and equivocal samples and nine randomly chosen C6 negative samples were further analyzed for B. burgdorferi antibody using IgG western blot and a modified two ELISA test system and for B. miyamotoi antibody using the GlpQ ELISA and B. miyamotoi whole cell sonicate western blot. Of the 1,700 samples tested in series, eight tested positive for antibodies to B. burgdorferi (0.47%, Exact 95% CI: 0.20, 0.93) and two tested positive for antibodies to B. miyamotoi (0.12%, Exact 95% CI: 0.01, 0.42). There was no statistically significant difference in seroprevalence for either pathogen between high and low Lyme disease endemic counties. Our results confirm a low frequency of Lyme disease and an even lower frequency of B. miyamotoi exposure among adult blood donors in California; however, our findings reinforce public health messaging that there is risk of infection by these emerging diseases in the state. |
Occurrence of Taenia species in pigs in slaughterhouses in Phu Tho province, northern Vietnam.
Nguyen TTM , Dermauw V , Noh J , Chien NH , Dao TTH , Nguyen TGT , Van Hul A , Dorny P . J Helminthol 2020 94 e201 Pigs act as the intermediate hosts of the zoonotic tapeworms Taenia solium and Taenia asiatica, as well as of the non-zoonotic Taenia hydatigena. In Vietnam, human taeniasis and cysticercosis have been reported throughout the country; however, data on porcine cysticercosis are scarce. Our study aimed to estimate the prevalence of Taenia spp. in slaughtered pigs in two districts in Phu Tho, a mountainous province in northern Vietnam from where neurocysticercosis patients commonly originate. The carcasses of 399 pigs from 51 small-scale abattoirs were checked for cysticerci, while tongue, liver, masseter muscles, diaphragm and heart were sliced and examined. Retrieved cysticerci underwent polymerase chain reaction-restriction fragment length polymorphism and sequencing for species confirmation. Blood was also collected to detect antibodies by lentil lectin-purified glycoprotein enzyme-linked immunoelectrotransfer blot (LLGP-EITB) and recombinant T24H antigen (rT24H)-EITB and circulating antigens by B158/B60 Ag-ELISA. In two pigs, T. asiatica cysticerci were found, confirming the presence of the parasite in pigs in Vietnam at a low prevalence (0.5%; 95% exact confidence interval (CI): 0-1.19%). Cysticerci of T. solium were found in none of the pigs, although one serum sample was positive for antibodies in both LLGP-EITB and rT24H-EITB. Furthermore, a high prevalence of T. hydatigena cysticercosis was observed (18.0%; 95% Wilson score CI: 14.6-22.1%). In more than half of the T. hydatigena-positive pigs, circulating antigens were detected by Ag-ELISA, confirming that this test cannot be used to diagnose T. solium cysticercosis in this region. Finally, Spirometra erinaceieuropaei was found in one pig liver. It is the first record of this zoonotic cestode species in pigs in Vietnam. Overall, the findings confirmed the complex epidemiology of Taenia spp. in pigs in Vietnam. |
Antibody responses against Anopheles darlingi immunogenic peptides in plasmodium infected humans
Londono-Renteria B , Montiel J , Calvo E , Tobón-Castaño A , Valdivia HO , Escobedo-Vargas K , Romero L , Bosantes M , Fisher ML , Conway MJ , Vásquez GM , Lenhart AE . Front Cell Infect Microbiol 2020 10 455 Introduction: Malaria is still an important vector-borne disease in the New World tropics. Despite the recent decline in malaria due to Plasmodium falciparum infection in Africa, a rise in Plasmodium infections has been detected in several low malaria transmission areas in Latin America. One of the main obstacles in the battle against malaria is the lack of innovative tools to assess malaria transmission risk, and the behavioral plasticity of one of the main malaria vectors in Latin America, Anopheles darlingi. Methods: We used human IgG antibodies against mosquito salivary gland proteins as a measure of disease risk. Whole salivary gland antigen (SGA) from Anopheles darlingi mosquitoes was used as antigen in Western blot experiments, in which a ~65 kDa protein was visualized as the main immunogenic band and sent for sequencing by mass spectrometry. Apyrase and peroxidase peptides were designed and used as antigens in an ELISA-based test to measure human IgG antibody responses in people with different clinical presentations of malaria. Results: Liquid chromatography–mass spectrometry revealed 17 proteins contained in the ~65 kDa band, with an apyrase and a peroxidase as the two most abundant proteins. Detection of IgG antibodies against salivary antigens by ELISA revealed a significant higher antibody levels in people with malaria infection when compared to uninfected volunteers using the AnDar_Apy1 and AnDar_Apy2 peptides. We also detected a significant positive correlation between the anti-peptides IgG levels and antibodies against the Plasmodium vivax and P. falciparum antigens PvMSP1 and PfMSP1. Odd ratios suggest that people with higher IgG antibodies against the apyrase peptides were up to five times more likely to have a malaria infection. Conclusion: Antibodies against salivary peptides from An. darlingi salivary gland proteins may be used as biomarkers for malaria risk. |
Seroprevalence of measles, rubella, tetanus, and diphtheria antibodies among children in Haiti, 2017
Minta AA , Andre-Alboth J , Childs L , Nace D , Rey-Benito G , Boncy J , Adrien P , Francois J , Phaimyr Jn Charles N , Blot V , Vanden Eng J , Priest JW , Rogier E , Tohme RA . Am J Trop Med Hyg 2020 103 (4) 1717-1725 In Haiti, measles, rubella, and maternal and neonatal tetanus have been eliminated, but a diphtheria outbreak is ongoing as of 2019. We conducted a national representative, household-based, two-stage cluster survey among children aged 5-7 years in 2017 to assess progress toward maintenance of control and elimination of selected vaccine-preventable diseases (VPDs). We stratified Haiti into west region (west department, including the capital city) and non-west region (all other departments). We obtained vaccination history and dried blood spots, and measured antibody concentrations to VPDs on a multiplex bead assay. Among 1,146 children, national seropositivity was 83% (95% CI: 80-86%) for tetanus, 83% (95% CI: 81-85%) for diphtheria, 87% (95% CI: 85-89%) for measles, and 84% (95% CI: 81-87%) for rubella. None of the children had long-term immunity to tetanus or diphtheria (IgG concentration >/= 1 international unit/mL). Seropositivity in the west region was lower than that in the non-west region. Vaccination coverage was 68% (95% CI: 61-74%) for >/= 3 doses of tetanus- and diphtheria-containing vaccine (DTP3), 84% (95% CI: 80-87%) for one dose of measles-rubella (MR1) vaccine, and 20% (95% CI: 16-24%) for MR2. The seroprevalence of measles, rubella, and diphtheria antibodies is lower than population immunity levels needed to prevent disease transmission, particularly in the west region; reintroduction of these diseases could lead to an outbreak. To maintain VPD control and elimination, Haiti should achieve DTP3 and MR2 coverage >/= 95%, and include tetanus and diphtheria booster doses in the routine immunization schedule. |
Review of influenza-associated pulmonary aspergillosis in ICU patients and proposal for a case definition: an expert opinion.
Verweij PE , Rijnders BJA , Bruggemann RJM , Azoulay E , Bassetti M , Blot S , Calandra T , Clancy CJ , Cornely OA , Chiller T , Depuydt P , Giacobbe DR , Janssen NAF , Kullberg BJ , Lagrou K , Lass-Flörl C , Lewis RE , Liu PW , Lortholary O , Maertens J , Martin-Loeches I , Nguyen MH , Patterson TF , Rogers TR , Schouten JA , Spriet I , Vanderbeke L , Wauters J , van de Veerdonk FL . Intensive Care Med 2020 46 (8) 1-12 PURPOSE: Invasive pulmonary aspergillosis is increasingly reported in patients with influenza admitted to the intensive care unit (ICU). Classification of patients with influenza-associated pulmonary aspergillosis (IAPA) using the current definitions for invasive fungal diseases has proven difficult, and our aim was to develop case definitions for IAPA that can facilitate clinical studies. METHODS: A group of 29 international experts reviewed current insights into the epidemiology, diagnosis and management of IAPA and proposed a case definition of IAPA through a process of informal consensus. RESULTS: Since IAPA may develop in a wide range of hosts, an entry criterion was proposed and not host factors. The entry criterion was defined as a patient requiring ICU admission for respiratory distress with a positive influenza test temporally related to ICU admission. In addition, proven IAPA required histological evidence of invasive septate hyphae and mycological evidence for Aspergillus. Probable IAPA required the detection of galactomannan or positive Aspergillus culture in bronchoalveolar lavage (BAL) or serum with pulmonary infiltrates or a positive culture in upper respiratory samples with bronchoscopic evidence for tracheobronchitis or cavitating pulmonary infiltrates of recent onset. The IAPA case definitions may be useful to classify patients with COVID-19-associated pulmonary aspergillosis (CAPA), while awaiting further studies that provide more insight into the interaction between Aspergillus and the SARS-CoV-2-infected lung. CONCLUSION: A consensus case definition of IAPA is proposed, which will facilitate research into the epidemiology, diagnosis and management of this emerging acute and severe Aspergillus disease, and may be of use to study CAPA. |
Distribution of Taenia solium diagnostic glycoproteins in the different developmental stages of the parasite
Cruz-Rivera M , Torres J , Carrillo-Farga J , Wilkins PP , Flisser A , Mendlovic F . J Parasitol 2019 105 (4) 642-650 Taenia solium is a helminth parasite that causes 2 diseases in humans: cysticercosis and taeniasis. The establishment of T. solium metacestodes in the central nervous system causes neurocysticercosis, while development of the adult tapeworm in the small intestine causes taeniasis. Serological diagnosis of neurocysticercosis is performed by Western blot with an enriched fraction of glycoproteins that has been extensively used for clinical diagnosis and epidemiological surveys. The lectin-bound fraction that is used for this assay contains 7 antigenic glycoproteins. These antigenic proteins are considered to be highly specific for cysticercosis when tested with heterologous parasitic diseases. However, recent studies show that people with taeniasis have cross-reactive antibodies against the neurocysticercosis diagnostic glycoproteins and vice versa. Nevertheless, it is not known if these diagnostic proteins are expressed in the adult stage of the parasite. In this paper, we describe the location of 3 of these glycoproteins in T. solium adults and cysticerci using polyclonal antibodies raised against a synthetic peptide based on the amino acid sequence of TS14, a recombinant protein T24H, and the native GP50. The glycoproteins' distribution was different in invaginated and evaginated cysticerci as well as in adult tapeworms. Specifically, the 3 glycoproteins studied were differentially expressed during embryogenesis. Our findings indicate that expression of the diagnostic glycoproteins is developmentally regulated; this is noteworthy since these glycoproteins are considered specific for the diagnosis of neurocysticercosis but nevertheless are present in different structures throughout the development of T. solium. Here we describe the glycoprotein expression and localization, which can be important in understanding their biological functions. In addition, our results help clarify the cross-reaction observed between people with neurocysticercosis and taeniasis to TS14, T24H, and GP50, which are used as diagnostic antigens for neurocysticercosis. |
Differences among diagnostic testing algorithms in the time from HIV diagnosis to care
Peruski AH , Wu B , Selik RM . J Clin Virol 2019 116 18-22 BACKGROUND: The association between the type of diagnostic testing algorithm for HIV infection and the time from diagnosis to care has not been fully evaluated. Here we extend an earlier analysis of this association by controlling for patient and diagnosing facility characteristics. STUDY DESIGN: Descriptive analysis of HIV infection diagnoses during 2016 reported to the National HIV Surveillance System through December 2017. Algorithm type: traditional = initial HIV antibody immunoassay followed by a Western blot or immunofluorescence antibody test; recommended = initial HIV antigen/antibody immunoassay followed by HIV-1/2 type-differentiating antibody test; rapid = two CLIA-waived rapid tests on the same date. RESULTS: In multivariate analyses controlling for patient and diagnosing facility characteristics, persons whose infection was diagnosed using the rapid algorithm were more likely to be linked to care within 30 days than those whose infection was diagnosed using the other testing algorithms (p < 0.01). The median time to link to care during a 30-day follow-up was 9.0 days (95% CI 8.0-12.0) after the rapid algorithm, 17.0 days (95% CI 17.0-18.0) after the recommended algorithm, and 23.0 days (95% CI 22.0-25.0) after the traditional algorithm. CONCLUSIONS: The time from HIV diagnosis to care varied with the type of testing algorithm. The median time to care was shortest for the rapid algorithm, longest for the traditional algorithm, and intermediate for the recommended algorithm. These results demonstrate the importance of choosing an algorithm with a short time between initial specimen collection and report of the final result to the patient. |
Evaluation of apparatus used to test liquid through protective materials: Comparison of a modified dot-blot apparatus to the ASTM penetration cell
Schwerin MR , Portnoff L , Furlong JL , Das SS , Gordon EA , Woods TO , Wood SC , Lucas AD . J Test Eval 2020 48 (1) Personal protective equipment (PPE), such as gowns used in the latest Ebola outbreak in Western Africa, are critical in preventing the spread of deadly diseases. Appropriate test systems and test soils are needed to adequately evaluate PPE. ASTM F903, Standard Test Method for Resistance of Materials Used in Protective Clothing to Penetration by Liquid, has been used for decades to test fabrics' resistance to liquid penetration. However, this test apparatus requires at least 60 mL of test solutions, is labor intensive, and has problems with leakage around the gaskets. We compared the F903 test apparatus to a modified dot-blot apparatus to evaluate the visual penetration of a blood test soil. A series of commercially available gowns and drapes were tested in each apparatus. Using blood test soil at 2 psi, there was no statistically significant difference between the two methods except for in one gown. By comparing this gown in the ASTM test apparatus with and without a screen, the particular screen selected did not account for the difference between the dot-blot and F903 apparatuses; however, it is conceivable that a particular screen/fabric combination could account for this difference. The modified dot-blot apparatus was evaluated using three different test solutions: blood, vomit, and a labeled protein (goat anti-rabbit immunoglobulin G-horseradish peroxidase [GaR IgG-HRP]) in a blood test soil solution. This testing revealed significant difference in penetration for some of the PPE garments. The modified dot-blot had several large advantages over the ASTM apparatus-over six times less specimen volume and no edge or gasket leakage. In addition, nitrocellulose can be easily incorporated into the modified dot-blot apparatus, enabling the trapping of viruses and proteins that penetrate PPE-thus permitting the use of antibodies to quickly and sensitively detect penetration. |
Prevalence of antibodies to orthopoxvirus in wild carnivores of northwestern Chihuahua, Mexico
Morgan CN , Lopez-Perez AM , Martinez-Duque P , Jackson FR , Suzan G , Gallardo-Romero NF . J Wildl Dis 2019 55 (3) 637-644 The distribution of orthopoxviruses (OPXVs) across the North American continent is suggested to be widespread in a wide range of mammalian hosts on the basis of serosurveillance studies. To address the question of whether carnivores in northwestern Mexico are exposed to naturally circulating OPXVs, wild carnivores were collected by live trapping within four different habitat types during fall of 2013 and spring of 2014 within the Janos Biosphere Reserve in northwestern Chihuahua, Mexico. A total of 51 blood samples was collected for testing. Anti-OPXV immunoglobulin G enzyme-linked immunosorbent assay, western blot, and rapid fluorescent focus inhibition test (RFFIT) assays were conducted. About 47% (24/51) of the carnivores tested were seropositive for anti-OPXV binding antibodies and had presence of immunodominant bands indicative of OPXV infection. All samples tested were negative for rabies virus neutralizing antibodies by RFFIT, suggesting that the OPXV antibodies were due to circulating OPXV, and not from exposure to oral rabies vaccine (vaccinia-vectored rabies glycoprotein vaccine) bait distributed along the US-Mexico border. Our results indicated that there may be one or more endemic OPXV circulating within six species of carnivores in northwestern Mexico. |
An automated immunoblot method for detection of IgG antibodies to hepatitis C virus: A potential supplemental antibody confirmatory assay
Kodani M , Martin M , de Castro VL , Drobeniuc J , Kamili S . J Clin Microbiol 2019 57 (3) An estimated 41,200 people were newly infected with hepatitis C virus (HCV) in 2016 in the United States. Screening tests for antibodies to HCV may generate up to 32% false positivity in low-risk populations. Current Centers for Disease Control and Prevention (CDC) screening recommendations do not require confirmatory testing of a screening anti-HCV positive test, however confirmation is valuable for surveillance in the absence of HCV RNA testing. Recombinant Immunoblot Assay (RIBA) was used as a confirmatory assay for anti-HCV reactive samples but was discontinued in 2013. Another anti-HCV confirmatory assay, INNO-LIA, is commercially available in Europe but not approved by the Food and Drug Administration (FDA) in the United States. We report the development of an anti-HCV assay performed on an automated immunoblot platform using a fourth generation HCV recombinant fusion protein. Based on testing of 70 well characterized samples of which 40 were HCV RNA and anti-HCV positive, 15 HCV RNA positive/anti-HCV negative and 15 HCV RNA and anti-HCV negative, the specificity and sensitivity of the HCV-WES assay was 100% and 95%, respectively. Concordance between INNO-LIA and HCV WES, was determined by testing 205 HCV RNA negative/anti-HCV positive samples, of which 149 (72.7%) were positive by HCV-WES, while 146 (71.2%) were positive by INNO-LIA. We have shown proof of concept for the use of this test for confirmation of screening anti-HCV results. The HCV-WES assay is advantageous over manual western blot assays and INNO-LIA including ease of use, low cost and reduced hands-on time. |
Detection and evaluation of antibody response to a Baylisascaris-specific antigen in rodent hosts with the use of Western blotting and ELISA
Sapp SGH , Handali S , Weinstein SB , Yabsley MJ . J Parasitol 2018 104 (6) 651-659 Diagnosis of parasitic diseases that involve tissue-stage larvae is challenging, and serology remains the most effective antemortem test for detecting these infections. Baylisascaris procyonis, the raccoon roundworm, is a zoonotic ascarid. Raccoons are the usual definitive host, and humans may be infected as accidental hosts. More than 150 species of birds and mammals may act as paratenic hosts, and rodents play an important role in the transmission and maintenance of this parasite in nature. Migratory larvae in paratenic host tissues can produce ocular disease and severe to fatal neurologic disease, but not all infected hosts develop signs. A sensitive and specific Western blot (WB) assay based on a recombinant Baylisascaris-specific antigen (rBpRAG-1) has been developed for use in humans. We evaluated the use of this antigen to detect Baylisascaris spp. infections in rodent paratenic hosts. With the use of 4 species of Peromyscus mice ( Peromyscus californicus, Peromyscus leucopus, Peromyscus maniculatus, Peromyscus polionotus) from a previous infection trial, we developed species-adapted WB and ELISA assays and evaluated performance compared to detection of larvae in tissue samples. These assays revealed species-level differences in seroconversion and terminal antibody concentrations, with P. leucopus developing significantly greater antibody concentrations than P. californicus and P. polionotus at all dose levels, and P. maniculatus at the low dose. Some P. californicus and P. polionotus failed to seroconvert despite the recovery of larvae from their tissues. WB and ELISA results were correlated; however, the WB demonstrated higher sensitivity than the ELISA overall (72.2% versus 63.9%, respectively). With the use of experimental samples, specificity was 100% for WB and 94.1% for ELISA. A WB was also used to test Mus and Rattus samples, and although numbers were too limited to evaluate sensitivity and specificity, all animals known to be infected by tissue digestion were WB positive, and all uninfected animals were negative. Finally, the Peromyscus-adapted WB and ELISA were used to test a set of serum samples from wild-trapped P. maniculatus and Rattus rattus. Both assays were generally sensitive, but specificity was equivocal. This emphasizes the challenge of using serology for investigation of wildlife diseases, in which hosts have unknown exposure histories. Nevertheless, serologic methods have utility in the study of Baylisascaris spp. in paratenic hosts, either wild or captive, and have advantageous attributes (non-lethal, high-throughput), but results should be interpreted carefully. |
Performance evaluation of the Bio-Rad Geenius HIV 1/2 supplemental assay
Luo W , Sullivan V , Smith T , Peters PJ , Gay C , Westheimer E , Cohen SE , Owen SM , Masciotra S . J Clin Virol 2018 111 24-28 BACKGROUND: In the US, the HIV diagnostic algorithm for laboratory settings recommends the use of an HIV-1/HIV-2 differentiation supplemental assay after an initial reactive antigen/antibody (Ag/Ab) assay result. Since the discontinuation of the Multispot HIV-1/HIV-2 Rapid Test (MS), the Geenius HIV-1/2 Supplemental assay (Geenius) is the only FDA-approved supplemental differentiation test. OBJECTIVE: We compared the performance of Geenius to MS and Western Blot (WB). STUDY DESIGN: The relative seroconversion plasma reactivity of Geenius and MS was assessed using a 50% cumulative frequency analysis from 17 HIV-1 seroconverters. In addition, previously characterized plasma specimens, 186 HIV-1 positive, 100 HIV-2 positive, and 93 Ag/Ab-positive/HIV-1 RNA-negative, were tested with Geenius v1.1 software. McNemar's test was used for paired comparison analysis. A subset of 48 specimens were retested with the upgraded Geenius v1.3 software. RESULTS: In HIV-1 seroconverters, the relative seroconversion reactivity was 2.5 and 2 days before the first positive HIV-1 WB for Geenius and MS, respectively. In HIV-1 positive samples, Geenius performed similarly to HIV-1 WB (p=0.1687) and MS (p=0.8312). In HIV-2 positive samples, Geenius underperformed compared to HIV-2 WB (p=0.0005) and MS (p=0.0012). When using the upgraded software among the HIV-1 positive and Ag/Ab-reactive/HIV-1 RNA-negative samples, gp140 reactivity decreased without affecting characterization of HIV-2 samples. CONCLUSIONS: With HIV-1 samples, Geenius, WB and MS performance was similar as supplemental tests. The updated Geenius software reduced false gp140 reactivity, but had no impact on identifying true HIV-2 infections. Further evaluation will assess the impact of the Geenius software update on final diagnostic interpretations. |
Biosafety evaluation of Janus Fe3O4-TiO2 nanoparticles in Sprague Dawley rats after intravenous injection
Su H , Song X , Li J , Iqbal MZ , Kenston SSF , Li Z , Wu A , Ding M , Zhao J . Int J Nanomedicine 2018 13 6987-7001 Introduction: Newly synthesized Janus-structured Fe3O4-TiO2 nanoparticles (NPs) appear to be a promising candidate for the diagnosis and therapy of cancer. Although the toxicity of individual Fe3O4 or TiO2 NPs has been studied extensively, the toxicity of Janus Fe3O4-TiO2 NPs is not clear. Methods: In this study, the biosafety of both Janus Fe3O4-TiO2 NPs (20-25 nm) and the maternal material TiO2 NPs (7-10 nm) were evaluated in Sprague Dawley rats after one intravenous injection into the tail vein. Healthy rats were randomly divided into one control group and six experimental groups. Thirty days after treatment, rats were killed, then blood and tissue samples were collected for hematological, biochemical, element-content, histopathological, and Western blot analysis. Results: The results show that only a slight Ti element accumulation in the heart, spleen, and liver could be found in the Janus Fe3O4-TiO2 NP groups (P>0.05 compared with control). However, significant Ti element accumulation in the spleen, lungs, and liver was found in the TiO2 NP-treated rats. Both Fe3O4-TiO2 NPs and TiO2 NPs could induce certain histopathological abnormalities. Western blot analysis showed that both NPs could induce certain apoptotic or inflammatory-related molecular protein upregulation in rat livers. A certain degree of alterations in liver function and electrolyte and lipid parameters was also observed in rats treated with both materials. However, compared to Janus structure Fe3O4-TiO2 NP-treated groups, TiO2 NPs at 30 mg/kg showed more severe adverse effects. Conclusion: Our results showed that under a low dose (5 mg/kg), both NP types had no significant toxicity in rats. Janus NPs certainly seem less toxic than TiO2 NPs in rats at 30 mg/kg. To ensure safe use of these newly developed Janus NPs in cancer diagnosis and therapy, further animal studies are needed to evaluate long-term bioeffects. |
Mass spectral detection of diethoxyphospho-tyrosine adducts on proteins from HEK293 cells using monoclonal antibody depY for enrichment
Onder S , Schopfer LM , Tacal O , Blake TA , Johnson RC , Lockridge O . Chem Res Toxicol 2018 31 (6) 520-530 Chronic illness from exposure to organophosphorus toxicants is hypothesized to involve modification of unknown proteins. Tyrosine in proteins that have no active site serine readily reacts with organophosphorus toxicants. We developed a monoclonal antibody, depY, that specifically recognizes diethoxyphospho-tyrosine in proteins and peptides, independent of the surrounding amino acid sequence. Our goal in the current study was to identify diethoxyphosphorylated proteins in human HEK293 cell lysate treated with chlorpyrifos oxon. Cell lysates treated with chlorpyrifos oxon were recognized by depY antibody in ELISA and capillary electrophoresis based Western blot. Tryptic peptides were analyzed by liquid chromatography tandem mass spectrometry. Liquid chromatography tandem mass spectrometry identified 116 diethoxyphospho-tyrosine peptides from 73 proteins in immunopurified samples, but found only 15 diethoxyphospho-tyrosine peptides from 12 proteins when the same sample was not immunopurified on depY. The most abundant proteins in the cell lysate, histone H4, heat shock 70 kDa protein 1A/1B, heat shock protein HSP 90 beta, and alpha-enolase, were represented by several diethoxyphospho-tyrosine peptides. It was concluded that use of immobilized depY improved the number of diethoxyphospho-tyrosine peptides identified in a complex mixture. The mass spectrometry results confirmed the specificity of depY for diethoxyphospho-tyrosine peptides independent of the context of the modified tyrosine, which means depY could be used to analyze modified proteins in any species. Use of the depY antibody could lead to an understanding of chronic illness from organophosphorus pesticide exposure. |
The epidemiology of porcine Taenia solium cysticercosis in communities of the Central Highlands in Vietnam
Ng-Nguyen D , Noh J , Breen K , Stevenson MA , Handali S , Traub RJ . Parasit Vectors 2018 11 (1) 360 BACKGROUND: Taenia solium cysticercosis, recognized as a neglected tropical disease by the WHO, is distributed mostly in developing countries of Latin America, sub-Saharan Africa and Asia. Pigs and humans act as intermediate hosts, acquiring T. solium cysticerci (larval stage) in their tissue, through the ingestion of T. solium eggs shed in the faeces of humans infected with adult tapeworms. The disease has a negative impact on rural economies due to losses in productivity arising from human disease, pork carcass condemnations and loss of market access. The aim of this study was to estimate the prevalence of T. solium cysticercosis in pigs in Dak Lak Province in the Central Highlands of Vietnam and to identify household level characteristics associated with T. solium porcine cysticercosis. METHODS: This was a cross-sectional study of household pigs in three districts of Dak Lak Province. A total of 408 households in six villages in three districts were visited between June and October 2015. A questionnaire was administered to the head of each household, and within each household, serum samples were collected from three pigs. Serum samples were analyzed using the recombinant T24H antigen in enzyme-linked immunoelectrotransfer blot assay and lentil lectin purified glycoprotein in EITB assay. A Bayesian, mixed-effects logistic regression model was developed to identify management factors associated with the probability of a household having at least one cysticercosis-positive pig. RESULTS: The prevalence of porcine T. solium cysticercosis in this study was low at 0.94 [95% confidence interval (CI) 0.51-1.68] cases per 100 pigs at risk, in agreement with other studies conducted throughout Vietnam. Scavenging of food and coprophagy were associated with T. solium cysticercosis [odds ratios 1.98 (95% CrI: 0.55-4.74) and 2.57 (95% CrI: 1.22-4.66), respectively]. CONCLUSIONS: This study proves that the seroprevalence of porcine cysticercosis in Dak Lak Province was as low as that of other studies conducted throughout Vietnam. Scavenging of food and coprophagy are modifiable factors, providing the opportunity to decrease the prevalence of porcine cysticercosis further in the province. |
Laboratory diagnosis of neurocysticercosis/Taenia solium
Garcia HH , O'Neal SE , Noh J , Handali S . J Clin Microbiol 2018 56 (9) Neurocysticercosis accounts for approximately 30% of all epilepsy cases in most developing countries. Immunodiagnosis of cysticercosis is complex and strongly influenced by the course of infection, the disease burden and cyst location, and the immune response of the host. The main approach to immunodiagnosis should thus be to evaluate whether the serological results are consistent with the diagnosis suggested by imaging. Antibody detection is performed using lentil-lectin purified parasite antigens in an enzyme-linked immunoelectrotransfer blot format while antigen detection uses a monoclonal antibody-based ELISA. Promising new assay configurations have been developed for detection of both antibody and antigen, including assays based on synthetic or recombinant antigens that may reduce costs and improve assay reproducibility, and multiplex bead based assays that may provide simultaneous quantitative results for several target antigens or antibodies. |
Prevalence of Rickettsia Species (Rickettsiales: Rickettsiaceae) in Dermacentor variabilis Ticks (Acari: Ixodidae) in North Carolina.
Kakumanu ML , Ponnusamy L , Sutton H , Meshnick SR , Nicholson WL , Apperson CS . J Med Entomol 2018 55 (5) 1284-1291 The American dog tick, Dermacentor variabilis (Say), is a vector of spotted fever group (SFG) rickettsiae, including Rickettsia rickettsii the causative organism of Rocky Mountain spotted fever (RMSF). In North Carolina, SFG rickettsioses (including RMSF) are a leading cause of tick-borne illness. Knowledge of the infection rate and geographic distribution of D. variabilis ticks infected with Rickettsia spp. provides information on the spatial distribution of public health risk. Accordingly, we extracted genomic DNA from adult D. variabilis collected from field habitats in 32 North Carolina counties from 2009 to 2013. A nested PCR assay of the 23S-5S intergenic spacer (IGS) region of Rickettsia coupled with reverse line blot hybridization (RLBH) with species-specific probes was used to detect and identify rickettsiae to species. Approximately half of the 532 tick DNA samples exhibited a band of the expected size on agarose gels, indicating infection with Rickettsia spp. RLBH analyses showed R. amblyommatis (formerly 'Candidatus R. amblyommii'), R. parkeri, and R. montanensis were predominant, while other Rickettsia species detected included R. conorii-like, R. massiliae, R. rhipicephali, R. canadensis, R. bellii, and some unknown Rickettsia spp. Some ticks were infected with more than one Rickettsia species. Notably, several Rickettsia-positive ticks harbored R. rickettsii. DNA sequencing was performed on a portion of the 23S-5S IGS amplicons and the results were concordant with RLB assay results. We conclude that Rickettsia spp. are common in D. variabilis in North Carolina. Geographic patterns in the occurrence of Rickettsia-infected D. variabilis ticks across the counties sampled are discussed. |
Trends in testing algorithms used to diagnose HIV infection, 2011-2015, United States and 6 dependent areas
Peruski AH , Dong X , Selik RM . J Clin Virol 2018 103 19-24 BACKGROUND: In 2014 the Centers for Disease Control and Prevention (CDC) and the Association of Public Health Laboratories (APHL) issued updated laboratory testing recommendations for the diagnosis of HIV infection. OBJECTIVES: To examine trends in the use of HIV diagnostic testing algorithms, and determine whether the use of different algorithms is associated with selected patient characteristics and linkage to HIV medical care. STUDY DESIGN: Analysis of HIV infection diagnoses during 2011-2015 reported to the National HIV Surveillance System through December 2016. Algorithm classification: traditional=initial HIV antibody immunoassay followed by a Western blot or immunofluorescence antibody test; recommended=initial HIV antibody IA followed by HIV-1/2 type-differentiating antibody test; rapid=two CLIA-waived rapid tests on same date. RESULTS: During 2011-2015, the percentage of HIV diagnoses made using the traditional algorithm decreased from 84% to 16%, the percentage using the recommended algorithm increased from 0.1% to 64%, and the percentage using the rapid testing algorithm increased from 0.1% to 2%. The percentage of persons linked to care within 30days after HIV diagnosis in 2015 was higher for diagnoses using the recommended algorithm (59%) than for diagnoses using the traditional algorithm (55%) (p<0.05). CONCLUSIONS: During 2011-2015, the percentage of HIV diagnoses reported using the recommended and rapid testing algorithms increased while the use of the traditional algorithm decreased. In 2015, persons with HIV diagnosed using the recommended algorithm were more promptly linked to care than those with diagnosis using the traditional algorithm. |
Heterologous expression of three antigenic proteins from Angiostrongylus cantonensis: ES-7, Lec-5, and 14-3-3 in mammalian cells
Cognato BB , Handali S , Morassutti AL , da Silva AJ , Graeff-Teixeira C . Mol Biochem Parasitol 2018 221 32-35 Angiostrongylus cantonensis is a parasitic nematode and the main causative agent of human cerebral eosinophilic meningoencephalitis (EoM). A definitive diagnosis of EoM usually requires serologic or molecular analysis of the patient's clinical sample. Currently, a 31kDa antigen is used in immunological tests for this purpose, however as a crude antigen preparation it may present cross-reactivity with other helminthic infections, especially echinococcosis. Heterologous expression studies using prokaryotic systems failed on producing antigenic proteins. The aim of this study was to express and purify three recombinant glycoproteins representing A. cantonensis antigens: ES-7, Lec-5, and 14-3-3, in Chinese hamster ovary (CHO) cells and ES-7 in human embryonic kidney (HEK) cells to develop a source of specific antigens to be used in the diagnosis of angiostrongyliasis. The potential diagnostic value of these three proteins was subsequently characterized in one- and two-dimensional electrophoresis and Western blot to dot blot analyses, with Angiostrongylus-positive sera, normal human sera (NHS), and a pool of Echinococcus-positive sera (included as a specificity control) used for detection. In addition, recognition of these three proteins following treatment with N-glycosidase F was examined. The ES-7 proteins that were expressed in HEK and CHO cells, and the Lec-5 protein that was expressed in CHO cells, were specifically recognized by A. cantonensis-positive sera in the 2D electrophoresis analysis. This recognition was shown to be dependent on the presence of glycidic portions, making mammalian cells a very promising source of heterologous expression antigenic proteins from Angiostrongylus. |
- Page last reviewed:Feb 1, 2024
- Page last updated:Mar 25, 2024
- Content source:
- Powered by CDC PHGKB Infrastructure