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Background A unified set of criteria for neurocysticercosis (NCC) has helped to standardize its diagnosis in different settings. Methods Cysticercosis experts were convened to update current diagnostic criteria for NCC according to two principles: neuroimaging studies are essential for diagnosis, and all other information provides indirect evidence favoring the diagnosis. Recent diagnostic advances were incorporated to this revised set. Results This revised set is structured in absolute, neuroimaging and clinical/exposure criteria. Absolute criteria include: histological confirmation of parasites, evidence of subretinal cysts, and demonstration of the scolex within a cyst. Neuroimaging criteria are categorized as major (cystic lesions without scolex, enhancing lesions, multilobulated cysts, and calcifications), confirmative (resolution of cysts after cysticidal drug therapy, spontaneous resolution of single enhancing lesions, and migrating ventricular cysts on sequential neuroimaging studies) and minor (hydrocephalus and leptomeningeal enhancement). Clinical/exposure criteria include: detection of anticysticercal antibodies or cysticercal antigens by well-standardized tests, systemic cysticercosis, evidence of a household Taenia carrier, suggestive clinical manifestations, and residency in endemic areas. Besides patients having absolute criteria, definitive diagnosis can be made in those having two major neuroimaging criteria (or one major plus one confirmative criteria) plus exposure. For patients presenting with one major and one minor neuroimaging criteria plus exposure, definitive diagnosis of NCC requires the exclusion of confounding pathologies. Probable diagnosis is reserved for individuals presenting with one neuroimaging criteria plus strong evidence of exposure. Conclusions This revised set of diagnostic criteria provides simpler definitions and may facilitate its more uniform and widespread applicability in different scenarios.

Infections caused by protozoan parasites affect millions of people around the world. Traditionally, diagnosis was made by microscopy, which is insensitive and in some cases not specific. Molecular methods are highly sensitive and specific, but equipment costs and personnel training limit its availability only to specialized centers, usually far from populations with the highest risk of infection. Inexpensive methods that can be applied at the point of care (POC), especially in places with limited health infrastructure, would be a major advantage. Isothermal amplification of nucleic acids does not require thermocyclers and is relatively inexpensive and easy to implement. Among isothermal methods, recombinase polymerase amplification (RPA) is sensitive and potentially applicable at POC. We and others have developed RPA diagnostic tests to detect protozoan parasites of medical importance. Overall, our results have shown high specificity with limits of detection similar to PCR. Currently, the optimization of RPA for use at the POC is under development, and in the near future the tests should become available to detect protozoan infections in the field. In this review we discuss the current status, challenges, and future of RPA in the field of molecular diagnosis of protozoan parasites.

Background Travelers receive medical advice from a variety of sources, including travel agencies. The aim of this study is to describe the quality of pre-travel advice provided by travel agencies in Cuzco to travelers interested in visiting malaria and yellow fever endemic areas. Methods Trained medical students posed as tourists and visited travel agencies in Cuzco requesting travel advice for a trip to the southern Amazon of Peru, recording advice regarding risk and prevention of malaria and yellow fever. Results A total of 163 registered travel agencies were included in the study. The mean proposed tour duration was 6.8 days (±1.4 days) with a median time to departure of 3 days and a median tour cost of 805 US dollars (USD) [interquartile range (IQR) 580–1,095]. Overall, 45% employees failed to mention the risk for any illness. Eighteen percent of the employees acknowledged risk of malaria and 53% risk of yellow fever. However, 36% denied malaria risk and 2% denied risk of yellow fever in the region. The price of tours from travel agencies that did not mention any health risk was significantly lower [1,009.6 ± 500.5 vs 783.9 ± 402 USD, t (152) = 3, p

We appreciate the interest of Drs. Garg and Malhotra in our work, but do not share their views on the importance of having a well-defined set of diagnostic criteria for neurocysticercosis (NCC). The previous version of this set played a major role in homogenizing diagnostic concepts and definitions of NCC, and has been widely accepted by the medical community, being the most frequently cited article in NCC according to Google Scholar, with more than 700 cites up to December 2016...

Giardia duodenalis is one of the most commonly identified parasites in stool samples. Although relatively easy to treat, giardiasis can be difficult to detect as it presents similar to other diarrheal diseases. Here, we present a recombinase polymerase amplification-based Giardia (RPAG) assay to detect the presence of Giardia in stool samples. The RPAG assay was characterized on the bench top using stool samples spiked with Giardia cysts where it showed a limit-of-detection nearly as low as the gold standard polymerase chain reaction assay. The RPAG assay was then tested in the highlands of Peru on 104 stool samples collected from the surrounding communities where it showed 73% sensitivity and 95% specificity against a polymerase chain reaction and microscopy composite gold standard. Further improvements in clinical sensitivity will be needed for the RPAG assay to have clinical relevance.

Diarrheal diseases cause more morbidity and mortality around the world than human immunodeficiency virus (HIV), malaria, or tuberculosis. Given that effective treatment of persistent diarrheal illness requires knowledge of the causative organism, diagnostic tests are of paramount importance. The protozoan parasites of the genus Cryptosporidium are increasingly recognized to be responsible for a significant portion of diarrhea morbidity. We present a novel nucleic acid test to detect the presence of Cryptosporidium species in DNA extracted from stool samples. The assay uses the isothermal amplification technique recombinase polymerase amplification (RPA) to amplify trace amounts of pathogen DNA extracted from stool to detectable levels in 30 min; products are then detected visually on simple lateral flow strips. The RPA-based Cryptosporidium assay (RPAC assay) was developed and optimized using DNA from human stool samples spiked with pathogen. It was then tested using DNA extracted from the stool of infected mice where it correctly identified the presence or absence of 27 out of 28 stool samples. It was finally tested using DNA extracted from the stool of infected patients where it correctly identified the presence or absence of 21 out of 21 stool samples. The assay was integrated into a foldable, paper and plastic device that enables DNA amplification with only the use of pipets, pipet tips, and a heater. The performance of the integrated assay is comparable to or better than polymerase chain reaction (PCR), without requiring the use of thermal cycling equipment. This platform can easily be adapted to detect DNA from multiple pathogens.

Background Human T-cell lymphotropic virus (HTLV-1) is a retrovirus endemic in Latin America, Africa, and Asia. Increasing numbers are being reported in the United States. HTLV-1 causes Adult T-cell Leukemia/Lymphoma (ATL) in 3–5% of HTLV-1 carriers, usually only after a prolonged latent period. Co-infection with the nematode Strongyloides stercoralis (SS) is associated with early onset of ATL. The exact mechanism by which SS accelerates ATL development in HTLV-1 subjects is not understood. CADM1 has been recently identified as a surface marker of HTLV-1 infected cells; CD7 is a probable marker of early cell transformation. We hypothesize that previous SS infection will increase the proportion of infected T cells (CADM1+) and lead to transformation of infected cells (CADM1+CD7low) in HTLV-1 subjects. Methods In this pilot study, we tested seven subjects that were diagnosed with HTLV-1 between 2006 and 2008 and actively followed up at the HTLV-1 Cohort Clinic at the Tropical Medicine Institute in Lima, Peru. Five had previous SS infection. We performed surface flow cytometry staining of peripheral blood mononuclear cells with monoclonal antibodies against CADM1, CD7, CD4, and CD3. Current SS infection was ruled out by the Baermann technique in a stool sample. Results Average age was 53 years (range 30–79). Average time since diagnosis of HTLV-1 was 10 years (range 9–11). One 30-year-old patient with prior SS infection was diagnosed with ATL and hospitalized in the ICU at the time of follow-up and excluded from group comparison. There was a trend for higher proportions of CADM1+ T-cells in subjects with previous SS co-infection compared with those without SS (median 16.20% vs. 9.55%, P = 0.13, Mann–Whitney). The proportion of PBMCs that were CADM1+CD7− was also increased in some of those with previous SS (Figure 1). Conclusion Our pilot data suggest that SS co-infection is associated with prolonged effects on HTLV-1 infection. We noted trends towards increased numbers of HTLV-1 infected cells (CADM1+) and a predisposition towards malignant transformation (CADM1+CD7low). Further studies are needed to confirm this observation and to determine whether CADM1 and CD7 expression may be useful as a screening tool to monitor HTLV-1 subjects at high risk of developing ATL. Figure 1. Representative flow cytometry. Disclosures All authors: No reported disclosures.