Minimally Invasive Saliva Testing to Monitor Norovirus Infection in Community Settings.

BACKGROUND: Norovirus is a leading cause of acute gastroenteritis worldwide. Routine norovirus diagnosis requires stool collection. The goal of this study was to develop and validate a noninvasive method to diagnose norovirus to complement stool diagnostics and to facilitate studies on transmission. METHODS: A multiplex immunoassay to measure salivary immunoglobulin G (IgG) responses to 5 common norovirus genotypes (GI.1, GII.2, GII.4, GII.6, and GII.17) was developed. The assay was validated using acute and convalescent saliva samples collected from Peruvian children <5 years of age with polymerase chain reaction (PCR)-diagnosed norovirus infections (n = 175) and controls (n = 32). The assay sensitivity and specificity were calculated to determine infection status based on fold rise of salivary norovirus genotype-specific IgG using norovirus genotype from stool as reference. RESULTS: The salivary assay detected recent norovirus infections and correctly assigned the infecting genotype. Sensitivity was 71% and specificity was 96% across the evaluated genotypes compared to PCR-diagnosed norovirus infection. CONCLUSIONS: This saliva-based assay will be a useful tool to monitor norovirus transmission in high-risk settings such as daycare centers or hospitals. Cross-reactivity is limited between the tested genotypes, which represent the most commonly circulating genotypes.

Provision of private, piped water and sewerage connections and directly observed handwashing of mothers in a peri-urban community of Lima, Peru.

OBJECTIVES: To estimate the association between improved water and sanitation access and handwashing of mothers living in a peri-urban community of Lima, Peru. METHODS: We observed 27 mothers directly, before and after installation of private, piped water and sewerage connections in the street just outside their housing plots, and measured changes in the proportion of faecal-hand contamination and hand-to-mouth transmission events with handwashing. RESULTS: After provision of water and sewerage connections, mothers were approximately two times more likely to be observed washing their hands within a minute of defecation, compared with when they relied on shared, external water sources and non-piped excreta disposal (RR = 2.14, 95% CI = 0.99-4.62). With piped water and sewerage available at housing plots, handwashing with or without soap occurred within a minute after 48% (10/21) of defecation events and within 15 min prior to 8% (11/136) of handling food events. CONCLUSIONS: Handwashing increased following installation of private, piped water and sewerage connections, but its practice remained infrequent, particularly before food-related events. Infrastructural interventions should be coupled with efforts to promote hygiene and ensure access to water and soap at multiple on-plot locations convenient to mothers.

Direct observation of hygiene in a Peruvian shantytown: not enough handwashing and too little water.

OBJECTIVE: To document frequency of hygiene practices of mothers and children in a shantytown in Lima, Peru. METHODS: Continuous monitoring over three 12-h sessions in households without in-house water connections to measure: (i) water and soap use of 32 mothers; (ii) frequency of interrupting faecal-hand contamination by washing; and (iii) the time until faecal-hand contamination became a possible transmission event. RESULTS: During 1008 h of observation, 55% (65/119) of mothers' and 69% (37/54) of children's faecal-hand contamination events were not followed within 15 min by handwashing or bathing. Nearly 40% (67/173) of faecal-hand contamination events became possible faecal-oral transmission events. There was no difference in the time-until-transmission between mothers and children (P = 0.43). Potential transmission of faecal material to food or mouth occurred in 64% of cases within 1 h of hand contamination. Mean water usage (6.5 l) was low compared to international disaster relief standards. CONCLUSIONS: We observed low volumes of water usage, inadequate handwashing, and frequent opportunities for faecal contamination and possible transmission in this water-scarce community.

Oral sampling methods are associated with differences in immune marker concentrations.

OBJECTIVE: To determine whether the concentration and distribution of immune markers in paired oral samples were similar. STUDY TYPE: Clinical research. STUDY DESIGN: Cross-sectional study. METHODS: Paired saliva and oral secretions (OS) samples were collected. The concentration of immune markers was estimated using Luminex multiplex assay (Thermo Fisher Scientific, Waltham, MA). For each sample, the concentration of respective immune markers was normalized to total protein present and log-transformed. Median concentrations of immune markers were compared between both types of samples. Intermarker correlation in each sampling method and across sampling methods was evaluated. RESULTS: There were 90 study participants. Concentrations of immune markers in saliva samples were significantly different from concentrations in OS samples. Oral secretions samples showed higher concentrations of immunoregulatory markers, whereas the saliva samples contained proinflammatory markers in higher concentration. CONCLUSION: The immune marker profile in saliva samples is distinct from the immune marker profile in paired OS samples. LEVEL OF EVIDENCE: 2b. Laryngoscope, 128:E214-E221, 2018.

Species identification after treatment for human taeniasis.

Identification of species of human tapeworms is crucial because the consequences of infection by Taenia solium and T saginata are very different. However, evacuation of species-identifiable tapeworms is uncommon and Taenia spp eggs are indistinguishable under the microscope. Treatment of taeniasis consists of niclosamide followed by a purgative. Recently, we adopted preniclosamide and postniclosamide electrolyte-polyethyleneglycol salt (EPS) purges to improve bowel cleaning. Retrospective comparison of traditional castor oil with EPS purge showed that recovery of the tapeworm scolex was significantly improved (20 of 68 vs none of 46, p=0.0001) in the EPS group. Furthermore, 42 of 68 (62%) individuals receiving EPS excreted identifiable gravid proglottids. EPS treatment helps the visual identification of Taenia spp.

Anti-triatomine saliva immunoassays for the evaluation of impregnated netting trials against Chagas disease transmission.

Insecticide-impregnated nets can kill triatomine bugs, but it remains unclear whether they can protect against Chagas disease transmission. In a field trial in Quequeña, Peru, sentinel guinea pigs placed in intervention enclosures covered by deltamethrin-treated nets showed significantly lower antibody responses to saliva of Triatoma infestans compared with animals placed in pre-existing control enclosures. Our results strongly suggest that insecticide-treated nets prevent triatomine bites and can thereby protect against infection with Trypanosoma cruzi. Anti-salivary immunoassays are powerful new tools to evaluate intervention strategies against Chagas disease.