Paired Saliva Samples Research Articles

881. Saliva-Based, Extraction-Free PCR Testing For The Detection Of Key Respiratory Pathogens

Abstract Background Efforts to control and monitor transmissible infectious diseases rely on large-scale screening often impaired by logistically difficult or invasive sample collection. The use of saliva as a non-invasive sample type could alleviate bottlenecks encountered in mass testing strategies. Having extensively demonstrated saliva as a sensitive sample type for SARS-CoV-2 detection, we sought to validate the approach for other common upper respiratory tract pathogens. Methods We modified our RNA-extraction-free SARS-CoV-2 PCR test for multiplexed detection of four additional respiratory viruses (“SalivaDirect+”): influenza A/B, RSV, and hMPV, and singleplex detection of pneumococcus. Stability of detection was tested after storage of saliva from pathogen-positive patients at +4°C, room temperature (∼19°C) and 30°C for 72 hours. De-identified saliva samples were collected from consenting adults ≥ 18 years of age with respiratory symptoms, requiring nasopharyngeal-swab based SARS-CoV-2 testing at Yale Health, New Haven, CT, USA. Saliva samples from individuals testing nasopharyngeal-swab negative for SARS-CoV-2 at the clinical laboratory were stored at -80°C until further processing in the research laboratory. Results We confirmed the limit of assay detection at 4 copies/µl for each target. We confirmed pathogen detection remained stable at +4°C, room temperature and 30°C for up to 72 hours. From the symptomatic testing site, 804 nasopharyngeal swabs tested negative for SARS-CoV-2; their paired saliva samples were tested with the SalivaDirect+ assay. Of those, 17 (2.1%) tested positive for one of the viruses targeted (influenza A, n=7; RSV, n=4; hMPV, n=6). No samples tested positive for influenza B. For influenza A and RSV, detection by SalivaDirect+ was comparable to testing following RNA extraction but detection of hMPV was less sensitive, even following assay modifications. In singleplex testing, 87 (10.8%) samples tested positive for pneumococcus. Conclusion We expanded a low-cost, open-source saliva-based PCR test for detection of other common respiratory pathogens. By testing saliva samples from symptomatic, SARS-CoV-2-negative adults, we detected common respiratory viruses which were otherwise missed in testing focused solely on SARS-CoV-2. Disclosures Anne L. Wyllie, PhD, Co-Diagnostics: Board Member|Merck: Grant/Research Support|Pfizer: Advisor/Consultant|Pfizer: Grant/Research Support

SARS-CoV-2 RT-qPCR Ct values in saliva and nasopharyngeal swab samples for disease severity prediction

ABSTRACT Background Comparison of clinical value of RT-qPCR-based SARS-CoV-2 tests performed on saliva samples (SSs) and nasopharyngeal swab samples (NPSs) for prediction of the COVID-19 disease severity. Methods Three paired SSs and NPSs collected every 3 days from 100 hospitalised COVID-19 patients during 2020 Jul-2021 Jan were tested by RT-qPCR for the original SARS-CoV-2 virus and compared to 150 healthy controls. Cases were divided into mild+moderate (Cohort I, N = 47) and severe disease (Cohort II, N = 53) cohorts and compared. Results SARS-CoV-2 was detected in 65% (91/140) vs. 53% (82/156) of NPSs and 49% (68/139) vs. 48% (75/157) of SSs collected from Cohort I and II, respectively, resulting in the total respective detection rates of 58% (173/296) vs. 48% (143/296) (P = 0.017). Ct values of SSs were lower than those of NPSs (mean Ct = 28.01 vs. 30.07, P = 0.002). Although Ct values of the first SSs were significantly lower in Cohort I than in Cohort II (P = 0.04), it became negative earlier (mean 11.7 vs. 14.8 days, P = 0.005). Multivariate Cox proportional hazards regression analysis showed that Ct value ≤30 from SSs was the independent predictor for severe COVID-19 (HR = 10.06, 95% CI: 1.84–55.14, P = 0.008). Conclusion Salivary RT-qPCR testing is suitable for SARS-CoV-2 infection control, while simple measurement of Ct values can assist in prediction of COVID-19 severity.

Evaluation of saliva and nasopharyngeal swab sampling for genomic detection of SARS-CoV-2 in children accessing a pediatric emergency department during the second pandemic wave.

SARS-CoV-2 infection is mainly detected by multiplex real-time RT-PCR from upper respiratory specimens, which is considered the gold-standard technique for SARS-CoV-2 infection diagnosis. A nasopharyngeal (NP) swab represents the clinical sample of choice, but NP swabbing can be uncomfortable to the patients, especially for pediatric-age participants, requires trained healthcare personnel, and may generate an aerosol, increasing the intrinsic exposure risk of healthcare workers. The objective of this study was to compare paired NP and saliva samples (SS) collected from pediatric patients to evaluate whether the saliva collection procedure may be considered a valuable alternative to the classical NP swab (NPS) sampling in children. In this study, we describe a SARS-CoV-2 multiplex real-time RT-PCR protocol for SS, comparing the results with the paired NPS specimens from 256 pediatric patients (mean age 4.24 ± 4.40 years) admitted to the hospital emergency room of Azienda Ospedaliera Universitaria Integrata (AOUI), Verona, and randomly enrolled between September 2020 and December 2020. The saliva sampling demonstrated consistent results when compared to NPS use. The SARS-CoV-2 genome was detected in 16 out of 256 (6.25%) NP samples, among which 13 (5.07%) were positive even when paired SS were analyzed. Moreover, SARS-CoV-2-negative NPS and SS were consistent, and the overall concordances between NPS and SS were detected in 253 out of 256 samples (98.83%). Our results suggest that saliva samples may be considered a valuable alternative to NPS for SARS-CoV-2 direct diagnosis with multiplex real-time RT-PCR in pediatric patients.

Validation of RT-qPCR test for SARS-CoV-2 in saliva specimens

BackgroundSaliva samples may be an easier, faster, safer, and cost-saving alternative to NPS samples, and can be self-collected by the patient. Whether SARS-CoV-2 RT-qPCR in saliva is more accurate than in nasopharyngeal swaps (NPS) is uncertain. We evaluated the accuracy of the RT-qPCR in both types of samples, assuming both approaches were imperfect. MethodsWe assessed the limit of detection (LoD) of RT-qPCR in each type of sample. We collected paired NPS and saliva samples and tested them using the Berlin Protocol to detect SARS-CoV-2 envelope protein (E). We used a Bayesian latent class analysis (BLCA) to estimate the sensitivity and specificity of each test, while accounting for their conditional dependence. ResultsThe LoD were 10 copies/mL in saliva and 100 copies/mL in NPS. Paired samples of saliva and NPS were collected in 412 participants. Out of 68 infected cases, 14 were positive only in saliva. RT-qPCR sensitivity ranged from 82.7 % (95 % CrI: 54.8, 94.8) in NPS to 84.5 % (50.9, 96.5) in saliva. Corresponding specificities were 99.1 % (95 % CrI: 95.3, 99.8) and 98.4 %(95 % CrI: 92.8, 99.7). ConclusionsSARS-CoV-2 RT-qPCR test in saliva specimens has a similar or better accuracy than RT-qPCR test in NPS. Saliva specimens may be ideal for surveillance in general population, particularly in children, and in healthcare or other personnel in need of serial testing.

Measurement of anti SARS-CoV-2 RBD IgG in saliva: validation of a highly sensitive assay and effects of the sampling collection method and correction by protein.

To develop and evaluate a new highly sensitive assay to detect IgG anti-SARS-CoV-2 RBD in saliva samples. A two-step sandwich type immunoassay based on the amplified luminescent proximity homogeneous technology was developed and an analytical validation was performed. As a part of this validation, the influence of factors, such as different sampling conditions (stimulated saliva and passive drool) and the correction of values by total protein content, in the ability of saliva to detect increases in antibodies after an immune stimulus and be an alternative to serum, was evaluated. For this purpose, paired samples of saliva and serum at different times after vaccination were used. Saliva concentrations were lower than serum, but both fluids showed similar kinetics, with higher correlations when saliva was obtained by passive flow and the results were not corrected by protein. The developed method showed a good analytical performance and can properly measure antibody concentrations in saliva of vaccinated individuals. However, saliva could have a lower sensitivity compared to serum at initial stages of the immune response and also when the antibody response decreased after a stimulus.

Investigating the utility of saliva immunoglobulins for the detection of myeloma and using myeloma proteins to clarify partition between oral and systemic immunity.

ObjectivesMyeloma is characterised by the presence of monoclonal immunoglobulin (M‐protein) and the free light chain (FLC) in blood. We investigated whether these M‐proteins and FLC are detectable in myeloma patients’ saliva to evaluate its utility for non‐invasive screening and monitoring of haematological malignancies.MethodsA total of 57 patients with monoclonal gammopathy and 26 age‐matched healthy participants provided paired serum and saliva samples for immunoglobulin characterisation and quantification.ResultsMyeloma patients had IgG or IgA M‐protein levels ranging up to five times and FLC levels up to a thousand times normal levels of polyclonal immunoglobulins. Despite these highly elevated levels, only two IgG and no IgA M‐proteins or FLC could be detected in paired saliva samples. Most patients had reduced levels of serum polyclonal immunoglobulins, but all had normal levels of salivary IgA.ConclusionsImmunoglobulin transfer from blood is not determined by levels in the systemic circulation and more likely dictated by periodontal inflammation and the integrity of the oral epithelium. Immunoglobulins secreted by bone marrow plasma cells do not substantially enter saliva, which represents a poor medium for myeloma diagnosis. These findings, along with normal salivary IgA levels despite systemic immunoparesis, support a strong partitioning of oral from systemic humoral immunity.

A Community Study of SARS-CoV-2 Detection by RT-PCR in Saliva: A Reliable and Effective Method.

Efficient, wide-scale testing for SARS-CoV-2 is crucial for monitoring the incidence of the infection in the community. The gold standard for COVID-19 diagnosis is the molecular analysis of epithelial secretions from the upper respiratory system captured by nasopharyngeal (NP) or oropharyngeal swabs. Given the ease of collection, saliva has been proposed as a possible substitute to support testing at the population level. Here, we used a novel saliva collection device designed to favour the safe and correct acquisition of the sample, as well as the processivity of the downstream molecular analysis. We tested 1003 nasopharyngeal swabs and paired saliva samples self-collected by individuals recruited at a public drive-through testing facility. An overall moderate concordance (68%) between the two tests was found, with evidence that neither system can diagnose the infection in 100% of the cases. While the two methods performed equally well in symptomatic individuals, their discordance was mainly restricted to samples from convalescent subjects. The saliva test was at least as effective as NP swabs in asymptomatic individuals recruited for contact tracing. Our study describes a testing strategy of self-collected saliva samples, which is reliable for wide-scale COVID-19 screening in the community and is particularly effective for contact tracing.

Quantitative SARS-CoV-2 Viral-Load Curves in Paired Saliva Samples and Nasal Swabs Inform Appropriate Respiratory Sampling Site and Analytical Test Sensitivity Required for Earliest Viral Detection.

ABSTRACTEarly detection of SARS-CoV-2 infection is critical to reduce asymptomatic and presymptomatic transmission, curb the spread of variants, and maximize treatment efficacy. Low-analytical-sensitivity nasal-swab testing is commonly used for surveillance and symptomatic testing, but the ability of these tests to detect the earliest stages of infection has not been established. In this study, conducted between September 2020 and June 2021 in the greater Los Angeles County, California, area, initially SARS-CoV-2-negative household contacts of individuals diagnosed with COVID-19 prospectively self-collected paired anterior-nares nasal-swab and saliva samples twice daily for viral-load quantification by high-sensitivity reverse-transcription quantitative PCR (RT-qPCR) and digital-RT-PCR assays. We captured viral-load profiles from the incidence of infection for seven individuals and compared diagnostic sensitivities between respiratory sites. Among unvaccinated persons, testing saliva with a high-analytical-sensitivity assay detected infection up to 4.5 days before viral loads in nasal swabs reached concentrations detectable by low-analytical-sensitivity nasal-swab tests. For most participants, nasal swabs reached higher peak viral loads than saliva but were undetectable or at lower loads during the first few days of infection. High-analytical-sensitivity saliva testing was most reliable for earliest detection. Our study illustrates the value of acquiring early (within hours after a negative high-sensitivity test) viral-load profiles to guide the appropriate analytical sensitivity and respiratory site for detecting earliest infections. Such data are challenging to acquire but critical to designing optimal testing strategies with emerging variants in the current pandemic and to respond to future viral pandemics.

Comparative Study on the Efficacy of Commercially Available Chemical and Herbal Mouthwash against Oral Microorganisms

Aim: The present study was done to determine the activity of Naturally prepared licorice mouthwash in comparison to chlorhexidine mouthwash. 
 Introduction: Maintenance of oral hygiene is very important in preventing the growth of a sticky film of bacteria and food particles that accumulates on teeth and hence Mouthwashes are prescribed in dentistry for treatment of several oral conditions and for prevention against various microorganisms. Licorice is derived from "liquiritiae” which is shrub or herb and the yellow colour of it is due to the flavonoids content of the plant, which includes liquiritin, isoliquiritin and other compounds. Herbal Mouthwashes (mouth rinses) are solutions or liquids intended to reduce the microbial load in the oral cavity.
 Materials and Methods: This study was conducted in Saveetha Dental Hospital, Chennai, Tamilnadu, India. The liquorice was extracted and formulated as mouth wash. Fig. 1 denotes the salivary samples were obtained from 20 volunteers (10 test group, 10 control group) and then, the participants were asked to rinse their mouth with freshly prepared licorice mouthwash(test group), chlorhexidine mouthwash (control group) and then paired saliva samples were obtained immediately after and before the mouthwash and finally the Colony forming units were recorded for pre and post usage of both the herbal and commercially available mouthwash.
 Results: Study showed that there was a mean reduction in the colony-forming units with herbal mouthwash and Chlorhexidine mouth washes. Herbal mouthwash showed reduction in colony forming growth after usage of herbal mouthwash.

Quantification of torque teno virus (TTV) DNA in saliva and plasma samples in patients at short time before and after kidney transplantation

ABSTRACT Background Several reports have proposed that the viral load of torque teno virus (TTV) in plasma is a biomarker of immune function in solid organ transplantation (SOT) and in allogeneic hematopoietic stem cell transplantation. Additionally, for the latter one, TTV-DNA quantification in saliva has also been suggested. Aim to investigate the correlation between the TTV viral load and immune function in paired saliva and plasma samples in patients on kidney transplantation. Materials and Methods TTV-DNA viral load was quantified in paired samples of saliva and plasma from 71 patients before and a short-time after renal-transplantation by real-time PCR. Results The data obtained from 213 paired samples showed a slight consistency in the comparison between saliva and plasma, with prevalence of TTV-DNA being 58%, 52% and 60% in saliva samples and 60%, 73% and 90% in plasma samples before and at 15–20 and 45–60 days after transplantation, respectively. Additionally, a high TTV viral load was observed in plasma at 15–20 and 45–60 days after transplantation compared to that observed in saliva at the same time. Conclusions Overall, monitoring TTV-DNA in saliva samples could be an additional fast non-invasive option to assess the immune functionality in SOT populations.

Development of an alternative saliva test for diagnosis of SARS-CoV-2 using TRIzol: Adapting to countries with lower incomes looking for a large-scale detection program.

The use of saliva for the diagnosis of SARS-CoV-2 has shown to be a good alternative to nasopharyngeal swabs (NPS), since it permits self-collection, avoids the exposure of healthy persons to infected patients, reduces waiting times, eliminates the need of personal protective equipment and is non-invasive. Yet current saliva testing is still expensive due to the need of specialized tubes containing buffers to stabilize the RNA of SARS-CoV-2 and inactivate the virus. These tubes are expensive and not always accessible in sufficient quantities. We now developed an alternative saliva testing method, using TRIzol for extraction, viral inactivation, and storage of SARS-CoV-2 RNA, combined with RT-qPCR, which was comparable in its performance to NPS. Paired saliva samples and NPS were taken from 15 asymptomatic healthcare workers and one patient with SARS-CoV-2. Further 13 patients with SARS-CoV-2 were only saliva-tested. All the tests were performed according to CDC 2019-Novel Coronavirus (2019-nCoV) Real-Time RT-PCR Diagnostic Panel. Saliva (4 mL) was taken in sterile 50 mL tubes, 1.5 mL TRIzol were added and mixed. Our results show that 5 μL of saliva RNA extracted with TRIzol allow for an adequate detection of the virus in patients positive for SARS-CoV-2 and was equally sensitive to NPS in TRIzol. We conclude that saliva testing using TRIzol is a recommendable method for diagnosis of SARS-CoV-2 since it has several advantages over currently used saliva tests: it can be done with normal sterile tubes, does not need cold-chain handling, is stable at room temperature, is non-invasive and less costly, making it more accessible for low-income countries. Cheaper saliva testing using TRIzol is especially relevant for low-income countries to optimize diagnosis and help define quarantine durations for families, healthcare workers, schools, and other public workplaces, thus decreasing infections and mortality caused by SARS-CoV-2.

Sensitivity of the Molecular Test in Saliva for Detection of COVID-19 in Pediatric Patients With Concurrent Conditions.

Background: The reference standard for the molecular diagnostic testing for COVID-19 is the use of nasopharyngeal or combined nasopharyngeal and oropharyngeal (NP/OP) swabs. Saliva has been proposed as a minimally invasive specimen whose collection reduces the risks for health care personnel.Objective: To assess the suitability of saliva for COVID-19 diagnosis as a replacement of the reference standard NP/OP swab in the setting of a tertiary care pediatric unit.Study design: A paired study based in the prospective cohort design in patients suspected of having COVID-19.Methods: RT-PCR was used to detect SARS-CoV-2 in paired samples of saliva and NP/OP swab collected from May through August 2020 from 156 pediatric participants, of whom 128 has at least one comorbidity and 91 showed clinical symptoms related to SARS-CoV-2 infection. Additionally, we studied a group of 326 members of the hospital staff, of whom 271 had symptoms related to SARS-CoV-2 infection.Results: In the group of pediatric participants the sensitivity of the diagnostic test in saliva was 82.3% (95% CI 56.6–96.2) and the specificity 95.6% (95% CI 90.8–98.4). The prevalence of COVID-19 was 10.9% (17/156). In 6 of the 23 participants who tested positive for SARS-CoV-2 in at least one specimen type, the virus was detected in saliva but not in NP/OP swab, while in 3 participants the NP/OP swab was positive and saliva negative. In the group of adults, the sensitivity of the test in saliva was 77.8% (95% CI 67.2–86.3) and prevalence 24.8% (81/326). Discordant results between the two types of specimens showed a significant association with low viral load in the pharynx of adults but not of pediatric participants.Interpretation: In the context of a pediatric tertiary care hospital, the sensibility of the test in saliva is not high enough to replace the use of NP/OP swab for COVID-19 diagnosis. Neither NP/OP swab nor saliva could detect all the participants infected with SARS-CoV-2.

Utility of entomological indices for predicting transmission of dengue virus: secondary analysis of data from the Camino Verde trial in Mexico and Nicaragua

BackgroundDengue vector entomological indices are widely used to monitor vector density and disease control activities. But the value of these indices as predictors of dengue infection is not established. We used data from the impact assessment of a trial of community mobilization for dengue prevention (Camino Verde) to examine the associations between vector indices and evidence of dengue infection and their value for predicting dengue infection levels. In 150 clusters in Mexico and Nicaragua, two entomological surveys, three months apart, allowed calculation of the mean Container Index, Breteau index, Pupae per Household Index, and Pupae per Container Index across the two surveys. We measured recent dengue virus infection in children, indicated by a doubling of dengue antibodies in paired saliva samples over the three-month period. We examined the associations between each of the vector indices and evidence of dengue infection at household level and at cluster level, accounting for trial intervention status. To examine the predictive value for dengue infection, we constructed receiver operating characteristic (ROC) curves at household and cluster level, considering the four vector indices as continuous variables, and calculated the positive and negative likelihood ratios for different levels of the indices. None of the vector indices was associated with recent dengue infection at household level. The Breteau Index was associated with recent infection at cluster level (Odds ratio 1.36, 95% confidence interval 1.14–1.61). The ROC curve confirmed the weak predictive value for dengue infection of the Breteau Index at cluster level. Other indices showed no predictive value. Conventional vector indices were not useful in predicting dengue infection in Mexico and Nicaragua. The findings are compatible with the idea of sources of infection outside the household which were tackled by community action in the Camino Verde trial.

Relationship between saliva and plasma rufinamide concentrations in patients with epilepsy.

The assay of saliva samples provides a valuable alternative to the use of blood samples for therapeutic drug monitoring (TDM), at least for certain categories of patients. To determine the feasibility of using saliva sampling for the TDM of rufinamide, we compared rufinamide concentrations in paired samples of saliva and plasma collected from 26 patients with epilepsy at steady state. Within-patient relationships between plasma rufinamide concentrations and dose, and the influence of comedication were also investigated. Assay results in the two tested fluids showed a good correlation (r2 =.78, P<.0001), but concentrations in saliva were moderately lower than those in plasma (mean saliva to plasma ratio = 0.7±0.2). In eight patients evaluated at three different dose levels, plasma rufinamide concentrations increased linearly with increasing dose. Patients receiving valproic acid comedication had higher dose-normalized plasma rufinamide levels than patients comedicated with drugs devoid of strong enzyme-inducing or enzyme-inhibiting activity. Overall, these findings indicate that use of saliva represents a feasible option for the application of TDM in patients treated with rufinamide. Because rufinamide concentrations are lower in saliva than in plasma, a correction factor is needed if measurements made in saliva are used as a surrogate for plasma concentrations.

Alterations in the oral microbiome in HIV-infected participants after antiretroviral therapy administration are influenced by immune status.

To characterize the oral bacterial microbiome in HIV-infected participants at baseline and after 24 weeks of EFV/FTC/TDF. Thirty-five participants co-enrolled in two AIDS Clinical Trials Group (ACTG) studies, A5272 and A5280, with paired saliva samples and complete data sets were assessed. Paired saliva samples were evaluated for bacterial microbiome using 16S rDNA PCR followed by Illumina sequencing. Diversity and differential abundance was compared between groups. A random forest classification scheme was used to determine the contribution of parameters in classifying participants' CD4+ T-cell count. Bacterial communities demonstrated considerable variability both within participants and between timepoints, although they became more similar after 24 weeks of ART. At baseline, both the number of taxa detected and the average alpha diversity were variable between participants, but did not differ significantly based on CD4+ cell count, viral load or other factors. After 24 weeks of ART samples obtained from participants with persistently low CD4+ T-cell counts had significantly higher bacterial richness and diversity. Several differentially abundant taxa, including Porphyromonas species associated with periodontal disease, were identified, which discriminated between baseline and posttreatment samples. Analysis demonstrated that although inflammatory markers are important in untreated disease, the salivary microbiome may play an important role in CD4+ T-cell count recovery after ART. Shifts in the oral microbiome after ART initiation are complex, and may play an important role in immune function and inflammatory disease.

\u201cWhere we put little fish in the water there are no mosquitoes:\u201d a cross-sectional study on biological control of the Aedes aegypti vector in 90 coastal-region communities of Guerrero, Mexico

BackgroundIn the Mexican state of Guerrero, some households place fish in water storage containers to prevent the development of mosquito larvae. Studies have shown that larvivorous fish reduce larva count in household water containers, but there is a lack of evidence about whether the use of fish is associated with a reduction in dengue virus infection. We used data from the follow up survey of the Camino Verde cluster randomised controlled trial of community mobilisation to reduce dengue risk to study this association.MethodsThe survey in 2012, among 90 clusters in the three coastal regions of Guerrero State, included a questionnaire to 10,864 households about socio-demographic factors and self-reported cases of dengue illness in the previous year. Paired saliva samples provided serological evidence of recent dengue infection among 4856 children aged 3–9 years. An entomological survey in the same households looked for larvae and pupae of Aedes aegypti and recorded presence of fish and temephos in water containers. We examined associations with the two outcomes of recent dengue infection and reported dengue illness in bivariate analysis and then multivariate analysis using generalized linear mixed modelling.ResultsSome 17% (1730/10,111) of households had fish in their water containers. The presence of fish was associated with lower levels of recent dengue virus infection in children aged 3–9 years (OR 0.64; 95% CI 0.45–0.91), as was living in a rural area (OR 0.57; 95% CI 0.45–0.71), and being aged 3–5 years (OR 0.65; 95% CI 0.51–0.83). Factors associated with lower likelihood of self-reported dengue illness were: the presence of fish (OR 0.79; 95% CI 0.64–0.97), and living in a rural area (OR 0.74; 95% CI 0.65–0.84). Factors associated with higher likelihood of self-reported dengue illness were: higher education level of the household head (OR 1.28; 95% CI 1.07–1.52), living in a household with five people or less (OR 1.33; 95% CI 1.16–1.52) and household use of insecticide anti-mosquito products (OR 1.68; 95% CI 1.47–1.92).ConclusionsOur study suggests that fish in water containers may reduce the risk of dengue virus infection and dengue illness. This could be a useful part of interventions to control the Aedes aegypti vector.

Dengue occurrence relations and serology: cross-sectional analysis of results from the Guerrero State, Mexico, baseline for a cluster-randomised controlled trial of community mobilisation for dengue prevention

BackgroundThe Mexican arm of the Camino Verde trial of community mobilisation for dengue prevention covered three coastal regions of Guerrero state: Acapulco, Costa Grande and Costa Chica. A baseline cross-sectional survey provided data for community mobilisation and for adapting the intervention design to concrete conditions in the intervention areas.MethodsTrained field teams constructed community profiles in randomly selected clusters, based on observation and key informant interviews. In each household they carried out an entomological inspection of water containers, collected information on socio-demographic variables and cases of dengue illness among household members in the last year, and gathered paired saliva samples from children aged 3–9 years, which were subjected to ELISA testing to detect recent dengue infection. We examined associations with dengue illness and recent dengue infection in bivariate and then multivariate analysis.ResultsIn 70/90 clusters, key informants were unable to identify any organized community groups. Some 1.9% (1029/55,723) of the household population reported dengue illness in the past year, with a higher rate in Acapulco region. Among children 3–9 years old, 6.1% (392/6382) had serological evidence of recent dengue infection. In all three regions, household use of anti-mosquito products, household heads working, and households having less than 5 members were associated with self-reported dengue illness. In Acapulco region, people aged less than 25 years, those with a more educated household head and those from urban sites were also more likely to report dengue illness, while in Costa Chica and Costa Grande, females were more likely to report dengue illness. Among children aged 3–9 years, those aged 3–4 years and those living in Acapulco were more likely to have evidence of recent dengue infection.ConclusionsThe evidence from the baseline survey provided important support for the design and implementation of the trial intervention. The weakness of community leadership and the relatively low rates of self-reported dengue illness were challenges that the Mexican intervention team had to overcome. The higher dengue illness occurrence among women in Costa Grande and Costa Chica may help explain why women participated more than men in activities during the Camino Verde trial.

Comparing methods to collect saliva from children to analyze cytokines related to allergic inflammation

Comparing methods to collect saliva from children to analyze cytokines related to allergic inflammation

Analysis of salivary fluid and chemosensory functions in patients treated for primary malignant brain tumors

ObjectivesThe frequency and causes of chemosensory (taste and smell) disorders in cancer patients remain under-reported. This study examined the impact of cancer therapy on taste/smell functions and salivary constituents in brain tumor patients.Materials and methodsTwenty-two newly diagnosed patients with primary malignant gliomas underwent 6 weeks of combined modality treatment (CMD) with radiation and temozolomide followed by six monthly cycles of temozolomide. Chemosensory functions were assessed at 0, 3, 6, 10, 18, and 30 weeks with paired samples of saliva collected before and after an oral rinse with ferrous-spiked water. Iron (Fe)-induced oxidative stress was measured by salivary lipid oxidation (SLO); salivary proteins, electrolytes, and metals were determined. Parallel salivary analyses were performed on 22 healthy subjects.ResultsChemosensory complaints of cancer patients increased significantly during treatment (p = 0.04) except at 30 weeks. Fe-induced SLO increased at 10 and 18 weeks. When compared with healthy subjects, SLO, total protein, Na, K, Cu, P, S, and Mg levels, as averaged across all times, were significantly higher (p < 0.05), whereas salivary Zn, Fe, and oral pH levels were significantly lower in cancer patients (p < 0.05). Neither time nor treatment had a significant impact on these salivary parameters in cancer patients.ConclusionsImpact of CMT treatment on chemosensory functions can range from minimal to moderate impairment. Analysis of SLO, metals, and total protein do not provide for reliable measures of chemosensory dysfunctions over time.Clinical relevanceTaste and smell functions are relevant in health and diseases; study of salivary constituents may provide clues on the causes of their dysfunctions.

Interferon-γ and interleukin-4 detected in serum and saliva from patients with oral lichen planus

Our previous salivary study had demonstrated an apparent T helper 2 (Th2)-predominance in saliva of oral lichen planus (OLP) patients and suggested a potential of salivary interleukin-4 (IL-4) as a biomarker for monitoring disease severity. To further determine the consistency of Th1/Th2 bias of OLP, this study investigated the expression profile of interferon-γ (IFN-γ) and IL-4 in serum and the relationship of the serum levels of these cytokines with their saliva partners. Sixty ethnic Chinese patients with OLP (40 of the erythematous/ulcerative form and 20 of the reticular form) were recruited for this study, with 40 age–sex-matched healthy volunteers as control group. IFN-γ and IL-4 levels in serum and paired saliva samples were screened by enzyme-linked immunosorbent assay. OLP patient showed a low-level IFN-γ but high-level IL-4 expression profile in both serum and saliva, with a lower IFN-γ/IL-4 ratio. Serum IL-4 level in the erythematous/ulcerative group was significantly higher than that in the reticular group. Serum levels of IFN-γ and IL-4 were significantly and positively correlated with their saliva partners. These results provided more evidence for Th2 cytokine-predominant immune imbalance in OLP, as well as the potential of IL-4 as the biomarker for monitoring severity of OLP.