Factors associated with human West Nile virus infection in Ontario: a generalized linear mixed modelling approach.

BACKGROUND: West Nile Virus (WNV) is a mosquito-borne pathogen that has become established in North America. Risk for human infection varies geographically in accordance with climate and population factors. Though often asymptomatic, human WNV infection can cause febrile illness or, rarely, neurologic disease. WNV has become a public health concern in Canada since its introduction in 2001. METHODS: To identify predictors of human WNV incidence at the public health unit (PHU) level in Ontario, Canada, we combined data on environmental and population characteristics of PHUs with historical mosquito and human surveillance records from 2002 to 2013. We examined the associations between annual WNV incidence and monthly climate indices (e.g. minimum and maximum temperature, average precipitation), land cover (e.g. deciduous forest, water), population structure (e.g. age and sex composition) and the annual percentage of WNV-positive mosquito pools from 2002 to 2013. We then developed a generalized linear mixed model with a Poisson distribution adjusting for spatial autocorrelation and repeat measures. Further to this, to examine potential 'early season' predictors of WNV incidence in a given year, we developed a model based on winter and spring monthly climate indices. RESULTS: Several climate indices, including mean minimum temperature (o C) in February (RR = 1.58, CI: [1.42, 1.75]), and the annual percentage of WNV-positive mosquito pools (RR = 1.07, CI: [1.04, 1.11]) were significantly associated with human WNV incidence at the PHU level. Higher winter minimum temperatures were also strongly associated with annual WNV incidence in the 'early season' model (e.g. February minimum temperature (RR = 1.91, CI: [1.73, 2.12]). CONCLUSIONS: Our study demonstrates that early season temperature and precipitation indices, in addition to the percentage of WNV-positive mosquito pools in a given area, may assist in predicting the likelihood of a more severe human WNV season in southern regions of Ontario, where WNV epidemics occur sporadically.

A multicenter, community-based, mixed methods assessment of the acceptability of a triple drug regimen for elimination of lymphatic filariasis.

BACKGROUND: Many countries will not reach elimination targets for lymphatic filariasis in 2020 using the two-drug treatment regimen (diethylcarbamazine citrate [DEC] and albendazole [DA]). A cluster-randomized, community-based safety study performed in Fiji, Haiti, India, Indonesia and Papua New Guinea tested the safety and efficacy of a new regimen of ivermectin, DEC and albendazole (IDA). METHODOLOGY/PRINCIPAL FINDINGS: To assess acceptability of IDA and DA, a mixed methods study was embedded within this community-based safety study. The study objective was to assess the acceptability of IDA versus DA. Community surveys were performed in each country with randomly selected participants (>14 years) from the safety study participant list in both DA and IDA arms. In depth interviews (IDI) and focus group discussions (FGD) assessed acceptability-related themes. In 1919 individuals, distribution of sex, microfilariae (Mf) presence and circulating filarial antigenemia (CFA), adverse events (AE) and age were similar across arms. A composite acceptability score summed the values from nine indicators (range 9-36). The median (22.5) score indicated threshold of acceptability. There was no difference in scores for IDA and DA regimens. Mean acceptability scores across both treatment arms were: Fiji 33.7 (95% CI: 33.1-34.3); Papua New Guinea 32.9 (95% CI: 31.9-33.8); Indonesia 30.6 (95% CI: 29.8-31.3); Haiti 28.6 (95% CI: 27.8-29.4); India 26.8 (95% CI: 25.6-28) (P<0.001). AE, Mf or CFA were not associated with acceptability. Qualitative research (27 FGD; 42 IDI) highlighted professionalism and appreciation for AE support. No major concerns were detected about number of tablets. Increased uptake of LF treatment by individuals who had never complied with MDA was observed. CONCLUSIONS/SIGNIFICANCE: IDA and DA regimens for LF elimination were highly and equally acceptable in individuals participating in the community-based safety study in Fiji, Haiti, India, Indonesia, and Papua New Guinea. Country variation in acceptability was significant. Acceptability of the professionalism of the treatment delivery was highlighted.

Comparative characterisation of the biofilm-production abilities of Staphylococcus epidermidis isolated from human skin and platelet concentrates.

PURPOSE: Staphylococcus epidermidis is the predominant contaminant of platelet concentrates (PCs), a blood product used to treat patients with platelet deficiencies. This microorganism is able to form surface-attached aggregates (biofilms) in human skin. Herein, the abundance of S. epidermidis biofilm-producers in contaminated PCs compared to skin isolates was explored. Furthermore, the potential positive selection of S. epidermidis biofilm-producers during the blood donation process and PC manufacturing was investigated. METHODOLOGY: Twenty-four S. epidermidis isolates obtained from contaminated PCs and 48 S. epidermidis isolates obtained from the venipuncture area of human volunteers were compared for their ability to form biofilms in laboratory media and in PCs using a semi quantitative crystal violet assay. Also, the presence of the biofilm-associated icaA and icaD genes was assessed by PCR-amplification.Results/Key findings.Biofilm production in laboratory media showed a higher number of S. epidermidis biofilm-producers in the skin-derived group (43.7 %) compared to the PC-derived isolates (25 %). However, all skin and PC isolates formed biofilms in PCs. The prevalence of ica-positive biofilm-producer isolates was similar in PC and skin isolates (16.6 and 18.8 %, respectively). In contrast, the abundance of ica-negative biofilm-producers was lower in PC isolates compared to skin isolates (8.3 vs 25 %, respectively). CONCLUSION: Positive selection of S. epidermidis biofilm-producers during blood donation and PC manufacturing was not observed. Interestingly, ica-negative biofilm-producers seem to be negatively affected by skin disinfection, blood processing and PC storage. Furthermore, this study shows that S. epidermidis adopts a biofilm-forming phenotype in PCs regardless of its genetic background or origin.

Review of the factors influencing the motivation of community drug distributors towards the control and elimination of neglected tropical diseases (NTDs).

BACKGROUND: Community drug distributors or neglected tropical disease (NTD) volunteers have played a crucial role in ensuring the success of mass drug administration (MDA) programs using preventive chemotherapy (PC) for lymphatic filariasis, onchocerciasis, schistosomiasis, trachoma and soil transmitted helminths. In recent years however, a noticeable decline in motivation of some of these volunteers has been perceived, potentially negatively impacting the success of these programs. Potential hypotheses for this change in motivation include the long duration of many MDA programs, the change in sociocultural environments as well as the changes to the programs over time. This literature review identifies factors that affect NTD volunteer performance and motivation, which may be used to influence and improve future programming. METHODOLOGY/PRINCIPAL FINDINGS: A systematic search was conducted to identify studies published between January 1995 and September 2016 that investigate factors pertaining to volunteer motivation and performance in NTD drug distribution programs. Searches from several databases and grey literature yielded 400 records, of which 28 articles from 10 countries met the inclusion criteria. Quality assessment of studies was performed using the Critical Appraisal Skills Programme(CASP) checklist. Data pertaining to motivation, performance, retention and satisfaction was extracted and examined for themes. Recurring themes in the literature included monetary and material incentives, intrinsic motivation, gender, cost to participate, and health systems and community support. Of these, community support and the health system were found to be particularly impactful. Very few studies were found to explicitly look at novel incentives for volunteers and very few studies have considered the out of pocket and opportunity costs that NTD volunteers bear carrying out their tasks. CONCLUSIONS/SIGNIFICANCE: There is currently great interest in incorporating more attractive incentive schemes for NTD volunteers. However, our results show that the important challenges that volunteers face (cultural, health systems, financial and community related) may have less to do with financial incentives and may actually have a larger impact on their motivation than has previously been understood. Further integration of NTD programs into existing health systems is expected to improve the NTD volunteer working environment. Relevant community engagement related to the MDA program should also provide the supportive environment needed in the community to support NTD volunteers. Programs need to consider these issues to improve working conditions for NTD volunteers.