Clinical Evaluation of a Multiplex PCR for the Detection of Salmonella enterica Serovars Typhi and Paratyphi A from Blood Specimens in a High-Endemic Setting.

Enteric fever is a major public health concern in endemic areas, particularly in infrastructure-limited countries where Salmonella Paratyphi A has emerged in increasing proportion of cases. We aimed to evaluate a method to detect Salmonella Typhi (S. Typhi) and Salmonella Paratyphi A (S. Paratyphi A) in febrile patients in Bangladesh. We conducted a prospective study enrolling patients with fever > 38°C admitted to two large urban hospitals and two outpatient clinics located in Dhaka, Bangladesh. We developed and evaluated a method combining short culture with a new molecular assay to simultaneously detect and differentiate S. Typhi and S. Paratyphi A from other Salmonella directly from 2 to 4 mL of whole blood in febrile patients (n = 680). A total of 680 cases were enrolled from the four participating sites. An increase in the detection rate (+38.8%) in S. Typhi and S. Paratyphi A was observed with a multiplex polymerase chain reaction (PCR) assay, and absence of non-typhoidal Salmonella detection was reported. All 45 healthy controls were culture and PCR negative, generating an estimated 92.9% of specificity on clinical samples. When clinical performance was assessed in the absence of blood volume prioritization for testing, a latent class model estimates clinical performance ≥ 95% in sensitivity and specificity with likelihood ratio (LR) LR+ > 10 and LR- < 0.1 for the multiplex PCR assay. The alternative method to blood culture we developed may be useful alone or in combination with culture or serological tests for epidemiological studies in high disease burden settings and should be considered as secondary endpoint test for future vaccine trials.

Automated innovative diagnostic, data management and communication tool, for improving malaria vector control in endemic settings.

Malaria is a life-threatening disease that caused more than 400,000 deaths in sub-Saharan Africa in 2015. Mass prevention of the disease is best achieved by vector control which heavily relies on the use of insecticides. Monitoring mosquito vector populations is an integral component of control programs and a prerequisite for effective interventions. Several individual methods are used for this task; however, there are obstacles to their uptake, as well as challenges in organizing, interpreting and communicating vector population data. The Horizon 2020 project "DMC-MALVEC" consortium will develop a fully integrated and automated multiplex vector-diagnostic platform (LabDisk) for characterizing mosquito populations in terms of species composition, Plasmodium infections and biochemical insecticide resistance markers. The LabDisk will be interfaced with a Disease Data Management System (DDMS), a custom made data management software which will collate and manage data from routine entomological monitoring activities providing information in a timely fashion based on user needs and in a standardized way. The ResistanceSim, a serious game, a modern ICT platform that uses interactive ways of communicating guidelines and exemplifying good practices of optimal use of interventions in the health sector will also be a key element. The use of the tool will teach operational end users the value of quality data (relevant, timely and accurate) to make informed decisions. The integrated system (LabDisk, DDMS & ResistanceSim) will be evaluated in four malaria endemic countries, representative of the vector control challenges in sub-Saharan Africa, (Cameroon, Ivory Coast, Ethiopia and Zambia), highly representative of malaria settings with different levels of endemicity and vector control challenges, to support informed decision-making in vector control and disease management.

Ranking predictors of a sustained viral response for patients with chronic hepatitis C treated with pegylated interferon and ribavirin in Scotland.

OBJECTIVES: From the literature on the hepatitis C virus, the existence of a gap between a sustained virologic response (SVR) attainable in randomized clinical trials (RCTs) versus routine practice is not clear. Further, in terms of the pretreatment prediction of SVR, to date, studies have focused only on reporting the magnitude of association (MOA) between each predictor and an SVR. They fail to acknowledge that a predictor with a large MOA is of little value to clinicians if it has low variability in the treatment population. METHODS: Hepatitis C virus clinical databases were used to derive a large, representative cohort of Scottish pegylated interferon and ribavirin initiates. RESULTS: Overall, 39% [123/315, 95% confidence interval (CI) 34-45%] of genotype 1 and 70% (414/594, 95% CI 66-73%) of genotype 2/3 patients achieved an SVR; this compares with the pooled estimates of 47% for genotype 1 (95% CI 41-52%) and 80% for genotype 2/3 (95% CI 75-85%) RCT participants. Significant predictors of SVR identified from logistic regression were ranked on the basis of the akaike information criteria (reflecting an approach that will account for each predictor's MOA and variability) as follows: (i) genotype, % increase in akaike information criteria of the final model when variables are excluded, 58.49%; (ii) γ-glutamyl transferase, 18.64%; (iii) platelet count, 6.48%; (iv) alanine aminotransferase quotient, 4.63%; (v) ever infected with hepatitis B virus, 4.31% and (vi) sex, 3.10%. CONCLUSION: (i) The proportion of patients attaining an SVR in Scottish routine practice is marginally lower than in RCTs and (ii) other than genotype, γ-glutamyl transferase emerges as a valuable predictor of an SVR in routine practice. Further, we demonstrate an approach to more clearly discern the predictive value of response predictors.