METHODS AND FINDINGS: Our approach is based on a parsimonious mathematical model of disease transmission and only requires data collected through routine surveillance and standard case investigations. We apply it to assess the transmissibility of swine-origin influenza A H3N2v-M virus in the US, Nipah virus in Malaysia and Bangladesh, and also present a non-zoonotic example (cholera in the Dominican Republic). Estimation is based on two simple summary statistics, the proportion infected by the natural reservoir among detected cases (G) and among the subset of the first detected cases in each cluster (F). If detection of a case does not affect detection of other cases from the same cluster, we find that R can be estimated by 1-G; otherwise R can be estimated by 1-F when the case detection rate is low. In more general cases, bounds on R can still be derived.
CONCLUSIONS: We have developed a simple approach with limited data requirements that enables robust assessment of the risks posed by emerging zoonoses. We illustrate this by deriving transmissibility estimates for the H3N2v-M virus, an important step in evaluating the possible pandemic threat posed by this virus. Please see later in the article for the Editors' Summary.
METHODS: All patients presenting to the University of Malaya Medical Centre, Kuala Lumpur, Malaysia with haemoptysis were recruited prospectively and evaluated.
RESULTS: One hundred and sixty patients were evaluated for haemoptysis; 71 (44.4%) were aged 60 years or more. Significantly more patients smoked in the older age group (P = 0.002). The main causes of haemoptysis in the older patients were bronchogenic carcinoma (49.3%), pneumonia (11.3%), bronchiectasis (8.6%), cryptogenic (5.6%) and active TB (4.2%). Significantly more older patients had carcinoma (P < 0.001), while the younger patients more often had TB (P < 0.001). Chest pain was significantly more common in the older patients (P = 0.025), particularly in patients with carcinoma. Bronchoscopy alone or combined with CT of the thorax was significantly more diagnostic in the older patient (P = 0.006).
CONCLUSION: Bronchogenic carcinoma is the commonest cause of haemoptysis in patients aged 60 years and above. Presumptive anti-TB therapy should not be encouraged despite the regional high prevalence of TB.
SUBJECTS AND METHODS: A sample of 1462 school-children aged between 9 and 15 years were randomly selected from all schools in Kuala Langat, a rural district in Malaysia. Those with recurrent abdominal pain, defined according to Apley's criteria, were recruited and divided into consulters and non-consulters. A consulter was defined as a child who had sought the help of a medical practitioner at least once in the past year for recurrent abdominal pain. A detailed clinical, social and family history was obtained in all recruited children.
RESULTS: A total of 161 children were recruited: 78 (48.4%) consulters, 83 (51.6%) non-consulters. Of the consulters, 40 were boys, 38 were girls (male:female ratio = 1.1:1). The two sexes did not show a significant difference in prevalence of consulters [p=0.189). Of the ethnic groups, only Indians had a significantly higher likelihood to consult a doctor (Indians, p=0.006; Malays, p=0.742; Chinese, p=0.050]. Younger children (under 12 years) had a significantly higher chance of having been brought to see a medical practitioner (p=0.014). Children in whom age of onset of abdominal pain was below ten years were also more likely to have been seen by a doctor (p=0.012). Children who had consulted a doctor were more likely to be missing school because of abdominal pain (p<0.001). Pain severity was not a significant factor (p=0.429). Multiple logistic regression analysis revealed that the only variable that remained significantly associated with health-care consultation was school absence (p<0.001).
CONCLUSIONS: Children who saw their doctors for recurrent abdominal pain were also more likely to be those who missed school on account of abdominal pain. Following multiple regression analysis, other factors were no longer significant.
MATERIALS AND METHODS: The Singapore Cardiovascular Cohort Study is a longitudinal follow-up study on a general population cohort of 5920 persons drawn from 3 previous cross-sectional surveys. Morbidity and mortality from IHD and stroke were ascertained by record linkage using a unique identification number with the death registry, Singapore Myocardial Infarct Registry and in-patient discharge databases.
RESULTS: There were 193 first IHD events and 97 first strokes during 52,806 person-years of observation. The overall incidence of IHD was 3.8/1000 person-years and that of stroke was 1.8/1000 person-years. In both males and females, Indians had the highest IHD incidence, followed by Malays and then Chinese. For males after adjusting for age, Indians were 2.78 times (95% CI 1.86, 4.17; P < 0.0001) and 2.28 times (95% CI 1.34, 3.88; P = 0.002) more likely to get IHD than Chinese and Malays respectively. For females after adjusting for age, Indians were 1.97 times (95% CI 1.07, 3.63; P = 0.03) and 1.37 times (95% CI 0.67, 2.80; P = 0.39) more likely to get IHD than Chinese and Malays respectively. For stroke, male Chinese and Indians had higher incidence than Malays (though not statistically significant). However, in females, Malays had the highest incidence of stroke, being 2.57 times (95% CI 1.31, 5.05; P = 0.008) more likely to get stroke than Chinese after adjustment for age.
CONCLUSIONS: This prospective study of both mortality and morbidity has confirmed the higher risk of IHD in Indians. It has also found that Malay females have a higher incidence of stroke, which deserves further study because of its potential public health importance.
MATERIALS/METHODS: Multivariable models developed to predict atomised and generalised urinary symptoms, both acute and late, were considered for validation using a dataset representing 754 participants from the TROG 03.04-RADAR trial. Endpoints and features were harmonised to match the predictive models. The overall performance, calibration and discrimination were assessed.
RESULTS: 14 models from four publications were validated. The discrimination of the predictive models in an independent external validation cohort, measured using the area under the receiver operating characteristic (ROC) curve, ranged from 0.473 to 0.695, generally lower than in internal validation. 4 models had ROC >0.6. Shrinkage was required for all predictive models' coefficients ranging from -0.309 (prediction probability was inverse to observed proportion) to 0.823. Predictive models which include baseline symptoms as a feature produced the highest discrimination. Two models produced a predicted probability of 0 and 1 for all patients.
CONCLUSIONS: Predictive models vary in performance and transferability illustrating the need for improvements in model development and reporting. Several models showed reasonable potential but efforts should be increased to improve performance. Baseline symptoms should always be considered as potential features for predictive models.
METHODS: The derivation cohort included 90 Malaysian GBS patients with two sets of NCS performed early (1-20days) and late (3-8 weeks). Potential predictors of AIDP were considered in univariate and multivariate logistic regression models to develop a predictive model. The model was externally validated in 102 Japanese GBS patients.
RESULTS: Median motor conduction velocity (MCV), ulnar distal motor latency (DML) and abnormal ulnar/normal sural pattern were independently associated with AIDP at both timepoints (median MCV: p = 0.038, p = 0.014; ulnar DML: p = 0.002, p = 0.003; sural sparing: p = 0.033, p = 0.009). There was good discrimination of AIDP (area under the curve (AUC) 0.86-0.89) and this was valid in the validation cohort (AUC 0.74-0.94). Scores ranged from 0 to 6, and corresponded to AIDP probabilities of 15-98% at early NCS and 6-100% at late NCS.
CONCLUSION: The probabilities of AIDP could be reliably predicted based on median MCV, ulnar DML and ulnar/sural sparing pattern that were determined at early and late stages of GBS.
SIGNIFICANCE: A simple and valid model was developed which can accurately predict the probability of AIDP.
METHODS: This prospective cross-sectional study consecutively recruited 494 patients with suspected dengue from a health clinic in Malaysia. Both RDTs were performed onsite. The evaluated ELISA and reference tests were performed in a virology laboratory. The reference tests comprised of a reverse transcription-polymerase chain reaction and three ELISAs for the detection of dengue NS1 antigen, IgM and IgG antibodies, respectively. The diagnostic performance of evaluated tests was computed using STATA version 12.
RESULTS: The sensitivity and specificity of ViroTrack were 62.3% (95%CI 55.6-68.7) and 95.0% (95%CI 91.7-97.3), versus 66.5% (95%CI 60.0-72.6) and 95.4% (95%CI 92.1-97.6) for SD NS1 ELISA, and 52.4% (95%CI 45.7-59.1) and 97.7% (95%CI 95.1-99.2) for NS1 component of SD Bioline, respectively. The combination of the latter with its IgM and IgG components were able to increase test sensitivity to 82.4% (95%CI 76.8-87.1) with corresponding decrease in specificity to 87.4% (95%CI 82.8-91.2). Although a positive test on any of the NS1 assays would increase the probability of dengue to above 90% in a patient, a negative result would only reduce this probability to 23.0-29.3%. In contrast, this probability of false negative diagnosis would be further reduced to 14.7% (95%CI 11.4-18.6) if SD Bioline NS1/IgM/IgG combo was negative.
CONCLUSIONS: The performance of ViroTrack Dengue Acute was comparable to SD Dengue NS1 Ag ELISA. Addition of serology components to SD Bioline Dengue Duo significantly improved its sensitivity and reduced its false negative rate such that it missed the fewest dengue patients, making it a better point-of-care diagnostic tool. New RDT like ViroTrack Dengue Acute may be a potential alternative to existing RDT if its combination with serology components is proven better in future studies.
METHODS AND RESULTS: This was a retrospective longitudinal study of HF patients aged ≥18 years hospitalized at a tertiary healthcare center between January 1, 2009 and December 31, 2013 in Ghana. Patients were eligible if they were discharged from first admission for HF (index admission) and followed up to time of all-cause, cardiovascular, and HF mortality or end of study. Multivariable time-dependent Cox model and inverse-probability-of-treatment weighting of marginal structural model were used to estimate associations between statin treatment and outcomes. Adjusted hazard ratios were also estimated for lipophilic and hydrophilic statin compared with no statin use. The study included 1488 patients (mean age 60.3±14.2 years) with 9306 person-years of observation. Using the time-dependent Cox model, the 5-year adjusted hazard ratios with 95% CI for statin treatment on all-cause, cardiovascular, and HF mortality were 0.68 (0.55-0.83), 0.67 (0.54-0.82), and 0.63 (0.51-0.79), respectively. Use of inverse-probability-of-treatment weighting resulted in estimates of 0.79 (0.65-0.96), 0.77 (0.63-0.96), and 0.77 (0.61-0.95) for statin treatment on all-cause, cardiovascular, and HF mortality, respectively, compared with no statin use.
CONCLUSIONS: Among Africans with HF, statin treatment was associated with significant reduction in mortality.