Involvement and readiness of fellows from Papua New Guinea's Field Epidemiology Training Programme in the COVID-19 response, 2020-2021.

Problem: Fellows of the Papua New Guinea Field Epidemiology Training Programme (FETP) were part of the national coronavirus disease (COVID-19) response. However, the specific activities and challenges experienced by fellows in the field were unknown. Context: The advanced FETP cohort commenced just before the COVID-19 pandemic and all fellows were involved in the response. The advanced fellows participating in this review represented a cross-section of the country's public health workforce. Action: A review was conducted to better understand the scope of activities undertaken by FETP fellows, identify the challenges experienced and assess how well the programme prepared fellows for their COVID-19 response roles. A facilitated discussion based on the World Health Organization COVID-19 intra-action review methodology and an online survey was conducted with advanced FETP fellows. Outcome: The fellows made important contributions to the national COVID-19 response by assuming leadership positions at all levels of government, leading training activities and applying core field epidemiology competencies in surveillance and response activities. The programme had prepared them well for the response, giving them the confidence and skills to undertake a diverse range of response roles. Discussion: The FETP review of the COVID-19 response in Papua New Guinea highlighted the role and influence of the fellows during the pandemic response. Fellows were able to apply core field epidemiology competencies across a range of roles. The recommendations derived from this review will be instructive for the FETP specifically and the COVID-19 response generally.

Acoustical Direction Finding with Time-Modulated Arrays.

Time-Modulated Linear Arrays (TMLAs) offer useful efficiency savings over conventional phased arrays when applied in parameter estimation applications. The present paper considers the application of TMLAs to acoustic systems and proposes an algorithm for efficiently deriving the arrival angle of a signal. The proposed technique is applied in the frequency domain, where the signal and harmonic content is captured. Using a weighted average method on harmonic amplitudes and their respective main beam angles, it is possible to determine an estimate for the signal's direction of arrival. The method is demonstrated and evaluated using results from both numerical and practical implementations and performance data is provided. The use of Micro-Electromechanical Systems (MEMS) sensors allows time-modulation techniques to be applied at ultrasonic frequencies. Theoretical predictions for an array of five isotropic elements with half-wavelength spacing and 1000 data samples suggest an accuracy of ± 1 ∘ within an angular range of approximately ± 50 ∘ . In experiments of a 40 kHz five-element microphone array, a Direction of Arrival (DoA) estimation within ± 2 . 5 ∘ of the target signal is readily achieved inside a ± 45 ∘ range using a single switched input stage and a simple hardware setup.

Comparison of the burden of diarrhoeal illness among individuals with and without household cisterns in northeast Brazil.

BACKGROUND: Lack of access to safe and secure water is an international issue recognized by the United Nations. To address this problem, the One Million Cisterns Project was initiated in 2001 in Brazil's semi-arid region to provide a sustainable source of water to households. The objectives of this study were to determine the 30-day period prevalence of diarrhoea in individuals with and without cisterns and determine symptomology, duration of illness and type of health care sought among those with diarrhoea. A subgroup analysis was also conducted among children less than five years old. METHODS: A face-to-face survey was conducted between August 20th and September 20th, 2007 in the Agreste Central Region of Pernambuco State, Brazil. Households with and without a cistern that had at least one child under the age of five years were selected using systematic convenient sampling. Differences in health outcomes between groups were assessed using Pearson's Chi-squared and two-way t-tests. Demographic variables were tested for univariable associations with diarrhoea using logistic regression with random effects. P-values of 0.05 or less were considered statistically significant. RESULTS: A total of 3679 people from 774 households were included in the analysis (1863 people from 377 households with cisterns and 1816 people from 397 households without cisterns). People from households with a cistern had a significantly lower 30-day period prevalence of diarrhoea (prevalence = 11.0%; 95% CI 9.5-12.4) than people from households without a cistern (prevalence = 18.2%; 95% CI 16.4-20.0). This significant difference was also found in a subgroup analysis of children under five years old; those children with a cistern had a 30-day period prevalence of 15.6% (95% CI 12.3-18.9) versus 26.7% (95% CI 22.8-30.6) in children without a cistern. There were no significant differences between those people with and without cisterns in terms of the types of symptoms, duration of illness and health care sought for diarrhoea. CONCLUSIONS: Our results indicate that the use of cisterns for drinking water is associated with a decreased occurrence of diarrhoea in this study population. Further research accounting for additional risk factors and preventative factors should be conducted.

Impacto do uso da água de cisternas na ocorrência de episódios diarréicos na população rural do agreste central de Pernambuco, Brasil / The impact of the use of water from water-tanks on the occurrence of diarrhea in the rural population of the Central Agreste region of the Brazilian State of Pernambuco

OBJETIVOS: avaliar o impacto do uso da água de cisternas na ocorrência de episódios diarréicos comparando o número e a duração de episódios entre moradores de domicílios com e sem cisternas, numa mesma área geográfica. MÉTODOS: estudo longitudinal prospectivo aninhado a um estudo de corte transversal com dois grupos de comparação (domicílios com e sem cisternas) realizado, em 21 municípios do Agreste Central de Pernambuco, em 2007. O período de coleta foi de 60 dias, e incluiu 1765 indivíduos. Para análise descritiva utilizou-se modelos mistos hierárquicos, Mann-Whitney e Kaplan-Meyer com nível de significância de 5 por cento. RESULTADOS: entre os 949 indivíduos com cisternas, obteve-se uma redução no risco de ocorrência de episódios diarréicos de 73 por cento quando comparados aos 816 indivíduos sem cisternas (RR=0,27; p<0.001). O número médio de episódios registrados nos residentes de domicílios sem cisternas foi de 0,48 (DP=1,17), contra 0,08 (DP=0,32) nos domicílios com cisternas(z=-10,26; p<0,001). A duração média dos episódios foi 1,5 vezes maior nos domicílios sem cisternas (χ²=8,99; p=0,003). CONCLUSÕES: os achados deste estudo destacam a importância do acesso à água potável na redução de doenças. A ocorrência de diarréia, bem como, seus indicadores de gravidade - número de episódios e duração da diarréia foram consistentemente maiores nos residentes de domicílios sem cisternas.

OBJECTIVES: to evaluate the impact of the use of water-tanks on the occurrence of episodes of diarrhea, comparing the number and duration of episodes among the residents of households with and without water-tanks in the same geographical area. METHODS: a longitudinal prospective study, nested in a cross-section study comparing two groups (households with and without water-tanks), was carried out in 21 municipalities in the Central Agreste region of the Brazilian State of Pernambuco, in 2007. Data was gathered over 60 days and included 1,765 individuals. Descriptive analysis was carried out using mixed hierarchical models, Mann-Whitney and Kaplan-Meyer with the level of significance set at 5 percent. RESULTS: among the 949 individuals with water-tanks, there was a reduction in the risk of the occurrence of episodes of diarrhea of 73 percent compared with the 816 individuals without water-tanks (RR=0.27; p<0.001). The mean number of episodes registered among residents of households without water-tanks was 0.48 (SC=1.17), compared with 0.08 (SC=0.32) among households with water-tanks (z=-10.26; p<0.001). The mean during of episodes was 1.5 times greater in households without water-tanks (χ2=8.99; p=0.003). CONCLUSIONS: the findings of this study point to the importance of access to drinking water for the reduction of disease. The occurrence of diarrhea and its concomitant severity indicators-number of episodes and duration-were consistently higher among residents of households without water-tanks.

Wind turbines and bat mortality: Doppler shift profiles and ultrasonic bat-like pulse reflection from moving turbine blades.

Bat mortality resulting from actual or near-collision with operational wind turbine rotors is a phenomenon that is widespread but not well understood. Because bats rely on information contained in high-frequency echoes to determine the nature and movement of a target, it is important to consider how ultrasonic pulses similar to those used by bats for echolocation may be interacting with operational turbine rotor blades. By assessing the characteristics of reflected ultrasonic echoes, moving turbine blades operating under low wind speed conditions (<6 m s(-1)) were found to produce distinct Doppler shift profiles at different angles to the rotor. Frequency shifts of up to ±700-800 Hz were produced, which may not be perceptible by some bat species. Monte Carlo simulation of bat-like sampling by echolocation revealed that over 50 rotor echoes could be required by species such as Pipistrellus pipistrellus for accurate interpretation of blade movement, which may not be achieved in the bat's approach time-window. In summary, it was found that echoes returned from moving blades had features which could render them attractive to bats or which might make it difficult for the bat to accurately detect and locate blades in sufficient time to avoid a collision.

Physician diagnostic and reporting practices for gastrointestinal illnesses in three health regions of British Columbia.

OBJECTIVES: To estimate seasonal proportions of patient visits due to acute gastrointestinal illness (GI), assess factors influencing physicians' stool sample requests, their understanding of laboratory testing protocols and adherence to provincial stool request guidelines in three British Columbia (BC) health regions. METHODS: During a one-year period, eligible physicians were mailed four self-administered questionnaires used to estimate proportions of patients diagnosed with GI, related stool sample requests in the preceding month, and to assess factors prompting stool sample requests. RESULTS: The response rate overall for the initial comprehensive questionnaire was 18.6%; 7.4% responded to all four questionnaires. An estimated 2.5% of patient visits had a GI diagnosis; of these, 24.8% were asked to submit stool samples. Significant (p < 0.05) regional and seasonal variations were found in rates of GI and stool sample requests. Top-ranked factors prompting stool sample requests were: bloody diarrhoea, recent overseas travel, immunocompromised status, and duration of illness > 7 days; "non-patient" factors included: laboratory availability, time to receive laboratory results, and cost. Physicians' perceptions of which organisms were tested for in a 'routine' stool culture varied. INTERPRETATION: BC physicians appear to adhere to existing standardized guidelines for sample requests. This may result in systematic under-representation of certain diseases in reportable communicable disease statistics.

Microtransponder-based multiplex assay for genotyping cystic fibrosis.

BACKGROUND: We developed and evaluated a genotyping assay for detection of 50 cystic fibrosis (CF) mutations. The assay is based on small (500 microm) electronic chips, radio frequency (RF) microtransponders (MTPs). The chips are analyzed on a unique fluorescence and RF readout instrument. METHODS: We divided the CF assay into 4 panels: core, Hispanic, African-American, and Caucasian. We amplified 18 CF transmembrane regulator (CFTR) DNA fragments covering 50 mutations by use of multiplex PCR using 18 CFTR gene-specific primer pairs. PCR was followed by multiplex allele-specific primer extension (ASPE) reactions and hybridization to capture probes synthesized on MTPs. We used 100 ASPE primers and 100 capture probes. We performed fluorescence measurements of hybridized MTP kits and assay analysis using a custom automated bench-top flow instrument. RESULTS: We validated the system by performing the assay on 23 commercial DNA samples in an internal study and 32 DNA samples in an external study. For internal and external studies, correct calls were 98.8% and 95.7%, false-positive calls 1.1% and 3.9%, and false-negative calls 0.12% and 0.36%, respectively. CONCLUSIONS: The MTP-based multiplex assay and analysis platform can be used for CF genotyping.

Population distribution and burden of acute gastrointestinal illness in British Columbia, Canada.

BACKGROUND: In developed countries, gastrointestinal illness (GI) is typically mild and self-limiting, however, it has considerable economic impact due to high morbidity. METHODS: The magnitude and distribution of acute GI in British Columbia (BC), Canada was evaluated via a cross-sectional telephone survey of 4,612 randomly selected residents, conducted from June 2002 to June 2003. Respondents were asked if they had experienced vomiting or diarrhoea in the 28 days prior to the interview. RESULTS: A response rate of 44.3% was achieved. A monthly prevalence of 9.2% (95% CI 8.4-10.0), an incidence rate of 1.3 (95% CI 1.1-1.4) episodes of acute GI per person-year, and an average probability that an individual developed illness in the year of 71.6% (95% CI 68.0-74.8), weighted by population size were observed. The average duration of illness was 3.7 days, translating into 19.2 million days annually of acute GI in BC. CONCLUSION: The results corroborate those from previous Canadian and international studies, highlighting the substantial burden of acute GI.

Estimated Numbers of Community Cases of Illness Due to Salmonella, Campylobacter and Verotoxigenic Escherichia Coli: Pathogen-specific Community Rates.

OBJECTIVE: To estimate the annual number of cases of illness due to verotoxigenic Escherichia coli (VTEC), Salmonella and Campylobacter in the Canadian population, using data from the National Notifiable Disease registry (NND), estimates of under-reporting derived from several National Studies on Acute Gastrointestinal Illness, and the literature. METHODS: For each of the three pathogens (VTEC, Salmonella and Campylobacter), data were used to estimate the percentage of cases reported at each step in the surveillance system. The number of reported cases in the NND for each pathogen was then divided by these percentages. In cases where the pathogen-specific estimates were unavailable, data on acute gastrointestinal illness were used, accounting for differences between those with bloody and nonbloody diarrhea. RESULTS: For every case of VTEC, Salmonella and Campylobacter infection reported in the NND, there were an estimated 10 to 47, 13 to 37, and 23 to 49 cases annually in the Canadian population, respectively. CONCLUSIONS: The authors estimate that a significant number of infections due to VTEC, Salmonella and Campylobacter occur each year in Canada, highlighting the fact that these enteric pathogens still pose a significant health burden. Recognizing the significant amount of under-reporting is essential to designing appropriate interventions and assessing the impact of these pathogens in the population.

Estimating the burden of acute gastroenteritis, foodborne disease, and pathogens commonly transmitted by food: an international review.

The burden of foodborne disease is not well defined in many countries or regions or on a global level. The World Health Organization (WHO), in conjunction with other national public health agencies, is coordinating a number of international activities designed to assist countries in the strengthening of disease surveillance and to determine the burden of acute gastroenteritis. These data can then be used to estimate the following situations: (1) the burden associated with acute gastroenteritis of foodborne origin, (2) the burden caused by specific pathogens commonly transmitted by food, and (3) the burden caused by specific foods or food groups. Many of the scientists collaborating with the WHO on these activities have been involved in quantifying the burden of acute gastroenteritis on a national basis. This article reviews these key national studies and the international efforts that are providing the necessary information and technical resources to derive national, regional, and global burden of disease estimates.

Estimating the under-reporting rate for infectious gastrointestinal illness in Ontario.

BACKGROUND: In Ontario, infectious gastrointestinal illness (IGI) reporting can be represented by a linear model of several sequential steps required for a case to be captured in the provincial reportable disease surveillance system. Since reportable enteric data are known to represent only a small fraction of the total IGI in the community, the objective of this study was to estimate the under-reporting rate for IGI in Ontario. METHODS: A distribution of plausible values for the under-reporting rate was estimated by specifying input distributions for the proportions reported at each step in the reporting chain, and multiplying these distributions together using simulation methods. Input distributions (type of distribution and parameters) for the proportion of cases reported at each step of the reporting chain were determined using data from the Public Health Agency of Canada's National Studies on Acute Gastrointestinal Illness (NSAGI) initiative. RESULTS: For each case of enteric illness reported to the province of Ontario, the estimated number of cases of IGI in the community ranged from 105 to 1,389, with a median of 285, and a mean and standard deviation of 313 and 128, respectively. CONCLUSIONS: Each case of enteric illness reported to the province of Ontario represents an estimated several hundred cases of IGI in the community. Thus, reportable disease data should be used with caution when estimating the burden of such illness. Program planners and public health personnel may want to consider this fact when developing population-based interventions.

From stool to statistics: reporting of acute gastrointestinal illnesses in Canada.

BACKGROUND: Limitations associated with the under-reporting of enteric illnesses have long been recognized but the extent and variation of this under-reporting in Canada has not been examined. Given the public health value of surveillance data, a closer examination of under-reporting of enteric illnesses in Canada was warranted. METHODS: Paper-based surveys were administered (a) to all laboratories in Canada licensed to process stool specimens and (b) to all local public health authorities in two provinces. RESULTS: Of the laboratories surveyed, 67% (n=274) conducted on-site testing of stool specimens for enteric bacteria, 31% (n=126) for parasites and 10% (n=42) for viruses. In the year 2000, these laboratories processed 459,982 stool specimens, of which 5%, 15%, 8% and 19% were positive for enteric bacteria (excluding C. difficile), C. difficile, parasites and viruses, respectively. Variations in laboratory testing and health authority reporting protocols and policies were identified. Of the laboratory-confirmed cases of AGI reported to local public health authorities, 5% (n=846) were not reported to provincial counterparts. CONCLUSION: A significant proportion of AGI cases submitting stool specimens are not captured in Canada's passive surveillance system due to unknown etiology. A much smaller proportion of laboratory-confirmed cases reported to local public health authorities are not captured at the provincial or national level. Given that the number of laboratory-confirmed AGI cases represents such a small fraction of all community cases, strategies to compensate for under-reporting and efforts directed at harmonizing laboratory and local public health authority policies and practices would be welcomed.