Most infections with pandemic Vibrio cholerae are thought to result in subclinical disease and are not captured by surveillance. Previous estimates of the ratio of infections to clinical cases have varied widely (2 to 100 infections per case). Understanding cholera epidemiology and immunity relies on the ability to translate between numbers of clinical cases and the underlying number of infections in the population. We estimated the infection incidence during the first months of an outbreak in a cholera-naive population using a Bayesian vibriocidal antibody titer decay model combining measurements from a representative serosurvey and clinical surveillance data. 3,880 suspected cases were reported in Grande Saline, Haiti, between 20 October 2010 and 6 April 2011 (clinical attack rate 18.4%). We found that more than 52.6% (95% Credible Interval (CrI) 49.4-55.7) of the population ≥2 years showed serologic evidence of infection, with a lower infection rate among children aged 2-4 years (35.5%; 95%CrI 24.2-51.6) compared with people ≥5 years (53.1%; 95%CrI 49.4-56.4). This estimated infection rate, nearly three times the clinical attack rate, with underdetection mainly seen in those ≥5 years, has likely impacted subsequent outbreak dynamics. Our findings show how seroincidence estimates improve understanding of links between cholera burden, transmission dynamics and immunity.

Multiplex-based serological surveillance is a valuable but underutilized tool to understand gaps in population-level exposure, susceptibility, and immunity to infectious diseases. Assays for which blood samples can be tested for antibodies against several pathogens simultaneously, such as multiplex bead immunoassays, can more efficiently integrate public health surveillance in low- and middle-income countries. On March 7-8, 2023 a group of experts representing research institutions, multilateral organizations, private industry, and country partners met to discuss experiences, identify challenges and solutions, and create a community of practice for integrated, multi-pathogen serosurveillance using multiplex bead assay technologies. Participants were divided into six working groups: 1) supply chain; 2) laboratory assays; 3) seroepidemiology; 4) data analytics; 5) sustainable implementation; and 6) use case scenarios. These working groups discussed experiences, challenges, solutions, and research needs to facilitate integrated, multi-pathogen serosurveillance for public health. Several solutions were proposed to address challenges that cut across working groups.

Noise-induced hearing loss (NIHL) continues to be a pervasive problem for the nation's workforce, particularly the nation's mining personnel. As one of the leading health and safety organizations in the world, the National Institute for Occupational Health and Safety (NIOSH) in Pittsburgh maintains a Hearing Loss Prevention Program (HLPP) to conduct research to reduce NIHL loss among the nation's miners. This document provides a brief overview of this HLPP, describing some of the research techniques involved in the development of engineering noise controls, methods for the development of administrative noise controls, and some of the products available to the public to protect the nation's workers hearing.

We used publicly available data to describe epidemiology, genomic surveillance, and public health and social measures from the first 3 COVID-19 pandemic waves in southern Africa during April 6, 2020-September 19, 2021. South Africa detected regional waves on average 7.2 weeks before other countries. Average testing volume 244 tests/million/day) increased across waves and was highest in upper-middle-income countries. Across the 3 waves, average reported regional incidence increased (17.4, 51.9, 123.3 cases/1 million population/day), as did positivity of diagnostic tests (8.8%, 12.2%, 14.5%); mortality (0.3, 1.5, 2.7 deaths/1 million populaiton/day); and case-fatality ratios (1.9%, 2.1%, 2.5%). Beta variant (B.1.351) drove the second wave and Delta (B.1.617.2) the third. Stringent implementation of safety measures declined across waves. As of September 19, 2021, completed vaccination coverage remained low (8.1% of total population). Our findings highlight opportunities for strengthening surveillance, health systems, and access to realistically available therapeutics, and scaling up risk-based vaccination.

INTRODUCTION: Malawi experienced two waves of COVID-19 between April 2020 and February 2021. A High negative impact of COVID-19 was experienced in the second wave, with increased hospital admissions that overwhelmed the healthcare system. This paper describes a protocol to implement a telephone-based syndromic surveillance system to assist public health leaders in the guidance, implementation, and evaluation of programs and policies for COVID-19 prevention and control in Malawi. STUDY DESIGN: This is a serial cross-sectional telephonic-based national survey focusing on the general population and People living with HIV and AIDS. METHODS: We will conduct a serial cross-sectional telephone survey to assess self-reported recent and current experience of influenza-like illness (ILI)/COVID-19-like-illness (CLI), household deaths, access to routine health services, and knowledge related to COVID-19. Structured questionnaires will be administered to two populations: 1) the general population and 2) people living with HIV (PLHIV) on antiretroviral therapy (ART) at EGPAF-supported health facilities. Electronic data collection forms using secure tablets will be used based on randomly selected mobile numbers from electronic medical records (EMR) for PLHIV. We will use random digit dialing (RDD) for the general population to generate phone numbers to dial respondents. The technique uses computer-generated random numbers, using the 10-digit basic structure of mobile phone numbers for the two existing mobile phone companies in Malawi. Interviews will be conducted only with respondents that will verbally consent. A near real-time online dashboard will be developed to help visualize the data and share results with key policymakers. CONCLUSION: The designed syndromic surveillance system is low-cost and feasible to implement under COVID-19 restrictions, with no physical contact with respondents and limited movement of the study teams and communities. The system will allow estimation proportions of those reporting ILI/CLI among the general population and PLHIV on ART and monitor trends over time to detect locations with possible COVID-19 transmission. Reported household deaths in Malawi, access to health services, and COVID-19 knowledge will be monitored to assess the burden and impact on communities in Malawi.

BACKGROUND: Household transmission studies inform how viruses spread among close contacts, but few characterize household transmission of endemic coronaviruses. METHODS: We used data collected from 223 households with school-age children participating in weekly disease surveillance over two respiratory virus seasons (December 2015 to May 2017), to describe clinical characteristics of endemic human coronaviruses (HCoV-229E, HCoV-HKU1, HCoV-NL63, HCoV-OC43) infections, and community and household transmission probabilities using a chain-binomial model correcting for missing data from untested households. RESULTS: Among 947 participants in 223 households, we observed 121 infections during the study, most commonly subtype HCoV-OC43. Higher proportions of infected children (<19y) displayed ILI symptoms than infected adults (relative risk 3.0, 95% credible interval (CrI) 1.5, 6.9). The estimated weekly household transmission probability was 9% (95% CrI 6, 13) and weekly community acquisition probability was 7% (95% CrI 5, 10). We found no evidence for differences in community or household transmission probabilities by age or symptom status. Simulations suggest that our study was underpowered to detect such differences. CONCLUSION: Our study highlights the need for large household studies to inform household transmission, the challenges in estimating household transmission probabilities from asymptomatic individuals, and implications for controlling endemic CoVs.

Repeated noise exposure and occupational hearing loss are common health problems across industries and especially within the mining industry. Large mechanized processes, blasting, grinding, drilling, and work that is often in close quarters put many miners at an increased risk of noise overexposure. In stone, sand, and gravel mining, noise is generated from a variety of sources, depending on the type of ore being mined as well as the final consumer product provided by that mine. Depending on the source of noise generation, different strategies to reduce and avoid that noise should be implemented. The National Institute for Occupational Safety and Health (NIOSH) has evaluated the noise profile at three operational surface stone, sand, and gravel mines. A-weighted sound level meter data as well as phase array beamforming data were collected throughout the mines in areas with high noise exposure or high personnel foot or vehicle traffic. Sound level meter data collected on a grid pattern was used to develop sound profiles of the working areas. These sound contour maps as well as phase array beamforming plots were provided to the mines as well as guidance to modify work areas or personnel traffic to reduce noise exposure. 2020, This is a U.S. government work and its text is not subject to copyright protection in the United States; however, its text may be subject to foreign copyright protection.

BACKGROUND: The purpose of this study was to estimate the prevalence of hearing loss (HL) among noise-exposed US workers within the Mining, and Oil and Gas Extraction (OGE) sectors. METHODS: Audiograms of 1.9 million workers across all industries (including 9389 in Mining and 1076 in OGE) from 2006 to 2015 were examined. Prevalence and adjusted risk as compared to a reference industry (Couriers and Messengers) were estimated for all industries combined and the Mining and OGE sectors and subsectors. RESULTS: The prevalences of HL in Mining and OGE were 24% and 14%, respectively, compared with 16% for all industries combined. Many Mining and one OGE subsector exceeded these prevalences and most had an adjusted risk (prevalence ratio) significantly greater than the reference industry. Some subsectors, particularly in OGE, could not be examined due to low sample size. The prevalences in Construction Sand and Gravel Mining and Natural Gas Liquid Extraction were 36% and 28%, respectively. Workers within Support Activities for Coal Mining had double the risk of HL than workers in the reference industry. CONCLUSIONS: The many subsectors identified with high prevalences and/or worker risks for HL well above risks in the reference industry need critical attention to conserve worker hearing and maintain worker quality of life. Administrative and engineering controls can reduce worker hazardous noise exposures. Noise and ototoxic chemical exposure information is needed for many subsectors, as is audiometric testing results for OGE workers. Additional research is also needed to further characterize exposures and improve hearing conservation measures.

Objective: To evaluate the hearing loss risk in different sectors and subunits in the mining industry and to identify associated occupations, in an attempt to locate gaps between hearing conservation efforts and hearing loss risks.Design: Descriptive statistics and frequency tables were generated by commodity types, subunit operations, and/or occupations. Temporal trends of the incidences of hearing loss were reported by commodity types.Study Sample: The MSHA Accident/Injury/Illness and MSHA Address/Employment databases from 2000 to 2014 were used.Results: Incidence rate of OHL was reported highest in the coal sector compared to other commodity types. Those members of the workforce that entered the mining industry after the year 2000 accounted for 6.5% and 19.0% of the total hearing loss records for coal and non-coal, respectively. High-risk occupations found in all three commodity sectors (coal; stone, sand, and gravel; and metal/non-metal) were electrician/helper/wireman, mechanic/repairman/helper, bulldozer/tractor operator, and truck driver.Conclusion: Hearing loss risks were not uniform across mining sectors, subunit operations, and occupations. In addition to the continuous efforts of implementing engineering controls to reduce machinery sound level exposure for operators, a multi-level approach may benefit those occupations with a more dynamic exposure profile - e.g., labour/utilityman/bullgang, electrician/helper/wireman, and mechanic/repairman/helper.

Many mobile sound measurement applications (apps) have been developed to take advantage of the built-in or fit-in sensors of the smartphone. One of the concerns is the accuracy of these apps when compared to professional sound measurement instruments. Previously, a research team from the National Institute for Occupational Safety and Health (NIOSH) developed the NIOSH Sound Level Meter (SLM) app for iOS smart devices. The team found the average accuracy of this app to be within 1 dBA when using calibrated external microphones with a type 1 reference device and measuring pink noise at levels from 65 to 95 dBA in 5-dBA increments. The studies were conducted in a reverberant noise chamber at the NIOSH Acoustics Laboratory in Cincinnati. However, it is still unknown how this app performs in measuring industrial/mining sound levels outside of a controlled laboratory environment. The current NIOSH study evaluates the NIOSH SLM app to measure sound levels from a jumbo drill (a large mining machine). The study was conducted in a hemi-anechoic chamber at the NIOSH Pittsburgh Mining Research Division and followed by a field evaluation in an underground metal mine. Six different iOS smart devices were used with two types of external microphones chosen from previous studies to measure sound levels during jumbo drill operations, and the results were compared with a reference device. Results show that the average sound levels measured by the NIOSH SLM app are within 1 dBA of the reference device both in the laboratory and field. However, the type of operation being performed, the selection and use of external microphones, distance from a noise source, and environmental factors (e.g., air movement) may all influence the accuracy of the app's performance. Although additional validation is still needed, the results from this study suggest a potential for using the NIOSH SLM app, with calibrated external microphones, to measure sound levels in mining operations.

Zambia has experienced recurrent cholera outbreaks since the late 1970s, primarily during the rainy season. The 2017–2018 cholera outbreak started on October 6, 2017, initially localized to 2 peri-urban areas of Lusaka, the capital, and was linked to contaminated water consumption. From mid-December 2017 to early February 2018 cases spread city-wide, with 3938 cases and 82 deaths (case fatality rate, 2.1%) by February 17, 2018 (Figure 1).

A new noise regulation for the mining industry became effective in 2000, providing a consistent regulatory requirement for both coal and non-coal mining divisions. The new rule required mines to implement hearing conservation programs, including a system of continuous noise monitoring, provision of hearing protection devices, audiometric testing, hearing loss training, and record keeping. The goal of this study was to assess hearing conservation program compliance, and excessive noise exposure and hearing loss risks for both coal and non-coal mining divisions through evaluating MSHA citations. We analyzed 13,446 MSHA citations from 2000 to 2014 pertinent to 30 CFR Part 62. Descriptive statistics were generated and comparisons were made among mines of different commodities. In addition, one-way ANOVA on ranks was conducted to estimate the correlation between excess risks and establishment size. Results showed that 25.6% of coal mines and 14.7% of non-coal mines were cited at least once during this period of time. Larger numbers of noncompliance were seen in stone, sand and gravel mines (SSG). Results also suggested inadequate efforts in both audiometric testing and minimizing risk after excessive noise exposure. Finally, establishment size of mine was correlated with the increasing risk of noncompliance. We anticipate that this study can guide resource allocation for preventing noise-induced hearing loss, and help improve risk management in mining.

BACKGROUND: Killed whole-cell oral cholera vaccines (kOCVs) are becoming a standard cholera control and prevention tool. However, vaccine efficacy and direct effectiveness estimates have varied, with differences in study design, location, follow-up duration, and vaccine composition posing challenges for public health decision making. We did a systematic review and meta-analysis to generate average estimates of kOCV efficacy and direct effectiveness from the available literature. METHODS: For this systematic review and meta-analysis, we searched PubMed, Embase, Scopus, and the Cochrane Review Library on July 9, 2016, and ISI Web of Science on July 11, 2016, for randomised controlled trials and observational studies that reported estimates of direct protection against medically attended confirmed cholera conferred by kOCVs. We included studies published on any date in English, Spanish, French, or Chinese. We extracted from the published reports the primary efficacy and effectiveness estimates from each study and also estimates according to number of vaccine doses, duration, and age group. The main study outcome was average efficacy and direct effectiveness of two kOCV doses, which we estimated with random-effect models. This study is registered with PROSPERO, number CRD42016048232. FINDINGS: Seven trials (with 695 patients with cholera) and six observational studies (217 patients with cholera) met the inclusion criteria, with an average two-dose efficacy of 58% (95% CI 42-69, I2=58%) and effectiveness of 76% (62-85, I2=0). Average two-dose efficacy in children younger than 5 years (30% [95% CI 15-42], I2=0%) was lower than in those 5 years or older (64% [58-70], I2=0%; p<0.0001). Two-dose efficacy estimates of kOCV were similar during the first 2 years after vaccination, with estimates of 56% (95% CI 42-66, I2=45%) in the first year and 59% (49-67, I2=0) in the second year. The efficacy reduced to 39% (13 to 57, I2=48%) in the third year, and 26% (-46 to 63, I2=74%) in the fourth year. INTERPRETATION: Two kOCV doses provide protection against cholera for at least 3 years. One kOCV dose provides at least short-term protection, which has important implications for outbreak management. kOCVs are effective tools for cholera control. FUNDING: The Bill & Melinda Gates Foundation.

The El Nino Southern Oscillation (ENSO) and other climate patterns can have profound impacts on the occurrence of infectious diseases ranging from dengue to cholera. In Africa, El Nino conditions are associated with increased rainfall in East Africa and decreased rainfall in southern Africa, West Africa, and parts of the Sahel. Because of the key role of water supplies in cholera transmission, a relationship between El Nino events and cholera incidence is highly plausible, and previous research has shown a link between ENSO patterns and cholera in Bangladesh. However, there is little systematic evidence for this link in Africa. Using high-resolution mapping techniques, we find that the annual geographic distribution of cholera in Africa from 2000 to 2014 changes dramatically, with the burden shifting to continental East Africa-and away from Madagascar and portions of southern, Central, and West Africa-where almost 50,000 additional cases occur during El Nino years. Cholera incidence during El Nino years was higher in regions of East Africa with increased rainfall, but incidence was also higher in some areas with decreased rainfall, suggesting a complex relationship between rainfall and cholera incidence. Here, we show clear evidence for a shift in the distribution of cholera incidence throughout Africa in El Nino years, likely mediated by El Nino's impact on local climatic factors. Knowledge of this relationship between cholera and climate patterns coupled with ENSO forecasting could be used to notify countries in Africa when they are likely to see a major shift in their cholera risk.

Powerful mining systems typically generate high-level noise that can damage the hearing ability of miners. Engineering noise controls are the most desirable and effective control for overexposure to noise. However, the effects of these noise controls on the actual hearing status of workers are not easily measured. A tool that can provide guidance in assigning workers to jobs based on the noise levels to which they will be exposed is highly desirable. Therefore, the Pittsburgh Mining Research Division (PMRD) of the U.S. National Institute for Occupational Safety and Health (NIOSH) developed a tool to estimate in a systematic way the hearing loss due to occupational noise exposure and to evaluate the effectiveness of developed engineering controls. This computer program is based on the ISO 1999 standard and can be used to estimate the loss of hearing ability caused by occupational noise exposures. In this paper, the functionalities of this software are discussed and several case studies related to mining machinery are presented to demonstrate the functionalities of this software.

Noise-induced hearing loss is the second most pervasive disease in the mining industry. The exposure of miners to noise levels above the permissible exposure level results in hearing loss of approximately 80% of coal miners by retirement age. In addition, between 2002 and 2011, approximately 48% of longwall shearer operators were overexposed in coal mines in the United States. Previous research identified the two rotating cutting drums used by the longwall shearer to extract coal as the most significant sound-radiating components. In this context, the National Institute for Occupational Safety and Health conducted research to develop noise controls for longwall mining systems. To this end, structural and acoustic numerical models of a single cutting drum were developed to assess its dynamic and acoustic response, respectively. Once validated, these models were used to explore various noise control concepts including force isolation, varying structural damping and varying component stiffness. Upon multiple simulations, it was determined that structural modifications to increase the stiffness of the outer vane plates were the most practical and durable approach to reduce the sound radiated by the cutting drums. Furthermore, these modifications did not adversely affect the cutting performance, nor the loading ability of the drums. As a result, these structural modifications were implemented into an actual set of drums for evaluation purposes. Results from the underground evaluation, when the modified cutting drums were used under normal operation conditions, showed noise reduction across the entire frequency spectrum with an overall noise reduction of 3 dB in the sound pressure level at the operator location, confirming the validity of the developed noise controls.

Firdausi Qadri and colleagues (July 8, p 1362)1 reported results from a trial of the oral cholera vaccine, which included an arm combining the oral cholera vaccine with an intervention promoting handwashing and drinking water treatment at home. The authors reported no significant protective effect of the behaviour change intervention over that of the vaccine alone. Despite the authors' cautions against drawing conclusions from a study that had no independent water and hygiene intervention arm, media sources misinterpreted the results2 as “…the oral vaccine worked way better than…getting people to wash their hands and drink clean water”.3 | Receipt of the intervention for behaviour change was contingent on the oral cholera vaccine, biasing any interpretation of its independent effectiveness, and was a poor proxy for access to potable water, soap, and sanitation, which eliminated cholera from much of the world more than a century ago. 2 months after vaccination, participants were offered a handwashing station, a sachet of soap, and a bottle of soapy water, and were trained in the use of these items. 4 months after vaccination, chlorine for water treatment was introduced and its use promoted. No measures of intervention uptake or compliance were described.

In collaboration with Kennametal Inc. and Corry Rubber Corporation, the U.S. National Institute for Occupational Safety and Health (NIOSH) developed a drill bit isolator to address noise overexposures associated with roof bolting machines in underground coal mines. NIOSH laboratory studies confirmed that the drill bit isolator reduces noise during drilling. Field studies were needed to confirm that a noise reduction could be obtained under working conditions and that the device was sufficiently durable. This paper reports results of field tests of the device conducted at five underground coal mines. Noise reduction was assessed by comparing the operator’s noise exposure during drilling with and without the drill bit isolator. Durability was assessed by recording the number of holes and total feet drilled with each bit isolator until either the test period ended or the device failed. The results from these tests showed that the device is an effective noise control in a mine environment. The field-tested drill bit isolators provided a noise reduction of 3-5 dB(A). Of nine devices tested for durability, five exceeded 610 m (2,000 ft) drilled and two exceeded 762 m (2,500 ft) drilled before failure. Durability issues found in the field tests led to final production optimizations that have resulted in a commercially available product for drilling with 35-mm- (1.3-in.-) diameter roof bits and hexagonal drill steels.

Despite advancements in engineering noise controls and the use of administrative controls, miners are still dependent on hearing protection devices for prevention of noise-induced hearing loss. However, miners often complain of reduced audibility or confusion about identifying spoken words when wearing conventional hearing protectors. This leads to an increased risk of miners being struck by moving equipment or errors in communication with co-workers. Miners will often remove their hearing protectors to overcome these obstacles. To address this problem, electronic technology exists that allows some amount of sound to pass through the hearing protector, therefore restoring some audibility of the passively attenuated sounds. This paper will present the results of testing completed on a selection of four sound restoration hearing protection devices, with the objective of determining if they provide improved speech intelligibility to workers near certain types of mining equipment.