Waterborne Disease Surveillance Research Articles

Estimation of population size with heterogeneous catchability and behavioural dependence: applications to air- and water-borne disease surveillance

Abstract Population size estimation based on the capture–recapture experiment is an interesting problem in various fields including epidemiology, criminology, demography, etc. In many real-life scenarios, there exists inherent heterogeneity among the individuals and dependency between capture and recapture attempts. A novel trivariate Bernoulli model is considered to incorporate these features, and the Bayesian estimation of the model parameters is suggested using data augmentation. Simulation results show robustness under model misspecification and the superiority of the performance of the proposed method over existing competitors. The method is applied to analyse real case studies on epidemiological surveillance. The results provide interesting insight on the heterogeneity and dependence involved in the capture–recapture mechanism. The methodology proposed can assist in effective decision-making and policy formulation.

Correction: Hospitalization Records as a Tool for Evaluating Performance of Food- and Water-Borne Disease Surveillance Systems: A Massachusetts Case Study

Correction: Hospitalization Records as a Tool for Evaluating Performance of Food- and Water-Borne Disease Surveillance Systems: A Massachusetts Case Study

Hospitalization records as a tool for evaluating performance of food- and water-borne disease surveillance systems: a Massachusetts case study.

We outline a framework for evaluating food- and water-borne surveillance systems using hospitalization records, and demonstrate the approach using data on salmonellosis, campylobacteriosis and giardiasis in persons aged ≥65 years in Massachusetts. For each infection, and for each reporting jurisdiction, we generated smoothed standardized morbidity ratios (SMR) and surveillance to hospitalization ratios (SHR) by comparing observed surveillance counts with expected values or the number of hospitalized cases, respectively. We examined the spatial distribution of SHR and related this to the mean for the entire state. Through this approach municipalities that deviated from the typical experience were identified and suspected of under-reporting. Regression analysis revealed that SHR was a significant predictor of SMR, after adjusting for population age-structure. This confirms that the spatial “signal” depicted by surveillance is in part influenced by inconsistent testing and reporting practices since municipalities that reported fewer cases relative to the number of hospitalizations had a lower relative risk (as estimated by SMR). Periodic assessment of SHR has potential in assessing the performance of surveillance systems.

Causes of Outbreaks Associated with Drinking Water in the United States from 1971 to 2006

Since 1971, the CDC, EPA, and Council of State and Territorial Epidemiologists (CSTE) have maintained the collaborative national Waterborne Disease and Outbreak Surveillance System (WBDOSS) to document waterborne disease outbreaks (WBDOs) reported by local, state, and territorial health departments. WBDOs were recently reclassified to better characterize water system deficiencies and risk factors; data were analyzed for trends in outbreak occurrence, etiologies, and deficiencies during 1971 to 2006. A total of 833 WBDOs, 577,991 cases of illness, and 106 deaths were reported during 1971 to 2006. Trends of public health significance include (i) a decrease in the number of reported outbreaks over time and in the annual proportion of outbreaks reported in public water systems, (ii) an increase in the annual proportion of outbreaks reported in individual water systems and in the proportion of outbreaks associated with premise plumbing deficiencies in public water systems, (iii) no change in the annual proportion of outbreaks associated with distribution system deficiencies or the use of untreated and improperly treated groundwater in public water systems, and (iv) the increasing importance of Legionella since its inclusion in WBDOSS in 2001. Data from WBDOSS have helped inform public health and regulatory responses. Additional resources for waterborne disease surveillance and outbreak detection are essential to improve our ability to monitor, detect, and prevent waterborne disease in the United States.

Waterborne Disease Surveillance: The Case for a Closer Interaction between the UNECE Protocol on Water and Health and the International Health Regulations (2005)

AbstractThe UNECE Protocol on Water and Health prioritises prevention and control of waterborne diseases in the European Region. In order to protect public health from water-related outbreaks, the Protocol mandates the Parties to establish, improve and maintain comprehensive national and local surveillance as well as early warning systems. It also promotes international cooperation among Member States and fosters the development of joint and coordinated action aimed to complement or strengthen national capacities of response. Coordination and liaison with competent international agencies and organisations acting in the field of public health and disease surveillance is instead almost completely neglected. Despite the gap in the agreement, the relevance to the Protocol of existing surveillance networks has increasingly been acknowledged. Following this trend, the Protocol Bodies are exploring the opportunities for a closer interaction with regional and global alert and response systems. This effort is commendable, but much more can be done to reach a more intense cooperation and achieve a globally integrated system of disease surveillance. Harmonisation of legal frameworks (in this case, the UNECE Protocol, the EU legislation and the IHR 2005) and a better synergy among relevant networks will enhance protection of global health security, avoid useless duplications of efforts, and ensure coherence of the whole body of international law on public health.

Calicivirus—An Emerging Contaminant in Water: State of the Art

There has been a noteworthy surge of interest with regard to the viruses known as human Caliciviruses (HuCVs) and their impact on water-borne disease. Recent epidemiologic studies in Europe combined with an active waterborne disease surveillance system in the United States has identified the Norovirus, a member of the HuCVs, as a prominent agent of waterborne disease. Current estimates suggest that upwards of 95–96% of nonbacterial gastroenteritis outbreaks of unidentified etiology may be due to HuCV. Moreover, there have been a number of documented waterborne outbreaks of Norovirus both in the United States as well as abroad. It is with the advent of advanced molecular techniques that we have begun to develop a strategy for the detection of this organism in various water matrices. However, because HuCV have not yet been cultured in the laboratory, it is difficult to conduct research on their fate in the environment and their removal or inactivation during water and wastewater treatment processes. Therefo...

Water quality laws and waterborne diseases: Cryptosporidium and other emerging pathogens.

Waterborne diseases, such as cryptosporidiosis, cause many cases of serious illness in the United States annually. Water quality is regulated by a complex system of federal and state legal provisions and agencies, which has been poorly studied. The authors surveyed state and territorial agencies responsible for water quality about their laws, regulations, policies, and practices related to water quality and surveillance of cryptosporidiosis related to drinking water. In this commentary they review the development and current status of federal drinking water regulations, identify conflicts or gaps in legal authority between federal agencies and state and territorial agencies, and describe court-imposed limitations on federal authority with regard to regulation of water quality. Recommendations are made for government actions that would increase the efficiency of efforts to ensure water quality; protect watersheds; strengthen waterborne disease surveillance; and protect the health of vulnerable populations.