Infectious Diseases in a Changing Climate.

This JAMA Insights in the Climate Change and Health series discusses the importance of clinicians having awareness of changes in the geographic range, seasonality, and intensity of transmission of infectious diseases to help them diagnose, treat, and prevent these diseases.

Microbial Waterborne Diseases in India: Status, Interventions, and Future Perspectives.

Water plays a vital role as a natural resource since life is unsustainable without it. If water is polluted or contaminated, it results in several health issues among people. Millions of people are infected with waterborne diseases globally, and India is no exception. In the present review, we have analyzed the outbreaks of waterborne diseases that occurred in several Indian states between 2014 and 2020, identified the key infections, and provided insights into the performance of sanitation improvement programs. We noted that acute diarrheal disease (ADD), typhoid, cholera, hepatitis, and shigellosis are common waterborne diseases in India. These diseases have caused about 11,728 deaths between 2014 and 2018 out of which 10,738 deaths occurred only after 2017. The outbreaks of these diseases have been rising because of a lack of adequate sanitation, poor hygiene, and the absence of proper disposal systems. Despite various efforts by the government such as awareness campaigns, guidance on diet for infected individuals, and sanitation improvement programs, the situation is still grim. Disease hotspots and risk factors must be identified, water, sanitation, and hygiene (WASH) services must be improved, and ongoing policies must be effectively implemented to improve the situation. The efforts must be customized to the local environment. In addition, the possible effects of climate change must be projected, and strategies must be accordingly optimized.

Waterborne Infectious Diseases Associated with Exposure to Tropical Cyclonic Storms, United States, 1996-2018.

In the United States, tropical cyclones cause destructive flooding that can lead to adverse health outcomes. Storm-driven flooding contaminates environmental, recreational, and drinking water sources, but few studies have examined effects on specific infections over time. We used 23 years of exposure and case data to assess the effects of tropical cyclones on 6 waterborne diseases in a conditional quasi-Poisson model. We separately defined storm exposure for windspeed, rainfall, and proximity to the storm track. Exposure to storm-related rainfall was associated with a 48% (95% CI 27%-69%) increase in Shiga toxin-producing Escherichia coli infections 1 week after storms and a 42% (95% CI 22%-62%) in increase Legionnaires' disease 2 weeks after storms. Cryptosporidiosis cases increased 52% (95% CI 42%-62%) during storm weeks but declined over ensuing weeks. Cyclones are a risk to public health that will likely become more serious with climate change and aging water infrastructure systems.

Estimating Waterborne Infectious Disease Burden by Exposure Route, United States, 2014.

More than 7.15 million cases of domestically acquired infectious waterborne illnesses occurred in the United States in 2014, causing 120,000 hospitalizations and 6,600 deaths. We estimated disease incidence for 17 pathogens according to recreational, drinking, and nonrecreational nondrinking (NRND) water exposure routes by using previously published estimates. In 2014, a total of 5.61 million (95% credible interval [CrI] 2.97-9.00 million) illnesses were linked to recreational water, 1.13 million (95% CrI 255,000-3.54 million) to drinking water, and 407,000 (95% CrI 72,800-1.29 million) to NRND water. Recreational water exposure was responsible for 36%, drinking water for 40%, and NRND water for 24% of hospitalizations from waterborne illnesses. Most direct costs were associated with pathogens found in biofilms. Estimating disease burden by water exposure route helps direct prevention activities. For each exposure route, water management programs are needed to control biofilm-associated pathogen growth; public health programs are needed to prevent biofilm-associated diseases.

Demographic dynamics of waterborne disease and perceived associated WASH factors in Bushenyi and Sheema districts of South-Western Uganda.

Water remains a significant player in spreading pathogens, including those associated with neglected tropical diseases. The implications of socio-demographic delineations of water quality, sanitation, and hygiene ("WASH") interventions are on the downswing. This study assessed waterborne diseases and perceived associated WASH factors in the Bushenyi and Sheema districts of South-Western Uganda. This study examines the linear relationship between WASH and identifies the association of specific demographic factors as well as their contributions/correlations to waterborne disease in the study area. A structured qualitative and quantitative data collection approach was adopted in face-to-face questionnaire-guided interviews of 200 respondents on eight surface water usage. Most participants, 65.5%, were females and had a higher score of knowledge of WASH (71%), 68% score on the improper practice of WASH, and 64% score on unsafe water quality. Low score for basic economic status was (57%), report of common diarrhoea was (47%), and a low incidence of waterborne disease outbreaks (27%). The principal component analysis (PCA) depicts the knowledge and practice of WASH to have a strong positive correlation (r = 0.84, p < 0.001; r = 0.82, p < 0.001); also economic status positively correlated with grade of water source, knowledge, and practice of WASH (correlation coefficient = 0.72; 0.99; 0.76 and p-values = 0.001; < 0.001; < 0.001 respectively). Occupation (p = 0.0001, OR = 6.798) was significantly associated with knowledge and practice of WASH, while age (r = -0.21, p < 0.001) was negatively associated with knowledge and practice of WASH. The basic economic status explains why "low economic population groups" in the remote villages may not effectively implement WASH, and diarrhoea was common among the population. Diarrhoea associated with unsafe water quality and improper practice of WASH is common among the study population, and there is a low incidence of waterborne disease outbreaks. Therefore, government, stakeholders, and non-governmental organisations should work together to promote proper practice of WASH conditions to limit the occurrence of diarrhoea and prevent potential waterborne disease outbreaks.

Waterborne infections in haemato-oncology units - a narrative review.

Bone marrow transplant and haemato-oncology patients are at risk of healthcare-associated infections due to waterborne pathogens. We undertook a narrative review of waterborne outbreaks in haemato-oncology patients from 2000 to 2022. Databases searched included PubMed, DARE and CDSR, and were undertaken by two authors. We analysed the organisms implicated, sources identified and infection prevention and control strategies implemented. The most commonly implicated pathogens were Pseudomonas aeruginosa, non-tuberculous mycobacteria and Legionella pneumophila. Bloodstream infection was the most common clinical presentation. The majority of incidents employed multi-modal strategies to achieve control, addressing both the water source and routes of transmission. This review highlights the risk to haemato-oncology patients from waterborne pathogens and discusses future preventative strategies and the requirement for new UK guidance for haemato-oncology units.

Changes in access to water and incidence of waterborne diseases after the Vale dam collapse in Brumadinho (MG), Brazil.

OBJECTIVE: To describe, within the Human Rights to Water and Sanitation (HRWS) framework, the access to water supply services and the incidence of waterborne diseases in the communities affected by the dam disaster in Brumadinho (MG), Brazil. METHODS: A quantitative and qualitative methodology was used, having as variables information on access to water supply services and waterborne diseases. The primary data were extracted from the "Brumadinho Health Project", using a sample stratum with 981 people interviewed, totaling 92.5% of the eligible population in the affected communities of Córrego do Feijão and Parque da Cachoeira. The secondary data from Brumadinho was extracted from the project "Sanitation conditions and the River Basin of the B1 River Basin of Mineradora Vale between 2017 and 2020", available in public databases between 2017 and 2020, and qualitative data was collected in 2022 through individual interviews with health professional also live in the communities. RESULTS: With regard to access to water supply services, the results of this combined data analysis indicate that the HRWS is being neglected, especially with regard to availability, accessibility, acceptability and quality of water. The study also shows a significant increase in the incidence of waterborne diseases in the region after the disaster. CONCLUSION: It is necessary to use the HRWS as the basis to the implementation of public policies aiming to reduce vulnerability in access to water supply services.

Interrupted time series segmented regression analysis for detecting waterborne disease outbreaks by syndromic surveillance.

Introduction: Pathogens can enter the drinking water supply and cause gastroenteritis outbreaks. Such events can affect many people in a short time, making them a high risk for public health. In Australia, the Victoria State Government Department of Health is deploying a syndromic surveillance system for drinking water contamination events. We assessed the utility of segmented regression models for detecting such events and determined the number of excess presentations needed for such methods to signal a detection. Methods: The study involved an interrupted time series study of a past lapse in water treatment. The baseline period comprised the four weeks before the minimum incubation period of suspected pathogens, set at two days post-event. The surveillance period comprised the week after. We used segmented linear regression to compare the count of gastroenteritis presentations to public hospital emergency departments (EDs) between the surveillance and baseline periods. We then simulated events resulting in varying excess presentations. These were superimposed onto the ED data over fifty different dates across 2020. Using the same regression, we calculated the detection probability at p < 0.05 for each outbreak size. Results: In the retrospective analysis, there was strong evidence for an increase in presentations shortly after the event. In the simulations, with no excess presentations (i.e., with the ED data as is) the models signalled 8% probability of detection. The models returned 50% probability of detection with 28 excess presentations and 100% probability of detection with 78 excess presentations. Conclusions: The transient increase in presentations after the event may be attributed to microbiological hazards or increased health-seeking behaviour following the issuing of boil water advisories. The simulations demonstrated the ability for segmented regressions to signal a detection, even without a large excess in presentations. The approach also demonstrated high specificity and should be considered for informing Victoria's syndromic surveillance system.

Machine learning based efficient prediction of positive cases of waterborne diseases.

BACKGROUND: Water quality has been compromised and endangered by different contaminants due to Pakistan's rapid population development, which has resulted in a dramatic rise in waterborne infections and afflicted many regions of Pakistan. Because of this, modeling and predicting waterborne diseases has become a hot topic for researchers and is very important for controlling waterborne disease pollution. METHODS: In our study, first, we collected typhoid and malaria patient data for the years 2017-2020 from Ayub Medical Hospital. The collected data set has seven important input features. In the current study, different ML models were first trained and tested on the current study dataset using the tenfold cross-validation method. Second, we investigated the importance of input features in waterborne disease-positive case detection. The experiment results showed that Random Forest correctly predicted malaria-positive cases 60% of the time and typhoid-positive cases 77% of the time, which is better than other machine-learning models. In this research, we have also investigated the input features that are more important in the prediction and will help analyze positive cases of waterborne disease. The random forest feature selection technique has been used, and experimental results have shown that age, history, and test results play an important role in predicting waterborne disease-positive cases. In the end, we concluded that this interesting study could help health departments in different areas reduce the number of people who get sick from the water.

Waterborne disease outbreaks in treated recreational water facilities: a Socio-Ecological Model perspective.

Treated recreational water facilities, including swimming pools and water play parks, have often been implicated in infectious disease outbreaks. Addressing this problem is complex due to the multiple and interrelated factors contributing to outbreaks in these settings. These factors may relate to inappropriate behaviours of users and operators, lack of and inconsistent regulation of these facilities, insufficient facility maintenance, and problems associated with the design of these facilities. Given the complexity of this issue, we argue that the Socio-Ecological Model (SEM) provides a useful framework to help identify the multi-level influences and factors that have implications for designing interventions to prevent this public health problem, whilst assisting in guiding future research in this area. We apply the SEM to the current literature to help identify the influences and factors contributing to infectious disease outbreaks in treated recreational water facilities to support this argument. We also identify several gaps in the existing research that would benefit from further examination to help prevent infectious disease outbreaks in treated recreational water facilities such as public swimming pools and water play parks.

Expected annual probability of infection: A flood-risk approach to waterborne infectious diseases.

This study introduces a new approach for the investigation of infections after an accidental ingestion of contaminated floodwater. The concept of Expected Annual Probability of Infection (EAPI) is introduced and implemented in an infection risk-model approach, by combining a Quantitative Microbial Risk Assessment (QMRA) with the four steps in flood risk assessment. Two groups and exposure paths are considered: adults wading in floodwater and small children swimming/playing in floodwater. The study area is located in Ghana, West Africa. Even though Ghana is one of the most urbanized countries in Africa it has significant problems with water resources management and public health. While cholera is classified as endemic in Accra, the natural and human-made characteristics of the capital makes it prone to flooding. The results of the EAPI approach show that on one hand the concentration of pathogens in floodwater, and thus the risk of infection, decreases with the increase of the flood magnitude. On the other hand, larger floods can spread the pathogens further from the point source, threatening populations previously not identified as at risk by small-scale floods. The concept of EAPI is demonstrated for cholera but it can be extended to other waterborne diseases and also different pathways of exposure, requiring minimal adaptations. For future applications, better estimation of EAPI key components and improvement points are discussed and recommendations given for all the assessment steps.

Cryptosporidiosis outbreak in Amazonia, French Guiana, 2018.

BACKGROUND: Cryptosporidiosis outbreaks in South America are poorly documented. In March 2018, 51 cases of cryptosporidiosis were reported in Maripasoula, a village located in a remote forest area along the border between Surinam and French Guiana. METHOD: To identify the origin of the epidemic, we performed epidemiological, microbiological, and environmental investigations. Only the cases involving diarrhoea and Cryptosporidium-positive stool were considered as bona fide, while cases involving diarrhoea and close contact with a confirmed case were classified as "possible". RESULTS: We identified 16 confirmed cases and 35 possible ones. Confirmed cases comprised nine children (median age of 18 months, range: 6-21), one immunocompromised adult and six soldiers. One child required a hospitalisation for rehydration. All 16 Cryptosporidium stools were PCR positive, and sequencing of the gp60 gene confirmed only one Cryptosporidium hominis subtype IbA10G2. Tap water consumption was the only common risk factor identified. Contamination of the water network with Cryptosporidium parvum subtype IIdA19G2 was found. CONCLUSION: Water quality is a major public health issue in Amazonian French Guiana, especially for population at risk (children, people with comorbidity, travelers). For them, alternative water supply or treatment should be implemented.

Waterborne diseases and ethnic-related disparities: A 10 years nationwide mortality and burden of disease analysis from Ecuador.

Background: Despite worldwide progress in terms of clean water supply, sanitation, and hygiene knowledge, some middle and most of low-income countries are still experiencing many diseases transmitted using unsafe water and the lack of sanitation. Methods: To understand the impact of all waterborne diseases (WBD) registered in Ecuador. We performed a population-based analysis of all cases and deaths due to WBD in Ecuador based on the national public databases of hospital discharges as a proxy of incidence, in-hospital mortality, and countrywide general mortality rates from 2011 to 2020. Results: In Ecuador, mestizos (mixed European and Indigenous American ancestry) had the greatest morbidity rate (141/100,000), followed by indigenous (63/100,000) and self-determined white patients (21/100,000). However, in terms of mortality, indigenous population have the greatest risk and rates, having a 790% additional mortality rate (2.6/100,000) than the reference group (self-determined white populations) at 0.29/100,000. The burden of disease analysis demonstrated that indigenous had the highest burden of disease caused by WBD with 964 YLL per every 100,000 people while mestizos have 360 YYL per 100,000 and self-determined white Ecuadorians have 109 YYL per 100,000. Conclusions: In Ecuador, waterborne diseases (WBD) are still a major public health problem. We found that indigenous population had higher probability of getting sick and die due to WBD than the rest of the ethnic groups in Ecuador. We also found that younger children and the elderly are more likely to be admitted to the hospital due to a WBD. These epidemiological trends are probably associated with the lower life expectancy found among Indigenous than among the rest of the ethnic groups, who die at least, 39 years earlier than the self-determined white populations, 28 years earlier than Afro-Ecuadorians and 12 years earlier than the mestizos.

Conceptual frameworks regarding waterborne diseases in sub-Saharan Africa and the need of for a new approach to urban exposomes.

Sub-Saharan African countries, like many other low-income countries, have experienced urban socioeconomic inequalities due to rapid and unplanned urbanization. These processes have resulted in the creation of poor urban areas lacking basic sanitation, water, and hygiene facilities, and subjacent public health issues such as the spread of waterborne diseases. A system for the demarcation of disease transmission areas already exists, but the traditional framework is less appropriate in sub-Saharan Africa, making it necessary to divide these urban areas more adequately. In addition, the construction of frameworks and tools more specific to waterborne disease-related issues is essential. We propose restructuring sub-Saharan urban areas into more specific areas of exposure to waterborne diseases and associated exposomes, and then use this restructuring of urban areas of exposure to waterborne diseases in a conceptual framework that takes into account causes of exposure, impacts, and interventions. The division of urban areas into public, domestic, and individual exposure areas facilitates a more straightforward understanding of the dynamics of waterborne exposomes. Moreover, the inclusion of this division in the driving force-pressure-state-exposure-effect-action framework allows an effective stratified implementation of urban public health policies.

Implementation of a national waterborne disease outbreak surveillance system: overview and preliminary results, France, 2010 to 2019.

BackgroundWaterborne disease outbreaks (WBDO) associated with tap water consumption are probably underestimated in France.AimIn order to improve their detection, Santé publique France launched a surveillance system in 2019, based on the periodical analysis of health insurance data for medicalised acute gastroenteritis (mAGE).MethodsSpatio-temporal cluster detection methods were applied to mAGE cases to prioritise clusters for further investigation. These investigations determined the plausibility that infection is of waterborne origin and the strength of association.ResultsBetween January 2010 and December 2019, 3,323 priority clusters were detected (53,878 excess mAGE cases). They involved 3,717 drinking water supply zones (WSZ), 15.4% of all French WSZ. One third of these WSZ (33.4%; n = 1,242 WSZ) were linked to repeated clusters. Moreover, our system detected 79% of WBDO voluntarily notified to health authorities.ConclusionEnvironmental investigations of detected clusters are necessary to determine the plausibility that infection is of waterborne origin. Consequently, they contribute to identifying which WSZ are linked to clusters and for which specific actions are needed to avoid future outbreaks. The surveillance system incorporates three priority elements: linking environmental investigations with water safety plan management, promoting the systematic use of rainfall data to assess waterborne origin, and focusing on repeat clusters. In the absence of an alternative clear hypothesis, the occurrence of a mAGE cluster in a territory completely matching a distribution zone indicates a high plausibility of water origin.

Trends of potential waterborne diseases at different health facilities in Bamboutos Division, West Region, Cameroon: a retrospective appraisal of routine data from 2013 to 2017.

Many Cameroonian cities lack access to potable drinking water where populations rely on alternative water sources of doubtful quality. This study aimed at describing the trends and patterns of waterborne diseases (WBDs) reported in some health facilities in Bamboutos Division between 2013 and 2017 as baseline data towards understanding the profile of WBDs in this area. A retrospective review of clinical data kept on patients who visited the main health facilities in Bamboutos Division from January 2013 to December 2017 was conducted. Overall, 39.1% (n = 8,124) of total patients were positive for at least one WBD. Categories of WBDs were dysenteries (18.6%), gastroenteritis (4.2%), viral hepatitis (0.2%) and typhoid was the most preponderant (24.4%). The most affected age groups were those above 24 years but significant differences were observed only in 2013 and 2017. Distribution of potential WBDs was locality dependent. The highest prevalence of typhoid fever was recorded in Bameboro (35.4%), dysenteries in Bamedjinda (20.4%) and gastroenteritis (17.3%) in Bamekoumbou. The study shows very high overall prevalence of WBDs in some localities which could be considered as 'hotspots' of WBDs in Bamboutos. This suggests the urgent need for setting up measures to tackle the challenges of potable drinking water supply.

The effectiveness of syndromic surveillance for the early detection of waterborne outbreaks: a systematic review.

BACKGROUND: Waterborne outbreaks are still a risk in high-income countries, and their early detection is crucial to limit their societal consequences. Although syndromic surveillance is widely used for the purpose of detecting outbreaks days earlier than traditional surveillance systems, evidence of the effectiveness of such systems is lacking. Thus, our objective was to conduct a systematic review of the effectiveness of syndromic surveillance to detect waterborne outbreaks. METHOD: We searched the Cochrane Library, Medline/PubMed, EMBASE, Scopus, and Web of Science for relevant published articles using a combination of the keywords 'drinking water', 'surveillance', and 'waterborne disease' for the period of 1990 to 2018. The references lists of the identified articles for full-text record assessment were screened, and searches in Google Scholar using the same key words were conducted. We assessed the risk of bias in the included articles using the ROBINS-I tool and PRECEPT for the cumulative body of evidence. RESULTS: From the 1959 articles identified, we reviewed 52 articles, of which 18 met the eligibility criteria. Twelve were descriptive/analytical studies, whereas six were simulation studies. There is no clear evidence for syndromic surveillance in terms of the ability to detect waterborne outbreaks (low sensitivity and high specificity). However, one simulation study implied that multiple sources of signals combined with spatial information may increase the timeliness in detecting a waterborne outbreak and reduce false alarms. CONCLUSION: This review demonstrates that there is no conclusive evidence on the effectiveness of syndromic surveillance for the detection of waterborne outbreaks, thus suggesting the need to focus on primary prevention measures to reduce the risk of waterborne outbreaks. Future studies should investigate methods for combining health and environmental data with an assessment of needed financial and human resources for implementing such surveillance systems. In addition, a more critical thematic narrative synthesis on the most promising sources of data, and an assessment of the basis for arguments that joint analysis of different data or dimensions of data (e.g. spatial and temporal) might perform better, should be carried out. TRIAL REGISTRATION: PROSPERO: International prospective register of systematic reviews. 2019. CRD42019122332 .