Mathematical Analyses on the Effects of Control Measures for a Waterborne Disease Model with Socioeconomic Conditions.

Waterborne diseases are present major health problems to humanity especially in rural communities where many individuals belong to the lower socioeconomic classes (SECs). The impacts of introducing waterborne disease control measures for such communities are investigated by considering a waterborne disease model. The model is extended by introducing treatment of infected individuals and water purification as control measures. The possible benefits of considering these control measures for the various SECs are investigated. Further analyses show how different degrees of control impact the rate at which waterborne diseases are spread across SECs. The disease control model is validated by using it to study the cholera outbreak in Haiti.

Variation in microparasite free-living survival and indirect transmission can modulate the intensity of emerging outbreaks.

Variation in free-living microparasite survival can have a meaningful impact on the ecological dynamics of established and emerging infectious diseases. Nevertheless, resolving the importance of indirect and environmental transmission in the ecology of epidemics remains a persistent challenge. It requires accurately measuring the free-living survival of pathogens across reservoirs of various kinds and quantifying the extent to which interaction between hosts and reservoirs generates new infections. These questions are especially salient for emerging pathogens, where sparse and noisy data can obfuscate the relative contribution of different infection routes. In this study, we develop a mechanistic, mathematical model that permits both direct (host-to-host) and indirect (environmental) transmission and then fit this model to empirical data from 17 countries affected by an emerging virus (SARS-CoV-2). From an ecological perspective, our model highlights the potential for environmental transmission to drive complex, nonlinear dynamics during infectious disease outbreaks. Summarizing, we propose that fitting alternative models with indirect transmission to real outbreak data from SARS-CoV-2 can be useful, as it highlights that indirect mechanisms may play an underappreciated role in the dynamics of infectious diseases, with implications for public health.

Leptospirosis: a neglected tropical zoonotic infection of public health importance-an updated review.

Leptospirosis is a zoonotic and waterborne disease worldwide. It is a neglected, reemerging disease of global public health importance with respect to morbidity and mortality both in humans and animals. Due to negligence, rapid, unplanned urbanization, and poor sanitation, leptospirosis emerges as a leading cause of acute febrile illness in many of the developing countries. Every individual has a risk of getting infected as domestic and wild animals carry leptospires; the at-risk population varies from the healthcare professionals, animal caretakers, farmers and agricultural workers, fishermen, rodent catchers, water sports people, National Disaster Response Force (NDRF) personnel, people who volunteer rescue operations in flood-affected areas, sanitary workers, sewage workers, etc. The clinical manifestations of leptospirosis range from flu-like illness to acute kidney failure (AKF), pneumonia, jaundice, pulmonary hemorrhages, etc. But many rare and uncommon clinical manifestations are being reported worldwide. This review will cover all possible updates in leptospirosis from occurrence, transmission, rare clinical manifestations, diagnosis, treatment, and prophylactic measures that are currently available, their advantages and the future perspectives, elaborately. There are less or very few reviews on leptospirosis in recent years. Thus, this work will serve as background knowledge for the current understanding of leptospirosis for researchers. This will provide a detailed analysis of leptospirosis and also help in finding research gaps and areas to focus on regarding future research perspectives.

An optimal control problem for carrier dependent diseases.

In developing countries, several diseases spread in human population due to the abundance of houseflies (a kind of carrier). The main reason behind the spread of these diseases is the lack of awareness among peoples regarding the sanitation practices and economic constraints. To understand the dynamics of the spread and control of these diseases, in this paper, we propose a mathematical model by considering logistic growth of houseflies. In the model formulation, it is assumed that houseflies transport the bacteria responsible for the disease transmission from the environment to the edibles of human population. To reduce the density of houseflies and number of infected individuals, an optimization problem is also formulated and analyzed. Numerical simulations are performed to support analytically obtained results.

Tularemia as a waterborne disease: a review.

Francisella tularensis is a Gram-negative, intracellular bacterium causing the zoonosis tularemia. This highly infectious microorganism is considered a potential biological threat agent. Humans are usually infected through direct contact with the animal reservoir and tick bites. However, tularemia cases also occur after contact with a contaminated hydro-telluric environment. Water-borne tularemia outbreaks and sporadic cases have occurred worldwide in the last decades, with specific clinical and epidemiological traits. These infections represent a major public health and military challenge. Human contaminations have occurred through consumption or use of F. tularensis-contaminated water, and various aquatic activities such as swimming, canyoning and fishing. In addition, in Sweden and Finland, mosquitoes are primary vectors of tularemia due to infection of mosquito larvae in contaminated aquatic environments. The mechanisms of F. tularensis survival in water may include the formation of biofilms, interactions with free-living amoebae, and the transition to a 'viable but nonculturable' state, but the relative contribution of these possible mechanisms remains unknown. Many new aquatic species of Francisella have been characterized in recent years. F. tularensis likely shares with these species an ability of long-term survival in the aquatic environment, which has to be considered in terms of tularemia surveillance and control.

A Review and Update on Waterborne Viral Diseases Associated with Swimming Pools.

Infectious agents, including bacteria, viruses, protozoa, and molds, may threaten the health of swimming pool bathers. Viruses are a major cause of recreationally-associated waterborne diseases linked to pools, lakes, ponds, thermal pools/spas, rivers, and hot springs. They can make their way into waters through the accidental release of fecal matter, body fluids (saliva, mucus), or skin flakes by symptomatic or asymptomatic carriers. We present an updated overview of epidemiological data on viral outbreaks, a project motivated, among other things, by the availability of improved viral detection methodologies. Special attention is paid to outbreak investigations (source of the outbreak, pathways of transmission, chlorination/disinfection). Epidemiological studies on incidents of viral contamination of swimming pools under non-epidemic conditions are also reviewed.

Quantification of Leptospira interrogans Survival in Soil and Water Microcosms.

Leptospira interrogans is the etiological agent of leptospirosis, a globally distributed zoonotic disease. Human infection usually occurs through skin exposure with water and soil contaminated with the urine of chronically infected animals. In this study, we aimed to quantitatively characterize the survival of Leptospira interrogans serovar Copenhageni in environmental matrices. We constructed laboratory microcosms to simulate natural conditions and determined the persistence of DNA markers in soil, mud, spring water and sewage using a quantitative PCR (qPCR) and a propidium monoazide (PMA)-qPCR assay. We found that L. interrogans does not survive at high concentrations in the tested matrices. No net growth was detected in any of the experimental conditions and in all cases the concentration of the DNA markers targeted decreased from the beginning of the experiment following an exponential decay with a decreasing decay rate over time. After 12 and 21 days of incubation the spiked concentration of 106L. interrogans cells/ml or g decreased to approximately 100 cells/ml or g in soil and spring water microcosms, respectively. Furthermore, culturable L. interrogans persisted at concentrations under the limit of detection by PMA-qPCR or qPCR for at least 16 days in soil and 28 days in spring water. Altogether, our findings suggest that the environment is not a multiplication reservoir but a temporary carrier of L. interrogans Copenhageni, although the observed prolonged persistence at low concentrations may still enable the transmission of the disease.IMPORTANCE Leptospirosis is a zoonotic disease caused by spirochetes of the genus Leptospira that primarily affects impoverished populations worldwide. Although leptospirosis is transmitted by contact with water and soil, little is known about the ability of the pathogen to survive in the environment. In this study, we quantitatively characterized the survival of L. interrogans in environmental microcosms and found that although it cannot multiply in water, soil or sewage, it survives for extended time periods (days to weeks depending on the matrix). The survival parameters obtained here may help to better understand the distribution of pathogenic Leptospira in the environment and improve the predictions of human infection risks in areas where such infections are endemic.

Epidemicity thresholds for water-borne and water-related diseases.

Determining the conditions that favor pathogen establishment in a host community is key to disease control and eradication. However, focusing on long-term dynamics alone may lead to an underestimation of the threats imposed by outbreaks triggered by short-term transient phenomena. Achieving an effective epidemiological response thus requires to look at different timescales, each of which may be endowed with specific management objectives. In this work we aim to determine epidemicity thresholds for some prototypical examples of water-borne and water-related diseases, a diverse family of infections transmitted either directly through water infested with pathogens or by vectors whose lifecycles are closely associated with water. From a technical perspective, while conditions for endemicity are determined via stability analysis, epidemicity thresholds are defined through generalized reactivity analysis, a recently proposed method that allows the study of the short-term instability properties of ecological systems. Understanding the drivers of water-borne and water-related disease dynamics over timescales that may be relevant to epidemic and/or endemic transmission is a challenge of the utmost importance, as large portions of the developing world are still struggling with the burden imposed by these infections.

[Association between socioeconomic, health, and primary care conditions and hospital morbidity due to waterborne diseases in Brazil]. / Associação entre condições socioeconômicas, sanitárias e de atenção básica e a morbidade hospitalar por doenças de veiculação hídrica no Brasil.

The current study aimed to assess the association between socioeconomic conditions, basic sanitation, and coverage by family health teams and hospitalizations for waterborne diseases. The analysis of socioeconomic conditions and sanitation was based on an ecological study with data from the Brazilian National Household Sample Survey (PNAD) and the Brazilian Health Informatics Departament (DATASUS) database (observations for the States and Federal District) for the year 2013. Associations between family health teams and hospitalization were assessed by simple regressions, with data from DATASUS and the Department of Primary Care of Ministry of Health from 1998 to 2014. Connection to the public sewage system, low schooling, and family health team coverage were significantly associated (p < 0.05) with hospitalizations for waterborne diseases. Based on attributable risk analysis, for Brazil as a whole in 2013, 57,574 (16.3%) of hospital admissions for waterborne diseases could have been avoided by adequate sewage disposal, which would also have avoided BRL 20,372,559.90 in treatment costs and 172,722 days lost to hospitalization. The results emphasize the importance of integrated sanitation policies, education, and health care that consider regional inequalities, thereby contributing to improvement of the population's health conditions.

O presente estudo teve como objetivo avaliar a associação entre condições socioeconômicas, de saneamento básico e de cobertura por equipes de saúde da família (EqSF) sobre as internações por doenças de veiculação hídrica no Brasil. A análise das condições socioeconômicas e de saneamento se deu por meio de um estudo ecológico com dados da Pesquisa Nacional por Amostra de Domicílios (PNAD) e do Departamento de Informática do SUS (DATASUS) - observações dos Estados e Distrito Federal - para o ano de 2013. A relação das EqSF com as internações foi avaliada por meio da estimação de regressão simples, com dados coletados no DATASUS e Departamento de Atenção Básica do Ministério da Saúde, para o período de 1998 a 2014. A existência de coleta de esgoto por rede geral, a baixa escolaridade e a cobertura por EqSF influenciaram, com significância estatística (p < 0,05), as internações avaliadas. Pela análise do risco atribuível, estimou-se que no Brasil, tomando-se como base os dados de 2013, 57.574 (16,3%) das internações por doenças selecionadas poderiam ter sido evitadas, caso as condições de esgotamento sanitário fossem adequadas. Seriam ainda evitados os gastos com o tratamento delas, calculado em R$ 20.372.559,90 e os dias perdidos com as internações, 172.722. Sugere-se que a adoção integrada de políticas de saneamento, educação e assistência à saúde que considerem as desigualdades regionais contribuirá para a melhoria das condições de saúde da população.

El objetivo del presente estudio fue evaluar la asociación entre condiciones socioeconómicas, de saneamiento básico y de cobertura por equipos de salud de la familia sobre los internamientos por enfermedades de transmisión hídrica en Brasil. El análisis de las condiciones socioeconómicas y de saneamiento se realizó mediante un estudio ecológico, con datos de la Encuesta Nacional por Muestra de Domicilios (PNAD) y del Sistema de Información del Sistema Único de Salud (DATASUS) -observaciones de los Estados y Districto Federal- durante el año 2013. La relación de los equipos de salud de la familia con los internamientos se evaluó gracias a la estimación de regresión simple, con los datos recogidos en el DATASUS y el Departamento de Atención Básica del Ministerio de la Salud, para el período de 1998 a 2014. La existencia de desagües para los residuos, mediante una red general de alcantarillado, la baja escolaridad y la cobertura por equipos de salud de la familia influenciaron con significancia estadística (p < 0,05) los internamientos evaluados. Por el análisis del riesgo atribuible, se estimó que en Brasil, tomando como base los datos de 2013, 57.574 (16,3%) de los internamientos por enfermedades seleccionadas podrían haber sido evitados, si las condiciones del alcantarillado fueran las adecuadas. Se evitarían incluso los gastos con su tratamiento, calculado en BRL 20.372.559,90, y los días perdidos con los internamientos en 172.722. Se sugiere que la adopción integrada de políticas de saneamiento, educación y asistencia a la salud, que consideren las desigualdades regionales, contribuiría a la mejoría de las condiciones de salud de la población.

On the intrinsic dynamics of bacteria in waterborne infections.

The intrinsic dynamics of bacteria often play an important role in the transmission and spread of waterborne infectious diseases. In this paper, we construct mathematical models for waterborne infections and analyze two types of nontrivial bacterial dynamics: logistic growth, and growth with Allee effects. For the model with logistic growth, we find that regular threshold dynamics take place, and the basic reproduction number can be used to characterize disease extinction and persistence. In contrast, the model with Allee effects exhibits much more complex dynamics, including the existence of multiple endemic equilibria and the presence of backward bifurcation and forward hysteresis.

A Perspective on the Global Pandemic of Waterborne Disease.

Waterborne diseases continue to take a heavy toll on the global community, with developing nations, and particularly young children carrying most of the burden of morbidity and mortality. Starting with the historical context, this article explores some of the reasons why this burden continues today, despite our advances in public health over the past century or so. While molecular biology has revolutionized our abilities to define the ecosystems and etiologies of waterborne pathogens, control remains elusive. Lack of basic hygiene and sanitation, and failing infrastructure, remain two of the greatest challenges in the global fight against waterborne disease. Emerging risks continue to be the specter of multiple drug resistance and the ease with which determinants of virulence appear to be transmitted between strains of pathogens, both within and outside the human host.

Associação entre condições socioeconômicas, sanitárias e de atenção básica e a morbidade hospitalar por doenças de veiculação hídrica no Brasil / Association between socioeconomic, health, and primary care conditions and hospital morbidity due to waterborne diseases in Brazil / Asociación entre condiciones socioeconómicas, sanitarias y de atención básica y la morbilidad hospitalaria por enfermedades de transmisión hídrica en Brasil

Resumo: O presente estudo teve como objetivo avaliar a associação entre condições socioeconômicas, de saneamento básico e de cobertura por equipes de saúde da família (EqSF) sobre as internações por doenças de veiculação hídrica no Brasil. A análise das condições socioeconômicas e de saneamento se deu por meio de um estudo ecológico com dados da Pesquisa Nacional por Amostra de Domicílios (PNAD) e do Departamento de Informática do SUS (DATASUS) - observações dos Estados e Distrito Federal - para o ano de 2013. A relação das EqSF com as internações foi avaliada por meio da estimação de regressão simples, com dados coletados no DATASUS e Departamento de Atenção Básica do Ministério da Saúde, para o período de 1998 a 2014. A existência de coleta de esgoto por rede geral, a baixa escolaridade e a cobertura por EqSF influenciaram, com significância estatística (p < 0,05), as internações avaliadas. Pela análise do risco atribuível, estimou-se que no Brasil, tomando-se como base os dados de 2013, 57.574 (16,3%) das internações por doenças selecionadas poderiam ter sido evitadas, caso as condições de esgotamento sanitário fossem adequadas. Seriam ainda evitados os gastos com o tratamento delas, calculado em R$ 20.372.559,90 e os dias perdidos com as internações, 172.722. Sugere-se que a adoção integrada de políticas de saneamento, educação e assistência à saúde que considerem as desigualdades regionais contribuirá para a melhoria das condições de saúde da população.

Abstract: The current study aimed to assess the association between socioeconomic conditions, basic sanitation, and coverage by family health teams and hospitalizations for waterborne diseases. The analysis of socioeconomic conditions and sanitation was based on an ecological study with data from the Brazilian National Household Sample Survey (PNAD) and the Brazilian Health Informatics Departament (DATASUS) database (observations for the States and Federal District) for the year 2013. Associations between family health teams and hospitalization were assessed by simple regressions, with data from DATASUS and the Department of Primary Care of Ministry of Health from 1998 to 2014. Connection to the public sewage system, low schooling, and family health team coverage were significantly associated (p < 0.05) with hospitalizations for waterborne diseases. Based on attributable risk analysis, for Brazil as a whole in 2013, 57,574 (16.3%) of hospital admissions for waterborne diseases could have been avoided by adequate sewage disposal, which would also have avoided BRL 20,372,559.90 in treatment costs and 172,722 days lost to hospitalization. The results emphasize the importance of integrated sanitation policies, education, and health care that consider regional inequalities, thereby contributing to improvement of the population's health conditions.

Resumen: El objetivo del presente estudio fue evaluar la asociación entre condiciones socioeconómicas, de saneamiento básico y de cobertura por equipos de salud de la familia sobre los internamientos por enfermedades de transmisión hídrica en Brasil. El análisis de las condiciones socioeconómicas y de saneamiento se realizó mediante un estudio ecológico, con datos de la Encuesta Nacional por Muestra de Domicilios (PNAD) y del Sistema de Información del Sistema Único de Salud (DATASUS) -observaciones de los Estados y Districto Federal- durante el año 2013. La relación de los equipos de salud de la familia con los internamientos se evaluó gracias a la estimación de regresión simple, con los datos recogidos en el DATASUS y el Departamento de Atención Básica del Ministerio de la Salud, para el período de 1998 a 2014. La existencia de desagües para los residuos, mediante una red general de alcantarillado, la baja escolaridad y la cobertura por equipos de salud de la familia influenciaron con significancia estadística (p < 0,05) los internamientos evaluados. Por el análisis del riesgo atribuible, se estimó que en Brasil, tomando como base los datos de 2013, 57.574 (16,3%) de los internamientos por enfermedades seleccionadas podrían haber sido evitados, si las condiciones del alcantarillado fueran las adecuadas. Se evitarían incluso los gastos con su tratamiento, calculado en BRL 20.372.559,90, y los días perdidos con los internamientos en 172.722. Se sugiere que la adopción integrada de políticas de saneamiento, educación y asistencia a la salud, que consideren las desigualdades regionales, contribuiría a la mejoría de las condiciones de salud de la población.

Waterparks are high risk for cryptosporidiosis: A case-control study in Victoria, 2015.

BACKGROUND: An increase in notifications of cryptosporidiosis was observed in Victoria between March and April 2015. Cases mostly resided in one metropolitan region and hypothesis-generating interviews identified common exposures to aquatic facilities. We conducted a case-control study to determine exposure source(s) and facilitate control measures. METHODS: Laboratory-confirmed cases of cryptosporidiosis from the region of interest notified between 1 March and 23 April 2015 were included. Controls residing in the same region were recruited from participants in a population health survey and frequency matched (2 per case) by age group. Details of exposure to potential risk factors were collected using a standardised telephone questionnaire for the 14-days prior to illness for cases, and an analogous exposure period for controls. Univariable and multivariable logistic regression were used to determine risk factors associated with illness using STATA SE 13.1. RESULTS: Thirty cases and 66 controls were included in the study. Half the cases were less than 12 years of age and 62% were female. Illness was most strongly associated with recreational water exposure at any waterpark (adjusted odds ratio (aOR)=73.5; 95% confidence interval (CI):6.74-802), and specifically at Victorian waterparks (aOR=45.6; 95% CI:5.20-399). Cases were linked with attendance at either a waterpark in the region or an adjacent region. As a result of this investigation, hyperchlorination was completed at identified facilities and swim hygiene information distributed. CONCLUSION: This study reinforces the potential for recreational water facilities, particularly waterparks, to act as a transmission source of Cryptosporidium infections. Continued communication to patrons is required to ensure healthy swimming practice in Victorian aquatic facilities.

The impact of anthropogenic pressure on the virological quality of water from the Tiber River, Italy.

The objective of the present study was to assess the occurrence of major waterborne enteric viruses (enterovirus, norovirus, adenovirus, rotavirus, hepatitis A and E virus) along the Tiber River in Italy, in areas affected by different kinds of anthropogenic pressure (agricultural, urban, industrial and pristine). Moreover, in light of the recent abundant detection of human bocavirus in urban wastewater samples in Italy, the occurrence of this virus was also assessed. Virus detection was based on nested PCR followed by sequencing, and on real-time PCR. A correlation with anthropogenic pressure was observed. The urban and industrial areas were the most contaminated (100 and 75% of samples were positive for at least one virus respectively). The agricultural area was less contaminated, with 50% of samples positive. None of the samples collected in a pristine area were positive for viruses. The most frequently detected virus was human bocavirus, identified in 37·5% of samples, followed by norovirus and enterovirus (28% each) and adenovirus (21·6%). Rotavirus, and hepatitis A and E viruses were less common (<9%). Although Human Bocavirus is not considered a waterborne pathogen, the widespread contamination of river waters suggests that virus transmission via the water route should not be neglected. SIGNIFICANCE AND IMPACT OF THE STUDY: To the best of our knowledge, this study constitutes the first attempt to assess the occurrence of enteric viruses in river waters, in areas differentially influenced by anthropogenic pressure. Enteric viruses (enterovirus, norovirus, adenovirus, rotavirus, hepatitis A and E viruses, and bocavirus) were widespread in the industrial and urban areas, and were less frequently detected in the agricultural area. Interestingly, human bocavirus was the most frequently detected virus, outnumbering even adenoviruses, known to be widespread in water environments. The widespread presence of bocavirus in surface waters suggests that a potential role of water in its transmission should not be excluded.

Modeling Key Drivers of Cholera Transmission Dynamics Provides New Perspectives for Parasitology.

Hydroclimatological and anthropogenic factors are key drivers of waterborne disease transmission. Information on human settlements and host mobility on waterways along which pathogens and hosts disperse, and relevant hydroclimatological processes, can be acquired remotely and included in spatially explicit mathematical models of disease transmission. In the case of epidemic cholera, such models allowed the description of complex disease patterns and provided insight into the course of ongoing epidemics. The inclusion of spatial information in models of disease transmission can aid in emergency management and the assessment of alternative interventions. Here, we review the study of drivers of transmission via spatially explicit approaches and argue that, because many parasitic waterborne diseases share the same drivers as cholera, similar principles may apply.

A community-based survey of Toxoplasma gondii infection among pregnant women in rural areas of Taiz governorate, Yemen: the risk of waterborne transmission.

BACKGROUND: Toxoplasma gondii is a zoonotic coccidian parasite causing morbidity and mortality. In Yemen, T. gondii infection has been reported among pregnant women seeking healthcare in the main cities. However, no data are available on the prevalence of T. gondii infection and its associated risk factors among pregnant women in the rural communities of the country. Thus, the present study aimed to determine the seroprevalence of T. gondii and identify its risk factors among pregnant women in the rural communities of Taiz governorate, Yemen. METHODS: A total of 359 pregnant women living in the rural communities of Taiz governorate were enrolled in this study by house-to-house visits. Data were collected using a pre-designed questionnaire, and blood samples were collected and tested for the detection of anti- T. gondii IgM and IgG antibodies by enzyme-linked immunosorbent assay. RESULTS: The prevalence of T. gondii infection among pregnant women in this study was 46.2% (166/359). Bivariate analysis identified the age of ≥ 30 years (odds ratio [OR] = 1.7; 95% confidence interval [CI] = 1.09-2.65, P = 0.019) and unimproved water sources (OR = 2.2; 95% CI = 1.10-4.55, P = 0.023) as factors associated with T. gondii infection among pregnant women. The multivariable analysis, however, identified unimproved water sources as an independent risk factor (adjusted OR = 2.4; 95% CI = 1.16-5.0, P = 0.018) associated with T. gondii infection among pregnant women. CONCLUSIONS: Pregnant women in the rural communities of Taiz, Yemen are at high risk of contracting T. gondii infection. Unimproved water sources (wells, water streams and water tanks) are significantly associated with T. gondii infection and should be considered in prevention and control strategies, especially among pregnant women.

Environmental contamination and risk factors for transmission of highly pathogenic avian influenza A(H5N1) to humans, Cambodia, 2006-2010.

BACKGROUND: Highly pathogenic avian influenza A (H5N1) virus has been of public health concern since 2003. Probable risk factors for A(H5N1) transmission to human have been demonstrated in several studies or epidemiological reports. However, transmission patterns may differ according to demographic characteristics of the population and local practices. This article aggregates these data from three studies with data collected in the previous surveys in 2006 and 2007 to further examine the risks factors associated with presence of anti-A(H5) antibodies among villagers residing within outbreak areas. METHODS: We aggregated 5-year data (2006-2010) from serology survey and matched case-control studies in Cambodia to further examine the risks factors associated with A(H5N1) infection among villagers in the outbreak areas. RESULTS: Serotesting among villagers detected 35 (1.5 % [0-2.6]) positive cases suggesting recent exposure to A(H5N1) virus. Practices associated with A(H5N1) infection among all ages were: having poultry cage or nesting area under or adjacent to the house (OR: 6.7 [1.6-28.3]; p = 0.010) and transporting poultry to market (OR: 17.6 [1.6-193.7]; p = 0.019). Practices found as risk factors for the infection among age under 20 years were swimming/bathing in ponds also accessed by domestic poultry (OR: 4.6 [1.1-19.1]; p = 0.038). Association with consuming wild birds reached borderline significance (p = 0.066). CONCLUSION: Our results suggest that swimming/bathing in contaminated pond water and close contact with poultry may present a risk of A(H5N1) transmission to human.

Association of Urogenital Symptoms with History of Water Contact in Young Women in Areas Endemic for S. haematobium. A Cross-Sectional Study in Rural South Africa.

Female genital schistosomiasis is a neglected tropical disease caused by Schistosoma haematobium. Infected females may suffer from symptoms mimicking sexually transmitted infections. We explored if self-reported history of unsafe water contact could be used as a simple predictor of genital schistosomiasis. In a cross-sectional study in rural South Africa, 883 sexually active women aged 16-22 years were included. Questions were asked about urogenital symptoms and water contact history. Urine samples were tested for S. haematobium ova. A score based on self-reported water contact was calculated and the association with symptoms was explored while adjusting for other genital infections using multivariable logistic regression analyses. S. haematobium ova were detected in the urine of 30.5% of subjects. Having ova in the urine was associated with the water contact score (p < 0.001). Symptoms that were associated with water contact included burning sensation in the genitals (p = 0.005), spot bleeding (p = 0.012), abnormal discharge smell (p = 0.018), bloody discharge (p = 0.020), genital ulcer (p = 0.038), red urine (p < 0.001), stress incontinence (p = 0.001) and lower abdominal pain (p = 0.028). In S. haematobium endemic areas, self-reported water contact was strongly associated with urogenital symptoms. In low-resource settings, a simple history including risk of water contact behaviour can serve as an indicator of urogenital schistosomiasis.