disease transmission

This study has two goals. The first is to explain the geo-environmental determinants of the accelerated diffusion
of COVID-19 that is generating a high level of deaths. The second is to suggest a strategy to cope with future epidemic
threats similar to COVID-19 having an accelerated viral infectivity in society. Using data on sample of N=
55 Italian province capitals, and data of infected individuals at as of April 7th, 2020, results reveal that the accelerate
and vast diffusion of COVID-19 in North Italy has a high association with air pollution of cities measured
with days exceeding the limits set for PM10 (particulate matter 10 μmor less in diameter) or ozone. In particular,
hinterland cities with average high number of days exceeding the limits set for PM10 (and also having a lowwind
speed) have a very high number of infected people on 7th April 2020 (arithmetic mean is about 2200 infected
individuals, with average polluted days greater than 80 days per year), whereas coastal cities also having days
exceeding the limits set for PM10 or ozone but with high wind speed have about 944.70 average infected individuals,
with about 60 average polluted days per year; moreover, cities having more than 100 days of air pollution
(exceeding the limits set for PM10), they have a very high average number of infected people (about 3350 infected
individuals, 7th April 2020), whereas cities having less than 100 days of air pollution per year, they have
a lower average number of infected people (about 1014 individuals). The findings here also suggest that to minimize
the impact of future epidemics similar to COVID-19, the max number of days per year that Italian provincial
capitals or similar industrialized cities can exceed the limits set for PM10 or for ozone, considering their meteorological
conditions, is about 48 days. Moreover, results here reveal that the explanatory variable of air pollution in  cities seems to be a more important predictor in the initial phase of diffusion of viral infectivity (on 17th March
2020, b1=1.27, p b 0.001) than interpersonal contacts (b2=0.31, p b 0.05). In the second phase of maturity of
the transmission dynamics of COVID-19, air pollution reduces intensity (on 7th April 2020 with b′1 = 0.81,
p b 0.001) also because of the indirect effect of lockdown, whereas regression coefficient of transmission based
on interpersonal contacts has a stable level (b′2=0.31, p b 0.01). This result reveals that accelerated transmission
dynamics of COVID-19 is due tomainly to the mechanismof “air pollution-to-human transmission” (airborne viral infectivity)
rather than “human-to-human transmission”. Overall, then, transmission dynamics of viral infectivity,
such as COVID-19, is due to systemic causes: general factors that are the same for all regions (e.g., biological characteristics
of virus, incubation period, etc.) and specific factors which are different for each region and/or city
(e.g., complex interaction between air pollution, meteorological conditions and biological characteristics of
viral infectivity) and health level of individuals (habits, immune system, age, sex, etc.). Lessons learned for
COVID-19 in the case study here suggest that a proactive strategy to cope with future epidemics is also to
apply especially an environmental and sustainable policy based on reduction of levels of air pollution mainly
in hinterland and polluting cities- (having low wind speed, high percentage of moisture and number of fog
days) -that seem to have an environment that foster a fast transmission dynamics of viral infectivity in society.
Hence, in the presence of polluting industrialization in regions that can trigger the mechanism of air pollutionto-
human transmission dynamics of viral infectivity, this study must conclude that a comprehensive strategy
to prevent future epidemics similar to COVID-19 has to be also designed in environmental and socioeconomic
terms, that is also based on sustainability science and environmental science, and not only in terms of biology,
medicine, healthcare and health sector.

Deteriorating water treatment facilities and distribution systems pose a significant public health threat, particularly in republics of the former Soviet Union. Interventions to decrease the disease burden associated with these water systems range from upgrading distribution networks to installing reverse osmosis technology. To provide insight into this decision process, we conducted a randomized intervention study to provide epidemiologic data for water policy decisions in Nukus, Uzbekistan, where drinking water quality is suboptimal. We interviewed residents of 240 households, 120 with and 120 without access to municipal piped water. Residents of 62 households without piped water were trained to chlorinate their drinking water at home in a narrow-necked water container with a spout. All study subjects (1583 individuals) were monitored biweekly for self-reported diarrheal illness over a period of 9.5 weeks. The home chlorination intervention group had the lowest diarrheal rate (28....

Sub-Saharan Africa is the region most severely affected by the HIV/AIDS pandemic. Of the 40 million HIV infected individuals at the end of 2003, 26 million (65%) were living in the area. Reasons for the high infection rate include historical, political, economic, and cultural factors. The diversity of populations, combined with destitution, political and economic instability and hunger, has led to a number of strategies for combating the disease in Sub-Saharan Africa. These include voluntary counseling and testing, community involvement, facilitating behavior modifications, which include consistent and correct use of condoms, reduction in the number of sexual partners, increasing antiretroviral availability, and the involvement of non-governmental organizations in prevention, treatment, care, and support of the infected population. While Uganda has accomplished significant success through these mechanisms, other countries have not yet been able to control the disease. The population...

The physical and chemical properties and microbiological constituents of wastewater are important parameters in the design and operation of collection, treatment and use of treated effluent. Reuse of reclaimed wastewater may adversely affect public health and the environment of particular concern is degree of purification but also the selection of the most appropriate methods of irrigation and the water use efficiency by which wastewater is applied at the farmers level irrigation method and scheduling of irrigation are important components in the overall system for efficient and safe use of the reclaimed wastewater on environmentally sound bases. (Asano et al, 1984) Irrigation with wastewater has been extensively practiced with traditional irrigation methods over the centuries. Some of these methods are still used, but recently modern irrigation technology has been developed and widely accepted. This new technology, although very useful with all irrigation waters, might be of partic...

Participaram deste trabalho 131 pacientes chagásicos procedentes de diferentes áreas endêmicas atendidos pelo Laboratório de Doença de Chagas da Universidade Estadual de Maringá (UEM). Estes pacientes descobriram que estavam infectados principalmente porque apresentaram sintomatologia (58,1%) ou porque se dispuseram a doar sangue (29,4%). Durante o tratamento etiológico contra o Trypanosoma cruzi,45,2% apresentaram queixas relacionadas a efeitos colaterais do benznidazol. Com base nestes dados foi criado o Programa ACHEI: Atenção ao Chagásico com Educação Integral. Implantado como um projeto de extensão, tem caráter multiprofissional/interdisciplinar. Foi programado com uma reunião mensal composta de uma primeira parte informativa específica, quando é também distribuído um folder explicando transmissão, sintomatologia e tratamento da doença de Chagas. Na segunda parte é trabalhado o apoio psico-social, enfocando auto-estima e cidadania. É um espaço onde pacientes chagásicos podem co...

BackgroundEpidemics with multiple infection waves have been documented for some human diseases, most notably during past influenza pandemics. While pathogen evolution, co-infection, and behavioural changes have been proposed as possible mechanisms for the occurrence of subsequent outbreaks, the effect of public health interventions remains undetermined.MethodsWe develop mean-field and stochastic epidemiological models for disease transmission, and perform simulations to show how control measures, such as drug treatment and isolation of ill individuals, can influence the epidemic profile and generate sequences of infection waves with different characteristics.ResultsWe demonstrate the impact of parameters representing the effectiveness and adverse consequences of intervention measures, such as treatment and emergence of drug resistance, on the spread of a pathogen in the population. If pathogen resistant strains evolve under drug pressure, multiple outbreaks are possible with variability in their characteristics, magnitude, and timing. In this context, the level of drug use and isolation capacity play an important role in the occurrence of subsequent outbreaks. Our simulations for influenza infection as a case study indicate that the intensive use of these interventions during the early stages of the epidemic could delay the spread of disease, but it may also result in later infection waves with possibly larger magnitudes.ConclusionsThe findings highlight the importance of intervention parameters in the process of public health decision-making, and in evaluating control measures when facing substantial uncertainty regarding the epidemiological characteristics of an emerging infectious pathogen. Critical factors that influence population health including evolutionary responses of the pathogen under the pressure of different intervention measures during an epidemic should be considered for the design of effective strategies that address short-term targets compatible with long-term disease outcomes.

We reformulate a model for botanical epidemics into an SIR form for susceptible ( S ), infected ( I ) and removed ( R ) plant organs, in order to examine the effects of different models for the effect of host responses to the load of infection on the production of susceptible tissue. The new formulation also allows for a decline in host susceptibility with age. The model is analysed and tested for the stem canker disease of potatoes, caused by the soil–borne fungus, Rhizoctonia solani . Using a combination of model fitting to field data and analysis of model behaviour, we show that a function for host response to the amount (load) of parasite infection is critical in the description of the temporal dynamics of susceptible and infected stems in epidemics of R. solani . Several different types of host response to infection are compared including two that allow for stimulation of the plant to produce more susceptible tissue at low levels of disease and inhibition at higher levels. We s...

Changing scale, for example, the ability to move seamlessly from an individual-based model to a population-based model, is an important problem in many fields. In this paper, we introduce process algebra as a novel solution to this problem in the context of models of infectious disease spread. Process algebra allows us to describe a system in terms of the stochastic

Purpose The present work documents an outbreak of epidemic keratoconjunctivitis among ophthalmology residents, its influence in the presentation of the community cases, the use of molecular techniques for its diagnosis, and the implementation of successful control ...

Baird's tapir ( Tapirus bairdii) is endangered primarily because of habitat loss and fragmentation, and overhunting throughout its distribution range (ca. 21,000 km2) in the Mexican states of Campeche, Chiapas, Quintana Roo, Oaxaca, Veracruz, and possibly Yucatan and Tabasco. The number of tapirs occurring in Mexico is estimated around 2,600 individuals, which are also threatened by factors such as forest fires, large-scale infrastructure projects (building of dams and highways), disease transmission from domestic animals, pollution of water bodies, and global climatic change effects. A strategy for tapir conservation in Mexico should include: 1) protection and management of extant habitat; 2) creation and maintaining of corridors among isolated forest fragments containing tapirs; 3) community-based control of poaching; 4) development of economic alternatives for people living near tapir habitat; 5) captive breeding programs with educational, scientific, and conservationist purp...

This paper describes the development and application of a community based Health Benefit Group and Healthcare Resource Group (HBG/HRG) classification in the Northern Territory of Australia (NT). HBG/HRG classifications were defined following the framework develope d in the United Kingdom. Data were obtained from the hospital morbidity database, notifiable disease register and the NT government accounting system for the 1997/98

The detection and molecular characterization of pathogenic human viruses in urban sewage have been used extensively to derive information on circulating viruses in given populations throughout the world. In this study, a similar approach was applied to provide an overview of the epidemiology of waterborne gastroenteritis viruses circulating in urban areas of Caracas, the capital city of Venezuela in South America. Dry season sampling was conducted in sewers and in a major river severely polluted with urban sewage discharges. Nested PCR was used for detection of human adenoviruses (HAds), while reverse transcription plus nested or seminested PCR was used for detection of enteroviruses (HuEVs), rotaviruses (HRVs), noroviruses (HuNoVs), and astroviruses (HAstVs). HRVs were fully characterized with genotype-specific primers for VP4 (genotype P), VP7 (genotype G), and the rotavirus nonstructural protein 4 (NSP4). HuNoVs and HAstVs were characterized by sequencing and phylogenetic analysi...

The physical and chemical properties and microbiological constituents of wastewater are important parameters in the design and operation of collection, treatment and use of treated effluent. Reuse of reclaimed wastewater may adversely affect public health and the environment of particular concern is degree of purification but also the selection of the most appropriate methods of irrigation and the water use efficiency by which wastewater is applied at the farmers level irrigation method and scheduling of irrigation are important components in the overall system for efficient and safe use of the reclaimed wastewater on environmentally sound bases. (Asano et al, 1984) Irrigation with wastewater has been extensively practiced with traditional irrigation methods over the centuries. Some of these methods are still used, but recently modern irrigation technology has been developed and widely accepted. This new technology, although very useful with all irrigation waters, might be of partic...

Statistical methods are formulated for fitting and testing percolation-based, spatio-temporal models that are generally applicable to biological or physical processes that evolve in spatially distributed populations. The approach is developed and illustrated in the context of the spread of Rhizoctonia solani, a fungal pathogen, in radish but is readily generalized to other scenarios. The particular model considered represents processes of

Mosquitoes transmit malaria, but only a few species permit the complete development and transmission of the parasite. Also, only a fraction of the ingested parasites develop in the vector. The attrition occurs in different compartments during the parasite's complex ...