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1.
Environ Monit Assess ; 192(2): 134, 2020 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-31970501

RESUMO

Healthcare-acquired infections (HAIs) contribute to maternal and neonatal morbidity and mortality, especially in low- and middle-income countries (LMICs). Deficient environmental health (EH) conditions and infection prevention and control (IPC) practices in healthcare facilities (HCFs) contribute to the spread of HAIs, but microbial sampling of sources of contamination is rarely conducted nor reported in low-resource settings. The purpose of this study was to assess EH conditions and IPC practices in Malawian HCFs and evaluate how EH deficiencies contribute to pathogen exposures and HAIs, and to provide recommendations to inform improvements in EH conditions using a mixed-methods approach. Thirty-one maternity wards in government-run HCFs were surveyed in the three regions of Malawi. Questionnaires were administered in parallel with structured observations of EH conditions and IPC practices and microbial testing of water sources and facility surfaces. Results indicated significant associations between IPC practices and microbial contamination. Facilities where separate wards were not available for mothers and newborns with infections and where linens were not used for patients during healthcare services were more likely to have delivery tables with surface contamination (relative risk = 2.23; 1.49, 3.34). E. coli was detected in water samples from seven (23%) HCFs. Our results suggest that Malawian maternity wards could reduce microbial contamination, and potentially reduce the occurrence of HAIs, by improving EH conditions and IPC practices. HCF staff can use the simple, low-cost EH monitoring methods used in this study to incorporate microbial monitoring of EH conditions and IPC practices in HCFs in low-resource settings.

2.
Health Policy Plan ; 2019 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-31722372

RESUMO

Many healthcare facilities (HCFs) in low-income countries experience unreliable connectivity to energy sources, which adversely impacts the quality of health service delivery and provision of adequate environmental health services. This assessment explores the status and consequences of energy access through interviews and surveys with administrators and healthcare workers from 44 HCFs (central hospitals, district hospitals, health centres and health posts) in Malawi. Most HCFs are connected to the electrical grid but experience weekly power interruptions averaging 10 h; less than one-third of facilities have a functional back-up source. Inadequate energy availability is associated with irregular water supply and poor medical equipment sterilization; it adversely affects provider safety and contributes to poor lighting and working conditions. Some challenges, such as poor availability and maintenance of back-up energy sources, disproportionately affect smaller HCFs. Policymakers, health system actors and third-party organizations seeking to improve energy access and quality of care in Malawi and similar settings should address these challenges in a way that prioritizes the specific needs of different facility types.

3.
Int J Hyg Environ Health ; 220(8): 1199-1206, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28827123

RESUMO

BACKGROUND: Water is an important, overlooked, and controllable source of nosocomial infection. Hospitalized neonates and their mothers are particularly vulnerable to nosocomial waterborne infections. Our objectives through this systematic review were to: investigate water sources, reservoirs, and transmission routes that lead to nosocomial waterborne infections in neonates and their mothers; establish patient risk factors; compile measures for controlling outbreaks and recommended strategies for prevention; and identify information gaps to improve guidelines for reporting future outbreaks. METHODS: We searched PubMed, Web of Science, Embase, and clinicaltrials.gov. Peer-reviewed studies reporting contaminated water as a route of transmission to neonates and/or their mothers were included. RESULTS: Twenty-five studies were included. The most common contaminated water sources in healthcare facilities associated with infection transmission were tap water, sinks, and faucets. Low birthweights, preterm or premature birth, and underlying disease increased neonatal risk of infection. Effective control measures commonly included replacing or cleaning faucets and increased or alternative methods for hand disinfection, and recommendations for prevention of future infections highlighted the need for additional surveillance. DISCUSSION/CONCLUSION: The implementation of control measures and recommended prevention strategies by healthcare workers and managing authorities of healthcare facilities and improved reporting of future outbreaks may contribute to a reduction in the incidence of nosocomial waterborne infections in neonates and their mothers.


Assuntos
Infecção Hospitalar/epidemiologia , Doenças Transmitidas pela Água/epidemiologia , Humanos , Recém-Nascido , Mães
4.
J Water Health ; 15(2): 175-184, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28362299

RESUMO

Clinically relevant antimicrobial resistant bacteria, genetic resistance elements, and antibiotic residues (so-called AMR) from human and animal waste are abundantly present in environmental samples. This presence could lead to human exposure to AMR. In 2015, the World Health Organization (WHO) developed a Global Action Plan for Antimicrobial Resistance with one of its strategic objectives being to strengthen knowledge through surveillance and research. With respect to a strategic research agenda on water, sanitation and hygiene and AMR, WHO organized a workshop to solicit input by scientists and other stakeholders. The workshop resulted in three main conclusions. The first conclusion was that guidance is needed on how to reduce the spread of AMR to humans via the environment and to introduce effective intervention measures. Second, human exposure to AMR via water and its health impact should be investigated and quantified, in order to compare with other human exposure routes, such as direct transmission or via food consumption. Finally, a uniform and global surveillance strategy that complements existing strategies and includes analytical methods that can be used in low-income countries too, is needed to monitor the magnitude and dissemination of AMR.


Assuntos
Anti-Infecciosos/farmacologia , Resistência Microbiana a Medicamentos , Saneamento , Microbiologia da Água , Humanos , Saneamento/normas , Microbiologia da Água/normas , Organização Mundial da Saúde
5.
Int J Hyg Environ Health ; 220(3): 611-620, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28017547

RESUMO

Healthcare-acquired infections are an increasing problem for health care providers and policy makers. Water is an overlooked source of infectious microorganisms in health care facilities. Waterborne nontuberculous mycobacteria (NTM) are ubiquitous, and particularly problematic in health care facility water systems, and cause a variety of diseases. The purpose of this review is to assess health care associated NTM infections from health care facility water systems. We documented susceptible populations, modes of transmission, and the median attack rate (e.g. patients infected per patients exposed). We aimed to identify transmission risk factors and inform evidence-based policies for infection control and prevention. We searched Embase, PubMed, Web of Science and clinicaltrials.gov without date restrictions. English language articles with original data on NTM waterborne infections in health care settings were included. Randomized controlled trials, descriptive studies (case reports, case series), case-control studies, cohort studies, cross-sectional surveys, and quasi-experimental studies on nosocomial waterborne infections were included. Three investigators independently screened titles and abstracts for relevant articles, and one screened full-text articles. Data were extracted by one investigator, and a second confirmed accuracy for 10% of results. We included 22 observational studies. Immunocompromised, post-surgical, and hemodialysis patients were commonly affected populations. A range of exposure routes such as uncovered central venous catheters (CVCs), wound exposure, and contamination during surgical procedures was reported. The median attack rate was 12.1% (interquartile range, 11-27.2). Waterborne NTM infection affects susceptible patients through common, preventable exposure routes. Effective prevention strategies will require both medical and environmental health expertise, and inter-professional cooperation will optimize these efforts.


Assuntos
Infecção Hospitalar/epidemiologia , Infecções por Mycobacterium/epidemiologia , Micobactérias não Tuberculosas , Doenças Transmitidas pela Água/epidemiologia , Monitoramento Ambiental , Instalações de Saúde , Humanos , Microbiologia da Água , Abastecimento de Água
6.
Artigo em Inglês | MEDLINE | ID: mdl-26927152

RESUMO

The use of porous ceramic filters is promoted globally for household water treatment, but these filters are ineffective in removing viruses from water. In order to increase virus removal, we combine a promising natural coagulant, chitosan, as a pretreatment for ceramic water filters (CWFs) and evaluate the performance of this dual barrier water treatment system. Chitosan is a non-toxic and biodegradable organic polymer derived by simple chemical treatments from chitin, a major source of which is the leftover shells of crustacean seafoods, such as shrimp, prawns, crabs, and lobsters. To determine the effectiveness of chitosan, model test water was contaminated with Escherichia coli K011 and coliphage MS2 as a model enteric bacterium and virus, respectively. Kaolinite clay was used to model turbidity. Coagulation effectiveness of three types of modified chitosans was determine at various doses ranging from 5 to 30 mg/L, followed by flocculation and sedimentation. The pre-treated supernatant water was then decanted into the CWF for further treatment by filtration. There were appreciable microbial removals by chitosan HCl, acetate, and lactate pretreatment followed by CWF treatment, with mean reductions (95% CI) between 4.7 (± 1.56) and 7.5 (± 0.02) log10 for Escherichia coli, and between 2.8 (± 0.10) and 4.5 (± 1.04) log10 for MS2. Turbidity reduction with chitosan treatment and filtration consistently resulted in turbidities < 1 NTU, which meet turbidity standards of the US EPA and guidance by the World Health Organization (WHO). According to WHO health-based microbial removal targets for household water treatment technology, chitosan coagulation achieved health protective targets for both viruses and bacteria. Therefore, the results of this study support the use of chitosan to improve household drinking water filtration processes by increasing virus and bacteria reductions.


Assuntos
Cerâmica/química , Quitosana/química , Água Potável/análise , Filtração , Microbiologia da Água/normas , Purificação da Água/instrumentação , Países em Desenvolvimento , Enterobacteriaceae/crescimento & desenvolvimento , Escherichia coli/crescimento & desenvolvimento , Características da Família , Filtração/métodos , Humanos , Nefelometria e Turbidimetria , Purificação da Água/métodos
7.
Environ Sci Technol ; 49(21): 12958-67, 2015 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-26398590

RESUMO

Ceramic water filters (CWFs) impregnated with silver nanoparticles are a means of household-level water treatment. CWFs remove/deactivate microbial pathogens by employing two mechanisms: metallic disinfection and physical filtration. Herein we report on the independent effects of silver salt and nanoparticles on Cryptosporidium parvum and the removal of C. parvum by physical filtration in porous ceramic filter media. Using a murine (mouse) model, we observed that treatment of oocysts with silver nitrate and proteinate-capped silver nanoparticles resulted in decreased infection relative to untreated oocysts. Microscopy and excystation experiments were conducted to support the disinfection investigation. Heat and proteinate-capped silver-nanoparticle treatment of oocysts resulted in morphological modifications and decreased excystation rates of sporozoites. Subsequently, disk-shaped ceramic filters were produced to investigate the transport of C. parvum. Two factors were varied: sawdust size and clay-to-sawdust ratio. Five disks were prepared with combinations of 10, 16, and 20 mesh sawdust and sawdust percentage that ranged from 9 to 11%. C. parvum removal efficiencies ranged from 1.5 log (96.4%) to 2.1 log (99.2%). The 16-mesh/10% sawdust had the greatest mean reduction of 2.1-log (99.2%), though there was no statistically significant difference in removal efficiency. Based on our findings, physical filtration and silver nanoparticle disinfection likely contribute to treatment of C. parvum for silver impregnated ceramic water filters, although the contribution of physical filtration is likely greater than silver disinfection.


Assuntos
Cerâmica/farmacologia , Cryptosporidium parvum/isolamento & purificação , Desinfecção/métodos , Filtração/métodos , Nanopartículas Metálicas/química , Prata/farmacologia , Água/parasitologia , Animais , Peso Corporal , Cryptosporidium parvum/efeitos dos fármacos , Feminino , Imagem Tridimensional , Íons , Camundongos Endogâmicos C57BL , Oocistos/citologia , Porosidade , Nitrato de Prata/farmacologia , Purificação da Água
8.
J Water Health ; 12(2): 288-300, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24937223

RESUMO

Waterborne pathogens present a significant threat to people living with the human immunodeficiency virus (PLWH). This study presents a randomized, controlled trial that evaluates whether a household-level ceramic water filter (CWF) intervention can improve drinking water quality and decrease days of diarrhea in PLWH in rural South Africa. Seventy-four participants were randomized in an intervention group with CWFs and a control group without filters. Participants in the CWF arm received CWFs impregnated with silver nanoparticles and associated safe-storage containers. Water and stool samples were collected at baseline and 12 months. Diarrhea incidence was self-reported weekly for 12 months. The average diarrhea rate in the control group was 0.064 days/week compared to 0.015 days/week in the intervention group (p < 0.001, Mann-Whitney). Median reduction of total coliform bacteria was 100% at enrollment and final collection. CWFs are an acceptable technology that can significantly improve the quality of household water and decrease days of diarrhea for PLWH in rural South Africa.


Assuntos
Diarreia/prevenção & controle , Água Potável/análise , Filtração/métodos , Nanopartículas Metálicas/química , Purificação da Água/métodos , Qualidade da Água , Adulto , Cerâmica/uso terapêutico , Criptosporidiose/epidemiologia , Criptosporidiose/parasitologia , Criptosporidiose/prevenção & controle , Cryptosporidium/isolamento & purificação , Diarreia/epidemiologia , Diarreia/microbiologia , Diarreia/parasitologia , Água Potável/microbiologia , Água Potável/parasitologia , Enterobacteriaceae/isolamento & purificação , Infecções por Enterobacteriaceae/epidemiologia , Infecções por Enterobacteriaceae/microbiologia , Infecções por Enterobacteriaceae/prevenção & controle , Fezes/microbiologia , Fezes/parasitologia , Feminino , Soropositividade para HIV/epidemiologia , Soropositividade para HIV/virologia , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Reação em Cadeia da Polimerase em Tempo Real , População Rural , Prata/química , África do Sul/epidemiologia , Adulto Jovem
9.
Water Res ; 49: 286-99, 2014 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-24355289

RESUMO

Ceramic water filters (CWFs) are a point-of-use water treatment technology that has shown promise in preventing early childhood diarrhea (ECD) in resource-limited settings. Despite this promise, some researchers have questioned their ability to reduce ECD incidences over the long term since most effectiveness trials conducted to date are less than one year in duration limiting their ability to assess long-term sustainability factors. Most trials also suffer from lack of blinding making them potentially biased. This study uses an agent-based model (ABM) to explore factors related to the long-term sustainability of CWFs in preventing ECD and was based on a three year longitudinal field study. Factors such as filter user compliance, microbial removal effectiveness, filter cleaning and compliance declines were explored. Modeled results indicate that broadly defined human behaviors like compliance and declining microbial effectiveness due to improper maintenance are primary drivers of the outcome metrics of household drinking water quality and ECD rates. The model predicts that a ceramic filter intervention can reduce ECD incidence amongst under two year old children by 41.3%. However, after three years, the average filter is almost entirely ineffective at reducing ECD incidence due to declining filter microbial removal effectiveness resulting from improper maintenance. The model predicts very low ECD rates are possible if compliance rates are 80-90%, filter log reduction efficiency is 3 or greater and there are minimal long-term compliance declines. Cleaning filters at least once every 4 months makes it more likely to achieve very low ECD rates as does the availability of replacement filters for purchase. These results help to understand the heterogeneity seen in previous intervention-control trials and reemphasize the need for researchers to accurately measure confounding variables and ensure that field trials are at least 2-3 years in duration. In summary, the CWF can be a highly effective tool in the fight against ECD, but every effort should be made by implementing agencies to ensure consistent use and maintenance.


Assuntos
Cerâmica/química , Filtração/instrumentação , Modelos Teóricos , Purificação da Água/instrumentação , Criança , Diarreia/epidemiologia , Diarreia/etiologia , Humanos , Qualidade da Água
10.
Analyst ; 139(1): 66-73, 2014 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-24225592

RESUMO

Microbial persistence to antibiotics is attributed to subpopulations with phenotypic variations that cause a spread of susceptibility levels, leading to the recurrence of infections and stability of biofilms. Herein, persistent oocyst subpopulations identified by animal infectivity and excystation assays during the disinfection of Cryptosporidium parvum, a water-borne pathogen capable of causing enteric infections at ultra-low doses, are separated and characterized by quantitative dielectrophoretic tracking over a wide frequency range (10 kHz-10 MHz). To enable the simultaneous and facile dielectrophoretic tracking of individual oocysts, insulator constrictions in a microfluidic channel are utilized to spatially modulate the localized field over the extent needed for defining oocyst trajectories and for obtaining high-resolution displacement versus time measurements under both, positive and negative dielectrophoresis. In this manner, by obviating the need for averaging dielectrophoretic data over a large collection region, the force response is more sensitive to differences in electrophysiology from sub-population fractions. Hence, the electrophysiology of sensitive and persistent oocysts after heat and silver nanoparticle treatments can be quantified by correlating the force response at low frequencies (<100 kHz) to the integrity of the oocyst wall and at high frequencies (0.4-1 MHz) to the sporozoites in the oocyst. This label-free method can characterize heterogeneous microbial samples with subpopulations of phenotypically different alterations, for quantifying the intensity of alteration and fraction with a particular alteration type.


Assuntos
Cryptosporidium parvum/química , Cryptosporidium parvum/isolamento & purificação , Eletroforese/métodos , Oocistos/química , Animais , Camundongos
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