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Zheng S, Li J, Ye C, Xian X, Feng M, Yu X. Microbiological risks increased by ammonia-oxidizing bacteria under global warming: The neglected issue in chloraminated drinking water distribution system. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 874:162353. [PMID: 36822432 DOI: 10.1016/j.scitotenv.2023.162353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 02/14/2023] [Accepted: 02/16/2023] [Indexed: 06/18/2023]
Abstract
A rising outbreak of waterborne diseases caused by global warming requires higher microbial stability in the drinking water distribution system (DWDS). Chloramine disinfection is gaining popularity in this context due to its good persistent stability and fewer disinfection byproducts. However, the microbiological risks may be significantly magnified by ammonia-oxidizing bacteria (AOB) in distribution systems during global warming, which is rarely noticed. Hence, this work mainly focuses on AOB to explore its impact on water quality biosafety in the context of global warming. Research indicates that global warming-induced high temperatures can directly or indirectly promote the growth of AOB, thus leading to nitrification. Further, its metabolites or cellular residues can be used as substrates for the growth of heterotrophic bacteria (e.g., waterborne pathogens). Thus, biofilm may be more persistent in the pipelines due to the presence of AOB. Breakpoint chlorination is usually applied to control such situations. However, switching between this strategy and chloramine disinfection would result in even more severe nitrification and other adverse effects. Based on the elevated microbiological risks in DWDS, the following aspects should be paid attention to in future research: (1) to understand the response of nitrifying bacteria to high temperatures and the possible association between AOB and pathogenic growth, (2) to reveal the mechanisms of AOB-mediated biofilm formation under high-temperature stress, and (3) to develop new technologies to prevent and control the occurrence of nitrification in drinking water distribution system.
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Affiliation(s)
- Shikan Zheng
- College of the Environment and Ecology, Xiamen University, Xiamen 361102, China
| | - Jianguo Li
- College of the Environment and Ecology, Xiamen University, Xiamen 361102, China
| | - Chengsong Ye
- College of the Environment and Ecology, Xiamen University, Xiamen 361102, China
| | - Xuanxuan Xian
- College of the Environment and Ecology, Xiamen University, Xiamen 361102, China
| | - Mingbao Feng
- College of the Environment and Ecology, Xiamen University, Xiamen 361102, China
| | - Xin Yu
- College of the Environment and Ecology, Xiamen University, Xiamen 361102, China.
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Chae SR, Lukupulo H, Kim S, Walker T, Hardy C, Abade A, Urio LJ, Mghamba J, Quick R. An Assessment of Household Knowledge and Practices during a Cholera Epidemic- Dar es Salaam, Tanzania, 2016. Am J Trop Med Hyg 2022; 107:766-772. [PMID: 36067990 PMCID: PMC9651532 DOI: 10.4269/ajtmh.21-0597] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 03/05/2022] [Indexed: 12/30/2022] Open
Abstract
From August 15, 2015 to March 5, 2016, Tanzania reported 16,521 cholera cases and 251 deaths, with 4,596 cases and 44 deaths in its largest city, Dar es Salaam. To evaluate outbreak response efforts, we conducted a household survey with drinking water testing in the five most affected wards in Dar es Salaam. We interviewed 641 households 6 months after the beginning of the outbreak. Although most respondents knew that cholera causes diarrhea (90%) and would seek care if suspecting cholera (95%), only 45% were aware of the current outbreak in the area and only 5% would use oral rehydration salts (ORS) if ill. Of 200 (31%) respondents reporting no regular water treatment, 46% believed treatment was unnecessary and 18% believed treatment was too expensive. Fecal contamination was found in 45% of water samples and was associated with water availability (P = 0.047). Only 11% of samples had detectable free chlorine residual, which was associated with water availability (P = 0.025), reported current water treatment (P = 0.006), and observed free chlorine product in the household (P = 0.015). The provision of accessible, adequately chlorinated water supply, and implementation of social mobilization campaigns advocating household water treatment and use of ORS should be prioritized to address gaps in cholera prevention and treatment activities.
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Affiliation(s)
- Sae-Rom Chae
- Division of Foodborne and Waterborne and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia;,Address correspondence to Sae-Rom Chae, Division of Foodborne and Waterborne and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, GA. E-mail:
| | - Haji Lukupulo
- Tanzania Field Epidemiology and Laboratory Training Program, Dar es Salaam, Tanzania
| | - Sunkyung Kim
- Division of Foodborne and Waterborne and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Tiffany Walker
- Division of Foodborne and Waterborne and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Colleen Hardy
- Division of Global Health Protection, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Ahmed Abade
- Tanzania Field Epidemiology and Laboratory Training Program, Dar es Salaam, Tanzania
| | - Loveness J. Urio
- Tanzania Field Epidemiology and Laboratory Training Program, Dar es Salaam, Tanzania
| | - Janneth Mghamba
- Ministry of Health, Community Development, Gender, Elderly and Children, United Republic of Tanzania, Dar es Salaam, Tanzania
| | - Robert Quick
- Division of Foodborne and Waterborne and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
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Exploring relationships between drought and epidemic cholera in Africa using generalised linear models. BMC Infect Dis 2021; 21:1177. [PMID: 34809609 PMCID: PMC8609751 DOI: 10.1186/s12879-021-06856-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 11/08/2021] [Indexed: 11/18/2022] Open
Abstract
Background Temperature and precipitation are known to affect Vibrio cholerae outbreaks. Despite this, the impact of drought on outbreaks has been largely understudied. Africa is both drought and cholera prone and more research is needed in Africa to understand cholera dynamics in relation to drought. Methods Here, we analyse a range of environmental and socioeconomic covariates and fit generalised linear models to publicly available national data, to test for associations with several indices of drought and make cholera outbreak projections to 2070 under three scenarios of global change, reflecting varying trajectories of CO2 emissions, socio-economic development, and population growth. Results The best-fit model implies that drought is a significant risk factor for African cholera outbreaks, alongside positive effects of population, temperature and poverty and a negative effect of freshwater withdrawal. The projections show that following stringent emissions pathways and expanding sustainable development may reduce cholera outbreak occurrence in Africa, although these changes were spatially heterogeneous. Conclusions Despite an effect of drought in explaining recent cholera outbreaks, future projections highlighted the potential for sustainable development gains to offset drought-related impacts on cholera risk. Future work should build on this research investigating the impacts of drought on cholera on a finer spatial scale and potential non-linear relationships, especially in high-burden countries which saw little cholera change in the scenario analysis. Supplementary Information The online version contains supplementary material available at 10.1186/s12879-021-06856-4.
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The Impact of Climate Change on Cholera: A Review on the Global Status and Future Challenges. ATMOSPHERE 2020. [DOI: 10.3390/atmos11050449] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Water ecosystems can be rather sensitive to evolving or sudden changes in weather parameters. These changes can result in alterations in the natural habitat of pathogens, vectors, and human hosts, as well as in the transmission dynamics and geographic distribution of infectious agents. However, the interaction between climate change and infectious disease is rather complicated and not deeply understood. In this narrative review, we discuss climate-driven changes in the epidemiology of Vibrio species-associated diseases with an emphasis on cholera. Changes in environmental parameters do shape the epidemiology of Vibrio cholerae. Outbreaks of cholera cause significant disease burden, especially in developing countries. Improved sanitation systems, access to clean water, educational strategies, and vaccination campaigns can help control vibriosis. In addition, real-time assessment of climatic parameters with remote-sensing technologies in combination with robust surveillance systems could help detect environmental changes in high-risk areas and result in early public health interventions that can mitigate potential outbreaks.
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Mabvouna Biguioh R, Sali Ben Béchir Adogaye, Nkamedjie Pete PM, Sanou Sobze M, Kemogne JB, Colizzi V. Microbiological quality of water sources in the West region of Cameroon: quantitative detection of total coliforms using Micro Biological Survey method. BMC Public Health 2020; 20:346. [PMID: 32183747 PMCID: PMC7076929 DOI: 10.1186/s12889-020-8443-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 03/02/2020] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND Adequate supply of safe drinking-water remains a critical issue in most developing countries. The whole western region of Cameroon doesn't have a sustainable continuous water supply system, which leads most people to use potentially contaminated water sources to meet their daily water needs. Previous, studies carried out in similar areas of Cameroon have highlighted the poor bacteriological quality of water sources used as drinking-water by the local populations. METHODS This study used the Micro Biological Survey method, a rapid colorimetric test for the quantitative detection of Coliforms in water samples. 22 water sources (12 improved and 10 unimproved) were identified; 1 water sample of 50 ml was collected in sterile plastic tubes, immediately kept in a refrigerator box and transported to the laboratory for analysis. 1 ml of each sample was inoculated in the Coliforms Micro Biological Survey (Coli MBS) vials initially rehydrated with 10 ml of sterile distilled water. The Coli MBS vials were closed, shaken for about 30 s for homogenization and then incubated at 37 °C. From the initial red color of the Coli MBS vials, changes in color of the reaction vials were monitored at three different time intervals (12 h, 19 h and 24 h), corresponding to three levels of contamination. RESULTS The average distance (8.7 m) of the latrines from the nearest water source was less than the minimal recommended distance (15 m) to ovoid external contamination. The pH of water samples ranged from 5.5 to 8.3 and the maximum temperature found (26 °C) was almost at level favorable to outbreaks of waterborne diseases such as cholera. The presence of Total Coliforms was detected in 90.91% of the samples. 40% of samples were positive 12 h after the analysis beginning. High level of contamination was observed in unimproved water sources, 50% after 12 h corresponding to Total Coliforms concentration of 10 < x < 103 CFU/ml and the other samples after 19 h (Total Coliforms concentration: 1 < x < 10 CFU/ml). CONCLUSION This study revealed the poor microbiological quality of water used by local populations of our study sites. There is need to conduct further qualitative microbiology studies to isolate potential germs involved in outcome of diarrheal diseases.
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Affiliation(s)
| | | | | | - Martin Sanou Sobze
- Faculty of Medicine and pharmaceutical Sciences, University of Dschang, Dschang, Cameroon
| | | | - Vittorio Colizzi
- Faculty of Medicine and surgery, University of Roma “Tor Vergata”, Rome, Italy
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Adekiya TA, Aruleba RT, Oyinloye BE, Okosun KO, Kappo AP. The Effect of Climate Change and the Snail-Schistosome Cycle in Transmission and Bio-Control of Schistosomiasis in Sub-Saharan Africa. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 17:E181. [PMID: 31887979 PMCID: PMC6981654 DOI: 10.3390/ijerph17010181] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 12/17/2019] [Accepted: 12/19/2019] [Indexed: 01/30/2023]
Abstract
In the next century, global warming, due to changes in climatic factors, is expected to have an enormous influence on the interactions between pathogens and their hosts. Over the years, the rate at which vector-borne diseases and their transmission dynamics modify and develop has been shown to be highly dependent to a certain extent on changes in temperature and geographical distribution. Schistosomiasis has been recognized as a tropical and neglected vector-borne disease whose rate of infection has been predicted to be elevated worldwide, especially in sub-Saharan Africa; the region currently with the highest proportion of people at risk, due to changes in climate. This review not only suggests the need to develop an efficient and effective model that will predict Schistosoma spp. population dynamics but seeks to evaluate the effectiveness of several current control strategies. The design of a framework model to predict and accommodate the future incidence of schistosomiasis in human population dynamics in sub-Saharan Africa is proposed. The impact of climate change on schistosomiasis transmission as well as the distribution of several freshwater snails responsible for the transmission of Schistosoma parasites in the region is also reviewed. Lastly, this article advocates for modelling several control mechanisms for schistosomiasis in sub-Saharan Africa so as to tackle the re-infection of the disease, even after treating infected people with praziquantel, the first-line treatment drug for schistosomiasis.
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Affiliation(s)
- Tayo Alex Adekiya
- Biotechnology and Structural Biology Group, Department of Biochemistry and Microbiology, University of Zululand, KwaDlangezwa 3886, South Africa; (R.T.A.); (B.E.O.)
| | - Raphael Taiwo Aruleba
- Biotechnology and Structural Biology Group, Department of Biochemistry and Microbiology, University of Zululand, KwaDlangezwa 3886, South Africa; (R.T.A.); (B.E.O.)
| | - Babatunji Emmanuel Oyinloye
- Biotechnology and Structural Biology Group, Department of Biochemistry and Microbiology, University of Zululand, KwaDlangezwa 3886, South Africa; (R.T.A.); (B.E.O.)
- Department of Biochemistry, Afe Babalola University, PMB 5454, Ado-Ekiti 360001, Nigeria
| | - Kazeem Oare Okosun
- Department of Mathematics, Vaal University of Technology, Vanderbijlpark 1900, South Africa;
| | - Abidemi Paul Kappo
- Biotechnology and Structural Biology Group, Department of Biochemistry and Microbiology, University of Zululand, KwaDlangezwa 3886, South Africa; (R.T.A.); (B.E.O.)
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Environmental Reservoirs of Vibrio cholerae: Challenges and Opportunities for Ocean-Color Remote Sensing. REMOTE SENSING 2019. [DOI: 10.3390/rs11232763] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The World Health Organization has estimated the burden of the on-going pandemic of cholera at 1.3 to 4 million cases per year worldwide in 2016, and a doubling of case-fatality-rate to 1.8% in 2016 from 0.8% in 2015. The disease cholera is caused by the bacterium Vibrio cholerae that can be found in environmental reservoirs, living either in free planktonic form or in association with host organisms, non-living particulate matter or in the sediment, and participating in various biogeochemical cycles. An increasing number of epidemiological studies are using land- and water-based remote-sensing observations for monitoring, surveillance, or risk mapping of Vibrio pathogens and cholera outbreaks. Although the Vibrio pathogens cannot be sensed directly by satellite sensors, remotely-sensed data can be used to infer their presence. Here, we review the use of ocean-color remote-sensing data, in conjunction with information on the ecology of the pathogen, to map its distribution and forecast risk of disease occurrence. Finally, we assess how satellite-based information on cholera may help support the Sustainable Development Goals and targets on Health (Goal 3), Water Quality (Goal 6), Climate (Goal 13), and Life Below Water (Goal 14).
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The effect of climate change on cholera disease: The road ahead using artificial neural network. PLoS One 2019; 14:e0224813. [PMID: 31693708 PMCID: PMC6834266 DOI: 10.1371/journal.pone.0224813] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 10/22/2019] [Indexed: 12/05/2022] Open
Abstract
Climate change has been described to raise outbreaks of water-born infectious diseases and increases public health concerns. This study aimed at finding out these impacts on cholera infections by using Artificial Neural Networks (ANNs) from 2021 to 2050. Daily data for cholera infection cases in Qom city, which is located in the center of Iran, were analyzed from 1998 to 2016. To determine the best lag time and combination of inputs, Gamma Test (GT) was applied. General circulation model outputs were utilized to project future climate pattern under two scenarios of Representative Concentration Pathway (RCP2.6 and RCP8.5). Statistical downscaling was done to produce high-resolution synthetic time series weather dataset. ANNs were applied for simulating the impact of climate change on cholera. The observed climate variables including maximum and minimum temperatures and precipitation were tagged as predictors in ANNs. Cholera cases were considered as the target outcome variable. Projected future (2020–2050) climate in previous step was carried out to assess future cholera incidence. A seasonal trend in cholera infection was seen. Our results elucidated that the best lag time was 21 days. According to the results of downscaling tool, future climate in the study area by 2050 will be warmer and wetter. Simulation of cholera cases indicated that there is a clear trend of increasing cholera cases under the worst scenario (RCP8.5) by the year 2050 and the highest cholera cases observe in warmer months. The precipitation was recognized as the most effective input variable by sensitivity analysis. We observed a significant correlation between low precipitation and cholera infection. There is a strong evidence to show that cholera disease is correlated with environment variables, as low precipitation and high temperatures in warmer months could provide the swifter bacterial replication. These conditions in Iran, especially in the central parts, may raise the cholera infection rates. Furthermore, ANNs is an executive tool to simulate the impact of climate change on cholera to estimate the future trend of cholera incidence for adopting protective measures in endemic areas.
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Chersich MF, Wright CY. Climate change adaptation in South Africa: a case study on the role of the health sector. Global Health 2019; 15:22. [PMID: 30890178 PMCID: PMC6423888 DOI: 10.1186/s12992-019-0466-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Accepted: 03/12/2019] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Globally, the response to climate change is gradually gaining momentum as the impacts of climate change unfold. In South Africa, it is increasingly apparent that delays in responding to climate change over the past decades have jeopardized human life and livelihoods. While slow progress with mitigation, especially in the energy sector, has garnered much attention, focus is now shifting to developing plans and systems to adapt to the impacts of climate change. METHODS We applied systematic review methods to assess progress with climate change adaptation in the health sector in South Africa. This case study provides useful lessons which could be applied in other countries in the African region, or globally. We reviewed the literature indexed in PubMed and Web of Science, together with relevant grey literature. We included articles describing adaptation interventions to reduce the impact of climate change on health in South Africa. All study designs were eligible. Data from included articles and grey literature were summed thematically. RESULTS Of the 820 publications screened, 21 were included, together with an additional xx papers. Very few studies presented findings of an intervention or used high-quality research designs. Several policy frameworks for climate change have been developed at national and local government levels. These, however, pay little attention to health concerns and the specific needs of vulnerable groups. Systems for forecasting extreme weather, and tracking malaria and other infections appear well established. Yet, there is little evidence about the country's preparedness for extreme weather events, or the ability of the already strained health system to respond to these events. Seemingly, few adaptation measures have taken place in occupational and other settings. To date, little attention has been given to climate change in training curricula for health workers. CONCLUSIONS Overall, the volume and quality of research is disappointing, and disproportionate to the threat posed by climate change in South Africa. This is surprising given that the requisite expertise for policy advocacy, identifying effective interventions and implementing systems-based approaches rests within the health sector. More effective use of data, a traditional strength of health professionals, could support adaptation and promote accountability of the state. With increased health-sector leadership, climate change could be reframed as predominately a health issue, one necessitating an urgent, adequately-resourced response. Such a shift in South Africa, but also beyond the country, may play a key role in accelerating climate change adaptation and mitigation.
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Affiliation(s)
- Matthew F Chersich
- Wits Reproductive Health and HIV Institute, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
| | - Caradee Y Wright
- Environment and Health Research Unit, South African Medical Research Council and Department of Geography, Geoinformatics and Meteorology, University of Pretoria, Pretoria, South Africa
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Hulland E, Subaiya S, Pierre K, Barthelemy N, Pierre JS, Dismer A, Juin S, Fitter D, Brunkard J. Increase in Reported Cholera Cases in Haiti Following Hurricane Matthew: An Interrupted Time Series Model. Am J Trop Med Hyg 2019; 100:368-373. [PMID: 30594260 PMCID: PMC6367609 DOI: 10.4269/ajtmh.17-0964] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 09/30/2018] [Indexed: 11/12/2022] Open
Abstract
Matthew, a category 4 hurricane, struck Haiti on October 4, 2016, causing widespread flooding and damage to buildings and crops, and resulted in many deaths. The damage caused by Matthew raised concerns of increased cholera transmission particularly in Sud and Grand'Anse departments, regions which were hit most heavily by the storm. To evaluate the change in reported cholera cases following Hurricane Matthew on reported cholera cases, we used interrupted time series regression models of daily reported cholera cases, controlling for the impact of both rainfall, following a 4-week lag, and seasonality, from 2013 through 2016. Our results indicate a significant increase in reported cholera cases after Matthew, suggesting that the storm resulted in an immediate surge in suspect cases, and a decline in reported cholera cases in the 46-day post-storm period, after controlling for rainfall and seasonality. Regression models stratified by the department indicate that the impact of the hurricane was regional, with larger surges in the two most highly storm-affected departments: Sud and Grand'Anse. These models were able to provide input to the Ministry of Health in Haiti on the national and regional impact of Hurricane Matthew and, with further development, could provide the flexibility of use in other emergency situations. This article highlights the need for continued cholera prevention and control efforts, particularly in the wake of natural disasters such as hurricanes, and the continued need for intensive cholera surveillance nationally.
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Affiliation(s)
- Erin Hulland
- Division of Global Health Protection, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Saleena Subaiya
- Global Immunization Division, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Katilla Pierre
- MSPP Haiti, Directorate of Epidemiology, Laboratory and Research, Delmas, Haiti
| | | | - Jean Samuel Pierre
- MSPP Haiti, Directorate of Epidemiology, Laboratory and Research, Delmas, Haiti
| | - Amber Dismer
- Division of Global Health Protection, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Stanley Juin
- Centers for Disease Control and Prevention Haiti, Tabarre, Haiti
| | - David Fitter
- Division of Global Health Protection, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia
- Centers for Disease Control and Prevention Haiti, Tabarre, Haiti
| | - Joan Brunkard
- Division of Foodborne, Waterborne and Environmental Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
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Osei FB, Stein A. Temporal trend and spatial clustering of cholera epidemic in Kumasi-Ghana. Sci Rep 2018; 8:17848. [PMID: 30552392 PMCID: PMC6294804 DOI: 10.1038/s41598-018-36029-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 11/10/2018] [Indexed: 12/02/2022] Open
Abstract
Knowledge of the temporal trends and spatial patterns will have significant implications for effective preparedness in future epidemics. Our objective was to investigate the temporal trends and the nature of the spatial interaction of cholera incidences, dwelling on an outbreak in the Kumasi Metropolis, Ghana. We developed generalized nonparametric and segmented regression models to describe the epidemic curve. We used the pair correlation function to describe the nature of spatial clustering parameters such as the maximum scale of interaction and the scale of maximal interaction. The epidemic rose suddenly to a peak with 40% daily increments of incidences. The decay, however, was slower with 5% daily reductions. Spatial interaction occurred within 1 km radius. Maximal interaction occurred within 0.3 km, suggesting a household level of interactions. Significant clustering during the first week suggests secondary transmissions sparked the outbreak. The nonparametric and segmented regression models, together with the pair correlation function, contribute to understanding the transmission dynamics. The issue of underreporting remains a challenge we seek to address in future. These findings, however, will have innovative implications for developing preventive measures during future epidemics.
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Affiliation(s)
- Frank Badu Osei
- Faculty of Geo-Information Science and Earth Observation (ITC), University of Twente, Enschede, Netherlands.
| | - Alfred Stein
- Faculty of Geo-Information Science and Earth Observation (ITC), University of Twente, Enschede, Netherlands
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Negev M, Teschner N, Rosenthal A, Levine H, Lew-Levy C, Davidovitch N. Adaptation of health systems to climate-related migration in Sub-Saharan Africa: Closing the gap. Int J Hyg Environ Health 2018; 222:311-314. [PMID: 30503929 DOI: 10.1016/j.ijheh.2018.10.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 10/06/2018] [Accepted: 10/30/2018] [Indexed: 11/19/2022]
Abstract
Health systems worldwide need to be adapted to cope with growing numbers of migrants and to climate-exacerbated morbidity. Heatwaves, water stress, desertification, flooding, and sea level rise are environmental stressors that increase morbidity, mortality, and poor mental health in Sub-Saharan Africa. While most migration is intra-African, climate change is also affecting migration patterns outside the continent. To tackle the health challenges induced by these events, such as infectious diseases and malnutrition, health care providers in Sub-Saharan Africa and in receiving countries in Europe must adapt their systems to provide appropriate health services to these communities. While health systems differ greatly across the global north and south, adaptation measures are similar and should be integrated. We present recommendations for adaptation of health systems to climate-related migration, including strengthening health systems, providing access to healthcare, culturally-appropriate services, policy-oriented research and training, and inter-sectoral collaboration.
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Affiliation(s)
- Maya Negev
- School of Public Health, University of Haifa, Mt. Carmel, Haifa, 3190501, Israel.
| | - Na'ama Teschner
- Geography and Environmental Development, Ben-Gurion University of the Negev, P.O.Box 653, Beer-Sheva, 84105, Israel
| | - Anat Rosenthal
- Department of Health Systems Management, School of Public Health, Faculty of Health Sciences & The Tamar Golan Africa Center, Ben-Gurion University of the Negev, P.O.Box 653, Be'er Sheva, 84105, Israel
| | - Hagai Levine
- Braun School of Public Health and Community Medicine, Hebrew University-Hadassah Faculty of Medicine, P.O. Box 12272, Kiryat Hadassah, Ein Kerem, Jerusalem, 9112002, Israel
| | - Clara Lew-Levy
- School of Public Health, University of Haifa, Mt. Carmel, Haifa, 3190501, Israel
| | - Nadav Davidovitch
- Department of Health Systems Management, School of Public Health, Faculty of Health Sciences & Guilford Glazer Faculty of Business, Management Ben-Gurion University of the Negev, P.O.Box 653, Be'er Sheva, 84105, Israel
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Chersich MF, Wright CY, Venter F, Rees H, Scorgie F, Erasmus B. Impacts of Climate Change on Health and Wellbeing in South Africa. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2018; 15:E1884. [PMID: 30200277 PMCID: PMC6164733 DOI: 10.3390/ijerph15091884] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 08/17/2018] [Accepted: 08/24/2018] [Indexed: 11/17/2022]
Abstract
Given its associated burden of disease, climate change in South Africa could be reframed as predominately a health issue, one necessitating an urgent health-sector response. The growing impact of climate change has major implications for South Africa, especially for the numerous vulnerable groups in the country. We systematically reviewed the literature by searching PubMed and Web of Science. Of the 820 papers screened, 34 were identified that assessed the impacts of climate change on health in the country. Most papers covered effects of heat on health or on infectious diseases (20/34; 59%). We found that extreme weather events are the most noticeable effects to date, especially droughts in the Western Cape, but rises in vector-borne diseases are gaining prominence. Climate aberration is also linked in myriad ways with outbreaks of food and waterborne diseases, and possibly with the recent Listeria epidemic. The potential impacts of climate change on mental health may compound the multiple social stressors that already beset the populace. Climate change heightens the pre-existing vulnerabilities of women, fishing communities, rural subsistence farmers and those living in informal settlements. Further gender disparities, eco-migration and social disruptions may undermine the prevention-but also treatment-of HIV. Our findings suggest that focused research and effective use of surveillance data are required to monitor climate change's impacts; traditional strengths of the country's health sector. The health sector, hitherto a fringe player, should assume a greater leadership role in promoting policies that protect the public's health, address inequities and advance the country's commitments to climate change accords.
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Affiliation(s)
- Matthew F Chersich
- Wits Reproductive Health and HIV Institute, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2000, South Africa.
| | - Caradee Y Wright
- Environment and Health Research Unit, South African Medical Research Council and Department of Geography, Geoinformatics and Meteorology, University of Pretoria, Pretoria, Hatfield, Private Bag X200028, South Africa.
| | - Francois Venter
- Wits Reproductive Health and HIV Institute, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2000, South Africa.
| | - Helen Rees
- Wits Reproductive Health and HIV Institute, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2000, South Africa.
| | - Fiona Scorgie
- Wits Reproductive Health and HIV Institute, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2000, South Africa.
| | - Barend Erasmus
- Global Change Institute, University of the Witwatersrand, Johannesburg 2000, South Africa.
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Ngwa MC, Liang S, Kracalik IT, Morris L, Blackburn JK, Mbam LM, Ba Pouth SFB, Teboh A, Yang Y, Arabi M, Sugimoto JD, Morris JG. Cholera in Cameroon, 2000-2012: Spatial and Temporal Analysis at the Operational (Health District) and Sub Climate Levels. PLoS Negl Trop Dis 2016; 10:e0005105. [PMID: 27855171 PMCID: PMC5113893 DOI: 10.1371/journal.pntd.0005105] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 10/12/2016] [Indexed: 11/18/2022] Open
Abstract
INTRODUCTION Recurrent cholera outbreaks have been reported in Cameroon since 1971. However, case fatality ratios remain high, and we do not have an optimal understanding of the epidemiology of the disease, due in part to the diversity of Cameroon's climate subzones and a lack of comprehensive data at the health district level. METHODS/FINDINGS A unique health district level dataset of reported cholera case numbers and related deaths from 2000-2012, obtained from the Ministry of Public Health of Cameroon and World Health Organization (WHO) country office, served as the basis for the analysis. During this time period, 43,474 cholera cases were reported: 1748 were fatal (mean annual case fatality ratio of 7.9%), with an attack rate of 17.9 reported cases per 100,000 inhabitants per year. Outbreaks occurred in three waves during the 13-year time period, with the highest case fatality ratios at the beginning of each wave. Seasonal patterns of illness differed strikingly between climate subzones (Sudano-Sahelian, Tropical Humid, Guinea Equatorial, and Equatorial Monsoon). In the northern Sudano-Sahelian subzone, highest number of cases tended to occur during the rainy season (July-September). The southern Equatorial Monsoon subzone reported cases year-round, with the lowest numbers during peak rainfall (July-September). A spatial clustering analysis identified multiple clusters of high incidence health districts during 2010 and 2011, which were the 2 years with the highest annual attack rates. A spatiotemporal autoregressive Poisson regression model fit to the 2010-2011 data identified significant associations between the risk of transmission and several factors, including the presence of major waterbody or highway, as well as the average daily maximum temperature and the precipitation levels over the preceding two weeks. The direction and/or magnitude of these associations differed between climate subzones, which, in turn, differed from national estimates that ignored subzones differences in climate variables. CONCLUSIONS/SIGNIFICANCE The epidemiology of cholera in Cameroon differs substantially between climate subzones. Development of an optimal comprehensive country-wide control strategy for cholera requires an understanding of the impact of the natural and built environment on transmission patterns at the local level, particularly in the setting of ongoing climate change.
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Affiliation(s)
- Moise C. Ngwa
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America
- Department of Environmental and Global Health, College of Public Health and Health Professions, University of Florida, Gainesville, Florida, United States of America
| | - Song Liang
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America
- Department of Environmental and Global Health, College of Public Health and Health Professions, University of Florida, Gainesville, Florida, United States of America
| | - Ian T. Kracalik
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America
- Spatial Epidemiology and Ecology Research Laboratory, Department of Geography, College of Liberal Arts and Sciences, University of Florida, Gainesville, Florida, United States of America
| | - Lillian Morris
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America
- Spatial Epidemiology and Ecology Research Laboratory, Department of Geography, College of Liberal Arts and Sciences, University of Florida, Gainesville, Florida, United States of America
| | - Jason K. Blackburn
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America
- Spatial Epidemiology and Ecology Research Laboratory, Department of Geography, College of Liberal Arts and Sciences, University of Florida, Gainesville, Florida, United States of America
| | - Leonard M. Mbam
- World Health Organization country office for The Republic of Cameroon, Yaoundé, Republic of Cameroon
| | - Simon Franky Baonga Ba Pouth
- Cellule de Supervision, Suivi et Evaluation, Délégation Régionale de la Santé Publique du Centre, Yaoundé, Cameroun
| | - Andrew Teboh
- Field Epidemiology and Laboratory Training Program, University of Yaoundé, Yaoundé, Republic of Cameroon
| | - Yang Yang
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America
- Department of Biostatistics, College of Public Health and Health Professions, University of Florida, Gainesville, Florida, United States of America
| | - Mouhaman Arabi
- Higher Institute of the Sahel, University of Maroua, Maroua, Republic of Cameroon
| | - Jonathan D. Sugimoto
- Center for Inference and Dynamics of Infectious Diseases and Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle Washington, United States of America
| | - John Glenn Morris
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America
- Department of Medicine, College of Medicine, University of Florida, Gainesville, Florida, United States of America
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Li X, Wang D, Li B, Zhou H, Liang S, Ke C, Deng X, Kan B, Morris JG, Cao W. Characterization of environmental Vibrio cholerae serogroups O1 and O139 in the Pearl River Estuary, China. Can J Microbiol 2015; 62:139-47. [PMID: 26674584 DOI: 10.1139/cjm-2015-0443] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Toxigenic isolates of Vibrio cholerae serogroups O1 and O139 from aquatic reservoirs are a key source for recurrent epidemics of cholera in human populations. However, we do not have an optimal understanding of the microbiology of the strains within these reservoirs, particularly outside of the time periods when there are active cholera cases in the surrounding community. The main objective of the present study was to identify and characterize V. cholerae O1 and O139 in the Pearl River Estuary at a time when active disease was not being identified, despite prior occurrence of epidemic cholera in the region. Water samples were collected at 24 sites in the research area at monthly intervals between 2007 and 2010, and screened for the presence of V. cholerae O1 and O139. All isolates were screened for the presence of ctxAB, ompW, toxR, and tcpA genes. Multilocus variable number tandem repeat analysis (MLVA) was used to assess possible relationships among strains. The results show that Vibrio cholerae O1 or O139 was isolated, on average, from 6.7% of the sites screened at each time point. All V. cholerae O1 and O139 isolates were ctxAB negative, and 37% were positive for tcpA. Isolation was most common in the oldest, most urbanized district compared with other districts, and was associated with lower pH. Despite year-to-year variability in isolation rates, there was no evidence of seasonality. MLVA of 27 selected isolates showed evidence of high genetic diversity, with no evidence of clustering by year or geographic location. In this region where cholera has been epidemic in the past, there is evidence of environmental persistence of V. cholerae O1 and O139 strains. However, environmental strains were consistently nontoxigenic, with a high level of genetic diversity; their role as current or future agents of human disease remains uncertain.
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Affiliation(s)
- Xiujun Li
- a School of Public Health Shandong University, Wenhuaxi Road, Shandong 250012, People's Republic of China
| | - Duochun Wang
- b Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, State Key Laboratory for Infectious Disease Prevention and Control, 155 Chang-Bai Street, Changping District, Beijing 102206, People's Republic of China
| | - Baisheng Li
- c Center for Diseases Control and Prevention of Guangdong Province, Guangzhou 510300, People's Republic of China
| | - Haijian Zhou
- b Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, State Key Laboratory for Infectious Disease Prevention and Control, 155 Chang-Bai Street, Changping District, Beijing 102206, People's Republic of China
| | - Song Liang
- d Emerging Pathogens Institute, University of Florida, Gainesville, FL 32610, USA
| | - Changwen Ke
- c Center for Diseases Control and Prevention of Guangdong Province, Guangzhou 510300, People's Republic of China
| | - Xiaoling Deng
- c Center for Diseases Control and Prevention of Guangdong Province, Guangzhou 510300, People's Republic of China
| | - Biao Kan
- b Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, State Key Laboratory for Infectious Disease Prevention and Control, 155 Chang-Bai Street, Changping District, Beijing 102206, People's Republic of China
| | - J Glenn Morris
- d Emerging Pathogens Institute, University of Florida, Gainesville, FL 32610, USA
| | - Wuchun Cao
- e State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, People's Republic of China
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Environmental factor analysis of cholera in China using remote sensing and geographical information systems. Epidemiol Infect 2015; 144:940-51. [PMID: 26464184 DOI: 10.1017/s095026881500223x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cholera is one of a number of infectious diseases that appears to be influenced by climate, geography and other natural environments. This study analysed the environmental factors of the spatial distribution of cholera in China. It shows that temperature, precipitation, elevation, and distance to the coastline have significant impact on the distribution of cholera. It also reveals the oceanic environmental factors associated with cholera in Zhejiang, which is a coastal province of China, using both remote sensing (RS) and geographical information systems (GIS). The analysis has validated the correlation between indirect satellite measurements of sea surface temperature (SST), sea surface height (SSH) and ocean chlorophyll concentration (OCC) and the local number of cholera cases based on 8-year monthly data from 2001 to 2008. The results show the number of cholera cases has been strongly affected by the variables of SST, SSH and OCC. Utilizing this information, a cholera prediction model has been established based on the oceanic and climatic environmental factors. The model indicates that RS and GIS have great potential for designing an early warning system for cholera.
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Satellite Based Assessment of Hydroclimatic Conditions Related to Cholera in Zimbabwe. PLoS One 2015; 10:e0137828. [PMID: 26417994 PMCID: PMC4587952 DOI: 10.1371/journal.pone.0137828] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 08/22/2015] [Indexed: 11/19/2022] Open
Abstract
INTRODUCTION Cholera, an infectious diarrheal disease, has been shown to be associated with large scale hydroclimatic processes. The sudden and sporadic occurrence of epidemic cholera is linked with high mortality rates, in part, due to uncertainty in timing and location of outbreaks. Improved understanding of the relationship between pathogenic abundance and climatic processes allows prediction of disease outbreak to be an achievable goal. In this study, we show association of large scale hydroclimatic processes with the cholera epidemic in Zimbabwe reported to have begun in Chitungwiza, a city in Mashonaland East province, in August, 2008. PRINCIPAL FINDINGS Climatic factors in the region were found to be associated with triggering cholera outbreak and are shown to be related to anomalies of temperature and precipitation, validating the hypothesis that poor conditions of sanitation, coupled with elevated temperatures, and followed by heavy rainfall can initiate outbreaks of cholera. Spatial estimation by satellite of precipitation and global gridded air temperature captured sensitivities in hydroclimatic conditions that permitted identification of the location in the region where the disease outbreak began. DISCUSSION Satellite derived hydroclimatic processes can be used to capture environmental conditions related to epidemic cholera, as occurred in Zimbabwe, thereby providing an early warning system. Since cholera cannot be eradicated because the causative agent, Vibrio cholerae, is autochthonous to the aquatic environment, prediction of conditions favorable for its growth and estimation of risks of triggering the disease in a given population can be used to alert responders, potentially decreasing infection and saving lives.
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Xu M, Cao C, Wang D, Kan B. Identifying environmental risk factors of cholera in a coastal area with geospatial technologies. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2014; 12:354-70. [PMID: 25551518 PMCID: PMC4306866 DOI: 10.3390/ijerph120100354] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Accepted: 12/15/2014] [Indexed: 11/23/2022]
Abstract
Satellites contribute significantly to environmental quality and public health. Environmental factors are important indicators for the prediction of disease outbreaks. This study reveals the environmental factors associated with cholera in Zhejiang, a coastal province of China, using both Remote Sensing (RS) and Geographic information System (GIS). The analysis validated the correlation between the indirect satellite measurements of sea surface temperature (SST), sea surface height (SSH) and ocean chlorophyll concentration (OCC) and the local cholera magnitude based on a ten-year monthly data from the year 1999 to 2008. Cholera magnitude has been strongly affected by the concurrent variables of SST and SSH, while OCC has a one-month time lag effect. A cholera prediction model has been established based on the sea environmental factors. The results of hot spot analysis showed the local cholera magnitude in counties significantly associated with the estuaries and rivers.
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Affiliation(s)
- Min Xu
- State Key Laboratory of Remote Sensing Science, Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences, Beijing 100101, China.
| | - Chunxiang Cao
- State Key Laboratory of Remote Sensing Science, Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences, Beijing 100101, China.
| | - Duochun Wang
- State Key Laboratory for Infectious Disease Prevention and Control, Institute for Infectious Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China.
| | - Biao Kan
- State Key Laboratory for Infectious Disease Prevention and Control, Institute for Infectious Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China.
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Mari L, Casagrandi R, Bertuzzo E, Rinaldo A, Gatto M. Floquet theory for seasonal environmental forcing of spatially explicit waterborne epidemics. THEOR ECOL-NETH 2014. [DOI: 10.1007/s12080-014-0223-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Grimes DJ, Ford TE, Colwell RR, Baker-Austin C, Martinez-Urtaza J, Subramaniam A, Capone DG. Viewing marine bacteria, their activity and response to environmental drivers from orbit: satellite remote sensing of bacteria. MICROBIAL ECOLOGY 2014; 67:489-500. [PMID: 24477922 PMCID: PMC4058845 DOI: 10.1007/s00248-013-0363-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Accepted: 12/26/2013] [Indexed: 05/24/2023]
Abstract
Satellite-based remote sensing of marine microorganisms has become a useful tool in predicting human health risks associated with these microscopic targets. Early applications were focused on harmful algal blooms, but more recently methods have been developed to interrogate the ocean for bacteria. As satellite-based sensors have become more sophisticated and our ability to interpret information derived from these sensors has advanced, we have progressed from merely making fascinating pictures from space to developing process models with predictive capability. Our understanding of the role of marine microorganisms in primary production and global elemental cycles has been vastly improved as has our ability to use the combination of remote sensing data and models to provide early warning systems for disease outbreaks. This manuscript will discuss current approaches to monitoring cyanobacteria and vibrios, their activity and response to environmental drivers, and will also suggest future directions.
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Affiliation(s)
- D. Jay Grimes
- Gulf Coast Research Laboratory, The University of Southern Mississippi, 703 East Beach Drive, Ocean Springs, MS 39564, USA
| | - Tim E. Ford
- University of New England, 716 Stevens Avenue, Portland, ME 04103, USA,
| | - Rita R. Colwell
- Center for Bioinformatics and Computational Biology, UMIACS, University of Maryland, 3103 Biomolecular Sciences Building #296, College Park, MD 20742, USA,
| | - Craig Baker-Austin
- Centre for Environment, Fisheries and Aquaculture Science (Cefas), Barrack Road, Weymouth, Dorset, UK,
| | - Jaime Martinez-Urtaza
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK,
| | - Ajit Subramaniam
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY 10964, USA,
| | - Douglas G. Capone
- Wrigley Institute for Environmental Studies, University of Southern California, Los Angeles, CA 90089-0371, USA,
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Abstract
During the current seventh cholera pandemic, Africa bore the major brunt of global disease burden. More than 40 years after its resurgence in Africa in 1970, cholera remains a grave public health problem, characterized by large disease burden, frequent outbreaks, persistent endemicity, and high CFRs, particularly in the region of the central African Great Lakes which might act as reservoirs for cholera. There, cases occur year round with a rise in incidence during the rainy season. Elsewhere in sub-Saharan Africa, cholera occurs mostly in outbreaks of varying size with a constant threat of widespread epidemics. Between 1970 and 2011, African countries reported 3,221,050 suspected cholera cases to the World Health Organization, representing 46 % of all cases reported globally. Excluding the Haitian epidemic, sub-Saharan Africa accounted for 86 % of reported cases and 99 % of deaths worldwide in 2011. The number of cholera cases is possibly much higher than what is reported to the WHO due to the variation in modalities, completeness, and case definition of national cholera data. One source on country specific incidence rates for Africa, adjusting for underreporting, estimates 1,341,080 cases and 160,930 deaths (52.6 % of 2,548,227 estimated cases and 79.6 % of 209,216 estimated deaths worldwide). Another estimates 1,411,453 cases and 53,632 deaths per year, respectively (50 % of 2,836,669 estimated cases and 58.6 % of 91,490 estimated deaths worldwide). Within Africa, half of all cases between 1970 and 2011 were notified from only seven countries: Angola, Democratic Republic of the Congo, Mozambique, Nigeria, Somalia, Tanzania, and South Africa. In contrast to a global trend of decreasing case fatality ratios (CFRs), CFRs have remained stable in Africa at approximately 2 %. Early propagation of cholera outbreaks depends largely on the extent of individual bacterial shedding, host and organism characteristics, the likelihood of people coming into contact with an infectious dose of Vibrio cholerae and on the virulence of the implicated strain. Cholera transmission can then be amplified by several factors including contamination of human water- or food sources; climate and extreme weather events; political and economic crises; high population density combined with poor quality informal housing and poor hygiene practices; spread beyond a local community through human travel and animals, e.g., water birds. At an individual level, cholera risk may increase with decreasing immunity and hypochlorhydria, such as that induced by Helicobacter pylori infection, which is endemic in much of Africa, and may increase individual susceptibility and cholera incidence. Since contaminated water is the main vehicle for the spread of cholera, the obvious long-term solution to eradicate the disease is the provision of safe water to all African populations. This requires considerable human and financial resources and time. In the short and medium term, vaccination may help to prevent and control the spread of cholera outbreaks. Regardless of the intervention, further understanding of cholera biology and epidemiology is essential to identify populations and areas at increased risk and thus ensure the most efficient use of scarce resources for the prevention and control of cholera.
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Affiliation(s)
- Martin A Mengel
- Agence de Médecine Préventive, 164 rue de Vaugirard, 75015, Paris, France,
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Gujral L, Sema C, Rebaudet S, Taibo CLA, Manjate AA, Piarroux R, Gessner BD, Jani IV. Cholera epidemiology in Mozambique using national surveillance data. J Infect Dis 2013; 208 Suppl 1:S107-14. [PMID: 24101638 DOI: 10.1093/infdis/jit212] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Mozambique has experienced cholera for several decades. This study was undertaken to evaluate epidemiologic patterns to assist in guiding public health interventions. METHODS We evaluated district-level Ministry of Health data for 123 consecutive weeks starting 1 January 2009. Cholera cases reported to the national level were based on clinical suspicion rather than microbiological confirmation. Time and space analyses with mapping and spatial statistics were undertaken. RESULTS During 2009-2011, Mozambique identified 220 deaths among the 25 431 reported suspected cholera cases (case fatality ratio [CFR], 0.87%). There were 108 outbreaks that occurred in 73 (50%) of Mozambique's 145 districts. Five distinct spatial clusters were identified involving inland and coastal as well as rural and urban populations. Among 78 outbreaks whose duration was known, average duration was 7.2 weeks (median, 6; range, 1-25). During weeks 1-3, 4-6, 7-9, and ≥ 10 after an outbreak, CFRs were 1.6%, 0.66%, 0.33%, and 0.25%, respectively. During 2010, districts that experienced an outbreak during 2009 had a CFR of 0.2% compared with 4.3% among other districts. DISCUSSION Mozambique continues to experience widespread cholera outbreaks of short duration involving distinct spatial clusters. These findings will influence choice of public health strategies.
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Affiliation(s)
- Lorna Gujral
- National Direction of Public Health, Ministry of Health, Maputo, Mozambique
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Eisenberg MC, Kujbida G, Tuite AR, Fisman DN, Tien JH. Examining rainfall and cholera dynamics in Haiti using statistical and dynamic modeling approaches. Epidemics 2013; 5:197-207. [PMID: 24267876 DOI: 10.1016/j.epidem.2013.09.004] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2012] [Revised: 09/24/2013] [Accepted: 09/26/2013] [Indexed: 10/26/2022] Open
Abstract
Haiti has been in the midst of a cholera epidemic since October 2010. Rainfall is thought to be associated with cholera here, but this relationship has only begun to be quantitatively examined. In this paper, we quantitatively examine the link between rainfall and cholera in Haiti for several different settings (including urban, rural, and displaced person camps) and spatial scales, using a combination of statistical and dynamic models. Statistical analysis of the lagged relationship between rainfall and cholera incidence was conducted using case crossover analysis and distributed lag nonlinear models. Dynamic models consisted of compartmental differential equation models including direct (fast) and indirect (delayed) disease transmission, where indirect transmission was forced by empirical rainfall data. Data sources include cholera case and hospitalization time series from the Haitian Ministry of Public Health, the United Nations Water, Sanitation and Health Cluster, International Organization for Migration, and Hôpital Albert Schweitzer. Rainfall data was obtained from rain gauges from the U.S. Geological Survey and Haiti Regeneration Initiative, and remote sensing rainfall data from the National Aeronautics and Space Administration Tropical Rainfall Measuring Mission. A strong relationship between rainfall and cholera was found for all spatial scales and locations examined. Increased rainfall was significantly correlated with increased cholera incidence 4-7 days later. Forcing the dynamic models with rainfall data resulted in good fits to the cholera case data, and rainfall-based predictions from the dynamic models closely matched observed cholera cases. These models provide a tool for planning and managing the epidemic as it continues.
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Affiliation(s)
- Marisa C Eisenberg
- Mathematical Biosciences Institute, The Ohio State University, United States; Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, United States; Department of Mathematics, University of Michigan, Ann Arbor, United States.
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de Magny GC, Thiaw W, Kumar V, Manga NM, Diop BM, Gueye L, Kamara M, Roche B, Murtugudde R, Colwell RR. Cholera outbreak in Senegal in 2005: was climate a factor? PLoS One 2012; 7:e44577. [PMID: 22952995 PMCID: PMC3432123 DOI: 10.1371/journal.pone.0044577] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2012] [Accepted: 08/08/2012] [Indexed: 11/20/2022] Open
Abstract
Cholera is an acute diarrheal illness caused by Vibrio cholerae and occurs as widespread epidemics in Africa. In 2005, there were 31,719 cholera cases, with 458 deaths in the Republic of Senegal. We retrospectively investigated the climate origin of the devastating floods in mid-August 2005, in the Dakar Region of Senegal and the subsequent outbreak of cholera along with the pattern of cholera outbreaks in three other regions of that country. We compared rainfall patterns between 2002 and 2005 and the relationship between the sea surface temperature (SST) gradient in the tropical Atlantic Ocean and precipitation over Senegal for 2005. Results showed a specific pattern of rainfall throughout the Dakar region during August, 2005, and the associated rainfall anomaly coincided with an exacerbation of the cholera epidemic. Comparison of rainfall and epidemiological patterns revealed that the temporal dynamics of precipitation, which was abrupt and heavy, was presumably the determining factor. Analysis of the SST gradient showed that the Atlantic Ocean SST variability in 2005 differed from that of 2002 to 2004, a result of a prominent Atlantic meridional mode. The influence of this intense precipitation on cholera transmission over a densely populated and crowded region was detectable for both Dakar and Thiès, Senegal. Thus, high resolution rainfall forecasts at subseasonal time scales should provide a way forward for an early warning system in Africa for cholera and, thereby, trigger epidemic preparedness. Clearly, attention must be paid to both natural and human induced environmental factors to devise appropriate action to prevent cholera and other waterborne disease epidemics in the region.
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Wright JA, Yang H, Rivett U, Gundry SW. Public perception of drinking water safety in South Africa 2002-2009: a repeated cross-sectional study. BMC Public Health 2012; 12:556. [PMID: 22834485 PMCID: PMC3491026 DOI: 10.1186/1471-2458-12-556] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Accepted: 07/13/2012] [Indexed: 11/10/2022] Open
Abstract
Background In low and middle income countries, public perceptions of drinking water safety are relevant to promotion of household water treatment and to household choices over drinking water sources. However, most studies of this topic have been cross-sectional and not considered temporal variation in drinking water safety perceptions. The objective of this study is to explore trends in perceived drinking water safety in South Africa and its association with disease outbreaks, water supply and household characteristics. Methods This repeated cross-sectional study draws on General Household Surveys from 2002–2009, a series of annual nationally representative surveys of South African households, which include a question about perceived drinking water safety. Trends in responses to this question were examined from 2002–2009 in relation to reported cholera cases. The relationship between perceived drinking water safety and organoleptic qualities of drinking water, supply characteristics, and socio-economic and demographic household characteristics was explored in 2002 and 2008 using hierarchical stepwise logistic regression. Results The results suggest that perceived drinking water safety has remained relatively stable over time in South Africa, once the expansion of improved supplies is controlled for. A large cholera outbreak in 2000–02 had no apparent effect on public perception of drinking water safety in 2002. Perceived drinking water safety is primarily related to water taste, odour, and clarity rather than socio-economic or demographic characteristics. Conclusion This suggests that household perceptions of drinking water safety in South Africa follow similar patterns to those observed in studies in developed countries. The stability over time in public perception of drinking water safety is particularly surprising, given the large cholera outbreak that took place at the start of this period.
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Affiliation(s)
- Jim A Wright
- Geography and Environment, University of Southampton, University Road, Southampton, SO17 1BJ, UK.
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Luque Fernandez MA, Schomaker M, Mason PR, Fesselet JF, Baudot Y, Boulle A, Maes P. Elevation and cholera: an epidemiological spatial analysis of the cholera epidemic in Harare, Zimbabwe, 2008-2009. BMC Public Health 2012; 12:442. [PMID: 22708576 PMCID: PMC3483262 DOI: 10.1186/1471-2458-12-442] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2011] [Accepted: 06/18/2012] [Indexed: 11/17/2022] Open
Abstract
Background In highly populated African urban areas where access to clean water is a challenge, water source contamination is one of the most cited risk factors in a cholera epidemic. During the rainy season, where there is either no sewage disposal or working sewer system, runoff of rains follows the slopes and gets into the lower parts of towns where shallow wells could easily become contaminated by excretes. In cholera endemic areas, spatial information about topographical elevation could help to guide preventive interventions. This study aims to analyze the association between topographic elevation and the distribution of cholera cases in Harare during the cholera epidemic in 2008 and 2009. Methods We developed an ecological study using secondary data. First, we described attack rates by suburb and then calculated rate ratios using whole Harare as reference. We illustrated the average elevation and cholera cases by suburbs using geographical information. Finally, we estimated a generalized linear mixed model (under the assumption of a Poisson distribution) with an Empirical Bayesian approach to model the relation between the risk of cholera and the elevation in meters in Harare. We used a random intercept to allow for spatial correlation of neighboring suburbs. Results This study identifies a spatial pattern of the distribution of cholera cases in the Harare epidemic, characterized by a lower cholera risk in the highest elevation suburbs of Harare. The generalized linear mixed model showed that for each 100 meters of increase in the topographical elevation, the cholera risk was 30% lower with a rate ratio of 0.70 (95% confidence interval=0.66-0.76). Sensitivity analysis confirmed the risk reduction with an overall estimate of the rate ratio between 20% and 40%. Conclusion This study highlights the importance of considering topographical elevation as a geographical and environmental risk factor in order to plan cholera preventive activities linked with water and sanitation in endemic areas. Furthermore, elevation information, among other risk factors, could help to spatially orientate cholera control interventions during an epidemic.
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Affiliation(s)
- Miguel A Luque Fernandez
- Centre of Infectious Disease Epidemiology and Research, University of Cape Town, Cape Town, South Africa.
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Kotchi SO, Turgeon P, Michel P, Lavigne MP, Brazeau S. Assessing and Monitoring Microbiological Quality of Surface Waters Using Tele-Epidemiology. Glob Bioeth 2011. [DOI: 10.1080/11287462.2011.10800700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Affiliation(s)
- S. O. Kotchi
- Laboratory for Foodborne Zoonoses (LFZ) - Public Health Agency of Canada (PHAC) - 3190 Sicotte, Saint-Hyacinthe (QC) J2S 2M1, Canada
- Groupe de Recherche en Épidémiologie des Zoonoses et Santé Publique (GREZOSP) Faculté de médecine vétérinaire Université de Montréal 3190 Sicotte, Saint-Hyacinthe (QC) J2S 2M1, Canada
| | - P. Turgeon
- Laboratory for Foodborne Zoonoses (LFZ) - Public Health Agency of Canada (PHAC) - 3190 Sicotte, Saint-Hyacinthe (QC) J2S 2M1, Canada
- Groupe de Recherche en Épidémiologie des Zoonoses et Santé Publique (GREZOSP) Faculté de médecine vétérinaire Université de Montréal 3190 Sicotte, Saint-Hyacinthe (QC) J2S 2M1, Canada
| | - P. Michel
- Laboratory for Foodborne Zoonoses (LFZ) - Public Health Agency of Canada (PHAC) - 3190 Sicotte, Saint-Hyacinthe (QC) J2S 2M1, Canada
- Groupe de Recherche en Épidémiologie des Zoonoses et Santé Publique (GREZOSP) Faculté de médecine vétérinaire Université de Montréal 3190 Sicotte, Saint-Hyacinthe (QC) J2S 2M1, Canada
| | - M.-P. Lavigne
- Laboratory for Foodborne Zoonoses (LFZ) - Public Health Agency of Canada (PHAC) - 3190 Sicotte, Saint-Hyacinthe (QC) J2S 2M1, Canada
- Groupe de Recherche en Épidémiologie des Zoonoses et Santé Publique (GREZOSP) Faculté de médecine vétérinaire Université de Montréal 3190 Sicotte, Saint-Hyacinthe (QC) J2S 2M1, Canada
| | - S. Brazeau
- Laboratory for Foodborne Zoonoses (LFZ) - Public Health Agency of Canada (PHAC) - 3190 Sicotte, Saint-Hyacinthe (QC) J2S 2M1, Canada
- Groupe de Recherche en Épidémiologie des Zoonoses et Santé Publique (GREZOSP) Faculté de médecine vétérinaire Université de Montréal 3190 Sicotte, Saint-Hyacinthe (QC) J2S 2M1, Canada
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Jutla AS, Akanda AS, Islam S. Tracking Cholera in Coastal Regions using Satellite Observations. JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION 2010; 46:651-662. [PMID: 21072249 PMCID: PMC2975368 DOI: 10.1111/j.1752-1688.2010.00448.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Cholera remains a significant health threat across the globe. The pattern and magnitude of the seven global pandemics suggest that cholera outbreaks primarily originate in coastal regions and then spread inland through secondary means. Cholera bacteria show strong association with plankton abundance in coastal ecosystems. This review study investigates relationship(s) between cholera incidence and coastal processes and explores utility of using remote sensing data to track coastal plankton blooms, using chlorophyll as a surrogate variable for plankton abundance, and subsequent cholera outbreaks. Most studies over the last several decades have primarily focused on the microbiological and epidemiological understanding of cholera outbreaks. Accurate identification and mechanistic understanding of large scale climatic, geophysical and oceanic processes governing cholera-chlorophyll relationship is important for developing cholera prediction models. Development of a holistic understanding of these processes requires long and reliable chlorophyll dataset(s), which are beginning to be available through satellites. We have presented a schematic pathway and a modeling framework that relate cholera with various hydroclimatic and oceanic variables for understanding disease dynamics using latest advances in remote sensing. Satellite data, with its unprecedented spatial and temporal coverage, have potentials to monitor coastal processes and track cholera outbreaks in endemic regions.
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Affiliation(s)
- Antarpreet S Jutla
- WE REASoN (Water and Environmental Research, Education, and Actionable Solutions Network), Department of Civil and Environmental Engineering, Tufts University, Medford, MA 02155
| | - Ali S Akanda
- WE REASoN, Department of Civil and Environmental Engineering, Tufts University, Medford, MA 02155
| | - Shafiqul Islam
- Civil and Environmental Engineering, School of Engineering, Water and Diplomacy, The Fletcher School of Law and Diplomacy, Bernard M. Gordon Senior Faculty Fellow in Engineering. 113 Anderson Hall, 200 College Avenue, Tufts University, Medford, MA 02155 Shafiqul Islam
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Selowa SC, Shai LJ, Masoko P, Mokgotho MP, Magano SR. Antibacterial activity of extracts of three Croton species collected in Mpumalanga region in South Africa. AFRICAN JOURNAL OF TRADITIONAL, COMPLEMENTARY, AND ALTERNATIVE MEDICINES : AJTCAM 2009; 7:98-103. [PMID: 21304619 PMCID: PMC3021162 DOI: 10.4314/ajtcam.v7i2.50861] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The antibacterial activities of three Croton species were compared using bioautography and the serial microdilution methods. The methanolic extracts of all the species had low activity against Escherichia coli. The highest activity was observed with Croton megalobotrys against Enterococcus faecalis with a minimal inhibitory concentration (MIC) value of 0.02 mg/ml. Croton steenkapianus extracts were the least active of the species investigated, only managing an MIC value of 0.625 mg/ml against Pseudomonas aeruginosa. Croton megalobotrys leaf powder was serially extracted using solvents of various polarities. The lowest MIC value (0.06 mg/ml) of the serially extracted fractions was observed with acetone against Pseudomonas aeruginosa. The liquid-liquid fractions of the methanol extract of Croton megalobotrys were also tested. The lowest MIC value of 0.02 mg/ml was observed with n-hexane fraction against Enterococcus faecalis. The carbon tetrachloride fraction was further fractionated using column chromatography with silica as the immobile phase. The resulting seven fractions were tested for activity following the bioassay-guided practice, and it emerged that the first three fractions had active compounds against Staphylococcus aureus when the bioautography method was used.
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Affiliation(s)
- S C Selowa
- Department of Biochemistry, University of Limpopo, Medunsa, South Africa
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Sasaki S, Suzuki H, Fujino Y, Kimura Y, Cheelo M. Impact of drainage networks on cholera outbreaks in Lusaka, Zambia. Am J Public Health 2009; 99:1982-7. [PMID: 19762668 DOI: 10.2105/ajph.2008.151076] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVES We investigated the association between precipitation patterns and cholera outbreaks and the preventative roles of drainage networks against outbreaks in Lusaka, Zambia. METHODS We collected data on 6542 registered cholera patients in the 2003-2004 outbreak season and on 6045 cholera patients in the 2005-2006 season. Correlations between monthly cholera incidences and amount of precipitation were examined. The distribution pattern of the disease was analyzed by a kriging spatial analysis method. We analyzed cholera case distribution and spatiotemporal cluster by using 2590 cholera cases traced with a global positioning system in the 2005-2006 season. The association between drainage networks and cholera cases was analyzed with regression analysis. RESULTS Increased precipitation was associated with the occurrence of cholera outbreaks, and insufficient drainage networks were statistically associated with cholera incidences. CONCLUSIONS Insufficient coverage of drainage networks elevated the risk of cholera outbreaks. Integrated development is required to upgrade high-risk areas with sufficient infrastructure for a long-term cholera prevention strategy.
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Affiliation(s)
- Satoshi Sasaki
- Division of Public Health, Department of Infectious Disease Control and International Medicine, Graduate School of Medical and Dental Sciences, Niigata University, 1-757 Asahimachi-dori Chuo ward, Niigata, 951-8510, Japan.
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Constantin de Magny G, Murtugudde R, Sapiano MRP, Nizam A, Brown CW, Busalacchi AJ, Yunus M, Nair GB, Gil AI, Lanata CF, Calkins J, Manna B, Rajendran K, Bhattacharya MK, Huq A, Sack RB, Colwell RR. Environmental signatures associated with cholera epidemics. Proc Natl Acad Sci U S A 2008; 105:17676-81. [PMID: 19001267 PMCID: PMC2584748 DOI: 10.1073/pnas.0809654105] [Citation(s) in RCA: 162] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2008] [Indexed: 11/18/2022] Open
Abstract
The causative agent of cholera, Vibrio cholerae, has been shown to be autochthonous to riverine, estuarine, and coastal waters along with its host, the copepod, a significant member of the zooplankton community. Temperature, salinity, rainfall and plankton have proven to be important factors in the ecology of V. cholerae, influencing the transmission of the disease in those regions of the world where the human population relies on untreated water as a source of drinking water. In this study, the pattern of cholera outbreaks during 1998-2006 in Kolkata, India, and Matlab, Bangladesh, and the earth observation data were analyzed with the objective of developing a prediction model for cholera. Satellite sensors were used to measure chlorophyll a concentration (CHL) and sea surface temperature (SST). In addition, rainfall data were obtained from both satellite and in situ gauge measurements. From the analyses, a statistically significant relationship between the time series for cholera in Kolkata, India, and CHL and rainfall anomalies was determined. A statistically significant one month lag was observed between CHL anomaly and number of cholera cases in Matlab, Bangladesh. From the results of the study, it is concluded that ocean and climate patterns are useful predictors of cholera epidemics, with the dynamics of endemic cholera being related to climate and/or changes in the aquatic ecosystem. When the ecology of V. cholerae is considered in predictive models, a robust early warning system for cholera in endemic regions of the world can be developed for public health planning and decision making.
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Affiliation(s)
| | | | | | - Azhar Nizam
- Department of Biostatistics, Emory University Rollins School of Public Health, Atlanta, GA 30329
| | - Christopher W. Brown
- Earth System Science Interdisciplinary Center, and
- Satellite Climate Studies Branch, National Oceanic and Atmospheric Administration, College Park, MD 20742
| | | | - Mohammad Yunus
- International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, 1000, Bangladesh
| | - G. Balakrish Nair
- National Institute of Cholera and Enteric Diseases, Beliaghata, Kolkata 700010, India
| | - Ana I. Gil
- Instituto de Investigacion Nutricional, Lima 12, Peru
| | - Claudio F. Lanata
- Instituto de Investigacion Nutricional, Lima 12, Peru
- School of Medicine, Universidad Peruana de Ciencias Aplicadas, Lima 12, Peru
| | - John Calkins
- Environmental Systems Research Institute, Inc., Vienna, VA 22182; and
| | - Byomkesh Manna
- National Institute of Cholera and Enteric Diseases, Beliaghata, Kolkata 700010, India
| | - Krishnan Rajendran
- National Institute of Cholera and Enteric Diseases, Beliaghata, Kolkata 700010, India
| | | | - Anwar Huq
- Maryland Pathogen Research Institute, College of Chemical and Life Sciences, University of Maryland, College Park, MD 20742
| | | | - Rita R. Colwell
- Institute for Advanced Computer Studies
- Maryland Pathogen Research Institute, College of Chemical and Life Sciences, University of Maryland, College Park, MD 20742
- Department of Environmental Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205
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Luque Fernández MA, Bauernfeind A, Jiménez JD, Gil CL, El Omeiri N, Guibert DH. Influence of temperature and rainfall on the evolution of cholera epidemics in Lusaka, Zambia, 2003-2006: analysis of a time series. Trans R Soc Trop Med Hyg 2008; 103:137-43. [PMID: 18783808 DOI: 10.1016/j.trstmh.2008.07.017] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2008] [Revised: 07/28/2008] [Accepted: 07/28/2008] [Indexed: 10/21/2022] Open
Abstract
In this study, we aimed to describe the evolution of three cholera epidemics that occurred in Lusaka, Zambia, between 2003 and 2006 and to analyse the association between the increase in number of cases and climatic factors. A Poisson autoregressive model controlling for seasonality and trend was built to estimate the association between the increase in the weekly number of cases and weekly means of daily maximum temperature and rainfall. All epidemics showed a seasonal trend coinciding with the rainy season (November to March). A 1 degrees C rise in temperature 6 weeks before the onset of the outbreak explained 5.2% [relative risk (RR) 1.05, 95% CI 1.04-1.06] of the increase in the number of cholera cases (2003-2006). In addition, a 50 mm increase in rainfall 3 weeks before explained an increase of 2.5% (RR 1.02, 95% CI 1.01-1.04). The attributable risks were 4.9% for temperature and 2.4% for rainfall. If 6 weeks prior to the beginning of the rainy season an increase in temperature is observed followed by an increase in rainfall 3 weeks later, both exceeding expected levels, an increase in the number of cases of cholera within the following 3 weeks could be expected. Our explicative model could contribute to developing a warning signal to reduce the impact of a presumed cholera epidemic.
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Affiliation(s)
- Miguel Angel Luque Fernández
- National Centre of Epidemiology (CNE), Programa de Epidemiología Aplicada de Campo, Instituto de Salud Carlos III, C/Sinesio Delgado 6, Pabellón 12, 28029 Madrid, Spain.
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Bompangue D, Giraudoux P, Handschumacher P, Piarroux M, Sudre B, Ekwanzala M, Kebela I, Piarroux R. Lakes as source of cholera outbreaks, Democratic Republic of Congo. Emerg Infect Dis 2008; 14:798-800. [PMID: 18439365 PMCID: PMC2600234 DOI: 10.3201/eid1405.071260] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
We studied the epidemiology of cholera in Katanga and Eastern Kasai, in the Democratic Republic of Congo, by compiling a database including all cases recorded from 2000 through 2005. Results show that lakes were the sources of outbreaks and demonstrate the inadequacy of the strategy used to combat cholera.
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