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An optimal cost effectiveness study on Zimbabwe cholera seasonal data from 2008-2011.

ABSTRACT: Incidence of cholera outbreak is a serious issue in underdeveloped and developing countries. In Zimbabwe, after the massive outbreak in 2008-09, cholera cases and deaths are reported every year from some provinces. Substantial number of reported cholera cases in some provinces during and after the epidemic in 2008-09 indicates a plausible presence of seasonality in cholera incidence in those regions. We formulate a compartmental mathematical model with periodic slow-fast transmission rate to study such recurrent occurrences and fitted the model to cumulative cholera cases and deaths for different provinces of Zimbabwe from the beginning of cholera outbreak in 2008-09 to June 2011. Daily and weekly reported cholera incidence data were collected from Zimbabwe epidemiological bulletin, Zimbabwe Daily cholera updates and Office for the Coordination of Humanitarian Affairs Zimbabwe (OCHA, Zimbabwe). For each province, the basic reproduction number ([Formula: see text]) in periodic environment is estimated. To the best of our knowledge, this is probably a pioneering attempt to estimate [Formula: see text] in periodic environment using real-life data set of cholera epidemic for Zimbabwe. Our estimates of [Formula: see text] agree with the previous estimate for some provinces but differ significantly for Bulawayo, Mashonaland West, Manicaland, Matabeleland South and Matabeleland North. Seasonal trend in cholera incidence is observed in Harare, Mashonaland West, Mashonaland East, Manicaland and Matabeleland South. Our result suggests that, slow transmission is a dominating factor for cholera transmission in most of these provinces. Our model projects [Formula: see text] cholera cases and [Formula: see text] cholera deaths during the end of the epidemic in 2008-09 to January 1, 2012. We also determine an optimal cost-effective control strategy among the four government undertaken interventions namely promoting hand-hygiene & clean water distribution, vaccination, treatment and sanitation for each province.

SUBMITTER: Sardar T

PROVIDER: S-EPMC3849194 | biostudies-literature | 2013

REPOSITORIES: biostudies-literature

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An optimal cost effectiveness study on Zimbabwe cholera seasonal data from 2008-2011.

Sardar Tridip T Mukhopadhyay Soumalya S Bhowmick Amiya Ranjan AR Chattopadhyay Joydev J

PloS one 20131203 12

Incidence of cholera outbreak is a serious issue in underdeveloped and developing countries. In Zimbabwe, after the massive outbreak in 2008-09, cholera cases and deaths are reported every year from some provinces. Substantial number of reported cholera cases in some provinces during and after the epidemic in 2008-09 indicates a plausible presence of seasonality in cholera incidence in those regions. We formulate a compartmental mathematical model with periodic slow-fast transmission rate to stu ...[more]

PMID: 24312540

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Project description:BackgroundDespite advance in science and technology for prevention, detection and treatment of cholera, this infectious disease remains a major public health problem in many countries in sub-Saharan Africa, Uganda inclusive. The aim of this study was to identify cholera hotspots in Uganda to guide the development of a roadmap for prevention, control and elimination of cholera in the country.Methodology/principle findingsWe obtained district level confirmed cholera outbreak data from 2011 to 2016 from the Ministry of Health, Uganda. Population and rainfall data were obtained from the Uganda Bureau of Statistics, and water, sanitation and hygiene data from the Ministry of Water and Environment. A spatial scan test was performed to identify the significantly high risk clusters. Cholera hotspots were defined as districts whose center fell within a significantly high risk cluster or where a significantly high risk cluster was completely superimposed onto a district. A zero-inflated negative binomial regression model was employed to identify the district level risk factors for cholera. In total 11,030 cases of cholera were reported during the 6-year period. 37(33%) of 112 districts reported cholera outbreaks in one of the six years, and 20 (18%) districts experienced cholera at least twice in those years. We identified 22 districts as high risk for cholera, of which 13 were near a border of Democratic Republic of Congo (DRC), while 9 districts were near a border of Kenya. The relative risk of having cholera inside the high-risk districts (hotspots) were 2 to 22 times higher than elsewhere in the country. In total, 7 million people were within cholera hotspots. The negative binomial component of the ZINB model shows people living near a lake or the Nile river were at increased risk for cholera (incidence rate ratio, IRR = 0.98, 95% CI: 0.97 to 0.99, p < .01); people living near the border of DRC/Kenya or higher incidence rate in the neighboring districts were increased risk for cholera in a district (IRR = 0.99, 95% CI: 0.98 to 1.00, p = .02 and IRR = 1.02, 95% CI: 1.01 to 1.03, p < .01, respectively). The zero inflated component of the ZINB model yielded shorter distance to Kenya or DRC border, higher incidence rate in the neighboring districts, and higher annual rainfall in the district were associated with the risk of having cholera in the district.Conclusions/significanceThe study identified cholera hotspots during the period 2011-2016. The people located near the international borders, internationally shared lakes and river Nile were at higher risk for cholera outbreaks than elsewhere in the country. Targeting cholera interventions to these locations could prevent and ultimately eliminate cholera in Uganda.

Project description:The global burden of cholera is increasing, with the majority (60%) of the cases occurring in sub-Saharan Africa. In Zambia, widespread cholera outbreaks have occurred since 1977, predominantly in the capital city of Lusaka. During both the 2016 and 2018 outbreaks, the Ministry of Health implemented cholera vaccination in addition to other preventative and control measures, to stop the spread and control the outbreak. Given the limitations in vaccine availability and the logistical support required for vaccination, oral cholera vaccine (OCV) is now recommended for use in the high risk areas ("hotspots") for cholera. Hence, the aim of this study was to identify areas with an increased risk of cholera in Zambia. Retrospective cholera case data from 2008 to 2017 was obtained from the Ministry of Health, Department of Public Health and Disease Surveillance. The Zambian Central Statistical Office provided district-level population data, socioeconomic and water, sanitation and hygiene (WaSH) indicators. To identify districts at high risk, we performed a discrete Poisson-based space-time scan statistic to account for variations in cholera risk across both space and time over a 10-year study period. A zero-inflated negative binomial regression model was employed to identify the district level risk factors for cholera. The risk map was generated by classifying the relative risk of cholera in each district, as obtained from the space-scan test statistic. In total, 34,950 cases of cholera were reported in Zambia between 2008 and 2017. Cholera cases varied spatially by year. During the study period, Lusaka District had the highest burden of cholera, with 29,080 reported cases. The space-time scan statistic identified 16 districts to be at a significantly higher risk of having cholera. The relative risk of having cholera in these districts was significantly higher and ranged from 1.25 to 78.87 times higher when compared to elsewhere in the country. Proximity to waterbodies was the only factor associated with the increased risk for cholera (P<0.05). This study provides a basis for the cholera elimination program in Zambia. Outside Lusaka, the majority of high risk districts identified were near the border with the DRC, Tanzania, Mozambique, and Zimbabwe. This suggests that cholera in Zambia may be linked to movement of people from neighboring areas of cholera endemicity. A collaborative intervention program implemented in concert with neighboring countries could be an effective strategy for elimination of cholera in Zambia, while also reducing rates at a regional level.

Project description:BackgroundThe World Health Assembly has adopted a global strategy to eliminate cervical cancer. However, neither the optimal pathway nor the corresponding economic and health benefits have been evaluated. We take China as an example to assess the optimal pathway towards elimination and the cost-effectiveness of tailored actions.MethodsA validated hybrid model was used to assess the costs and benefits of alternative strategies combining human papillomavirus vaccination, cervical screening, and treatment of pre-invasive lesions and invasive cancer for females with different immunization history. All Chinese females living or projected to be born during 2015-2100, under projected trends in aging, urbanization, and sexual activity, were considered. Optimal strategies were determined by cost-effectiveness efficiency frontiers. Primary outcomes were cervical cancer cases and deaths averted and incremental cost-effectiveness ratios (ICERs). We employed a lifetime horizon from a societal perspective. One-way and probabilistic sensitivity analyses evaluate model uncertainty.ResultsThe optimal pathway represents an integration of multiple tailored strategies from females with different immunization history. If China adopts the optimal pathway, the age-standardized incidence of cervical cancer is predicted to decrease to fewer than four new cases per 100,000 women (i.e., elimination) by 2047 (95% confidence interval 2043 to 2050). Compared to the status quo, the optimal pathway would avert a total of 7,509,192 (6,922,744 to 8,359,074) cervical cancer cases and 2,529,873 (2,366,826 to 2,802,604) cervical cancer deaths in 2021-2100, with the discounted ICER being $- 339 (- 687 to - 79) per quality-adjusted life-year.ConclusionsBy adopting an optimal pathway from 2021 (namely, the year of the first Chinese Centennial Goals) onwards, cervical cancer could be eliminated by the late 2040s (namely, ahead of the second Chinese Centennial Goals) while saving net economic costs in China.

Project description:BackgroundThere is little evidence to date of the potential impact of vegetable gardens on people living with HIV (PLHIV), who often suffer from social and economic losses due to the disease. From 2008 through 2011, Action Contre la Faim France (ACF) implemented a project in Chipinge District, eastern Zimbabwe, providing low-input vegetable gardens (LIGs) to households of PLHIV. Program partners included Médecins du Monde, which provided medical support, and Zimbabwe's Agricultural Extension Service, which supported vegetable cultivation. A survey conducted at the end of the program found LIG participants to have higher Food Consumption Scores (FCS) and Household Dietary Diversity Scores (HDDS) relative to comparator households of PLHIV receiving other support programs. This study assessed the incremental cost-effectiveness of LIGs to improve FCS and HDDS of PLHIV compared to other support programs.MethodsThis analysis used an activity-based cost model, and combined ACF accounting data with estimates of partner and beneficiary costs derived using an ingredients approach to build an estimate of total program resource use. A societal perspective was adopted to encompass costs to beneficiary households, including their opportunity costs and an estimate of their income earned from vegetable sales. Qualitative methods were used to assess program benefits to beneficiary households. Effectiveness data was taken from a previously-conducted survey.ResultsProviding LIGs to PLHIV cost an additional 8,299 EUR per household with adequate FCS and 12,456 EUR per household with HDDS in the upper tertile, relative to comparator households of PLHIV receiving other support programs. Beneficiaries cited multiple tangible and intangible benefits from LIGs, and over 80% of gardens observed were still functioning more than one year after the program had finished.ConclusionsCost outcomes were 20-30 times Zimbabwe's per capita GDP, and unlikely to be affordable within government services. This analysis concludes that LIGs are not cost-effective or affordable relative to other interventions for improving health and nutrition status of PLHIV. Nonetheless, given the myriad benefits acquired by participant households, such programs hold important potential to improve quality of life and reduce stigma against PLHIV.

Project description:BackgroundSeasonal influenza imposes a significant health and economic burden in South Africa, particularly in populations vulnerable to severe consequences of influenza. This study assesses the cost-effectiveness of South Africa's seasonal influenza vaccination strategy, which involves vaccinating vulnerable populations with trivalent inactivated influenza vaccine (TIV) during routine facility visits. Vulnerable populations included in our analysis are persons aged ≥ 65 years; pregnant women; persons living with HIV/AIDS (PLWHA), persons of any age with underlying medical conditions (UMC) and children aged 6-59 months.MethodWe employed the World Health Organisation's (WHO) Cost Effectiveness Tool for Seasonal Influenza Vaccination (CETSIV), a decision tree model, to evaluate the 2018 seasonal influenza vaccination campaign from a public healthcare provider and societal perspective. CETSIV was populated with existing country-specific demographic, epidemiologic and coverage data to estimate incremental cost-effectiveness ratios (ICERs) by comparing costs and benefits of the influenza vaccination programme to no vaccination.ResultsThe highest number of clinical events (influenza cases, outpatient visits, hospitalisation and deaths) were averted in PLWHA and persons with other UMCs. Using a cost-effectiveness threshold of US$ 3400 per quality-adjusted life year (QALY), our findings suggest that the vaccination programme is cost-effective for all vulnerable populations except for children aged 6-59 months. ICERs ranged from ~US$ 1 750 /QALY in PLWHA to ~US$ 7500/QALY in children. In probabilistic sensitivity analyses, the vaccination programme was cost-effective in pregnant women, PLWHA, persons with UMCs and persons aged ≥65 years in >80% of simulations. These findings were robust to changes in many model inputs but were most sensitive to uncertainty in estimates of influenza-associated illness burden.ConclusionSouth Africa's seasonal influenza vaccination strategy of opportunistically targeting vulnerable populations during routine visits is cost-effective. A budget impact analysis will be useful for supporting future expansions of the programme.

Project description:BackgroundSeasonal influenza is a major cause of mortality worldwide. Routine immunization of children has the potential to reduce this mortality through both direct and indirect protection, but has not been adopted by any low- or middle-income countries. We developed a framework to evaluate the cost-effectiveness of influenza vaccination policies in developing countries and used it to consider annual vaccination of school- and preschool-aged children with either trivalent inactivated influenza vaccine (TIV) or trivalent live-attenuated influenza vaccine (LAIV) in Thailand. We also compared these approaches with a policy of expanding TIV coverage in the elderly.Methods and findingsWe developed an age-structured model to evaluate the cost-effectiveness of eight vaccination policies parameterized using country-level data from Thailand. For policies using LAIV, we considered five different age groups of children to vaccinate. We adopted a Bayesian evidence-synthesis framework, expressing uncertainty in parameters through probability distributions derived by fitting the model to prospectively collected laboratory-confirmed influenza data from 2005-2009, by meta-analysis of clinical trial data, and by using prior probability distributions derived from literature review and elicitation of expert opinion. We performed sensitivity analyses using alternative assumptions about prior immunity, contact patterns between age groups, the proportion of infections that are symptomatic, cost per unit vaccine, and vaccine effectiveness. Vaccination of children with LAIV was found to be highly cost-effective, with incremental cost-effectiveness ratios between about 2,000 and 5,000 international dollars per disability-adjusted life year averted, and was consistently preferred to TIV-based policies. These findings were robust to extensive sensitivity analyses. The optimal age group to vaccinate with LAIV, however, was sensitive both to the willingness to pay for health benefits and to assumptions about contact patterns between age groups.ConclusionsVaccinating school-aged children with LAIV is likely to be cost-effective in Thailand in the short term, though the long-term consequences of such a policy cannot be reliably predicted given current knowledge of influenza epidemiology and immunology. Our work provides a coherent framework that can be used for similar analyses in other low- and middle-income countries.

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An optimal cost effectiveness study on Zimbabwe cholera seasonal data from 2008-2011.

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An optimal cost effectiveness study on Zimbabwe cholera seasonal data from 2008-2011.

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