Yesim Tozan
Yesim Tozan
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Associate Professor of Global and Environmental Health
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Professional overview
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Dr. Yesim Tozan’s research centers on health decision science and priority setting, and explores the costs and cost-effectiveness of health care interventions using decision analytic models and the issues of health care resource allocation in low- and middle-income countries. Her main focus has been infectious disease prevention and control with an emphasis on dengue and malaria. Dr. Tozan is currently leading a health economics work package in a European Union-funded research project on dengue surveillance and control with field sites in Sri Lanka and Thailand. She is also leading a prospective multi-center study on the cost of dengue illness in international travelers utilizing a network of travel clinics in Europe, the US, the Middle East and Australia. Most recently, she has been working on economic evaluation of artemisinin-based combination therapies for the treatment of uncomplicated childhood malaria using data from multi-site randomized clinical trials in Africa and Asia. Dr. Tozan was a task force associate for the UN Millennium Project’s Task Force on HIV/AIDS, Malaria, Tuberculosis and Access to Essential Medicines and was lead author of the malaria task force report entitled “Coming to grips with malaria in the new millennium.”
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Education
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BS, Environmental Engineering, Istanbul Technical University, TurkeyMS, Environmental Technology, Bogazici University, TurkeyMA, Public Affairs, Princeton University, Princeton, NJPhD, Public Affairs, Princeton University, Princeton, NJ
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Areas of research and study
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Cost EffectivenessCost-effective Health Programs and PoliciesEconomic EvaluationHealth EconomicsInfectious DiseasesPrevention Interventions
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Publications
Publications
A pre-post evaluation study of a social media-based COVID-19 communication campaign to improve attitudes and behaviors toward COVID-19 vaccination in Tanzania
AbstractKim, S., Lilani, A., Redemptus, C., Campana, K., & Tozan, Y. (n.d.).Publication year
2024Journal title
PloS oneVolume
19Issue
5 MayAbstractIn Tanzania, the One by One: Target COVID-19 campaign was launched nationally in July 2022 to address the prevalent vaccine hesitancy and lack of confidence in COVID-19 vaccines. The campaign mobilized social media influencers and viral content with the ultimate goal of increasing COVID-19 vaccine uptake in the country. The objective of this study was to empirically assess the impact of the campaign on three outcomes: vaccine confidence, vaccine hesitancy, and vaccination status. Using programmatic data collected through an online survey before and after the campaign, we conducted a difference-in-difference (DiD) analysis and performed a crude, adjusted, and propensity score-matched analysis for each study outcome. Lastly, to observe whether there was any differential impact of the campaign across age groups, we repeated the analyses on age-stratified subgroups. Data included 5,804 survey responses, with 3,442 and 2,362 responses collected before and after the campaign, respectively. Although there was only weak evidence of increased COVID-19 vaccine confidence in the campaign-exposed group compared to the control group across all age groups, we observed a differential impact among different age groups. While no significant change was observed among young adults aged 18–24 years, the campaign exposure led to a statistically significant increase in vaccine confidence (weighted/adjusted DiD coefficient = 0.76; 95% CI: 0.06, 1.5; p-value = 0.034) and vaccination uptake (weighted/adjusted DiD coefficient = 1.69.; 95% CI: 1.02, 2.81; p-value = 0.023) among young adults aged 25–34 years. Among adults aged 35 years and above, the campaign exposure led to a significant decrease in vaccine hesitancy (weighted/adjusted DiD coefficient = -15; 95% CI: -21, -8.3; p-valueA pre-post evaluation study of a social media-based COVID-19 communication campaign to improve attitudes and behaviors toward COVID-19 vaccination in Tanzania
AbstractTozan, Y., Kim, S., Lilani, A., Redemptus, C., Campana, K., & Tozan, Y. (n.d.).Publication year
2024Journal title
PloS oneVolume
19Issue
5Page(s)
e0300206AbstractIn Tanzania, the One by One: Target COVID-19 campaign was launched nationally in July 2022 to address the prevalent vaccine hesitancy and lack of confidence in COVID-19 vaccines. The campaign mobilized social media influencers and viral content with the ultimate goal of increasing COVID-19 vaccine uptake in the country. The objective of this study was to empirically assess the impact of the campaign on three outcomes: vaccine confidence, vaccine hesitancy, and vaccination status. Using programmatic data collected through an online survey before and after the campaign, we conducted a difference-in-difference (DiD) analysis and performed a crude, adjusted, and propensity score-matched analysis for each study outcome. Lastly, to observe whether there was any differential impact of the campaign across age groups, we repeated the analyses on age-stratified subgroups. Data included 5,804 survey responses, with 3,442 and 2,362 responses collected before and after the campaign, respectively. Although there was only weak evidence of increased COVID-19 vaccine confidence in the campaign-exposed group compared to the control group across all age groups, we observed a differential impact among different age groups. While no significant change was observed among young adults aged 18-24 years, the campaign exposure led to a statistically significant increase in vaccine confidence (weighted/adjusted DiD coefficient = 0.76; 95% CI: 0.06, 1.5; p-value = 0.034) and vaccination uptake (weighted/adjusted DiD coefficient = 1.69.; 95% CI: 1.02, 2.81; p-value = 0.023) among young adults aged 25-34 years. Among adults aged 35 years and above, the campaign exposure led to a significant decrease in vaccine hesitancy (weighted/adjusted DiD coefficient = -15; 95% CI: -21, -8.3; p-valueChildhood Violence, High School Academic Environment, and Adult Alcohol Use Among Latinas and Black Women : A Structural Equation Modeling Study
AbstractCapasso, A., Tozan, Y., DiClemente, R. J., & Pahl, K. (n.d.).Publication year
2024Journal title
Journal of Interpersonal ViolenceAbstractObjective: Young Latinas and Black women drink less than women of other racial/ethnic groups but experience more alcohol-related problems in midlife. This study aims to identify modifiable factors to prevent adult onset of alcohol use disorder (AUD) in this population. Methods: Data were collected at six time points as part of the Harlem Longitudinal Development Study from 365 Latinas (47%) and Black (53%) women (mean age at time 1 = 14, standard deviation 1.3). Structural equation modeling was used to test hypothesized pathways from childhood physical and sexual abuse to AUD via depressive mood, anxiety disorders, and somatic complaints in the 20s. We also tested the moderation effect of the high school academic environment by including in the structural equation model two latent variable interaction terms between the school environment and each of the abuse variables. Results: Childhood physical and sexual abuse was positively associated with depressive mood, anxiety disorders, and somatic complaints when participants were in the 20s. Depressive mood mediated childhood abuse and AUD when women were in the 30s. The high school academic environment attenuated the effect of physical, but not sexual abuse, on depressive mood (β = −0.59, B = −9.38, 95% CI [−14.00, −4.76]), anxiety symptoms (β = −0.61, B = −14.19, 95% CI [−21.76, −6.61]), appetite loss (β = −0.41, B = −10.52, 95% CI [−15.61, −5.42]), and sleeplessness (β = −0.50, B = −9.56, 95% CI [−13.95, −5.17]) in the early 20s. Conclusions: Our findings underscore the need to invest in early violence prevention interventions and in education to ensure equitable access to quality, academically oriented, and safe schools.Childhood Violence, High School Academic Environment, and Adult Alcohol Use Among Latinas and Black Women: A Structural Equation Modeling Study
AbstractTozan, Y., Capasso, A., Tozan, Y., DiClemente, R. J., & Pahl, K. (n.d.).Publication year
2024Journal title
Journal of interpersonal violenceVolume
39Issue
23-24Page(s)
4924-4953AbstractYoung Latinas and Black women drink less than women of other racial/ethnic groups but experience more alcohol-related problems in midlife. This study aims to identify modifiable factors to prevent adult onset of alcohol use disorder (AUD) in this population.Costing of a Combination Intervention (Kyaterekera) Addressing Sexual Risk-Taking Behaviors among Vulnerable Women in Southern Uganda
AbstractTozan, Y., Kiyingi, J., Kim, S., Nabayinda, J., Namuwonge, F., Nsubuga, E., Nakabuye, F., Sensoy, O. B., Nabunya, P., Mayo-Wilson, L. J., McKay, M. M., Witte, S. S., & Ssewamala, F. M. (n.d.).Publication year
2024Journal title
American Journal of Tropical Medicine and HygieneVolume
110Issue
5Page(s)
1046-1056AbstractIn Uganda, women engaged in sex work (WESW) are a marginalized population at the intersection of multiple vulnerabilities. The Kyaterekera intervention is targeted at WESW in Rakai and the greater Masaka regions in Uganda and combines a traditional HIV risk-reduction approach with a savings-led economic empowerment intervention and financial literacy training. We estimated the economic costs of the Kyaterekera intervention from a program provider perspective using a prospective activity-based micro-costing method. All program activities and resource uses were measured and valued across the control arm receiving a traditional HIV risk-reduction intervention and the treatment arm receiving a matched individual development savings account and financial literacy training on top of HIV risk reduction. The total per-participant cost by arm was adjusted for inflation and discounted at an annual rate of 3% and presented in 2019 US dollars. The total per-participant costs of the control and intervention arms were estimated at $323 and $1,435, respectively, using the per-protocol sample. When calculated based on the intent-to-treat sample, the per-participant costs were reduced to $183 and $588, respectively. The key cost drivers were the capital invested in individual development accounts and personnel and transportation costs for program operations, linked to WESW's higher mobility and the dispersed pattern of hot spot locations. The findings provide evidence of the economic costs of implementing a targeted intervention for this marginalized population in resource-constrained settings and shed light on the scale of potential investment needed to better achieve the health equity goal of HIV prevention strategies.Opportunities and challenges for innovative and equitable healthcare
AbstractEcker, D. J., Aiello, C. D., Arron, J. R., Bennett, C. F., Bernard, A., Breakefield, X. O., Broderick, T. J., Callier, S. L., Canton, B., Chen, J. S., Fishburn, C. S., Garrett, B., Hecht, S. M., Janowitz, T., Kliegman, M., Krainer, A., Louis, C. U., Lowe, C., Sehgal, A., … Hayden, M. R. (n.d.).Publication year
2024Journal title
Nature Reviews Drug DiscoveryVolume
23Issue
5Page(s)
321-322AbstractAn unprecedented number of potentially disruptive therapeutic technologies are under development. Forward-looking policies, incentives and infrastructure are needed to harness these advances to provide effective and globally equitable healthcare.Opportunities and challenges for innovative and equitable healthcare
AbstractTozan, Y., Ecker, D. J., Aiello, C. D., Arron, J. R., Bennett, C. F., Bernard, A., Breakefield, X. O., Broderick, T. J., Callier, S. L., Canton, B., Chen, J. S., Fishburn, C. S., Garrett, B., Hecht, S. M., Janowitz, T., Kliegman, M., Krainer, A., Louis, C. U., Lowe, C., … Hayden, M. R. (n.d.).Publication year
2024Journal title
Nature reviews. Drug discoveryAbstract~Spatial-temporal analysis of climate and socioeconomic conditions on cholera incidence in Mozambique from 2000 to 2018 : an ecological longitudinal retrospective study
AbstractArmando, C. J., Rocklöv, J., Sidat, M., Tozan, Y., Mavume, A. F., Bunker, A., & Sewe, M. O. (n.d.).Publication year
2024Journal title
BMJ openVolume
14Issue
8AbstractObjectives This study aims to assess both socioeconomic and climatic factors of cholera morbidity in Mozambique considering both spatial and temporal dimensions. Design An ecological longitudinal retrospective study using monthly provincial cholera cases from Mozambican Ministry of Health between 2000 and 2018. The cholera cases were linked to socioeconomic data from Mozambique Demographic and Health Surveys conducted in the period 2000-2018 and climatic data; relative humidity (RH), mean temperature, precipitation and Normalised Difference Vegetation Index (NDVI). A negative binomial regression model in a Bayesian framework was used to model cholera incidence while adjusting for the spatiotemporal covariance, lagged effect of environmental factors and the socioeconomic indicators. Setting Eleven provinces in Mozambique. Results Over the 19-year period, a total of 153 941 cholera cases were notified to the surveillance system in Mozambique. Risk of cholera increased with higher monthly mean temperatures above 24°C in comparison to the reference mean temperature of 23°C. At mean temperature of 19°C, cholera risk was higher at a lag of 5-6 months. At a shorter lag of 1 month, precipitation of 223.3 mm resulted in an 57% increase in cholera risk (relative risk, RR 1.57 (95% CI 1.06 to 2.31)). Cholera risk was greatest at 3 lag months with monthly NDVI of 0.137 (RR 1.220 (95% CI 1.042 to 1.430)), compared with the reference value of 0.2. At an RH of 54%, cholera RR was increased by 62% (RR 1.620 (95% CI 1.124 to 2.342)) at a lag of 4 months. We found that ownership of radio RR 0.29, (95% CI 0.109 to 0.776) and mobile phones RR 0.262 (95% CI 0.097 to 0.711) were significantly associated with low cholera risk. Conclusion The derived lagged patterns can provide appropriate lead times in a climate-driven cholera early warning system that could contribute to the prevention and management of outbreaks.Spatial-temporal analysis of climate and socioeconomic conditions on cholera incidence in Mozambique from 2000 to 2018: an ecological longitudinal retrospective study
AbstractTozan, Y., Armando, C. J. J., Rocklöv, J., Sidat, M., Tozan, Y., Mavume, A. F. F., Bunker, A., & Sewe, M. O. O. (n.d.).Publication year
2024Journal title
BMJ openVolume
14Issue
8Page(s)
e082503AbstractThis study aims to assess both socioeconomic and climatic factors of cholera morbidity in Mozambique considering both spatial and temporal dimensions.The synergistic impact of Universal Health Coverage and Global Health Security on health service delivery during the Coronavirus Disease-19 pandemic : A difference-indifference study of childhood immunization coverage from 192 countries
AbstractKim, S., Headley, T. Y., & Tozan, Y. (n.d.).Publication year
2024Journal title
PLOS global public healthVolume
4Issue
5 MayAbstractUniversal Health Coverage (UHC) and Global Health Security (GHS) are two high-priority global health agendas that seek to foster health system resilience against health emergencies. Many countries have had to prioritize one agenda over the other due to scarce resources and political pressures. To aid policymakers’ decision-making, this study investigated the individual and synergistic effects of countries’ UHC and GHS capacities in safeguarding essential health service delivery during the COVID-19 pandemic. We used a quasi-experimental difference-in-difference methodology to quantify the relationship between 192 countries’ progress towards UHC and GHS and those countries’ abilities to provide 12 essential childhood immunization services between 2015 and 2021. We used the 2019 UHC Service Coverage Index (SCI) to divide countries into a “high UHC group” (UHC SCI≥75) and the rest (UHC SCI 75), and similarly used the 2019 GHS Index (GHSI) to divide countries into a “high GHS group” (GHSI≥65) and the rest (GHSIThe synergistic impact of Universal Health Coverage and Global Health Security on health service delivery during the Coronavirus Disease-19 pandemic: A difference-in-difference study of childhood immunization coverage from 192 countries
AbstractTozan, Y., Kim, S., Headley, T. Y., & Tozan, Y. (n.d.).Publication year
2024Journal title
PLOS global public healthVolume
4Issue
5Page(s)
e0003205AbstractUniversal Health Coverage (UHC) and Global Health Security (GHS) are two high-priority global health agendas that seek to foster health system resilience against health emergencies. Many countries have had to prioritize one agenda over the other due to scarce resources and political pressures. To aid policymakers' decision-making, this study investigated the individual and synergistic effects of countries' UHC and GHS capacities in safeguarding essential health service delivery during the COVID-19 pandemic. We used a quasi-experimental difference-in-difference methodology to quantify the relationship between 192 countries' progress towards UHC and GHS and those countries' abilities to provide 12 essential childhood immunization services between 2015 and 2021. We used the 2019 UHC Service Coverage Index (SCI) to divide countries into a "high UHC group" (UHC SCI≥75) and the rest (UHC SCI 75), and similarly used the 2019 GHS Index (GHSI) to divide countries into a "high GHS group" (GHSI≥65) and the rest (GHSIUnderstanding COVID-19 vaccine hesitancy in Meghalaya, India : Multiple correspondence and agglomerative hierarchical cluster analyses
AbstractKim, S., Sarkar, R., Kumar, S., Lewis, M. G., Tozan, Y., & Albert, S. (n.d.).Publication year
2024Journal title
PLOS global public healthVolume
4Issue
2AbstractMeghalaya, a state in the northeastern region of India, had a markedly low vaccine uptake compared to the other states in the country when COVID-19 vaccines were being rolled out in 2021. This study aimed to characterize the distinct vaccine-hesitant subpopulations in healthcare and community settings in Meghalaya state in the early days of the vaccination program. We used data from a cross-sectional survey that was administered to 200 healthcare workers (HCWs) and 200 community members, who were a priori identified as 'vaccine- eligible' and 'vaccine-hesitant,' in Shillong city, Meghalaya, in May 2021. The questionnaire collected information on participants' sociodemographic characteristics, COVID-19 history, and presence of medical comorbidities. Participants were also asked to provide a dichotomous answer to a set of 19 questions, probing the reasons for their hesitancy towards COVID-19 vaccines. A multiple correspondence analysis, followed by an agglomerative hierarchical cluster analysis, was performed to identify the distinct clusters of vaccine-hesitant participants. We identified seven clusters: indecisive HCWs (n = 71), HCWs skeptical of COVID-19 and COVID-19 vaccines (n = 128), highly educated male tribal/clan leaders concerned about infertility and future pregnancies (n = 14), less educated adults influenced by leaders and family (n = 47), older adults worried about vaccine safety (n = 76), middle-aged adults without young children (n = 56), and highly educated ethnic/religious minorities with misinformation (n = 8). Across all the clusters, perceived logistical challenges associated with receiving the vaccine was identified as a common factor contributing to vaccine hesitancy. Our study findings provide valuable insights for local and state health authorities to effectively target distinct subgroups of vaccine-hesitant populations with tailored health messaging, and also call for a comprehensive approach to address the common drivers of vaccine hesitancy in communities with low vaccination rates.Understanding COVID-19 vaccine hesitancy in Meghalaya, India: Multiple correspondence and agglomerative hierarchical cluster analyses
AbstractTozan, Y., Kim, S., Sarkar, R., Kumar, S., Lewis, M. G., Tozan, Y., & Albert, S. (n.d.).Publication year
2024Journal title
PLOS global public healthVolume
4Issue
2Page(s)
e0002250AbstractMeghalaya, a state in the northeastern region of India, had a markedly low vaccine uptake compared to the other states in the country when COVID-19 vaccines were being rolled out in 2021. This study aimed to characterize the distinct vaccine-hesitant subpopulations in healthcare and community settings in Meghalaya state in the early days of the vaccination program. We used data from a cross-sectional survey that was administered to 200 healthcare workers (HCWs) and 200 community members, who were a priori identified as 'vaccine-eligible' and 'vaccine-hesitant,' in Shillong city, Meghalaya, in May 2021. The questionnaire collected information on participants' sociodemographic characteristics, COVID-19 history, and presence of medical comorbidities. Participants were also asked to provide a dichotomous answer to a set of 19 questions, probing the reasons for their hesitancy towards COVID-19 vaccines. A multiple correspondence analysis, followed by an agglomerative hierarchical cluster analysis, was performed to identify the distinct clusters of vaccine-hesitant participants. We identified seven clusters: indecisive HCWs (n = 71), HCWs skeptical of COVID-19 and COVID-19 vaccines (n = 128), highly educated male tribal/clan leaders concerned about infertility and future pregnancies (n = 14), less educated adults influenced by leaders and family (n = 47), older adults worried about vaccine safety (n = 76), middle-aged adults without young children (n = 56), and highly educated ethnic/religious minorities with misinformation (n = 8). Across all the clusters, perceived logistical challenges associated with receiving the vaccine was identified as a common factor contributing to vaccine hesitancy. Our study findings provide valuable insights for local and state health authorities to effectively target distinct subgroups of vaccine-hesitant populations with tailored health messaging, and also call for a comprehensive approach to address the common drivers of vaccine hesitancy in communities with low vaccination rates."I decided in my heart I have to complete the sessions" : A qualitative study on the acceptability of an evidence-based HIV risk reduction intervention among women engaged in sex work in Uganda
AbstractBahar, O. S., Nabunya, P., Nabayinda, J., Witte, S., Kiyingi, J., Nsubuga, E., Schriger, S., Nattabi, J., Mayo-Wilson, L. J., Nakigudde, J., Tozan, Y., & Ssewamala, F. M. (n.d.).Publication year
2023Journal title
PloS oneVolume
18Issue
1 JanuaryAbstractBackground The HIV burden remains a critical public health concern and women engaged in sex work [WESW] are at significantly higher risk compared to the general adult population. Similar to other sub-Saharan African countries, Uganda reports high rates of HIV prevalence among WESW. Yet, they have not been targeted by theory-informed HIV prevention intervention approaches. Methods We conducted semi-structured in-depth interviews with 20 WESW upon intervention completion to explore their experiences with an evidence-based HIV risk reduction intervention that was implemented as part of a combination intervention tested in a clinical trial in Uganda (2018-2023. Specifically, we explored their initial motivations and concerns for participating in the intervention, barriers and facilitators to attendance, and their feedback on specific intervention characteristics. Results The main expectations revolved around access to health-related information, including information on STIs, HIV, and PrEP as well as on how one can protect themselves while engaging in sex work. Initial concerns were around potential breach of confidentiality and fear of arrest. The main facilitators for session attendance were the motivation to learn healthrelated information, the attitude of facilitators, and the incentives received for participation, whereas main challenges were related to family commitments and work schedules. WESW appreciated the group format of the intervention and found the location and times of the intervention delivery acceptable. Discussion and conclusions Overall, our findings suggest that the HIV risk reduction intervention was appropriate and acceptable to WESW. Yet, WESW experience unique concerns and barriers that need to be accounted for when designing interventions targeting this population, especially in resource-limited settings where sex work is illegal and highly stigmatized."I decided in my heart I have to complete the sessions": A qualitative study on the acceptability of an evidence-based HIV risk reduction intervention among women engaged in sex work in Uganda
AbstractTozan, Y., Sensoy Bahar, O., Nabunya, P., Nabayinda, J., Witte, S., Kiyingi, J., Nsubuga, E., Schriger, S., Nattabi, J., Mayo-Wilson, L. J. J., Nakigudde, J., Tozan, Y., & Ssewamala, F. M. (n.d.).Publication year
2023Journal title
PloS oneVolume
18Issue
1Page(s)
e0280138AbstractThe HIV burden remains a critical public health concern and women engaged in sex work [WESW] are at significantly higher risk compared to the general adult population. Similar to other sub-Saharan African countries, Uganda reports high rates of HIV prevalence among WESW. Yet, they have not been targeted by theory-informed HIV prevention intervention approaches.A Methodological Framework for Economic Evaluation of Operational Response to Vector-Borne Diseases Based on Early Warning Systems
AbstractTozan, Y., Sewe, M. O., Kim, S., & Rocklov, J. (n.d.).Publication year
2023Journal title
American Journal of Tropical Medicine and HygieneVolume
108Issue
3Page(s)
627-633AbstractDespite significant advances in improving the predictive models for vector-borne diseases, only a few countries have integrated an early warning system (EWS) with predictive and response capabilities into their disease surveillance systems. The limited understanding of forecast performance and uncertainties by decision-makers is one of the primary factors that precludes its operationalization in preparedness and response planning. Further, predictive models exhibit a decrease in forecast skill with longer lead times, a trade-off between forecast accuracy and timeliness and effectiveness of action. This study presents a methodological framework to evaluate the economic value of EWS-triggered responses from the health system perspective. Assuming an operational EWS in place, the framework makes explicit the trade-offs between forecast accuracy, timeliness of action, effectiveness of response, and costs, and uses the net benefit analysis, which measures the benefits of taking action minus the associated costs. Uncertainty in disease forecasts and other parameters is accounted for through probabilistic sensitivity analysis. The output is the probability distribution of the net benefit estimates at given forecast lead times. A non-negative net benefit and the probability of yielding such are considered a general signal that the EWS-triggered response at a given lead time is economically viable. In summary, the proposed framework translates uncertainties associated with disease forecasts and other parameters into decision uncertainty by quantifying the economic risk associated with operational response to vector-borne disease events of potential importance predicted by an EWS. The goal is to facilitate a more informed and transparent public health decision-making under uncertainty.Climate variability, socio-economic conditions and vulnerability to malaria infections in Mozambique 2016-2018: a spatial temporal analysis
AbstractTozan, Y., Armando, C. J. J., Rocklöv, J., Sidat, M., Tozan, Y., Mavume, A. F. F., Bunker, A., & Sewes, M. O. O. (n.d.).Publication year
2023Journal title
Frontiers in public healthVolume
11Page(s)
1162535AbstractTemperature, precipitation, relative humidity (RH), and Normalized Different Vegetation Index (NDVI), influence malaria transmission dynamics. However, an understanding of interactions between socioeconomic indicators, environmental factors and malaria incidence can help design interventions to alleviate the high burden of malaria infections on vulnerable populations. Our study thus aimed to investigate the socioeconomic and climatological factors influencing spatial and temporal variability of malaria infections in Mozambique.Climate variability, socio-economic conditions and vulnerability to malaria infections in Mozambique 2016–2018 : a spatial temporal analysis
AbstractArmando, C. J., Rocklöv, J., Sidat, M., Tozan, Y., Mavume, A. F., Bunker, A., & Sewes, M. O. (n.d.).Publication year
2023Journal title
Frontiers in Public HealthVolume
11AbstractBackground: Temperature, precipitation, relative humidity (RH), and Normalized Different Vegetation Index (NDVI), influence malaria transmission dynamics. However, an understanding of interactions between socioeconomic indicators, environmental factors and malaria incidence can help design interventions to alleviate the high burden of malaria infections on vulnerable populations. Our study thus aimed to investigate the socioeconomic and climatological factors influencing spatial and temporal variability of malaria infections in Mozambique. Methods: We used monthly malaria cases from 2016 to 2018 at the district level. We developed an hierarchical spatial–temporal model in a Bayesian framework. Monthly malaria cases were assumed to follow a negative binomial distribution. We used integrated nested Laplace approximation (INLA) in R for Bayesian inference and distributed lag nonlinear modeling (DLNM) framework to explore exposure-response relationships between climate variables and risk of malaria infection in Mozambique, while adjusting for socioeconomic factors. Results: A total of 19,948,295 malaria cases were reported between 2016 and 2018 in Mozambique. Malaria risk increased with higher monthly mean temperatures between 20 and 29°C, at mean temperature of 25°C, the risk of malaria was 3.45 times higher (RR 3.45 [95%CI: 2.37–5.03]). Malaria risk was greatest for NDVI above 0.22. The risk of malaria was 1.34 times higher (1.34 [1.01–1.79]) at monthly RH of 55%. Malaria risk reduced by 26.1%, for total monthly precipitation of 480 mm (0.739 [95%CI: 0.61–0.90]) at lag 2 months, while for lower total monthly precipitation of 10 mm, the risk of malaria was 1.87 times higher (1.87 [1.30–2.69]). After adjusting for climate variables, having lower level of education significantly increased malaria risk (1.034 [1.014–1.054]) and having electricity (0.979 [0.967–0.992]) and sharing toilet facilities (0.957 [0.924–0.991]) significantly reduced malaria risk. Conclusion: Our current study identified lag patterns and association between climate variables and malaria incidence in Mozambique. Extremes in climate variables were associated with an increased risk of malaria transmission, peaks in transmission were varied. Our findings provide insights for designing early warning, prevention, and control strategies to minimize seasonal malaria surges and associated infections in Mozambique a region where Malaria causes substantial burden from illness and deaths.Correlates of Intimate Partner Violence Among Young Women Engaged in Sex Work in Southern Uganda
AbstractNabayinda, J., Namirembe, R., Kizito, S., Nsubuga, E., Nabunya, P., Sensoy Bahar, O., Magorokosho, N., Kiyingi, J., Nattabi, J., Tozan, Y., Jennings Mayo-Wilson, L., Mwebembezi, A., Witte, S. S., & Ssewamala, F. M. (n.d.).Publication year
2023Journal title
Journal of Interpersonal ViolenceVolume
38Issue
19-20Page(s)
10749-10770AbstractIntimate partner violence (IPV) is a significant global public health problem that results in high social and economic costs to individuals and communities. Compared to women in the general population, women engaged in sex work (WESW) are more likely to experience physical, emotional, and sexual IPV. This study examines the correlates of IPV among young WESW with their intimate partners in Southern Uganda. We used baseline data from the Kyaterekera project, a 5 year NIH-funded longitudinal study aimed at reducing HIV risks among 542 WESW in Southern Uganda. To examine the factors associated with IPV, we fitted three separate multi-level Poisson regression models for physical, emotional, and sexual IPV, respectively. Average age was 31.4 years, and 54% of the women reported being victims of at least one form of IPV from their intimate partners. Model one assessed correlates of sexual IPV. Being married women (β =.71, 95% CI [0.24, 1.17]), divorced/separated/widowed (β =.52, [0.02, 1.02]), depressed (β =.04, [0.02, 0.05]), and having any sexually transmitted infections (STIs) (β =.58, [0.14, 1.01]) were associated with sexual IPV. Model two assessed correlates of physical IPV. Experience of childhood sexual abuse (β =.12, [0.04, 0.19]) was associated with an increase in physical IPV, and increasing age reduced its occurrence (β = −.02, [−0.04, −0.001]). Finally, model three assessed emotional IPV. Women with higher education (β =.49, [0.14, 0.85]) and symptoms of depression (β =.02, [0.001, 0.04]) had higher risks for emotional IPV. For WESW, IPV presents an additional potential pathway for HIV and STIs acquisition and transmission through a lack of negotiating power for safe sex. Efforts to reduce violence against WESW should be prioritized as a strategy for enhancing the well-being of WESW.European projections of West Nile virus transmission under climate change scenarios
AbstractFarooq, Z., Sjödin, H., Semenza, J. C., Tozan, Y., Sewe, M. O., Wallin, J., & Rocklöv, J. (n.d.).Publication year
2023Journal title
One HealthVolume
16AbstractWest Nile virus (WNV), a mosquito-borne zoonosis, has emerged as a disease of public health concern in Europe. Recent outbreaks have been attributed to suitable climatic conditions for its vectors favoring transmission. However, to date, projections of the risk for WNV expansion under climate change scenarios is lacking. Here, we estimate the WNV-outbreaks risk for a set of climate change and socioeconomic scenarios. We delineate the potential risk-areas and estimate the growth in the population at risk (PAR). We used supervised machine learning classifier, XGBoost, to estimate the WNV-outbreak risk using an ensemble climate model and multi-scenario approach. The model was trained by collating climatic, socioeconomic, and reported WNV-infections data (2010−22) and the out-of-sample results (1950–2009, 2023–99) were validated using a novel Confidence-Based Performance Estimation (CBPE) method. Projections of area specific outbreak risk trends, and corresponding population at risk were estimated and compared across scenarios. Our results show up to 5-fold increase in West Nile virus (WNV) risk for 2040-60 in Europe, depending on geographical region and climate scenario, compared to 2000-20. The proportion of disease-reported European land areas could increase from 15% to 23-30%, putting 161 to 244 million people at risk. Across scenarios, Western Europe appears to be facing the largest increase in the outbreak risk of WNV. The increase in the risk is not linear but undergoes periods of sharp changes governed by climatic thresholds associated with ideal conditions for WNV vectors. The increased risk will require a targeted public health response to manage the expansion of WNV with climate change in Europe.European projections of West Nile virus transmission under climate change scenarios
AbstractTozan, Y., Farooq, Z., Sjödin, H., Semenza, J. C., Tozan, Y., Sewe, M. O. O., Wallin, J., & Rocklöv, J. (n.d.).Publication year
2023Journal title
One health (Amsterdam, Netherlands)Volume
16Page(s)
100509AbstractWest Nile virus (WNV), a mosquito-borne zoonosis, has emerged as a disease of public health concern in Europe. Recent outbreaks have been attributed to suitable climatic conditions for its vectors favoring transmission. However, to date, projections of the risk for WNV expansion under climate change scenarios is lacking. Here, we estimate the WNV-outbreaks risk for a set of climate change and socioeconomic scenarios. We delineate the potential risk-areas and estimate the growth in the population at risk (PAR). We used supervised machine learning classifier, XGBoost, to estimate the WNV-outbreak risk using an ensemble climate model and multi-scenario approach. The model was trained by collating climatic, socioeconomic, and reported WNV-infections data (2010-22) and the out-of-sample results (1950-2009, 2023-99) were validated using a novel Confidence-Based Performance Estimation (CBPE) method. Projections of area specific outbreak risk trends, and corresponding population at risk were estimated and compared across scenarios. Our results show up to 5-fold increase in West Nile virus (WNV) risk for 2040-60 in Europe, depending on geographical region and climate scenario, compared to 2000-20. The proportion of disease-reported European land areas could increase from 15% to 23-30%, putting 161 to 244 million people at risk. Across scenarios, Western Europe appears to be facing the largest increase in the outbreak risk of WNV. The increase in the risk is not linear but undergoes periods of sharp changes governed by climatic thresholds associated with ideal conditions for WNV vectors. The increased risk will require a targeted public health response to manage the expansion of WNV with climate change in Europe.Evaluating the effect heterogeneity of malaria camp interventions in hard-to-reach areas of Odisha State, India
AbstractKim, S., Sahu, P. K., Padhan, T. K., Mohanty, S., Haque, M. A., Mohanty, S., Kessler, A., Ompad, D. C., Carlton, J., & Tozan, Y. (n.d.).Publication year
2023Abstract~Evaluating the effect heterogeneity of malaria camp interventions in hard-to-reach areas of Odisha State, India
AbstractKim, S., Sahu, P. K., Padhan, T. K., Mohanty, S., Haque, M. A., Mohanty, S., Kessler, A., Ompad, D. C., Carlton, J., & Tozan, Y. (n.d.).Publication year
2023Abstract~Impact, healthcare utilization and costs of travel-associated mosquito-borne diseases in international travellers : a prospective study
AbstractTozan, Y., Headley, T. Y., Javelle, E., Gautret, P., Grobusch, M., de Pijper, C., Asgeirsson, H., Chen, L. H., Bourque, D. L., Menéndez, M. D., Moro, L., Gobbi, F., Sánchez-Montalvá, A., Connor, B. A., Matteelli, A., Crosato, V., Huits, R., Libman, M., & Hamer, D. H. (n.d.).Publication year
2023Journal title
Journal of Travel MedicineVolume
30Issue
7AbstractBACKGROUND: International travellers frequently acquire infectious diseases whilst travelling, yet relatively little is known about the impact and economic burden of these illnesses on travellers. We conducted a prospective exploratory costing study on adult returning travellers with falciparum malaria, dengue, chikungunya or Zika virus. METHODS: Patients were recruited in eight Travel and Tropical Medicine clinics between June 2016 and March 2020 upon travellers' first contact with the health system in their country of residence. The patients were presented with a structured 52-question self-administered questionnaire after full recovery to collect information on patients' healthcare utilization and out-of-pocket costs both in the destination and home country, and about income and other financial losses due to the illness. RESULTS: A total of 134 patients participated in the study (malaria, 66; dengue, 51; chikungunya, 8; Zika virus, 9; all fully recovered; median age 40; range 18-72 years). Prior to travelling, 42% of patients reported procuring medical evacuation insurance. Across the four illnesses, only 7% of patients were hospitalized abroad compared with 61% at home. Similarly, 15% sought ambulatory services whilst abroad compared with 61% at home. The average direct out-of-pocket hospitalization cost in the destination country (USD $2236; range: $108-$5160) was higher than the direct out-of-pocket ambulatory cost in the destination country (USD $327; range: $0-$1560), the direct out-of-pocket hospitalization cost at home (USD $35; range: $0-$120) and the direct out-of-pocket ambulatory costs at home (US$45; range: $0-$192). Respondents with dengue or malaria lost a median of USD $570 (Interquartile range [IQR] 240-1140) and USD $240 (IQR 0-600), respectively, due to their illness, whilst those with chikungunya and Zika virus lost a median of USD $2400 (IQR 1200-3600) and USD $1500 (IQR 510-2625), respectively. CONCLUSION: Travellers often incur significant costs due to travel-acquired diseases. Further research into the economic impact of these diseases on travellers should be conducted.Private Payer-Negotiated Rates for FDA-Approved Head and Neck Cancer Immunotherapy and Chemotherapy Agents
AbstractTozan, Y., Talwar, A., Kim, S., Yu, S., Samant, S., Tozan, Y., & Givi, B. (n.d.).Publication year
2023Journal title
Otolaryngology--head and neck surgery : official journal of American Academy of Otolaryngology-Head and Neck SurgeryVolume
169Issue
4Page(s)
954-961AbstractTo quantify the price that private payers pay hospitals for head and neck squamous cell carcinoma (HNSCC) treatments and identify hospital-level factors associated with price variation.