Showing papers by "Ramanan Laxminarayan published in 2009"

Optimal control of epidemics in metapopulations.

Abstract: Little is known about how best to deploy scarce resources for disease control when epidemics occur in different but interconnected regions. We use a combination of optimal control methods and epidemiological theory for metapopulations to address this problem. We consider what strategy should be used if the objective is to minimize the discounted number of infected individuals during the course of an epidemic. We show, for a system with two interconnected regions and an epidemic in which infected individuals recover and can be reinfected, that equalizing infection in the two regions is the worst possible strategy in minimizing the total level of infection. Treatment should instead be preferentially directed at the region with the lower level of infection, treating the other subpopulation only when there is resource left over. The same strategy holds with preferential treatments of regions with lower levels of infection when quarantine is introduced.

Community-associated methicillin-resistant Staphylococcus aureus in outpatients, United States, 1999-2006.

Abstract: Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has become a major problem in US hospitals already dealing with high levels of hospital-associated MRSA (HA-MRSA) Using antimicrobial drug susceptibility data for 1999-2006 from The Surveillance Network, we characterized the relationship between outpatient and inpatient levels of CA-MRSA nationally In outpatients, the frequency of CA-MRSA isolates has increased >7 x during 1999-2006, which suggests that outpatients have become a major reservoir for CA-MRSA However, contrary to results in other reports, although CA-MRSA increases are associated with decreases in the frequency of HA-MRSA in hospitals, the decreases are only modest This finding suggests that instead of replacing HA-MRSA in the hospital, CA-MRSA is adding to the overall presence of MRSA already found within the hospital population

A Global Subsidy: Key To Affordable Drugs For Malaria?

Abstract: The global fight against malaria has been continually challenged by poor access to affordable, effective medicine. Growing resistance to chloroquine, the traditional treatment, has worsened the situation. Artemisinins, the successor therapy to chloroquine, are at least ten times more costly than the older drug. In developing countries, most malaria medicines are purchased in the private sector, where traditional aid mechanisms do not reach. So a new aid approach was needed. The Affordable Medicines Facility–malaria (AMFm) will efficiently supply publicly subsidized drugs to meet public- and private-sector demand in malaria-endemic countries. If artemisinins are priced more competitively, resistance to them will be delayed.

Cost-effectiveness projections of single and combination therapies for visceral leishmaniasis in Bihar, India.

Abstract: Summary Objectives To assess the cost-effectiveness of current monotherapies and prospective combinations for treating visceral leishmaniasis (VL) in Bihar, India in terms of years of life lost (YLL) averted as well as deaths averted. Methods We employed two methods to estimate the number of avertable deaths in our analysis: one using estimated mortality, the other using direct incidence estimates for VL. Costs of care are based on an average private hospital in Bihar, and data on drug costs were obtained both locally and from the World Health Organization. Results The cost of monotherapies per averted YLL ranged from US$2 for paromomycin in an outpatient setting to US$20–22 for AmBisome® at 20 mg/kg. The corresponding costs per death averted ranged from US$53–54 to US$523–527. Combinations ranged US$5–8 per YLL averted and US$124–213 per death averted. Conclusion The available treatments for VL are cost-effective, and our mortality and incidence-based methods produce consistent estimates. The combinations considered here were more cost-effective than most monotherapies. Having multiple treatment options and combining drugs are also likely to reduce drug pressure and prolong the drugs’ life-span of effective use. Projections du rapport cout/efficacite des monotherapies et therapies de combinaison de la leishmaniose viscerale a Bihar, en Inde Objectifs: Evaluer le rapport cout/efficacite des monotherapies actuelles et des traitements prospectifs de combinaisons de la LV a Bihar, en Inde, en termes d’annees de vie perdues (AVP) evitees et de deces evites. Methodes: Nous avons utilise dans notre analyse, deux methodes pour estimer le nombre de deces evitables: une basee sur l’estimation de la mortalite et l’autre sur des estimations directes de l’incidence de la LV. Les couts des soins ont ete estimes par rapport a un hopital prive moyen de Bihar et les donnees sur les couts des medicaments ont ete obtenues au niveau local et de celui de l’Organisation mondiale de la sante. Resultats: Le cout des monotherapies par AVP evitee vont de 2$ US pour la paromomycine en ambulatoire a 20-22$ US pour l’AmBisome®a 20 mg/kg. Les couts correspondants par deces evite varient de 53-54$ US a 523-527$ US. Les combinaisons allaient de 5$ US a 8$ US par AVP evitee et de 124$ US a 213$ US par deces evite. Conclusions: Les traitements disponibles pour la LV sont rentables et nos methodes basees sur la mortalite et l’incidence produisent des estimations coherentes. Les combinaisons considerees ici etaient plus rentables que la plupart des monotherapies. Le fait d’avoir multiples options de traitement et de combinaisons de medicaments est aussi susceptible de reduire la pression sur des medicaments et de prolonger la duree de vie de l’utilisation efficace de ceux-ci. Proyecciones de costo efectividad de terapias monoterapias y de combinacion para la leishmaniasis visceral en Bihar, India Objetivos: Evaluar la costo efectividad de las monoterapias actuales y posibles terapias de combinacion para tratar la leishmaniasis visceral (LV) en Bihar, India en terminos de anos de vida perdidos (AVP) evitados, asi como muertes evitadas. Metodos: Hemos utilizado dos metodos para estimar el numero de muertes evitadas en nuestro analisis: uno utilizando la mortalidad estimada, y otro utilizando estimativos de la incidencia directa de LV. Los costes de cuidados estan basados en la media de hospitales privados en Bihar, y los datos sobre costes de medicacion se obtuvieron tanto localmente como de la OMS. Resultados: El coste de las monoterapias por AVP evitados estaba entre US$2 para la paromomicina en un centro de consulta externa a US$20-22 para AmBisome® a 20 mg/kg. Los costes correspondientes para muerte evitada estaban entre US$53-54 y US$523-527. Las combinaciones estaban entre US$5-8 por AVP evitado y US$124-213 por muerte evitada. Conclusiones: Los tratamientos disponibles para LV son costo efectivos, y nuestros metodos basados en la mortalidad e incidencia producen estimativos consistentes. Las combinaciones que se consideraron en este estudio fueron mas costo efectivas que la mayoria de monoterapias. El tener multiples opciones de tratamiento y el combinar medicamentos tambien podria reducir la presion sobre los medicamentos, prolongando su vida util y uso efectivo.

Incentives for Surveillance of Infections Disease Outbreaks

Abstract: This paper examines the incentives for countries to report disease outbreaks such as swine flu, avian flu and SARS to the international community. Even cursory analysis suggests countries have conflicting incentives regarding whether to report an outbreak. Reporting an outbreak may bring medical assistance, but also trigger trade sanctions to contain an outbreak. Modeling the decision as a signaling game where a country has private but imperfect evidence of an outbreak provides additional insights. First, not all sanctions discourage reporting. Sanctions based on fears of an undetected outbreak (false negatives) encourage disclosure by reducing the relative cost of sanctions that follow a reported outbreak. Second, improving the quality of detection technology may not promote the disclosure of private information about an outbreak because more informative reports could also trigger harsher sanctions. Third, informal surveillance - an important channel for publicizing outbreaks - functions as an exogenous, public signal that is less likely to discourage disclosure than better technology. Informal surveillance can counter false positive and false negative formal disclosures, reducing the relative sanctions for disclosing an outbreak.

Global investments in TB control: Economic benefits

Abstract: The Global Plan to Stop TB calls for significant financial resources to meet the Millennium Development Goals for tuberculosis. However, it is unclear whether the economic benefits of TB control exceed the costs. Using an epidemiological model, we find that the economic benefits of the Global Plan relative to sustained DOTS (a commonly used treatment method) were unambiguously greater than the incremental costs in all nine high-burden countries in Africa and in Afghanistan, Pakistan, and Russia. Benefit-cost ratios of sustaining DOTS at current levels relative to having no DOTS exceeded 1 in all twenty-two high-burden, TB-endemic countries and sub-Saharan Africa.

Fiscal and Externality Rationales for Alcohol Policies

Abstract: Alcohol taxes are typically justified as a means to address externalities from alcohol abuse and to raise government revenue. Prior literature has focused on measuring the Pigouvian tax but has paid little attention to the fiscal rationale. This paper presents an analytical and simulation framework for assessing the optimal levels, and welfare effects, of alcohol taxes and drunk driver penalties, accounting for both externalities and how policies interact with the broader fiscal system.Under plausible parameter values and recycling possibilities, the fiscal component of the optimal alcohol tax may be as large, or larger, than the externality-correcting component. Therefore, fiscal considerations can significantly strengthen the case for higher alcohol taxes. They also raise the welfare gains from alcohol taxes relative to those from drunk driver penalties, and they warrant differential taxation of individual beverages on an alcohol equivalent basis.