The economic impact and cost-effectiveness of combined vector-control and dengue vaccination strategies in Thailand: results from a dynamic transmission model.

BACKGROUND AND AIMS: Dengue fever is a major public health problem in tropical/subtropical regions. Prior economic analyses have predominantly evaluated either vaccination or vector-control programmes in isolation and do not really consider the incremental benefits and cost-effectiveness of mixed strategies and combination control. We estimated the cost-effectiveness of single and combined approaches in Thailand. METHODS: The impacts of different control interventions were analysed using a previously published mathematical model of dengue epidemiology and control incorporating seasonality, age structure, consecutive infection, cross protection, immune enhancement and combined vector-host transmission. An economic model was applied to simulation results to estimate the cost-effectiveness of 4 interventions and their various combinations (6 strategies): i) routine vaccination of 1-year olds; ii) chemical vector control strategies targeting adult and larval stages separately; iii) environmental management/ public health education and awareness [EM/ PHEA]). Payer and societal perspectives were considered. The health burden of dengue fever was assessed using disability-adjusted life-years (DALYs) lost. Costs and effects were assessed for 10 years. Costs were discounted at 3% annually and updated to 2013 United States Dollars. Incremental cost-effectiveness analysis was carried out after strategies were rank-ordered by cost, with results presented in a table of incremental analysis. Sensitivity and scenario analyses were undertaken; and the impact and cost-effectiveness of Wolbachia was evaluated in exploratory scenario analyses. RESULTS: From the payer and societal perspectives, 2 combination strategies were considered optimal, as all other control strategies were dominated. Vaccination plus adulticide plus EM/ PHEA was deemed cost-effective according to multiple cost-effectiveness criteria. From the societal perspective, incremental differences vs. adulticide and EM/ PHEA resulted in costs of $157.6 million and DALYs lost of 12,599, giving an expected ICER of $12,508 per DALY averted. Exploratory scenario analyses showed Wolbachia to be highly cost-effective ($343 per DALY averted) vs. other single control measures. CONCLUSIONS: Our model shows that individual interventions can be cost-effective, but that important epidemiological reductions and economic impacts are demonstrated when interventions are combined as part of an integrated approach to combating dengue fever. Exploratory scenario analyses demonstrated the potential epidemiological and cost-effective impact of Wolbachia when deployed at scale on a nationwide basis. Our findings were robust in the face of sensitivity analyses.

Global Governing Bodies: A Pathway for Gene Drive Governance for Vector Mosquito Control.

Gene drive technologies represent powerful tools to develop vector control strategies that will complement the current approaches to mitigate arthropod-borne infectious diseases. The characteristics of gene drive technologies have raised additional concerns to those for standard genetically engineered organisms. This generates a need for adaptive governance that has not been met yet because of the rapid rate of progress in gene drive research. For the eventual release of gene drive insects into wild populations, an international governance network would be helpful in guiding scientists, stakeholders, public opinion, and affected communities in its use. We examined the current institutions and governing bodies among various continents that could have an impact on gene drive governance or the potential to adapt to its future use. Possible governance strategies also are proposed that seek to bridge gaps and promote an ethically sound policy framework. Ideally, governance strategies should be developed before or at the same pace as gene drive research to anticipate field releases and maximize their impact as a public health tool. However, this is not likely to happen as it takes years to develop global accords, and some countries may choose to move ahead independently on the new technology.

Malaria epidemiology and interventions in Ethiopia from 2001 to 2016.

BACKGROUND: Ethiopia is one of the African countries where Plasmodium falciparum and P. vivax co-exist. Monitoring and evaluation of current malaria transmission status is an important component of malaria control as it is a measure of the success of ongoing interventions and guides the planning of future control and elimination efforts. MAIN TEXT: We evaluated changes in malaria control policy in Ethiopia, and reviewed dynamics of country-wide confirmed and clinical malaria cases by Plasmodium species and reported deaths for all ages and less than five years from 2001 to 2016. Districts level annual parasite incidence was analysed to characterize the malaria transmission stratification as implemented by the Ministry of Health. We found that Ethiopia has experienced major changes from 2003 to 2005 and subsequent adjustment in malaria diagnosis, treatment and vector control policy. Malaria interventions have been intensified represented by the increased insecticide treated net (ITN) and indoor residual spraying (IRS) coverage, improved health services and improved malaria diagnosis. However, countrywide ITN and IRS coverages were low, with 64% ITN coverage in 2016 and IRS coverage of 92.5% in 2016 and only implemented in epidemic-prone areas of > 2500 m elevation. Clinical malaria incidence rate dropped from an average of 43.1 cases per 1000 population annually between 2001 and 2010 to 29.0 cases per 1000 population annually between 2011 and 2016. Malaria deaths decreased from 2.1 deaths per 100 000 people annually between 2001 and 2010 to 1.1 deaths per 100 000 people annually between 2011 to 2016. There was shrinkage in the malaria transmission map and high transmission is limited mainly to the western international border area. Proportion of P. falciparum malaria remained nearly unchanged from 2000 to 2016 indicating further efforts are needed to suppress transmission. CONCLUSIONS: Malaria morbidity and mortality have been significantly reduced in Ethiopia since 2001, however, malaria case incidence is still high, and there were major gaps between ITN ownership and compliance in malarious areas. Additional efforts are needed to target the high transmission area of western Ethiopia to sustain the achievements made to date.

Ivermectin to reduce malaria transmission III. Considerations regarding regulatory and policy pathways.

Vector control is a task previously relegated to products that (a) kill the mosquitoes directly at different stages (insecticides, larvicides, baited traps), or (b) avoid/reduce human-mosquito contact (bed nets, repellents, house screening), thereby reducing transmission. The potential community-based administration of the endectocide ivermectin with the intent to kill mosquitoes that bite humans, and thus reduce malaria transmission, offers a novel approach using a well-known drug, but additional steps are required to address technical, regulatory and policy gaps. The proposed community administration of this drug presents dual novel paradigms; first, indirect impact on the community rather than on individuals, and second, the use of a drug for vector control. In this paper, the main questions related to the regulatory and policy pathways for such an application are identified. Succinct answers are proposed for how the efficacy, safety, acceptability, cost-effectiveness and programmatic suitability could result in regulatory approval and ultimately policy recommendations on the use of ivermectin as a complementary vector control tool.

Zika in the United States of America and a Fateful 1969 Decision.

The United States Gulf Coast's current risk to Zika transmitted by Aedes aegypti mosquitoes can be traced back to some important federal health policy decisions made during the 1960s.

National malaria vector control policy: an analysis of the decision to scale-up larviciding in Nigeria.

BACKGROUND: New vector control tools are needed to combat insecticide resistance and reduce malaria transmission. The World Health Organization (WHO) endorses larviciding as a supplementary vector control intervention using larvicides recommended by the WHO Pesticides Evaluation Scheme (WHOPES). The decision to scale-up larviciding in Nigeria provided an opportunity to investigate the factors influencing policy adoption and assess the role that actors and evidence play in the policymaking process, in order to draw lessons that help accelerate the uptake of new methods for vector control. METHODS: A retrospective policy analysis was carried out using in-depth interviews with national level policy stakeholders to establish normative national vector control policy or strategy decision-making processes and compare these with the process that led to the decision to scale-up larviciding. The interviews were transcribed, then coded and analyzed using NVivo10. Data were coded according to pre-defined themes from an analytical policy framework developed a priori. RESULTS: Stakeholders reported that the larviciding decision-making process deviated from the normative vector control decision-making process. National malaria policy is normally strongly influenced by WHO recommendations, but the potential of larviciding to contribute to national economic development objectives through larvicide production in Nigeria was cited as a key factor shaping the decision. The larviciding decision involved a restricted range of policy actors, and notably excluded actors that usually play advisory, consultative and evidence generation roles. Powerful actors limited the access of some actors to the policy processes and content. This may have limited the influence of scientific evidence in this policy decision. CONCLUSIONS: This study demonstrates that national vector control policy change can be facilitated by linking malaria control objectives to wider socioeconomic considerations and through engaging powerful policy champions to drive policy change and thereby accelerate access to new vector control tools.

[Changes in the legally mandated distribution of competency for mosquito control based on experience on Reunion Island]. / De l'evolution daans la répartition juridique des compétences en matière de démoustication a travers l'exemple réunionnais.

The purpose of this article is to describe the legal framework for controlling mosquito vectors of diseases transmissible to human beings in certain locations such as Reunion Island. A distinction is made between general legal measures for insect vector control and specific measures for mosquito control. Regionalization is a major factor in the legal framework for insect vector control, thus limiting the scope of action by the prefecture. Another factor involves the increasing role of an important new player, i.e., the regional health agencies. Mosquito vector control raises the need to impose and enforce measures on the general public as well as private citizens. Failure to comply with these measures is punishable by sanctions and fines with no diminishing effect on de jure implementation of control measures by public agencies.

Status of insecticide resistance in Culex pipiens field populations from north-eastern areas of Italy before the withdrawal of OP compounds.

BACKGROUND: Heavy and constant use of organophosphorus (OP) larvicides selected Culex pipiens L. resistant populations through two main mechanisms of genetic resistance, the increased activity of detoxifying esterase and the production of alterate acetylcholinesterase-1 (AChE1) by G119S mutation. The aim of this study was the assessment of the distribution of Cx. pipiens populations resistant to temephos and chlorpyrifos in the north-eastern regions of Italy and the occurrence of the insensitive AChE in these populations. Data describe the situation in the last years before European legislation prohibited the use of OP larvicides in mosquito control, up until 2007. RESULTS: For the first time a high level of OP resistance in the samples from Ravenna (182-fold, 80% A4/B4 or A5/B5 esterases and 38.3% Ester(5)), Emilia Romagna region, was detected; therefore, new data from the Veneto and Friuli Venezia Giulia regions were obtained and reinforced existing knowledge about resistance previously studied along the Adriatic coast. Nearby, in the Villa Verucchio locality, the highest (87.5%) AChE1R was found. CONCLUSION: Cx. pipiens resistance esterases A5/B5 and A4/B4 spread southward along the Adriatic coastal plain while OPs were being used in mosquito control, as confirmed by the first molecular screening of the AChE1 gene in these populations.

Ethical, legal and social aspects of the approach in Sudan.

The global malaria situation, especially in Africa, and the problems frequently encountered in chemical control of vectors such as insecticide resistance, emphasize the urgency of research, development and implementation of new vector control technologies that are applicable at regional and local levels. The successful application of the sterile insect technique (SIT) for the control of the New World screwworm Cochliomyia hominivorax and several species of fruit flies has given impetus to the use of this method for suppression or elimination of malaria vectors in some areas of Africa including Northern State of Sudan. The research and development phase of the Northern State feasibility study has been started. Sudanese stakeholders are working side-by-side with the International Atomic Energy Agency in the activities of this important phase. Several ethical, legal and social issues associated with this approach arose during this phase of the project. They need to be seriously considered and handled with care. In this paper, these issues are described, and the current and proposed activities to overcome potential hurdles to ensure success of the project are listed.

Availability of insecticidal molecules to control Aedes albopictus (Skuse).

Following the implementation of the Directive 98/8/CE a few changes in the availability of insecticidal molecules to control Ae. albopictus have been outlined. Available products for larvicidal treatments will predominantly be based upon two growth regulators (diflubenzuron and pyriproxyfen). For the control of the adult forms there will mostly be active ingredients belonging to the pyrethroid group. Importance of surveillance for the onset of tolerance or resistance phenomena.

Control of the Asian tiger mosquito: technical and administrative aspects.

The Community legislator, through Directives 2004/17/CE and 2004/18/CE, wanted dictate to the Member States some "guidelines" to be used in the field of public procurement of services, in order to promote, through an inner market growth, developing appropriate operational protocols to document in the race; that, has the aim at testify the consolidated technical capacity of Company which conferred the health reclamation provided by the "Plans to put public health emergencies". By its nature, the legislative regulatory act which is capable of directing the gradual harmonization of national laws, giving also each state full autonomy on the form and means to be taken. Therefore, the objectives of the Community directives must be properly incorporated and interpreted, including the legislative adaptation about the regulation of the disinfestations Enterprises.

Comparison of mosquito control programs in seven urban sites in Africa, the Middle East, and the Americas

Mosquito control programs at seven urban sites in Kenya, Egypt, Israel, Costa Rica, and Trinidad are described and compared. Site-specific urban and disease characteristics, organizational diagrams, and strengths, weaknesses, obstacles and threats (SWOT) analysis tools are used to provide a descriptive assessment of each mosquito control program, and provide a comparison of the factors affecting mosquito abatement. The information for SWOT analysis is collected from surveys, focus-group discussions, and personal communication. SWOT analysis identified various issues affecting the efficiency and sustainability of mosquito control operations. The main outcome of our work was the description and comparison of mosquito control operations within the context of each study site's biological, social, political, management, and economic conditions. The issues identified in this study ranged from lack of inter-sector collaboration to operational issues of mosquito control efforts. A lack of sustainable funding for mosquito control was a common problem for most sites. Many unique problems were also identified, which included lack of mosquito surveillance, lack of law enforcement, and negative consequences of human behavior. Identifying common virtues and shortcomings of mosquito control operations is useful in identifying "best practices" for mosquito control operations, thus leading to better control of mosquito biting and mosquito-borne disease transmission.