Epidemic Containment Research Articles

From smallpox eradication to contemporary global health initiatives: Enhancing human capacity towards a global public health goal

The eradication of smallpox owes its success first and foremost to the thousands of lay health workers and community members who, throughout the campaign and across continents, took on the roles of advocates, educators, vaccinators, care providers and contributors to epidemic surveillance and containment. Bangladesh provides a good example where smallpox eradication and the capacity enhancement needed to achieve this goal resulted in a two-way mutually beneficial process. Smallpox-dedicated staff provided community members with information guidance, support and tools. In turn, communities not only created the enabling environment for smallpox program staff to perform their work but acquired the capacity to perform essential eradication tasks. Contemporary global health programmes can learn much from these core lessons including: the pivotal importance of supporting community aspirations, capacity and resilience; the critical need to enhance commitment, capacity and accountability across the workforce; and the high value of attentive human resources management and support. We owe to subsequent global disease control, elimination and eradication ventures recognition of the need for social and behavioural science to inform public health strategies; the essential roles that civil society organizations and public-private partnerships can play in public health discourse and action; the overall necessity of investing in broad-based health system strengthening; and the utility of applying human rights principles, norms and standards to public health policy and practice.

The response of the Liguria Region (Italy) to the pandemic influenza virus A/H1N1sv.

Influenza is a cause of acute respiratory disease. It has a typical epidemic nature during the winter season, but may also assume a pandemic pattern when a completely new virus spreads among humans. Influenza places a heavy economic and healthcare burden on both the National Health Service and society. During the 2009/2010 influenza pandemic season, the Liguria Region drew upon the specific skills of the various sectors of the Department of Health and Social Services. In collaboration with the Department of Health Sciences of the University of Genova, the Regional Health Agency (RHA) and other public organizations, steps were taken to address the issues of technical and scientific updating and the coordination of all the departments of Local Healthcare Units in Liguria. The main activities conducted at the regional level provided an adequate response to the influenza pandemic. These activities focused on Local and National Influenza Surveillance Systems, the regional Pandemic Plan, vaccination strategies for seasonal and pandemic influenza, and the communication of data from monitoring programs (sentinel physicians--syndromic surveillance). The prevention of influenza transmission and containment of epidemics and pandemics require effective communication strategies that should target the whole population.

Strategies for preventing influenza: future perspectives in influenza vaccine technology

Prevention of influenza transmission and containment of epidemics and pandemics require effective strategies that can be efficiently and easily addressed to the whole population. Annual vaccination is undoubtedly the most effective way to provide protection against influenza infection. Numbers of vaccines are actually available for yearly immunisation. However, the continuous increasing demand for rapidly available vaccine doses for immunisation of a larger proportion of population represents the stimulus for study and development of more efficient vaccine production technologies, which can guarantee reduction of vaccine manufacture times and better compliance by availability of easier routes of administration. New perspectives in influenza vaccination technology are making their way in the future panorama of influenza prevention strategies.

Invasion Threshold in Heterogeneous Metapopulation Networks

We study the dynamics of epidemic and reaction-diffusion processes in metapopulation models with heterogeneous connectivity patterns. In susceptible-infected-removed-like processes, along with the standard local epidemic threshold, the system exhibits a global invasion threshold. We provide an explicit expression of the threshold that sets a critical value of the diffusion/mobility rate below, which the epidemic is not able to spread to a macroscopic fraction of subpopulations. The invasion threshold is found to be affected by the topological fluctuations of the metapopulation network. The results presented provide a general framework for the understanding of the effect of travel restrictions in epidemic containment.

Dynamical patterns of epidemic outbreaks in complex heterogeneous networks

We present a thorough inspection of the dynamical behavior of epidemic phenomena in populations with complex and heterogeneous connectivity patterns. We show that the growth of the epidemic prevalence is virtually instantaneous in all networks characterized by diverging degree fluctuations, independently of the structure of the connectivity correlation functions characterizing the population network. By means of analytical and numerical results, we show that the outbreak time evolution follows a precise hierarchical dynamics. Once reached the most highly connected hubs, the infection pervades the network in a progressive cascade across smaller degree classes. Finally, we show the influence of the initial conditions and the relevance of statistical results in single case studies concerning heterogeneous networks. The emerging theoretical framework appears of general interest in view of the recently observed abundance of natural networks with complex topological features and might provide useful insights for the development of adaptive strategies aimed at epidemic containment.

Meningococcal meningitis in sub-Saharan Africa: the case for mass and routine vaccination with available polysaccharide vaccines.

Endemic and epidemic group A meningococcal meningitis remains a major cause of morbidity and mortality in sub-Saharan Africa, despite the availability of the safe and inexpensive group A meningococcal polysaccharide vaccine, which is protective at all ages when administered as directed. Despite optimal therapy, meningococcal meningitis has a 10% fatality rate and at least 15% central nervous system damage. WHO's policy of epidemic containment prevents, at best, about 50% of cases and ignores endemic meningitis, which is estimated at 50,000 cases per year. The effectiveness of group A, C, W135, and Y capsular polysaccharides is the basis for recommending universal vaccination with group A meningococcal polysaccharide twice in infancy, followed by the four-valent vaccine in children aged two and six years. This could eliminate epidemic and endemic disease, prepare for the use of conjugates when they become available, and probably could have prevented the recent epidemics of groups A and W135 meningitis in Burkina Faso.

Malaria control: constraints and opportunities

The malaria eradication campaign of the 1950s and 1960s achieved elimination of malaria from the industrialized world and drastic reduction of malaria elsewhere, especially Asia. In Africa, eradication was hardly attempted. For various reasons, results could not be maintained. Eradication had to be given up, control became the policy. Since 1992 malaria control is based on four principles: early diagnosis and treatment; selective and sustainable preventive measures, including vector control; detection, containment and prevention of epidemics, and building up of local capacity. Several constraints with the presently available tools are discussed. Major problems are drug resistance and poor performance of the health sector. International awareness of the problem and international co-operation, the financial resources now available and scientific advances offer opportunities for a concerted effort to reduce the burden of malaria. Operational research, field research and implementation and improvement of the peripheral health service will be of paramount importance.

Implications of pandemic influenza for bioterrorism response.

The 1918-1919 influenza pandemic (Spanish flu) had catastrophic effects upon urban populations in the United States. Large numbers of frightened, critically ill people overwhelmed health care providers. Mortuaries and cemeteries were severely strained by rapid accumulation of corpses of flu victims. Understanding of the outbreak's extent and effectiveness of containment measures was obscured by the swiftness of the disease and an inadequate health reporting system. Epidemic controls such as closing public gathering places elicited both community support and resistance, and fear of contagion incited social and ethnic tensions. Review of this infamous outbreak is intended to advance discussions among health professionals and policymakers about an effective medical and public health response to bioterrorism, an infectious disease crisis of increasing likelihood. Elements of an adequate response include building capacity to care for mass casualties, providing emergency burials that respect social mores, properly characterizing the outbreak, earning public confidence in epidemic containment measures, protecting against social discrimination, and fairly allocating health resources.

Malaria control stymied in 2010, mastered in 2025.

Presented in a question-and-answer form this article discusses: the availability of necessary tools for tackling parasite resistance to drugs and mosquito resistance to insecticides; the effectiveness of the Roll Back Malaria horizontal program; the accuracy of malaria control strategies; and the probability of the Roll Back Malaria program’s controlling malaria in 2010 and 2025. It is projected that in 2010 over 80% of the population in every village in malarious areas of Africa will be sleeping under insecticide-impregnated mosquito nets every night. Fever clinics with effective antimalarial drugs will exist within 5 km of 80% of the villages. However the strategies of patient management selective treatment and chemoprophylaxis during pregnancy bednet distribution and epidemic containment will have little long-term impact on transmission. In 2025 over 90% of persons in rural malarious areas will be sleeping under long-duration insecticide-impregnated bed nets and using insecticide-impregnated clothing and soap with effective nontoxic insect repellents. Malarial first-line therapy chloroquine and pyrimethamine-sulfadoxine will be replaced by new low-cost antimalarial drugs. New treatment and prevention interventions will be existent through the use of improved genetic understanding of mosquitoes parasites and human susceptibility to malaria.