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Biomedical subjects

David L Heymann

Publications and source records attributed to David L Heymann.

At least 19 recordsLinked to original sources
PubMed2006

New strategies for the elimination of polio from India.

The feasibility of global polio eradication is being questioned as a result of continued transmission in a few localities that act as sources for outbreaks elsewhere. Perhaps the greatest challenge is in India, where transmission has persisted in Uttar Pradesh and Bihar despite high coverage with multiple doses of vaccine. We estimate key parameters governing the seasonal epidemics in these areas and show that high population density and poor sanitation cause persistence by not only facilitating transmission of poliovirus but also severely compromising the efficacy of the trivalent vaccine. We analyze strategies to counteract this and show that switching to monovalent vaccine may finally interrupt virus transmission.

Child↗
PubMed2006

A vision of a world without polio: the OPV cessation strategy.

Once the eradication of wild poliovirus has been confirmed, the public health benefits of routine immunization with OPV will no longer outweigh the burden of disease either due to paralysis caused by OPV (vaccine associated paralytic polio), or by outbreaks caused by circulating vaccine-derived polioviruses. The eventual cessation of OPV use in routine immunization programmes worldwide will become necessary to assure a lasting eradication of polio. As the world moves towards polio eradication and its certification, preparations are therefore being intensified for OPV cessation, and the risk management framework for safe OPV cessation is being put in place. The framework includes bio-containment of all known poliovirus and potentially infected substances, development of an international stockpile of oral polio vaccine, ensuring a mechanism for continued global surveillance and response for polio after eradication has been certified, and national policies if countries decide to continue vaccinating with inactivated polio vaccine (IPV). It is ironic that the vaccine on which the world has depended for polio eradication will itself become a risk to eradication once the transmission of wild poliovirus has been interrupted. Final preparations for the eventual global and simultaneous cessation of OPV will require the same level of international cooperation and coordination that has brought the world to the verge of polio eradication.

Global Health↗
PubMed2006

SARS and emerging infectious diseases: a challenge to place global solidarity above national sovereignty.

Severe acute respiratory syndrome (SARS) emerged in a world where information about infectious disease outbreaks travels at speeds and in ways not imagined just 30 years ago, and where scientists are increasingly working together on detecting and responding to public health events that threaten international public health and economic security. The SARS outbreak clearly demonstrated that it is no longer the exclusive privilege of countries to report and respond to infectious diseases occurring in their own territories, but that the global community has also assumed this role, aided by the ease and power of electronic communication through the World Wide Web. This phenomenon has been cited by some scholars as a potential infringement on national sovereignty that compromises the concept that states reign supreme over their territories and peoples. At the same time, however, countries are increasingly seeking to collaborate internationally in infectious disease surveillance and response, as shown in the current situation of avian influenza (H5N1), and in the formal agreement leading to the revised International Health Regulations (IHR), suggesting that a new world order prevails over issues that once had been considered the sole domain of a sovereign nation.

Communicable Diseases, Emerging↗
PubMed2005

Policy. OPV cessation--the final step to a "polio-free" world.

The 20-year, U.S. $4 billion-dollar international effort to eradicate wild polioviruses now includes monovalent oral poliovirus type 1 vaccine (mOPV1), which was first given to 40 million children in India in April 2005. As this vaccine is being introduced to eliminate some of the last poliovirus reservoirs, the Global Polio Eradication Initiative is planning for the eventual synchronized worldwide cessation of the routine use of all oral poliovirus vaccines (OPVs) because of their capacity to cause, rarely, outbreaks of paralytic poliomyelitis. This Policy Forum reviews the feasibility and implications of eventually stopping the use of live polio vaccines.

Drug Utilization↗
PubMed2005

Social, behavioural and environmental factors and their impact on infectious disease outbreaks.

The microbes that cause infectious diseases are complex, dynamic, and constantly evolving. They reproduce rapidly, mutate frequently, breach species barriers, adapt with relative ease to new hosts and new environments, and develop resistance to the drugs used to treat them. In their article "Meeting the challenge of epidemic infectious diseases outbreaks: an agenda for research", Kai-Lit Phua and Lai Kah Lee clearly demonstrate how social, behavioural and environmental factors, linked to a host of human activities, have accelerated and amplified these natural phenomena. By reviewing published and non-published information about outbreaks of Nipah virus in Malaysia, severe acute respiratory syndrome (SARS) and avian influenza in Asia, and the HIV pandemic, they provide a series of examples that demonstrate the various social, behavioural and environmental factors of these recent infectious disease outbreaks. They then analyse some of these same determinants in important historical epidemics and pandemics such as plague in medieval Europe, and conclude that it is important to better understand the social conditions that facilitate the appearance of diseases outbreaks in order to determine why and how societies react to outbreaks and their impact on different population groups.

Communicable Disease Control↗
PubMed2005

Can we capitalize on the virtues of vaccines? Insights from the polio eradication initiative.

Twenty-five years after the eradication of smallpox, the ongoing effort to eradicate poliomyelitis has grown into the largest international health initiative ever undertaken. By 2004, however, the polio eradication effort was threatened by a challenge regularly faced by public health policymakers everywhere-misperception about the benefits and risks of vaccines. The propagation of false rumors about oral poliovirus vaccine safety led to the reinfection of 13 previously polio-free countries and the largest polio epidemic in Africa in recent years. With deft management of such challenges by local, national, and international health authorities, poliomyelitis, a disease that threatened children everywhere just 2 generations ago, could soon be relegated to history like smallpox before it.

Africa↗
PubMed2004

The international response to the outbreak of SARS in 2003.

The sudden arrival of an internationally spreading outbreak of a newly identified infectious disease in early 2003, severe acute respiratory syndrome (SARS), provided an opportunity for a coordinated international response based on information and evidence obtained in real time through standard and electronic communications. Its containment represents a new way of working internationally, and demonstrates how intense collaboration in virology, clinical medicine and epidemiology can rapidly provide the information necessary to create and implement evidence-based control measures. The SARS outbreak serves as a reminder of the need for a strong national surveillance and response to infectious diseases, evidence-based international travel recommendations, and a global alert and response network to serve as a safety net when national surveillance fails.

Disease Outbreaks↗
PubMed2004

Smallpox containment updated: considerations for the 21st century.

The emergence and re-emergence of infectious diseases since the eradication of smallpox has had a direct impact on preparedness for a deliberately-caused smallpox outbreak, should one occur. The emergence of HIV has placed restrictions on the safe and effective use of smallpox vaccines and made the need for vaccinia immune globulin important for outbreak control. At the same time, the threat of international spread of emerging and re-emerging infections has prompted global investments in surveillance and response mechanisms such as the Global Outbreak Alert and Response Network (GOARN), a mechanism that would enhance the world's collaboration in smallpox containment as it did during the recent outbreak of SARS. Though global preparedness for a deliberately-caused smallpox outbreak has increased with the creation of GOARN, it does not replace the need for increased national public health investment to expand surge capacity for the management of patients and their contacts and to strengthen emergency communication networks to ensure effective response.

Bioterrorism↗