Answer to Question #250983 in English for tee

Question

You have been shortlisted for a position of research officer and as part of an interview you are requested to produce a formal research proposal of the research project you intend to pursue if you are hired. 

Answer 1

The challenge of emerging and re-emerging infectious diseases

Introduction

Infectious diseases have for centuries ranked with wars and famine as major challenges to human progress and survival. They remain among the leading causes of death and disability worldwide. Against a constant background of established infections, epidemics of new and old infectious diseases periodically emerge, greatly magnifying the global burden of infections. Studies of these emerging infections reveal the evolutionary properties of pathogenic microorganisms and the dynamic relationships between microorganisms, their hosts and the environment.

Background

Emerging infections can be defined as “infections that have newly appeared in a population or have existed previously but are rapidly increasing in incidence or geographic range”. Emerging Infections have shaped the course of human history and have caused incalculable misery and death. In 1981, a new disease, Acquired Immune Deficiency Syndrome (AIDS), was first recognized. As a global killer, AIDS now threatens to surpass the Black Death of the fourteenth century and the 1918–1920 influenza pandemic, each of which killed at least 50 million people.

Problem Statement

We examine the nature and scope of emerging and re-emerging microbial threats, and consider methods for their control. We emphasize that emergence results from dynamic interactions between rapidly evolving infectious agents and changes in the environment and in host behavior that provide such agents with favorable new ecological niches.

Literature Review

The classification of Emerging Infections as ‘newly emerging’, ‘re-emerging/resurging’ or ‘deliberately emerging’ is useful because the underlying causes of emergence and the optimal prevention or control responses frequently differ between the groups. Newly emerging infections are those that have not previously been recognized in man. Many diverse factors contribute to their emergences; these include microbial genetic mutation and viral genetic recombination or reassortment, changes in populations of reservoir hosts or intermediate insect vectors, microbial switching from animal to human hosts, human behavioral changes (notably human movement and urbanization), and environmental factors. These numerous microbial, host and environmental factors interact to create opportunities for infectious agents to evolve into new ecological niches, reach and adapt to new hosts, and spread more easily between them.

• Tuberculosis

Tuberculosis is one of the most deadly re-emerging diseases. The discovery of isoniazid and other drugs initially led to effective tuberculosis cures, empty sanitoria and the dismantling of public health control systems in developed nations. Consequently, by the 1980s, when tuberculosis had re-emerged in the era of HIV/AIDS, local and state health departments in the United States lacked field, laboratory and clinical staff and so had to reinvent tuberculosis-control programmes. The remarkable re-emergence of tuberculosis was fueled by the immune deficiencies of people with AIDS, which greatly increases the risk of latent Mycobacterium tuberculosis infections progressing to active disease, and being transmitted to others. Inadequate courses of anti-tuberculosis therapy compound the problem, leading to the emergence and spread of drug-resistant and multidrug-resistant strains, and a need for more expensive treatment strategies such as directly observed therapy.

• Malaria

Plasmodium falciparum malaria was neglected for several decades, but is now among the most important re-emerging diseases worldwide. Years of effective use of dichlorodiphenyltrichloroethane (DDT) led to the abandonment of other mosquito-control programmes, but the insecticide fell into disuse because of mosquito resistance and concerns about the insecticide's potentially harmful effects on humans and wildlife. Consequently, malaria has re-emerged, and the situation has been worsened by the development of drug resistance to chloroquine and mefloquine. Research efforts focus on the development of vaccines and new drugs, and on re-establishing public health measures such as the use of bed nets.

References

1. Morse, S. S. Factors in the emergence of infectious diseases. Emerg. Infect. Dis. 1, 7–15 (1995)
2. Kohn, G. C. in The Wordsworth Encyclopedia of Plague and Pestilence (ed. Kohn, G. C.) 25–26 (Facts on File, New York, 1995).