Global challenges Study Guide

Diseases are conditions that impair the normal functioning of an organism. They can be broadly categorised into two main types: communicable and non-communicable diseases. Communicable diseases, also known as infectious diseases, are caused by pathogens (like bacteria, viruses, fungi, or protists) and can be spread from person to person, from animals to humans, or even through contaminated food, water, or objects. Examples include influenza, measles, and tuberculosis. Their spread often involves direct contact, airborne transmission, or vectors. In contrast, non-communicable diseases (NCDs), also known as non-infectious diseases, are not caused by pathogens and cannot be spread from one individual to another. These diseases typically develop over a long period and are influenced by a combination of genetic factors, lifestyle choices (such as diet, exercise, and smoking), and environmental factors. Examples of NCDs include heart disease, diabetes, cancer, and asthma. Understanding the distinctions between these disease types is crucial for public health, including prevention strategies, treatment approaches, and controlling their global impact. Public health efforts often focus on hygiene and vaccination for communicable diseases, while NCDs are addressed through health education, promoting healthy lifestyles, and early detection programmes.

Gene technology involves altering an organism's genes, the fundamental units of heredity, to treat or prevent diseases. This powerful tool offers significant potential in medicine, but also carries inherent risks that must be carefully considered. One major benefit is the ability to produce therapeutic proteins like insulin for diabetics or growth hormone for developmental deficiencies. By inserting the human gene for these proteins into bacteria, large quantities can be manufactured safely and affordably. Another benefit is gene therapy, where faulty genes causing genetic diseases are replaced or repaired with healthy ones. This could potentially cure previously untreatable conditions like cystic fibrosis or certain muscular dystrophies. Furthermore, gene technology can be used to develop more effective vaccines and diagnostic tools, improving disease prevention and early detection. However, there are significant risks. Ethical concerns arise regarding 'designer babies' and the potential for altering human traits beyond treating serious diseases. There's also the risk of unintended consequences; for instance, inserting a gene might disrupt other vital genes, leading to new health problems. The long-term effects of gene therapy are not fully understood, and there's a possibility of immune reactions to the introduced genes or viral vectors used to deliver them. The technology is also expensive and not universally accessible, raising equity concerns. Finally, there are potential environmental risks if genetically modified organisms were to escape control, although this is less of a direct concern in medical applications focused on human patients. Balancing these potential benefits against the risks is crucial for the responsible development and application of gene technology in healthcare.