Disease burden in the context of "Immunization"

Neglected tropical diseases (NTDs) are a diverse group of tropical infections that are common in low-income populations in developing regions of Africa, Asia, and the Americas. They are caused by a variety of pathogens, such as viruses, bacteria, protozoa, and parasitic worms (helminths). These diseases are contrasted with the "big three" infectious diseases (HIV/AIDS, tuberculosis, and malaria), which generally receive greater treatment and research funding. In sub-Saharan Africa, the effect of neglected tropical diseases as a group is comparable to that of malaria and tuberculosis. NTD co-infection can also make HIV/AIDS and tuberculosis more deadly.

Some treatments for NTDs are relatively inexpensive. For example, praziquantel for schistosomiasis costs about US $0.20 per child per year. Nevertheless, in 2010 it was estimated that control of neglected diseases would require funding of between US$2 billion and $3 billion over the subsequent five to seven years. Some pharmaceutical companies have committed to donating all the drug therapies required, and mass drug administration efforts (for example, mass deworming) have been successful in several countries. While preventive measures are often more accessible in the developed world, they are not universally available in poorer areas.

WASH (or WatSan, WaSH; stemming from the first letters of "water, sanitation and hygiene") is a sector in development cooperation, or within local governments, that provides water, sanitation, and hygiene services to communities. The main purposes of providing access to WASH services are to achieve public health gains, implement the human right to water and sanitation, reduce the burden of collecting drinking water for women, and improve education and health outcomes at schools and healthcare facilities. Access to WASH services is an important component of water security. Universal, affordable, and sustainable access to WASH is a key issue within international development, and is the focus of the first two targets of Sustainable Development Goal 6 (SDG 6). Targets 6.1 and 6.2 aim for equitable and accessible water and sanitation for all. In 2017, it was estimated that 2.3 billion people live without basic sanitation facilities, and 844 million people live without access to safe and clean drinking water. The acronym WASH is used widely by non-governmental organizations and aid agencies in developing countries.

The WASH-attributable burden of disease and injuries has been studied in depth. Typical diseases and conditions associated with a lack of WASH include diarrhea, malnutrition, and stunting, in addition to neglected tropical diseases. There are additional health risks for women, for example, during pregnancy and birth, or in connection with menstrual hygiene management. Chronic diarrhea can have long-term negative effects on children in terms of both physical and cognitive development. Still, collecting precise scientific evidence regarding health outcomes that result from improved access to WASH is difficult due to a range of complicating factors. Scholars suggest a need for longer-term studies of technological efficiency, greater analysis of sanitation interventions, and studies of the combined effects of multiple interventions to better analyze WASH health outcomes.

The quality-adjusted life year (QALY) is a generic measure of disease burden, including both the quality and the quantity of life lived. It is used in economic evaluation to assess the value of medical interventions. One QALY equates to one year in perfect health. QALY scores range from 1 (perfect health) to 0 (dead). QALYs can be used to inform health insurance coverage determinations, treatment decisions, to evaluate programs, and to set priorities for future programs.

Critics argue that the QALY oversimplifies how actual patients would assess risks and outcomes, and that its use may restrict patients with disabilities from accessing treatment. Proponents of the measure acknowledge that the QALY has some shortcomings, but that its ability to quantify tradeoffs and opportunity costs from the patient, and societal perspective make it a critical tool for equitably allocating resources.

Climate change is influencing the transmission and burden of many infectious diseases worldwide. Rising temperatures, shifting rainfall patterns, and more frequent extreme weather events affect how pathogens, vectors and disease hosts interact. These changes are altering the geographic ranges and seasonal activity of disease-carrying organisms such as mosquitoes and ticks, and influence the growth and survival of bacteria and other pathogens in food and water systems.

Infectious diseases that are sensitive to climate can be grouped into: vector-borne diseases (transmitted via mosquitos, ticks etc.), waterborne diseases (transmitted through viruses or bacteria in water), and food-borne diseases (spread through pathogens in food). In 2022 scientists stated a clear observation that "the occurrence of climate-related food-borne and waterborne diseases has increased."

A disability-adjusted life year (DALY) is a measure of overall disease burden, representing a year lost due to ill-health, disability, or early death. It was developed in the 1990s as a way of comparing the overall health and life expectancy of different countries.

The concept has become more common in the field of public health and health impact assessment (HIA). It combines both potential years of life lost due to premature death (mortality) and to poor health or disability (morbidity) into a single metric.

Artificial induction of immunity is immunization achieved by human efforts in preventive healthcare, as opposed to (and augmenting) natural immunity as produced by organisms' immune systems. It makes people immune to specific diseases by means other than waiting for them to catch the disease. The purpose is to reduce the risk of death and suffering, that is, the disease burden, even when eradication of the disease is not possible. Vaccination is the chief type of such immunization, greatly reducing the burden of vaccine-preventable diseases.

Immunity against infections that can cause serious illness is beneficial. Founded on a germ theory of infectious diseases, as demonstrated by Louis Pasteur's discoveries, modern medicine has provided means for inducing immunity against a widening range of diseases to prevent the associated risks from the wild infections. It is hoped that further understanding of the molecular basis of immunity will translate to improved clinical practice in the future.

The Global Burden of Disease Study (GBD) is a comprehensive regional and global research program of disease burden that assesses mortality and disability from major diseases, injuries, and risk factors. GBD is a collaboration of over 12,000 researchers from more than 160 countries. Under principal investigator Christopher J.L. Murray, GBD is based in the Institute for Health Metrics and Evaluation (IHME) at the University of Washington and funded by the Bill and Melinda Gates Foundation.