lies in the way these funds are allocated, as they are often disproportionately allocated to alleviating a single disease. labor shortages in its 2006 world health report, the who estimated a shortage of almost 4.3 million doctors, midwives, nurses, and support workers worldwide, especially in sub-saharan africa. a 2022 study estimated that, "in 2019, the world had 104.0 million (95% uncertainty interval 83.5–128.0) health workers, including 12.8 million (9.7–16.6) physicians, 29.8 million (23.3–37.7) nurses and midwives, 4.6 million (3.6–6.0) dentistry personnel, and 5.2 million (4.0–6.7) pharmaceutical personnel" and found that sub-saharan africa, south asia, and north africa and the middle east had the lowest densities of human resources for health. however, even when only considering current technologies and processes (such as only little use of telehealth as of 2022), overall numbers of personnel and shortages don't consider sub-national geographic distribution of various types of health workers (or expertise). global health security the covid-19 pandemic has highlighted how global health security is reliant on all countries around the world, including low- and middle-income countries, having strong health systems and at least a minimum of health research capacities. in an article 2020 in annals of global health, the essence group outlined a mechanism for review of investment in health research capacity building in low- and middle-income countries. the review mechanism will give funders of research for health the information to identify the gaps in the capacity that exist in low- and middle-income countries and the opportunity to work together to address those disparities. the overall goal is increased, coordinated support of research on national health priorities as well as improved pandemic preparedness in lmics, and, eventually, fewer countries with very limited health research capacity. global factors impacting health climate change this section is an excerpt from effects of climate change on human health. heat stroke treatment at baton rouge during 2016 louisiana floods. climate change is making heat waves more common, potentially leading to a higher risk of heat stroke. the effects of climate change on human health are increasingly well studied and quantified. they fall into three main categories: (i) direct effects (e.g. due to heat waves, extreme weather events), (ii) impacts from climate-related changes in ecological systems and relationships (e.g. crop yields, marine productivity), and (iii) the more indirect consequences such as impoverishment, displacement, and mental health problems. more specifically, the relationship between health and heat includes the following main aspects: exposure of vulnerable populations to heatwaves, heat-related mortality, reduced labour capacity for outdoor workers and impacts on mental health. there is a range of climate-sensitive infectious diseases which may increase in some regions, such as mosquito-borne diseases, cholera and some waterborne diseases. health is also acutely impacted by extreme weather events (floods, hurricanes, droughts, wildfires) through injuries, diseases, and air pollution in the case of wildfires. other indirect health impacts from climate change may be rising food insecurity, undernutrition and water insecurity. disadvantaged populations are especially vulnerable to climate change impacts.: 15 for example, young children and older people are the most vulnerable to extreme heat. the health effects of climate change are increasingly a matter of concern for the international public health policy community. already in 2009, a publication in the well-known general medical journal the lancet stated: "climate change is the biggest global health threat of the 21st century". this was re-iterated in 2015 by a statement of the world health organisation. in 2019, the australian medical association formally declared climate change a health emergency. studies have found that communication on climate change is more likely to lead to engagement by the public if it is framed as a health concern, rather than just as an environmental matter. a comprehensive annually scheduled study finds climate change is "undermining every dimension of global health monitored" and reports dire conclusions from tracking of impact indicators. the effects of climate change have also increased the risk of health conditions, such as lung disease or asthma which are caused by air pollution. these medical conditions are caused due to extreme heatwaves or by "higher concentrations of ground-level ozone". antimicrobial resistance this section is an excerpt from antimicrobial resistance. antibiotic resistance tests: bacteria are streaked on dishes with white disks, each impregnated with a different antibiotic. clear rings, such as those on the left, show that bacteria have not grown—indicating that these bacteria are not resistant. the bacteria on the right are fully resistant to three of seven and partially resistant to two of seven antibiotics tested. antimicrobial resistance (amr) occurs when microbes evolve mechanisms that protect them from the effects of antimicrobials (drugs used to treat infections). all classes of microbes can evolve resistance where the drugs are no longer effective. fungi evolve antifungal resistance. viruses evolve antiviral resistance. protozoa evolve antiprotozoal resistance, and bacteria evolve antibiotic resistance. together all of these come under the umbrella of antimicrobial resistance. microbes resistant to multiple antimicrobials are called multidrug resistant (mdr) and are sometimes referred to as a superbugs. although antimicrobial resistance is a naturally occurring process, it is often the result of improper usage of the drugs and management of the infections. antibiotic resistance is a major subset of amr, that applies specifically to bacteria that become resistant to antibiotics. resistance in bacteria can arise naturally by genetic mutation, or by one species acquiring resistance from another. resistance can appear spontaneously because of random mutations, but also arises through spreading of resistant genes through horizontal gene transfer. however, extended use of antibiotics appears to encourage selection for mutations which can render antibiotics ineffective. antifungal resistance is a subset of amr, that specifically applies to fungi that have become resistant to antifungals. resistance to antifungals can arise naturally, for example by genetic mutation or through aneuploidy. extended use of antifungals leads to development of antifungal resistance through various mechanisms. clinical conditions due to infections caused by microbes containing amr cause millions of deaths each year. in 2019 there were around 1,27 million deaths globally caused by bacterial amr. infections caused by resistant microbes are more difficult to treat, requiring higher doses of antimicrobial drugs, more expensive antibiotics, or alternative medications which may prove more toxic. these approaches may also cost more. the prevention of antibiotic misuse, which can lead to antibiotic resistance, includes taking antibiotics only when prescribed. narrow-spectrum antibiotics are preferred over broad-spectrum antibiotics when possible, as effectively and accurately targeting specific organisms is less likely to cause resistance, as well as side effects. for people who take these medications at home, education about proper use is essential. health care providers can minimize spread of resistant infections by use of proper sanitation and hygiene, including handwashing and disinfecting between patients, and should encourage the same of the patient, visitors, and family members. rising drug resistance is caused mainly by use of antimicrobials in humans and other animals, and spread of resistant strains between the two. growing resistance has also been linked to releasing inadequately treated effluents from the pharmaceutical industry, especially in countries where bulk drugs are manufactured. antibiotics increase selective pressure in bacterial populations, killing vulnerable bacteria; this increases the percentage of resistant bacteria which continue growing. even at very low levels of antibiotic, resistant bacteria can have a growth advantage and grow faster than vulnerable bacteria. similarly, the use of antifungals in agriculture increases selective pressure in fungal populations which triggers the emergence of antifungal resistance. as resistance to antimicrobials becomes more common there is greater need for alternative treatments. calls for new antimicrobial therapies have been issued, but there is very little development of new drugs which would lead to an improved research process. antimicrobial resistance is increasing globally due to increased prescription and dispensing of antibiotic drugs in developing countries. estimates are that 700,000 to several million deaths result per year and continues to pose a major public health threat worldwide. each year in the united states, at least 2.8 million people become infected with bacteria that are resistant to antibiotics and at least 35,000 people die and us$55 billion is spent on increased health care costs and lost productivity. according to world health organization (who) estimates, 350 million deaths could be caused by amr by 2050. by then, the yearly death toll will be 10 million, according to a united nations report. there are public calls for global collective action to address the threat that include proposals for international treaties on antimicrobial resistance. the burden of worldwide antibiotic resistance is not completely identified, but low-and middle- income countries with weaker healthcare systems are more affected, with mortality being the highest in sub-saharan africa. during the covid-19 pandemic, priorities changed with action against antimicrobial resistance slowing due to scientists and governments focusing more on sars-cov-2 research. at the same time the threat of amr has increased during the pandemic. amr has been described as a leading global health issue. globally, 1.27 million deaths in 2019 were attributable to amr. that year, amr may have contributed to 5 million deaths and one in five people who died due to amr were children under five years old. organization governmental or inter-governmental organizations focused on global health include: the united nations world health organization international agency for research on cancer (iarc) who centre for health development (wkc) united nations children's fund (unicef) world food programme (wfp) pan american health organization (paho) international committee of the red cross centers for disease control and prevention (cdc) the global fund to fight aids, tuberculosis and malaria non-governmental organizations focused on global health include: médecins sans frontières (doctors without borders, msf) bill & melinda gates foundation governments and analysis a study of select global health related organizations and initiatives suggests that major trends in global health governance appear to be "towards more discretionary funding and away from core or longer-term funding; towards defined multi-stakeholder governance and away from traditional government-centred representation and decision-making; and towards narrower mandates or problem-focused vertical initiatives and away from broader systemic goals." there is a growing willingness to use militaries in state-led support of global health efforts which have capabilities ranging from "research, surveillance, and medical expertise to rapidly deployable, large-scale assets for logistics, transportation, and security". global health security agenda the global health security agenda (ghsa) is "a multilateral, multi-sector effort that includes 60 participating countries and numerous private and public international organizations focused on building up worldwide health security capabilities toward meeting such threats" as the spread of infectious disease. on march 26–28, 2018, the ghsa held a high-level meeting in tbilisi, georgia, on biosurveillance of infectious disease threats, "which include such modern-day examples as hiv/aids, severe acute respiratory syndrome (sars), h1n1 influenza, multi-drug resistant tuberculosis — any emerging or reemerging disease that threatens human health and global economic stability." this event brought together ghsa partner countries, contributing countries of real-time surveillance action package, and international partner organizations supporting the strengthening of capacities to detect infectious disease threats within the real-time surveillance action package and other cross-cutting packages. ghsa works through four main mechanisms of member action, action packages, task forces and international cooperation. in 2015, the steering group of the ghsa agreed upon the implementation of their commitments through 11 action packages. action packages are a commitment by member countries and their partners to work collaboratively towards development and implementation of international health regulations (ihr). action packages are based on ghsa's aim to strengthen national and international capacity to prevent, detect, and respond to infectious disease threats. each action package consists of five-year targets, measures of progress, desired impacts, country commitments, and list of baseline assessments. the joint external evaluation process, derived as part of the ihr monitoring and evaluation framework is an assessment of a country's capacity for responding to public health threats. so far, g7 partners and eu have made a collective commitment to assist 76 countries whereas the us committed to helping 32 countries to achieve ghsa targets for ihr implementation. in september 2014, a pilot tool was developed to measure progress of the action packages and applied in countries (georgia, peru, uganda, portugal, the united kingdom, and ukraine) that volunteered to participate in an external assessment.