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Infectious diseases: what does it mean?Infectious DiseasesSeveral epidemics of infectious diseases are raging in the world at any given time. Today, the best-known epidemic is HIV/AIDS. Over 42 million people are HIV positive, including 5 million who contracted the virus in 2002. Nearly 3.1 million died of AIDS (the total number of AIDS victims reached 21.8 million by the year 2003, including about 4 million children). Tuberculosis kills from 2 to 3 million every year. About 5 million contract malaria and 2.7 million die of it. Some diseases, such as flu, are usually qualified as less dangerous, but they are taking a huge toll. Flu viruses mutate into dangerous-for-humans forms every 40 years. At present, mankind encounters both old and new infections. Their dissemination is fueled by social factors, such as migration, poor living conditions and civic riots; customs and diet of different nations; specific qualities of microorganisms, such as a change in virulence and toxin-producing ability and resistance. Other factors include the activity of health care systems, development of new medical devices and massive application of immunodepressants and antibiotics. The deteriorating performance of sanitary and epidemiological inspection - less attention to infectious diseases, curtailment of preventive programs and inadequate monitoring of patients - also plays an important role. With the exception of AIDS, the majority of new diseases, which appeared in the last two decades, did not pose serious danger for the entire humanity. It is possible to limit the spread of many ailments, such as flu, by preventing its transfer from man to man. Other diseases, such as Creutzfeldt-Jacob disease or BSE, commonly known as mad cow disease, are generated by the virus in food products and may be limited by the introduction of new sanitary standards. Still other diseases, such as West Nile fever, do not cause a high mortality rate, and usually hit people from high-risk groups. Epidemics like Ebola fever and Congo-Crimean fever are limited geographically and pose no threat to the rest of the world. Despite the development of health care systems and the appearance of better medicines and testing equipment, more and more people will contract diseases in the near future, but fewer will die of them. The World Health Organization (WHO) compiled the following list of the most deadly diseases: respiratory diseases (including flu and pneumonia), HIV/AIDS, digestive ailments, TB, malaria, measles and hepatitis B and C. Most infections develop into epidemics in case of an armed conflict or economic hardships in this or other country. Refugees become the main victim of infections. People cross borders and spread them to other countries. Military personnel, taking part in hostilities in foreign countries, disseminate diseases as well. Every day two million people cross state borders, which is conducive to an almost instantaneous spread of epidemics. There is an opinion that a reduction in the world air traffic after September 11 substantially slowed down the transmission of the flu epidemic. Many viruses of dangerous diseases travel to other countries in food imports. Moreover, new viruses are becoming increasingly resistant to the current antibiotics, and it is more and more difficult to fight them. Gradual change of the climate - the global warming - has a negative effect on the health of mankind. It helps malaria conquer more territory in Asia and Africa. In the 1970s, America almost stamped out the deadly Dengue fever, transmitted by mosquitoes. In 2001, scientists detected mosquitoes spreading this fever in 12 Latin American countries. Despite all measures to curb the epidemic, mosquitoes "seized" the whole of South and Central America and part of U.S. territory. Every year about 600,000 people contract this deadly fever. Mosquitoes penetrate passenger planes. Dengue cases were registered in Africa, Australia and Europe. In the last three decades we have seen the emergence of new infectious diseases, the recurrence of the old ones, and their increasing resistance to major antibiotics. Recent outbreaks of poliomyelitis threaten to neutralize success in an all but complete eradication of this disease, an outstanding achievement of the 20th century. This trend attests to a sharp decline in the medical potential at both local and global levels. International response to HIV/AIDS was incredibly slow. Up to this day, the shortage of funds in dealing with this problem is truly scandalous. The world community made its first global initiative on HIV/AIDS only in 1987 by adopting the Global AIDS Program (GAP), that is, six years after first HIV cases were registered, and millions of people were infected all over the world. Nine years later, when the number of HIV positive people reached 25 million, the UN launched UNAIDS to coordinate the efforts of UN institutions in combating the epidemic. By the year 2000, when the Security Council discussed the HIV/AIDS problem as a threat to international peace and security, the annual number of its African victims surpassed the human losses in all civil wars in the 1990s. By 2003, when the Global Fund to Fight AIDS, Tuberculosis and Malaria was set up, there were over 11 million orphans in Africa whose parents died of HIV/AIDS. Progress in combating other deadly diseases is not very impressive. The global fight against TB has produced some improvements, such as political commitment to the effort, funding, strategy, access to medicines, and research. However, more than 8.5 million new TB cases are registered and more than two million die of it every year. In the WHO estimate, if the current trend persists, the number of TB-positive people will go up by almost a billion by the year 2020, 150 million will reveal TB symptoms, and 36 million will die of the disease. A big problem is making medicines more accessible to patients, and not only to the TB-positive. Healthcare problems have not been initially included into the G8 agenda, but have gradually become central to the discussion at the forum, especially in the context of development goals. Until 1986, all healthcare statements of the Group were very brief and did not go beyond the effort to help the developing nations combat hunger and malnutrition. However, in 1987 the presidency published a statement that became the first major address to healthcare in the forum's final documents. In the 1990s, the G8 was increasingly laying emphasis on the need to solve the basic social problems in order to reduce the scale of poverty. In the new millennium the G8 has been paying more attention to medical issues, adopting bolder plans and bigger financial commitments to support the efforts aimed at implementing the millennium development goals in this sphere. African health problems rank high at G8 summits. In the last few years, the issue of help to the starving, which was not raised in the final statements for a long time, has again reappeared there, but this time as part of healthcare. Medical issues are also discussed in conjunction with other questions, such as safety of foods, biotechnology, ageing, and change in social demography. Many final papers of international, government and non-government organizations stress that global healthcare crises can only be overcome by concerted effort. In the last few decades, control of infectious diseases was on the agenda of major international health forums. The first conference took place in Ottawa in 1986 and the latest one in Bangkok in 2005. The WHO and other world organizations are attracting public attention to infectious diseases and coordinating efforts in fighting them. In this context strategy aims at improving monitoring, intensifying research, upgrading methods of preventing and treating infectious diseases, and developing the infrastructure. The WHO has played the first fiddle in controlling infectious diseases. This task is facilitated by the Global Outbreak Alert & Response Network (GOARN) set up in 2000, which unites volunteer public healthcare units and research establishments from more than 100 countries. The WHO continues to monitor the development of infectious diseases and alert the world to the need to take action whenever necessary. It shares its experience and knowledge and organizes protection of the population against the aftermath of epidemics. Global healthcare programs must be re-oriented from the currently prevailing crisis-fighting principles of organization to long-term strategic approaches to planning and implementation. The effectiveness of fighting specific diseases has led to the dominance of the crisis-fighting ideology, and more funds have been justifiably channeled into this task. Infectious disease control is complicated by the fact that epidemics of infection usually break out in developing countries, which are already suffering from lack of different resources. In the meantime, preventive measures should be primarily aimed at marginal groups, who are more susceptible to infectious diseases. These include people with high-risk behavior, homeless, inmates, migrants, and refugees. They account for the majority of TB, HIV/AIDS, and STD cases. Access to high-risk groups and their willingness to cooperate determine the effectiveness of the effort to help them. This approach conforms to the strategy of universal access to medical aid. Moreover, it is a condition of success in epidemic control, considering that these high-risk groups are quite often the driving force of the disease. The funding and planning of measures to counter infectious diseases are based on authentic epidemiological information, which facilitates effective and thrifty use of financial and human resources. The problem of monitoring of infectious diseases deserves particular attention in this context. In medicine and public healthcare monitoring is a comprehensive notion, which primarily stipulates epidemiological surveillance of infections. Experts in many countries believe that one of the tasks of the medical community is to upgrade national and global systems of epidemiological surveillance. Some Highly Contagious Diseases Avian flu is a high contagious virus infection, which may affect all types of birds. Among domesticated poultry, turkeys and chickens are the hardest hit. Owing to their natural resistance, wild birds may transmit infection without getting sick and may cover large distances. Waterfowl are a natural carrier of the avian flu virus. The avian flu virus belongs to Type A. There exist several subtypes of the pathogen, which are determined by antigenic structure. There are 15 subtypes of hemagglutinin (H1-H15) and nine subtypes of neuraminidase (N-N9), which may exist in different combinations. Four of them (H3N8, H1N1, H2N2, H3N2) caused flu pandemics among humans in the 20th century, while others cause illness in mammals and birds. The worst viruses for the poultry are H7N7 (the chicken plaque virus) and H5N1, which may kill all chicken without exception. Highly pathogenic versions of H7N7 caused huge damage to all chicken farms in the Netherlands in 2003, while H5N1 versions have killed millions of chicken in South East Asia since 1997. Another feature of highly pathogenic bird flu strains is their ability to infect people who come into direct contacts with sick birds or their organs. According to available reports, highly pathogenic H5N1 strains (isolates of 2004) have further mutated compared to the viruses of 1997-2003. These mutations have changed their antigenic properties. The majority of isolated strains have shown resistance to remantadine. For this reason oseltamivir, the virus neuraminidase inhibitor, is the only drug which can protect from avian flu high-risk groups, those who contact with birds, and especially those who destroy the infected species. It was believed until recently that bird flu viruses are not dangerous for humans and that all they could cause were fleeting symptoms of conjunctivitis, slight discomfort, and at worst, a weak respiratory syndrome. This opinion was proved wrong in 1997, when A viruses (H5N1) caused extremely grave forms of disease among people in Hong Kong, killing one third of those infected. Fast culling of all chicken in the region prevented further infections. However, five years later, in 2003, two members of the family, traveling in China, got infected with the avian flu virus. The head of the family died. One more child died when the family was on Chinese territory, but of unknown causes. In the estimate of the World Health Organization (WHO), 161 people were infected with the bird flu virus and 86 died of it in the period from 2003 to this time. In the World Bank data, two consecutive avian flu waves have done enormous economic damage to South East Asia since 2003 - 140 million birds were eradicated, which cost poultry farms $10 billion. The Vietnamese economy alone sustained about $140 million worth of damage. During 2005 avian flu spread over the territory of Russia, Mongolia, Kazakhstan, Ukraine, Romania, Turkey, and Croatia. These facts reveal a change in the biological properties of bird viruses - they have become more pathogenic both for birds and humans. Cases of infection with H5N1 and H9N2 were registered in China in the last few years, but the clinical picture was rather mild with no deaths. To sum up, as a result of mutations in the last seven years, H5N1 and H7N7 strains have drastically changed their biological properties and acquired a capacity not only to infect humans directly, bypassing the intermediary host, but also to cause very grave conditions with a high mortality rate. One of the most alarming aspects of recent avian flu outbreaks is that some viruses (H5N1, H7N3, H7N2, H10N7, H7N7, H9N2) can infect people bypassing "intermediary hosts." In other words, humans may simultaneously catch both human and avian viruses with the ensuing emergence of reassortants that harbor a combination of external avian and internal human genes, which may produce a new human-to-human pandemic virus. In response to the threat of a new flu pandemic the World Health Organization (WHO) has taken steps to enhance the awareness of its members of the problem and elaborate a number of specific documents, for instance, the Global Influenza Preparedness Plan. In recent time measures to counter a possible flu pandemic are being increasingly discussed by different international organizations and partnerships. Nevertheless, in the past most initiatives were of local rather than global nature, and did not fuel universal concern or generate collective financial and institutional measures. HIV/AIDS - prejudices the development of mankind. The global HIV/AIDS (Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome) epidemic is a major problem facing our generation. In fact, this is a worldwide emergency situation posing an unprecedented threat to mankind's development. What we need is sustained long-term efforts and commitment for coping with this situation. The HIV/AIDS crisis continues to get worse in Africa, while new epidemics are engulfing Asia and Eastern Europe at an alarming rate. Not a single region of the world remains unaffected. Although there exists an urgent need for additional resources and commitment, the report mentions some successful results that were attained by groups of people having HIV/AIDS, governments, non-governmental organizations and religious leaders. The HIV/AIDS epidemic began more than twenty years ago. Moreover, the world will have to tackle this problem for many decades. But we can achieve changes, we can prevent new HIV/AIDS cases, and we can provide better care and treatment for people having HIV/AIDS. This is the most important lesson that has been learned by us. Our most important task is as follows: we must popularize outstanding examples of leadership being described in this report. A massive mobilization involving all sectors of society remains our only weapon when treatment is impossible. The HIV/AIDS epidemic is a special kind of crisis. We must simultaneously treat this epidemic as an emergency situation and as a long-term problem for development. Consequently, we would not miss specific opportunities for effectively countering this epidemic. This means that we must not be tempted to accept HIV/AIDS as yet another unavoidable global problem. The HIV/AIDS epidemic is something exceptional, requiring exceptional flexible, creative, energetic and vigilant response measures. The HIV/AIDS epidemic is a unique occurrence in the history of mankind because of the speed of its spread, scale, and profound consequences. The first case of HIV/AIDS was diagnosed in 1981. The world has been exerting tremendous efforts in order to comprehend its colossal scale since that time. Initial efforts aiming to implement effective response measures were scattered, uncoordinated and woefully underfinanced. Few communities were able to predict danger well in advance and to organize effective response measures. The HIV/AIDS epidemic has claimed 20 million lives now, more than 20 years after. An estimated 34.6 million to 42.3 million people all over the world live with HIV/AIDS. Nevertheless, HIV/AIDS continues its relentless advance, wrecking human lives and seriously damaging society's infrastructure in many cases. However, experience shows that the epidemic's natural course can be changed by a correct combination of leadership and comprehensive actions. We have scored serious successes in our twenty-year fight against HIV/AIDS. Although no HIV/AIDS medication exists, we have analyzed serious lessons as regards the best approaches in this sphere. We already know that a comprehensive approach to preventive treatment yields the best results. Resolute national leadership, efforts to keep society informed and intensive preventive measures have enabled entire countries to reduce the level of HIV/AIDS infection. Speaking of Africa, Uganda remains an excellent example of sustained success. Comprehensive measures in Thailand made it possible to prevent about five million new cases of the HIV/AIDS infection in Asia throughout the 1990s. Cambodia also managed to curb this epidemic. Cities, regions or states on all continents have proved able to curb the epidemic through coordinated efforts. At the same time, we have received anti-retroviral (ARV) preparations making it possible to prolong the life of HIV/AIDS victims and to reduce this infection's physical impact. Coordinated national and international efforts have made it possible to reduce the prices of such medications in low-income and average-income countries and to provide vitally important ARV therapy to people having HIV/AIDS all over the world. Available statistics prove that relatively new East Asian, Central Asian and Eastern European epidemics are spreading rather quickly. Even though there exists ample evidence that AIDS is everywhere, many people still want to believe that AIDS is not their problem. In this situation preventive programs are often unavailable to stigmatized and underprivileged individuals, such as injecting drug users and homosexuals. Moreover, their medical support requirements are being regularly ignored in some countries. Tuberculosis Tuberculosis (TB) is a sufficiently widespread and highly contagious disease. One person contracts TB all over the world each second. On the whole, one third of the global population now suffers from TB. This disease mostly plagues countries with emerging economies because a considerable part of their population lives below the official poverty line. The risk group also includes prison inmates, migrants and refugees. One can say that the HIV/AIDS and TB epidemics fuel each other because HIV-positive individuals often contract TB as a secondary infection. The world lacked any effective TB medication about fifty years ago. At the same time, highly effective preparations in this category have created another problem. Incomplete and poorly controlled treatment leads to the appearance of stable TB stains requiring extremely expensive medications for long time periods. This problem faces poor and developing countries, as well as the industrial world. The medical community used to search for highly effective TB-control measures over the decades. The so-called Directly Observed Treatment (DOT) therapy, which was introduced in 1991, is the most effective treatment method. This method stipulates microscopic expectoration tests making it possible to register new TB cases at an early stage. Patients subsequently take several medications under the guidance of medical workers, public health specialists or trained volunteers. This cost-effective strategy has already helped 17 million patients, including those in the developing and poor countries. |
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