Control and elimination of infectious diseases

spectrum of disease control
Because of their specific epidemic, characteristics and different external environment, various infectious diseases have great differences in their prevention goals. At present, most infectious diseases can only aim at controlling the incidence and prevention of epidemics. Very few diseases are effective because they are mature and can meet the elimination requirements. Very few diseases can achieve the goal of elimination under the premise of mature conditions and the concerted efforts of all countries in the world. The prevention of infectious diseases, from control to elimination to elimination of the differences in disease prevention strategies and measures, is called the spectrum of disease control. In order to prevent diseases and promote human health, people expect to gradually control the diseases that are currently difficult to control, and on this basis, they can move toward elimination, and finally achieve the goal of elimination. This process is not only a beautiful ideal of mankind, but also an extremely arduous process. To achieve this goal depends on scientific progress, including the progress of epidemiology and the preparation of relevant conditions.

Control and elimination of infectious diseases

Control refers to reducing the incidence and/or prevalence of the disease. Some diseases have obvious control effects. Once the countermeasures and measures are implemented, the incidence rate drops significantly, such as polio vaccine against polio, measles vaccine against measles, and improved drinking water supply for chronic water-type typhoid fever. There are also some diseases or due to the complex environment, or there are still no effective countermeasures and measures at this stage, so even if measures are taken, the effect is not obvious. There are still many diseases that fall into this category.



Elimination refers to the adoption of effective prevention strategies and measures within a region to make certain infectious diseases disappear. The region can range from one country to one continent, but not globally. From a preventive point of view, the elimination of disease is far less stringent in quality requirements than elimination. For example, in 1989, WHO announced the global elimination of neonatal tetanus in 1995. It only requires that neonatal tetanus patients will no longer appear, but it is not required to completely eliminate tetanus spores in the external environment. In another example, the United States proposed in 1978 to "eliminate local measles." The so-called "native measles" refers to measles that occur only in the United States, and does not include measles introduced from abroad. Even so, the US local measles has not yet been eliminated. However, the incidence of measles in the United States has indeed decreased significantly.

Eradication means that the spread of an infectious disease is terminated forever from the date of extinction, and it will never happen in all countries of the world. Elimination of not only cases of clinical symptoms, but also carriers or latent infections that are sources of infection and pathogens that are present in the external environment, in addition to the need to vaccinate or take any other Preventive measures will never be harmed by the disease. Only under such conditions can the infection be considered to have been eliminated. Only one species of smallpox is currently reached. It can be seen that the requirements for elimination are more stringent than the requirements for elimination.

Some people confuse the elimination of the two terms, and often eliminate it as a synonym for elimination. Strictly speaking, the concept of terminology is wrong.

Choose the basic principle of eradicating disease
Eliminating disease is a good will for humans to fight disease, but it is impossible to treat any disease as a target of destruction. How can I choose a disease as the target of disease elimination? First of all, the disease is scientifically feasible to eliminate; secondly, the state has the intention to eliminate the disease and the corresponding measures; third, the public has a strong awareness of the disease, and actively support or participate in the disease plan. These three principles are interrelated and the three are indispensable.

The so-called scientific feasibility of disease elimination, in short, must grasp the epidemic weak link of the disease on the basis of understanding the occurrence and prevalence of the disease, and "organize and multiply" in the fight against it. For example, some infectious diseases are confined to humans, without animal hosts with pathogens, and without asymptomatic pathogen carriers; others have both human infections, animal hosts, and even pathogen carriers. . Compared with the two, it is obvious that the former is easier to fight against the disease, and the latter is more difficult. That is to say, the former has weak links in epidemiology, which can be multiplied and easier to eliminate. The latter is still "invulnerable" and "no gaps can be multiplied."

Whether the state has an intention to eliminate the disease depends mainly on the government's understanding of the dangers of the disease, the expected cost of eliminating the disease, and the possible financial, material, human input and the estimation of the benefits after the disease is eliminated.
Whether the masses support the elimination of the disease is related to the degree of harm the population suffers from the disease, self-care awareness, culture and health, and quality of life. In addition, the degree of harm to the disease is also very effective in evoking the public's awareness of disease elimination.

The scientific feasibility of eradicating disease is a long-term experience in the struggle of humans and diseases. Especially after the great achievement of global eradication of smallpox in 1977, it is more recognized that only in strengthening epidemiology and related disciplines In the study of diseases, after effectively grasping the epidemic law of the disease, effective measures of control and elimination, people can grasp the weak links of the disease and take effective measures to achieve better disease-killing effects.