Components of the Infectious Disease Process 1.1 Basics of Infectious Diseases Several terms in the main infectious diseases, namely: a. Pathogens are organisms or substances such as bacteria, viruses, or parasites that are capable of causing disease. b. Pathogenesis is the development, production or process of forming a disease c. Pathogenic is the cause or cause disease d. Pathogenicity is the potential ability or power of a pathogenic substance to cause disease. e. Virulence is the capacity and strength of a disease to cause severe and fatal disease f. Invasiveness is the capacity of a microorganism to enter and grow within or between the host's tissues g. The communicability (infectious power) of an organism depends on the host environment which is susceptible to inanimate objects (fomites). Diseases vary in severity, effect, duration, severity and extent. Based on these and other variables, diseases can be classified into three levels. 1. Acute: relatively severe, short duration and often treatable; Usually the sufferer will recover or die. 2. Chronic: not too severe, but the duration is long and continuous, ending over a long period of time and can last a lifetime. The patient may not recover as before and the disease may worsen at any time. Life may not be immediately threatened but the disease may persist over a long period of time. 1.2 Factors Causing Infectious Diseases There are several factors that play an important role in the course of infectious diseases, among others: a. Causal Factor (Agent) The causal agent of infectious disease is a biological source, which varies from the simplest viral particles to quite complex multi-cellular organisms that can cause disease in humans. Diseases can also be grouped based on their source or cause. The most common causes of infectious diseases are pathogenic organisms or organisms that cause disease. b. Source of Infection (Reservoir) Agant can stay inside because there is a reservoir. Reservoirs are a complex mechanism for maintaining species and helping them survive in the environment. Agents live in various media, animals and humans in a chain, and carry out their life cycle in these various media so that it is a mechanism to maintain their life. 1) Humans as a reservoir Humans as a reservoir are a very simple circle of disease, this form of transmission circle is a special form of various certain diseases where in general humans are the main subject. This disease generally moves from human to human and can only cause disease in humans. There are several types of carriers as follows: a) Active carrier , namely someone who is exposed to and becomes a nesting place for disease-causing organisms and this condition has been going on for some time even though they have recovered from the disease b) Convalescent carrier someone who is exposed to and becomes a nesting place for disease-causing organisms (pathogens) and is in the recovery period, but can still transmit the disease to other people. c) Healthy carrier is someone who is exposed to and becomes a nesting place for disease-causing organisms, but is not sick or does not show symptoms of illness. d) Incubator carrier is someone who is exposed and becomes a nesting place for diseasecausing organisms, who is still in the early stages of the disease or in the budding period and shows symptoms and the ability to transmit the disease. e) Intermittent carrier is someone who is exposed to and becomes a nesting place for disease-causing organisms and can repeatedly spread the disease. So humans are a reservoir for disease Infectious diseases can be divided into three main categories, namely: a) Reservoirs that generally appear as sufferers. b) Reservoir which can be either a patient or a carrier c) The reservoir is generally always a patient, but cannot transmit the disease directly to other potential hosts, but must go through a living intermediary such as a vector. 2) Reservoirs of animals or other objects If animals transmit diseases to humans, this is called zoonosis. Zoonotic diseases are diseases that are naturally found among vetebrate animals, which can also be transmitted to humans, even though the main reservoir is animals. c. Special Transmission Method (Mode Of Transmission) A transmission system is defined as a system that carries/ transports agents from one host to another host . The processes that take place sequentially are: 1) The agent must be able to leave the patient's/host's body. The place just now is called the portal of exit. The agent can come out with saliva, phlegm, tears, respiratory air, excretion from the sex glands, urine, feces, blood and so on. 2) Must be able to survive in the environment, until the agent can enter the transport medium or other host. 3) There must be a transport mechanism, which is usually carried out by insects (vectors) or by inanimate objects, or direct human contact between humans and humans or humans and animals. 4) There must be a place used by the agent to enter another host's body, called a portal of entry. The agent enters the host's body with the intention of multiplying or undergoing a change in the life cycle, so it is not intended to cause death, because the host dies, the agent also becomes extinct. After the element has left the reservoir, to get new potential, it must travel through a special travel circle or a special path called the transmission route from: a. Direct transmission Direct transmission is known as person-to-person transmission or direct transfer of a pathogen or agent from a host or reservoir to a host. prone to. Direct transmission can occur through direct physical contact or direct person-to-person contact. 1) Direct transmission from person to person. This group includes all diseases that can only attack humans where the only reservoir is humans. The largest group in direct transmission from person to person, are various venereal diseases that are transmitted sexually. 2) Direct transmission from animals to people Diseases that can be transmitted directly from animals to people in this group are diseases that are generally only found in animals but can bentransmitted and infect other people directly. Diseases in this group include mainly those belonging to the group of zoonotic diseases. 3) Transmission from plants to people This group includes diseases caused by fungi, which apart from being transmitted through direct contact with plants or soil containing fungi. b. Indirect transmission Indirect transmission occurs when pathogens or agents move or are carried through several items, organisms, objects or intermediary processes to a susceptible host, causing disease or other mechanisms that effectively spread disease-causing organisms are indirect means of transmission.