Key Terms - Chap 27 Infectious and Communicable Diseases Key Terms

asplenia

Absence of the spleen, caused by congenital condition or surgery

bacterial endocarditis

Inflammation and bacterial infection of the endocardium and one or more heart valves; also known as infective endocarditis.

bacterial meningitis

A life-threatening illness that causes meningeal inflammation resulting from bacterial infection of the meninges.

body lice

Tiny parasites that concentrate around the waist, shoulders, axillae, and neck.

C diff colitis

Inflammation of the colon caused by colonization and infection with the bacterium Clostridioides difficile

chancre

A painless ulcer, particularly one developing on the genitals, as a result of a sexually transmitted infection. Most commonly, a chancre is formed during the primary stage of syphilis.

chemotactic factors

Biochemical mediators that are important in activating the inflammatory response.

chickenpox

An acute, highly contagious viral disease caused by a herpesvirus, varicella-zoster virus. It occurs primarily during childhood and is characterized by crops of pruritic vesicular eruptions on the skin. Also known as varicella. Airborne precautions are required to mitigate transmission.

Chikungunya virus

A viral illness spread by mosquitoes that causes fever and joint pain, which is often severe and debilitating.

chlamydia

A sexually transmitted infection caused by infection with the bacterium Chlamydia trachomatis that frequently causes sterility.

Clostridioides difficile

A bacterium that normally is present in small numbers in the intestines that may cause symptoms ranging from diarrhea to life-threatening inflammation of the colon when present in high numbers; formerly known as Clostridium difficile. Contact precautions required to mitigate transmission.

communicability period

A contagious stage of infection that begins when the latent period ends and continues as long as the agent is present and can spread to other hosts.

communicable disease

An illness caused by an infectious agent or its toxins that occurs through the direct or indirect transmission of the infectious agent or its products from an infected individual or via an animal, a vector, or the inanimate environment to a susceptible animal or human host

complement system

A group of proteins that coat bacteria. The proteins then either help kill the bacteria directly or assist neutrophils (in the blood) and macrophages (in the tissues) to engulf and destroy the bacteria.

congenital rubella syndrome

A serious disease that may affect infants born to women infected with rubella during the first trimester of pregnancy. It is associated with multiple congenital anomalies, intellectual disability, and an increased risk of death.

contact precautions 

Steps taken to avoid infection spread by contact with a patient or contaminated items in a patient’s room or surroundings. Such steps include wearing a gown and gloves while caring for a patient or while in the patient’s room/surroundings.

contagious disease

An infectious disease that can be transmitted from one person to another via direct or indirect contact.

coronavirus disease 2019 (COVID-19)

Respiratory infection caused by the SARS-CoV-2 virus, which is spread to others primarily though aerosols and small airborne droplets.

croup

A childhood infection of the upper airways (larynx, trachea, bronchial tubes) that causes a distinctive “seallike” barking cough. It is usually caused by a virus (most commonly parainfluenza) but rarely can be bacterial. Also known as laryngotracheobronchitis.

dengue fever

A mosquito-borne illness caused by dengue virus in tropical and subtropical areas. Symptoms include high fever, joint pain, and rash. Severe cases may result in hemorrhage and shock. Also known as breakbone fever.

designated infection control officer (DICO)

A person who serves as a liaison between the public safety agency and community health agencies involved in monitoring and responding to communicable diseases.

disease period

A stage of infection that follows the incubation period. Symptoms are displayed during this stage. The duration of this stage varies with the disease.

endemic 

An infectious disease outbreak that is generally localized to a specific area.

endotoxins

Chemicals in the cell wall of gramnegative bacteria that are released when the cell is destroyed, activating the inflammatory process

epidemic

A widespread occurrence of an infectious disease in a community at a particular time (eg, influenza in the winter).

epiglottitis

Inflammation of the epiglottis; a severe form of the condition that primarily affects children and is characterized by fever, sore throat, stridor, croupy cough, and an erythematous epiglottis. The Haemophilus influenzae type B vaccine has reduced incidence of this disease

eukaryotic

Containing a nucleus

external barriers

The surface of the body that is exposed to the environment, including the skin and the mucous membranes of the digestive, respiratory, and genitourinary tracts. The body’s first line of defense against infection

gonorrhea

A sexually transmitted infection that results from contact with the causative organism Neisseria gonorrhoeae.

hantavirus

A virus that is carried by rodents and spread to humans through inhalation of viral particles from dried body fluids (urine, saliva, feces) of rodents. Several strains can cause different forms of severe illness, such as hemorrhagic fever with  renal  syndrome and hantavirus pulmonary syndrome.

head lice

Tiny parasites that concentrate around the scalp (sometimes including the eyebrows and eyelashes).

hepatitis

Inflammation of the liver caused by viruses, trauma, toxins, autoimmune or metabolic disorders, genetic diseases, or fat deposits.

herpes simplex virus type 1 (HSV-1) 

An infection caused by the herpes simplex virus that tends to occur above the waist, particularly in the facial area, such as around the mouth and nose. It is the causative agent of cold sores.

herpes simplex virus type 2 (HSV-2) 

An infection caused by the herpes simplex virus that usually is limited to the genital region.

host 

The human, plant, or animal reservoir of an infectious agent

host susceptibility 

Factors of the host that contribute to prevention or continuation of infection.

human immunodeficiency virus (HIV)

The viral agent responsible for acquired immunodeficiency syndrome.

incubation period

The stage of infection during which an organism reproduces. It begins with invasion of the agent and ends when the disease process  begins. The host is asymptomatic during this period.

indigenous flora

Agents normally found on various sites of the body that could produce disease if allowed access to the interior of the body, especially in susceptible hosts.

infectious disease

Any illness caused by a pathogenic microorganism.

influenza 

A highly contagious infection of the respiratory tract transmitted by droplet spread. Researchers have identified three main types of the virus (types A, B, and C) in humans. A fourth, type D, is not yet known to cause illness in people.

internal barriers

Protection against germs provided by the inflammatory response and the immune response; the body’s second line of defense against infection.

latent period

A stage of infection that begins when a pathogenic agent invades the body and ends when the agent can be shed or communicated.

latent TB infection 

Tuberculosis that is not symptomatic or infectious (communicable). It must be treated to prevent active TB disease. Caused by Mycobacterium tuberculosis

malaria 

An infection spread by mosquitoes and caused by Plasmodium parasites. It results in fever, vomiting, headache.

meningitis 

Inflammation of the membranes (meninges) surrounding the brain and spinal cord; can be bacterial (such as from Neisseria meningitidis) or viral (aka aseptic meningitis).

meningococcal meningitis 

Meningitis caused by the bacterium Neisseria meningitidis; the deadliest form of meningitis, which is spread by respiratory droplets.

methicillin-resistant Staphylococcus aureus (MRSA)

A Staphylococcus infection that is resistant to multiple antibiotics. It is spread by person-to-person contact.

mpox

A viral infection causing fever, malaise, and a painful rash; formerly referred to as monkeypox.

mononucleosis

A viral infection causing fever, sore throat, and swollen lymph glands, especially in the neck.

mumps

An acute viral disease characterized by swelling of the parotid glands.

opportunistic infections 

Agents that are pathogenic (disease-causing) only in immunocompromised hosts (eg, HIV-infected patients, patients receiving chemotherapy, patients following transplantation).

pandemic 

An infectious disease outbreak that affects large numbers of people worldwide.

pathogen

A disease-causing agent.

pertussis

An acute, highly contagious respiratory disease caused by Bordetella pertussis characterized by paroxysmal coughing that often ends in a loud, whooping inspiration; also known as whooping cough.

pneumonia

An acute inflammation of the lungs caused by infection with bacteria, virus, or fungus.

poliomyelitis (polio)

A viral illness that can infect the central nervous system and may cause paralysis of limbs and respiratory muscles.

portal of entry 

portal of exit 

The means by which the pathogenic agent enters a new host.

The method by which a pathogenic agent leaves one host to invade another.

prokaryotic 

Not containing a nucleus, such that genetic material is free-floating.

pubic lice

Tiny parasites that concentrate in the pubic area

rabies 

An acute, usually fatal viral disease of the central nervous system of animals. It is transmitted from animals to humans by infected blood, tissue, or, most commonly, saliva from bites.

reservoir

Any person, animal, plant, soil, or substance in which an infectious agent normally lives and multiplies. It typically harbors the infectious agent without injury to itself and serves as a source from which other people can be infected.

respiratory syncytial virus (RSV) 

A viral infection of the lower respiratory tract that causes cold symptoms in most cases but can be severe with bronchiolitis. Premature babies and infants younger than 1 year are most at risk of severe infection.

reticuloendothelial system 

Part of the immune system composed of immune cells in the spleen, lymph nodes, liver, bone marrow, lungs, and intestines. It stores mature B and T cells until the immune system is activated.

rubella 

A contagious viral disease characterized by fever, symptoms of mild upper respiratory tract infection, lymph node enlargement, and a diffuse, fine, red maculopapular rash. It is spread by droplet nuclei. It results in congenital rubella syndrome in unborn babies of pregnant people infected with the disease. Also known as German measles.

rubeola (measles)

An acute, highly contagious viral disease involving the respiratory tract. It is characterized by a spreading, maculopapular, cutaneous rash and occurs primarily in young children who have not been immunized. Complications include pneumonia, encephalitis, neurologic damage, and death. In pregnant people, this disease can result in premature delivery and/or low birth weight of their unborn babies.

scabies

A contagious parasitic skin infestation characterized by superficial burrows and intense pruritus; caused by the mite Sarcoptes scabiei.

severe acute respiratory syndrome (SARS) 

An infection caused by coronavirus, which resulted in a pandemic in 2003 with high mortality rates.

sexually transmitted infection (STI) 

Any of a group of infections that are passed from one person to another through sexual contact.

sexually transmitted nonspecific urethritis 

A sexually transmitted infection characterized by inflammation or infection of the urethra in which the cause is not defined; also known as nongonococcal urethritis.

shingles 

An acute infection caused by reactivation of the latent varicella-zoster virus. It is characterized by painful vesicular eruptions that follow a dermatome from a spinal root. Also known as herpes zoster

syphilis

A sexually transmitted infection, caused by Treponema pallidum, characterized by distinct stages of effects over a period of years; may involve any organ system.

tabes dorsalis 

An abnormal condition characterized by the slow degeneration of nerve fibers in the dorsal spinal cord; results from untreated syphilis infection that has spread to the spinal cord. It results in a characteristic gait disturbance causing the patient to ambulate with legs wide apart.

tuberculosis (TB) 

A chronic granulomatous infection caused by Mycobacterium tuberculosis. It usually affects the lungs and generally is transmitted by airborne spread.

vancomycin-resistant enterococci (VRE) 

Bacteria that commonly live in the bowel and have become resistant to many antibiotics. Contact precautions are required.

viral meningitis 

Meningitis caused by viral infection (eg, enteroviral infection, herpesvirus infection, mumps, and, less commonly, influenza); also known as aseptic meningitis.

virulence 

The relative harmfulness or severity of a pathogen.

West Nile virus 

A virus spread by mosquitoes that can cause fever, headache, body aches, vomiting, diarrhea, and rash.

Zika

A viral infection acquired from the bite of an infected mosquito or through blood or sexual contact with an infected person. Zika can spread from a pregnant person to the fetus, which can result in microcephaly, severe brain malformations, and other birth defects.