Immunizationis an effective means of controlling the spread of communica-
ble diseases by the use of safe vaccines. A vaccine is a preparation of killed, atten-
uated, inactivated, or fully virulent organisms that are administered to induce or
produce artificially acquired active immunity.
Vector controlis a good way of controlling the spread of infectious disease
when the vector, such as rodents or insects, is identified. This vector’s habitats
and breeding grounds can be treated with insecticides and poisons. Also, barri-
ers such as window screens, netting, and repellents can provide protection against
bites and infection.Nosocomial Infections
A nosocomial infection is an infection that is the result of a pathogen that was
acquired in a hospital or clinical care facility. Nosocomial is derived from the
Latin word nosocomium, which means “hospital.” These are the diseases that a
patient can obtain when he or she is being cared for in a hopital. These diseases
can also affect the caregivers, such as the hospital staff, nurses, doctors, aides, and
even visitors or anyone else who has contact with a hospital or medical facility.
The Centers for Disease Control and Prevention estimate that among the
patients that are admitted to hospitals, 5 to 15 percent acquire some type of noso-
comial infection. Nosocomial infections result directly in over 20,000 deaths
and indirectly in about 60,000 deaths.
Nosocomial disease-causing pathogens come from either endogenous or
exogenous sources. Endogenousinfections are caused by pathogens that were
brought into the hospital by the patient; the opportunistic pathogen is among the
patient’s own microbiota.
Exogenousinfections are caused by organisms that enter the patient’s body
from the external environment. These organisms can be acquired from animate
sources, such as hospital staff, other patients, or people visiting the hospital.
Organisms can also come from inanimate sources, like hospital equipment,
intravenous and respiratory therapy equipment, catheters, computer keyboards,
bathroom fixtures, doorknobs, soaps, and even certain disinfectants.Who Is Susceptible?
Aperson who is susceptible to a nosocomial infection is one who has a com-
promised immune system. Compared to the general public, patients in hospitals(^206) CHAPTER 13 Epidemiology and Disease