Septicemia

Septicemia /viremia

Septicemia is the acute invasion of the systemic circulation by pathogenic bacteria accompanied by sepsis or septic shock (Toxemia) with possible bacterial localization invarious body systems or organs if the animal survives.
Septicemia is a common cause of morbidity and mortality in newborn farm animals which have not received a sufficient quantity of colostrums in the first 24 hours after birth.
Bacteremia
is different from septicemia in that bacteremia is not accompanied by sepsis or septic shock.
The difference between septicemia and bacteremia is one of degree.

In bacteremia, bacteria are present in the bloodstream for only transitory periods

and do not produce clinical signs; for example, a clinically unimportant
bacteremia probably occurs frequently after rectal examination or other
manipulations in which mucosa is disturbed.

In septicemia, the pathogen is present throughout the course of the disease and

is directly responsible for initiation of the disease process.

Viremia is the invasion of the systemic circulation by pathogenic viruses with localization in various body tissues and in which the lesions produced are characteristic of the specific virus.
* Many infections associated with rickettsias, protozoa and fungi are also spread hematogenously throughout the body but do not initiate a systemic inflammatory response syndrome.


ETIOLOGY:
Many different infectious agents can result in septicemia or viremia.
such as Anthrax, pasteurellosis , salmonellosis.

PATH OGEN ESIS:

Two mechanisms operate in septicemia:
The exotoxins or endotoxins produced by the infectious agents initiate a profound toxemia and high fever .
The clinical manifestations are the result of the effect of the pathogens on monocytes and lymphocytes, which initiate the systemic inflammatory response syndrome.
Localization of certain pathogens occurs in many organs and may produce
severe lesions in animals. The same general principles apply to a viremia, except that toxins are not produced by viruses. It is more likely that the clinical manifestations are the result of direct injury of the cells invaded by the virus.

CLINICAL FINDINGS:

The major clinical findings in septicemia are
fever.
cardiovascular dysfunction and shock.
submucosal and subepidermal hemorrhages that are usually petechial and occasionally ecchymotic.
The hemorrhages are best seen under the conjunctiva and in the mucosae of the mouth and vulva.
4-Tachycardia, tachypnea and shock-induced organ dysfunction with cardiovascular hypotension, myocardial asthenia and respiratory distress may occur in severe cases .
Specific signs may occur as the result of localization of the infection in joints,
heart valves, meninges, eyes or other organs.


CLINICAL PATHOLOGY:
Blood culture
Isolation of the causative bacteria from the bloodstream should be attempted by culture. Ideally. blood cultures should be obtained just before the onset of fever and from a major vein or any artery.
Hemogram
The presence of leukopenia or leukocytosis.
Plasma fibrinogen concentrations may be increased.
Serology Serological tests are available for most infectious diseases

TREATMENT

The principles of treatment included:
1-Broad-spectrum antimicrobialagents .
2-General supportive treatment.