BRUCELLOSIS
د هديل فاضل فرهود
A systemic bacterial disease with acute or insidious onset, characterized by intermittent or irregular fever, headache, weakness, profuse sweating, chills, arthralgia, wt loss & generalized aching.
Localized suppurative infections of organs, including the liver & spleen may occur, subclinical disease has been reported & the disease may last for several days, months or occasionally a year or more if not adequately treated.
Osteoarticular complications are seen in 20-60% of cases, sacroilitis is the most frequent joint manifestation.
Genitourinary involvement is reported in 2-20 % of cases, with orchitis & epididymitis most common.
Recovery is usual but disability is often reported. The case fatality rate of untreated cases is 2% or less & usually result from endocarditis.
Laboratory diagnosis is made by isolation of the infectious agent from blood, BM or other tissues, or from discharges of the patients, also diagnosis by increase AB titer or tests measuring IgG AB may be useful in chronic cases.
@Infectious Agent:
Brucella abortus, brucella melitensis, brucella suis, & brucella canis
@Occurrence:
World wide, especially Mediterranean countries , middle east countries, India, central Asia & central & south America .
Brucellosis is predominantly an occupational ; disease of those working with infected animals or their tissues, especially farm workers , veterinarians & abattoirs workers, hence its more frequent among males.
@Reservoir: Cattle, swine, goats & sheep
Mode of transmission:
By contact with tissues, blood, urine, vaginal discharge , aborted fetus & especially placenta (through breaks in the skin), & by ingestion of raw milk& dairy products (unpasteurized cheese) from infected animals .
air borne infection of the animals occur in stables, & of humans in laboratories & abattoirs.
@Incubation period: usually 5-60 days , occasionally several months.
@Period of communicability: no evidence of communicability from person to person.
@Susceptibility & resistance:
Severity & duration of clinical illness are subject to wide variation. Duration of acquired immunity is uncertain
Methods of control:
A- preventive measures:
1- educate the public not to drink untreated milk or eat product made from unpasteurized or untreated milk . pasteurize milk & diary product from cows, sheep & goats. Boiling milk is effective when pasteurization is impossible.
2- educate farmer & workers in slaughterhouses, meat process plants & butchers shops as to the nature the disease & the risk in handling infected animals & to reduce exposure especially appropriate ventilation.
3- educate hunters to use barrier persuasions (gloves, clothing).
4- search for the infection among livestock by serological tests & ELISA or ring test of caws milk , eliminate infected animals by segregation & or slaughters. In areas of prevalence, immunize young goats & sheep with live attenuated Rev-1 strain of brucella melitensis & some times animals with strain 19, brucella abortus .
5- persons inoculated with strain 19 or Rev-1 vaccine be given doxycycline 100 mg twice daily combined with refampin 600-900 mg once daily for 21 days.
7- care in handling & disposable of placenta, discharge & fetus from aborted animal. Disinfect contaminated areas.
B- Control of patients, contact & the immediate environment:
1- obligatory case report to local health authority.
2- isolation draining & secretions precaution
3- concurrent disinfection : of purulent discharge
4- investigations of contact & source of infection: common or individual source, usually infected domestic goats, swine or cattle, or raw milk or dairy product from cows & goats
5- specific treatment: combination of refampin (600-900 mg daily) or streptomycine (1gm daily), & doxycycline 200 mg daily for at least 6 weeks is the treatment of the choice. .
C- Epidemic measures: search for common vehicle of infection, usually raw milk or milk product, especially cheese from infected herd. Recall incriminated product, stop production & distribution unless pasteurization is instituted.