Brucellosis

M.Karimi

Etiology• Brucella:

Abortus(Cattle),Melitensis (Sheep,Goat)Suis(Swin),Canis(Dog)

• G- Coccobacil• Aerobic, Non-spore

forming• Non motile• Blood or Choclate agar

Epidemiology

• Unpasteurized milk• Occupational events

Pathogenesis• Inoculation in skin ,Eye (Through abrasion or

conjunctiva)• Inhalation (Infected aerosol)• Ingestion (Meat, Dairy products)

Risk of infection depends1. Nutritional status2. Immune status3. Rout of inoculum4. Species of brucella

Pathogenesis• Survive& Replicate within phagocytes&Monocytes• Infected macrophages localized within reticuloendothelial

system(Granuloma formation in spleen,liver,bone marrow)

Clinical manifestationTriad: Fever, Arthralgia/Arthritis,Hepatosplenomegaly

• + History of animal or food exposure

• Acute or insidious symptoms(2-4 wk after inoculation)

• Refusal to eat• Refusal to bear weight• Lassitude• FTT• Headache• Inattention/Depression

• Abdominal pain• Headache• Diarrhea• Rash• Night sweets• Weakness• Fatigue• Cough• Vomiting• Pharyngitis

• Fever• Hepatosplenomegally• Arthralgia/Arthritis Sacroiliac,Hip,Ankle,

Diagnosis

• WBC Normal or low• + History of animal or food exposure• Recovering organisms (blood’ bone

marrow’..)• Serum agglutination test: >1/160(Antibody against Abortus ,Melitensis, Suis, but not Canis)• 2ME

• False positive SATYersinia entrocoliticaVibrio choleraeFrancislla tularensis

• False negative SAT

Prozen effect

Differential diagnosis

• Car-Scratch disease• Typhoid fever• TB• Fungal infections

Treatment> or = 9 years old

• 1-Doxycycline 200 mg/D PO 6 WK

+Streptomycin 1 g/D IM 1-2 WK

ORGentamycin 3-5 mg/kg/d IM/IV 1-2 WK

--------------------------------------------------• 2-Doxycycline 200 mg/D PO 6 WK

+Rifampin 600-900 mg/D PO 6 WK

< 9 years old

TMP-SMZ: po 45 days (TMP 10 mg/Kg/D) (SMZ 50 mg/KG/D)

+Rifampin 15-20 mg/kg/D PO 45

days

Meningitis,Osteomyelitis,Endocarditis:Doxy + Genta +/- Rifampin

calcified brucellomas in both kidneys calcified brucellomas in the spleen

Salmonellae Infections

M.Karimi

EtiologySalmonellae

(G- ‘Facultative’Bacilli)• Antigens: Flagellum(H)’ Cell wall(O)’ Envelope(Vi)• Serogroups on the basis of O antigen: A’ B’ C1’ C2’ D’ E• Serotypes: S.Typhi’ S.Paratyphi’….• Transmission: Water’ Food(beef’poultry’milk’egg’..)

Salmonella Gastroentritis (Nontyphoidal)

Epidemiology

• Age: <4 y/o (< 1y/o)• Source of infection: Poultry’eggs’ egg product ’meats’ pet reptile• Transmission: Carrier (Human)• Incubation period: 6-72 hr. (usually less than 24 hr.)

• Peak incidence: Late summer &Early fall

Pathogenesis

• Ingestion• Attached to “M” cells• Phagocytosed by macrophages• Replication• Bacteremia

Clinical manifestations

• Self limited diseases: 3-7 days• Onset: Abrupt• Nausea’ Vomiting’ Crampy abdominal pain• Loose watery stool• Malaise’ headache’ chills• Fever 38-38.9 c (70%) for 48 hour

At risk of complications• Impaired immune function(T-Cell)• HIV infection• Organ transplantation• Lymphoproliferative diseases• Hemoglobinopathies

(Sickle cell disease’..)• CGD• Malaria• Very old or very young

Complications• Dehydration’Shock• Localized infection: Pneumonia Empyema Abscesses Osteomyelitis Septic arthritis Postinfectious arthritis Pyelonephritis meningitis

Diagnosis

• Cultures (Stool’ Blood’ Urine’ Bone marrow’ CSF’…)

Treatment

• Correction of shock’ dehydration’…• Antibiotics: 1-Infants < 3 mo. 2-Child with immunodeficiency’ Malnutrition Malignancy’ Intravascular catheter or other foreign material

Treatment

• Ceftriaxone or Cefotaxime Septicemia’ Enteric fever’ Metastatic site of infection• Amoxicillin• Co-trimaxozole• Fluroqinolones• Chloramphenicol

Typhoid fever

Typhoid fever

• In US:400 Cases per year &Usually under 20 y/o

• Worldwide:16 million cases per year and 600’000 death

• Infected only human

Pathogenesis

• Invasions on upper small intestine• Monocyte phagocyte• Monocyte carry organism from blood to

other RES• Organism proliferation• Lymph node’ liver & spleen inflammation• Secondary septicemia

Salmonella Typhi

Clinical manifestation

• Infant: mild GE to severe septicemia without

diarrhea Fever’ hepatomegaly ’ jaundice’ anorexia’

lethargy’ weight loss

Clinical manifestation• Child: High fever’ malaise ’lethargy’ myalgia’ headache’ rash’

Hepatomegaly’ abdominal pain and tenderness’ diarrhea(50%)’ constipation

obtunded ’delirium’ confusion ’splenomegaly’ Macular (Rose spot) or Maculopapolar rash(30%) High T with low PR (Typically each 1 degree above 38.3° C Rise PR 10/min)

Rose spot

Complications• Intestinal perforation(0.5-3%)• Severe GI hemorrhage(1-10%)• Toxic encephalopathy• Cerebral thrombosis• Acute cerebral ataxia• Aphasia• Optic neuritis• Deafness• Transverse myelitis

• Acute cholecystitis• Pneumonia• Pyelonephritic• Endocarditis• Meningitis• Osteomyelitis• Septic arthritis

Dense chronic bone reaction due to typhoid

osteomyelitis.There is a central sequestrum

Typhoid

Diagnosis & Differential diagnosis

• Diagnosis

Cultures: Blood’ Urine’ Stool’

Bone marrow’ Lymph nodes’ Deudenal fluied’

Reticuloendothelial tissue’

• Differential diagnosis

BronchitisBronchopneumoniaGastroenteritisInfluenza

Treatment

Drugs:• Ceftriaxone• Ampicillin• Chloramphenicol• Co-Trimoxozole• Ciprofloxacin• Azithromycin

Surgery• Cholecystectomy

Prognosis

• With treatment : Mortality <1% • Without treatment : Relapse up to 10% • Chronic carrier: Excrete S.typhi for more

than 3 mo.