Brucellosis

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 (M,S >A,C)

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• 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

Differential diagnosis

• Cat-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

Salmonellae Infections

EtiologySalmonellae(G- 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’• Transmission:• Incubation period: 6-72 hr. (usually less than 24 hr.)

• Peak incidence: Late summer &Early fall

Pathogenesis

• Ingestion• 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

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

Clinical manifestation• Infant: mild GE to severe septicemia without diarrhea Fever’ hepatomegaly ’ jaundice’ anorexia’ lethargy’ weight

loss• 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)

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

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

Diagnosis & Differential diagnosis

• Diagnosis Cultures:

Blood’ Urine’ Stool’ Bone marrow’

Lymph nodes’ Deudenal fluied’

Reticuloendothelial tissue’

• Differential diagnosis

BronchitisBronchopneumoniaGastroenteritisInfluenzaMalariaTuberclusisbrucellosis

Treatment

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

Prognosis

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

than 3 mo.

Diphtheria• Diphtheria is an acute toxic infection

caused by Corynebacterium species, typically Corynebacterium diphtheriae .

Corynebacteria

Aerobic, nonencapsulated, non-spore- forming, mostly nonmotile,

pleomorphic, gram-positive bacilli

EPIDEMIOLOGY• Spread: airborne respiratory droplets direct contact• Asymptomatic respiratory tract

carriage is important in transmission. • Skin infection and skin carriage• contaminated milk • infected food handler

• serosanguineous, purulent, erosive rhinitis• Shallow ulceration of the external nares and

upper lip • sore throat• fever,Dysphagia,Hoarseness,Headache Malaise,• unilateral or bilateral tonsillar membrane

formation• enlarged lymph nodes can cause a bull-neck

appearance

Clinical manifestation

• Paralysis of the palate and hypopharynx is an early local effect of diphtheritic toxin.

• Toxin absorption can lead to systemic manifestations: kidney tubule necrosis, thrombocytopenia, cardiomyopathy, and/or demyelination of nerves

• DIAGNOSIS: culture • COMPLICATIONS:

Toxic CardiomyopathyToxic Neuropathy

• TREATMENT: Antitoxin penicillins, erythromycin

Tetanus• acute, spastic paralytic illness• Clostridium tetani :motile, gram-

positive, spore-forming obligate anaerobe

• Neurotoxin

EPIDEMIOLOGY• The most common form, neonatal (or umbilical) tetanus• maternal tetanus :postpartum, postabortal, or

postsurgical wound infection• traumatic injury• contaminated suture• intramuscular injection• animal bites• abscesses (including dental abscesses)• chronic skin ulceration• Burns• compound fractures,• frostbite, gangrene, intestinal surgery

CLINICAL MANIFESTATIONS• trismus • generalized tetanus• sardonic smile of

tetanus (risus sardonicus)

• opisthotonos

CLINICAL MANIFESTATIONS• painful spasms of the muscles adjacent

to the wound site • Cephalic tetanus : retracted eyelids, deviated gaze,

trismus, risus sardonicus, and spastic paralysis of the tongue and pharyngeal musculature

DIAGNOSIS• clinically unimmunized patient (and/or

mother) who was injured or born within the preceding 2 wk, who presents with trismus, other rigid muscles

• Routine laboratory studies are usually normal

TREATMENT• Surgical wound excision and

debridement • human tetanus immunoglobulin (TIG) • Penicillin G• muscle relaxants(Diazepam)

† For children <7 yr of age, DTaP is preferred to tetanus toxoid alone if <3 doses of DTaP have been previously given. If per-tussis vaccine is contraindicated, DT is given. For persons ≥7 yr of age, Td (or Tdap for adolescents 11–18 yr of age) is preferred to

tetanus toxoid alone. Tdap is preferred to Td for adolescents 11–18 yr of age who have never received Tdap. Td is preferred to tetanus toxoid for adolescents who received

Tdap previously or when Tdap is not available. ‡ TIG should be administered for tetanus-prone wounds in HIV-infected patients

regardless of the history of tetanus immunizations. § Yes, if ≥10 yr since the last tetanus toxoid-containing vaccine dose. ‖ Yes, if ≥5 yr since the last tetanus toxoid-containing vaccine dose

CLEAN, MINOR WOUNDS OTHER WOUNDS [*]

HISTORY OF ABSORBED TETANUS TOXOID (DOSES)

Tdap or Td[†] TIG[‡]

Tdap or Td[†] TIG[‡]

Uncertain, or <3

Yes No Yes Yes

3 or more No[§] NO No[‖] NO