Bacterial Infection Flashcards
Etiologic agent whooping cough
Bordetella pertusis gram + bacilli
Mot of pertusis
Close contact respiratotmry secretions
Incubation period pertussis
6-20days
Characteristic of whooping cough
100 days cough
Successive cough with inspiratory whoop
3 stages whooping cough
Catarrhal 1-3weeks
Paroxysmal 2-4week
Convalescent 100 days
What is catarrhal stage of pertussis
Most contagious stage Nonspecific manifestation Mild uri Low grade fever Important to diagnose early to shorten disease course
Paroxysmal phase pertussis
Obvious sign and symptoms
Successive cough ending with high pitched inspiratory whoop
Clinical pertussis
Machine gun burst of cough
Convalescent stage pertussis
Reduce frequency and severity of cough last 100 days
Diagnosis of patient with pertussis.
Cbc: highleucocyte count 15,000-100,000 with absolute lymphocytosis(leukemoid reaction)
Xray: perihilar infiltrate, atelectasis or emphysema
Total duration of pertussis
Up to 12 weeks
Complication and hospitalization of pertussis
Occur most commonly in the young under 6 months
Pneumonia, apnea, otitis, conjunctival hemorrhage,epistaxis, seizure, acute encephalopathy, hernia, pneumothorax
Differential diagnosis pertussis
Atypical pneumonia, chlamydia, mycoplasma, adenovirus
Tracheobronchial Tb
Foreign body
Bronchiolitis
Confirmation of diagnosis
Isolation of the organism from bordet gengou culture of nasopharyngeal mucus
Best yield during 3 weeks of illness
Pcr, fluorescent antibody, serology
Treatment of pertussis
Most effective during first 2weeks of illness
DOC: erythromycin 40-50mg/kg/day x 14 days
Other drugs: azithromycin, clarithromycin
All household contacts should be given chemoprophylaxis regardless the age and immunization status
Supportive:paracetamol, iv fluids
Vaccination
Drug of choice for whooping cough
Erythromycin
Etiologic agent syphilis
Treponema pallidum-spirochette
Mot of syphilis
Direct contact with the lesion
Perinatal intrauterine infection
Blood transfusion
Adult syphilis vs congenital syphilis
Adult syphilis
- sexually transmitted
- prevalent in adolescent
Congenital syphilis
- vertical transmission from pregnant mother
- transmission can occur at any stage
- usually infected fetus die in the utero or shortly after birth
- surviving babies have severe congenital and developmental anomalies
3stages of syphilis
Primary (site of penetration)
- painless indurated ulcer
- chancre usually found in the genitalia
- after few weeks ulcer heals then goes secondary
Secondary(dissemination)
- condyloma lata(wart like lesion on the anal verge)
- skin lesion, fever rash
Tertiary(deep organ involvement)
- gumma(granulomatous lesion)
- neurosyphilis(tabes dorsalis) most prominent
- cardiosyphilis
- not due to the bacteria but by the tissue damage brought about by the bacteria
Early onset of congenital syphilis
- first 2years of life
- hepatomegaly, snuffles, lymphadenopathy, mucocutaneous lesions, pneumonia, osteochondritis rash, pseudoparalysis, hemolytic anemia, thrombocytopenia
-can be mistaken with neonatal sepsis, maternal history is important
Late onset of congenital syphilis
2 yrs old and above
Bone malformation( frontal bossing, saddle nose, saber shin-bowing of tibia)
Neurosyphilis
Mulberry molars
Rhagades(fissure which appears at the mucocutaneous junction)
Hutchinson triad( keratitis, hutchinson teeth, 8th nerve deafness
Diagnosis of syphilis
Darkfield microscopy
Serology-mainstay
- non treponemal= VDRL, RPR ( screening monitor response to therapy- quantitative test to measure ab titer)
-treponemal= FTA TPHA (confirmatory)
Treatment of syphilis
DOC: penicillin G
Newborn: aqueous crystallography ne pen G or procaine pen G
Children: benzathine pen G
Alternative: erythromycin/ tetracycline
Etiologic agent of salmonellosis
Salmonella typhi(typhoidal human source) S. Enteritidis, s. Cholerasuis(non typhoidal animal zoonitic source)
MOT of salmonellosis
Fecal oral contaminated food and water
Bacteria goes to the terminal ileum submucosal lymph node, monocytic infiltration of peyers patches
Non typhoidal: contaminated milk, dairy products water, pastries
Typhoidal: humans
Clinical features of s. Typhi typhoidal
Mild to severe prolonged presentation
Congenital infection/fetal typhoid: high fever low BW
Typhoid fever: high grade intermittent fever(stepladder) on and off for 2 weeks
Diarrhea(pea soup) or constipation
Abdominal distention
Rose spots appears on the 7th and 2nd week of illness on the trunk
Bradycardia, hepatomegaly, meningeal sign, typhoidal psychosis
Complication of typhoid fever
Occur on 2nd and 3rd week of illness-intestinal hemorrhage/ perforation- most dreaded complication
Peritonitis,jaundice, splenic rupture, pneumonia , encephalitis, nephritis, meningitis psychosis
Salmonella gastro enteritis= most common presentation of salmonellosis
-intestinal hemorrhage secondary to typhitis/ typhoid ileitis
Most common presentation salmonellosis
Salmonella gastroenteritis
Most dreaded complication of typhoid fever
Intestinal hemorrhage or perforation
Diagnosis of salmonellosis
Fecalysis: pus cells , rbc in the stool
Culture of blood (1-3wks), urine(first 2wks), stool (2nd -4wks), bone marrow aspirate(90%sensitive) last resort due to invasiveness
Widal test- for non endemic areas
Cbc: leukopenia, lymphocytosis-typhoid fever
Leukocytosis-non typhoidal
Serologic test: latex particle, elisa typhi dot( detects specific igm and igG
Mean incubation period of salmonellosis
24 hours
Treatment for typhoid fever
DOC: chloramphenicol 57-75mg/kg/day q6hx 14 days
Others:amoxicillin ceftriaxone, cefotaxime
NO ANTIBIOTICS FOR SALMONELLOSIS(self limiting)
Treatment for salmonella gastroenteritis
Fluids and electrolytes Supportive antibiotics given only if: 1. <3 mos 2. Immunodeficient 3. Undernourished and blood culture positive
Treatment for extra intestinal salmonellosis
Antibiotics prolonged for 4-6wks(bone infection), 4 wks (meningitis)
Treatment for chronic carrier of salmonellosis
High dose ampicillin
Prevention for salmonellosis and typhoid fever
- Personal hygiene
- Public health measures in food preparation and storage
- Infection control
- Vaccine- vi capsular polysaccharide vaccine one dose IM
Etiologic agent of shigellosis
Shigella dysenteriae
Mean incubation period of shigella
24hrs
Though as few as 10 organism can cause diarrhea (shiga toxin)
Triad of shigellosis in infant
Dysentery
High grade fever
Seizure
Clinical manifestation of shigellosis
Bloody diarrhea(dysentery) Fever Abdominal pain, crampy borborygmous Neurologic Hus(just like EHEC)
What is the most common cause of bloody dysentery
Shigella
Treatment for shigellosis
Supportive and 3-5days antibiotics( cefixime, ceftriaxone,ciprofloxacin)
Etiologic agent of cholera
Vibrio cholerae, vibrio parahemolyticus
Usually it is associated in history of eating shellfish that may lead to food poisoning
Toxin of cholera responsible for epidemic disease
Strain 01 and 0139
Toxin is also called choleragen which causes severe secretory diarrhea
Most characteristic manifestation of cholera
Voluminous diarrhea( rice water)
Main problem in patient with cholera
Massive diarrhea that will lead to severe dehydration
Clinical manifestation of cholera
Emesis
Low grade fever
Shock due to fluid volume depletion
How to diagnose cholera
Stool rectal swab
Gold standard is culture of organism
Complication of cholera
Renal- renal and pre renal failure
Cardiac-due to hypovolemic shock
Coma-due to poor cerebral perfusion
Volume depletion
Treatment of cholera
- Correct hydration -very important to correct loss , antibiotics are only given for 3days so its not enough
2.antimicrobials- doxycyclinie, tetracycline, TMO-SMZ, erythromycin,
Ciprofloxacin,cotrimoxazole
K1 capsular is associated with
NeonatL sepsis and meningitis
Diarrhea strains
EPEC
EHEC
ETEC
EIEC
Escherichia coli is
Gram negative bacteria
Belongs to enterobactericiae
Travelers diarrhea strain
ETEC
Manifest with bloody stool strain
ETEC
EHEC
Manifest with watery stool strain e. Coli
EPEC
EAEC
Produces shiga like toxin
Enterohemorrhagic e. Coli
0157 H 7
Colitis with bloody diarrhea
Strain of infantile diarrhea
EPEC
MOT OF e. Coli
Fecal oral route
Most common cause of UTI
E coli due to poor perineal hygiene,ascending infection
Diagnosis of diarrhea
History of uncooked meat
Stool culture-gold standard
Treatment for diarrhea in patient with e.coli
- Rehydration
- ETEC-self limited
- Antibiotics are contraindicated with EHEC due to increase progression to HUS
- UTI- amoxicillin clavulanate, ampi sulbactam, cotrimoxazole
- Sepsis meningitis , pneumonia-ceftriaxone, cefotaxime
Etiologic agent of tetanus
Clostridium tetany- anaerobic sporeformer neurotoxin
Sourceof clostridium tetani
Soil, dust human and animal(feces, unsterile suture,rusty instruments nails scissors or pins)
MOT of tetanus
Spores introduce into the area of injury or wound(direct inoculation)
Portal entry of tetanus
Dental carried, otitis media, penetrating wounds, illiciting drug injections, abscesses, ear piercing, fire cracker injuries
Greater risk in deep punctured wounds, avulsion, crushing injuries
Incubation period of tetanus
2-14 days after the injury
Pathogenesis
Upon inoculation tetanospasmin bind with NMJ prevent neurotransmitter release-hypersympathetic state due to. Locked inhibitory neurons- nonstop tetanic spasm
Clinical forms of tetanus
Neonatal tetanus
Generalized tetanus- most common
Cephalic tetanus
Localized tetanus
Neonatal tetanus
Usually 3-10day
Difficulty in sucking, jaw stiffness
Excessive cry hoarse to starngled
Opisthotonous, apnea, paralysis,constipation, urinary retention spasm
Generalized tetanus
Stiffness of the voluntary muscle- trismus/lockjaw, risus sardonicus, dyasphagia, opisthotonus,board like rigidity, flexed arms extended legs laryngeal spasm, tachycardia, sweats
-excitants provoke painful spasm and seizure
-intact sensorium
-dysuria
Urinary retention
Accumulation of secretion
Hyperactive dtr
Cephalic tetanus
Involve bulbar musculature
Retracted eyelids,deviated gaze, trismus, risus, spastic paralysis of the tongue and pharungeal muscle(CN 3,4,7,9,10,11)
Localized tetanus
Painful spasm of muscle adjacent to wound site
Ddx of tetanus
Rabies Tetany Polio Bacterial meningitis Drug reaction or withdrawal syndrom
Diagnosis of tetanus
Based mainly on clnical lab testing, cant confirm or exclude the disease
CBC: mild pmn leukocytosis
Normal csf with mild opening pressure
Complication of tetanus
- aspiration pneumonia
- atelectasis
- laryngospasm
- vertebral fracture
- im hematoma
- tongue lacerations
Treatment of tetanus
Tetanus immuniglobulin 500units IM for infants 3000-6000 units IM (children and adults)
Antitetanus serum (ATS) caution for side effect—serum sickness
Recommended antibiotics:pen G and metronidazole
Alternatives: erythromycin and tetracycline(>8y/o)
Wound debridement
Admit to a quiet area with minimal stimuli
Supportive management
Etiologic agent of staphylococcal infection
S. Aureus abscesses and toxin related
Colonizer of anterior nares
Patient came in with high grade intermittent fever stepladder for 2 weeks with diarrhea(pea soup), abdominal pain and rose spots
Typhoid Fever
