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alimentary tract 2 (Typhoid fever (Clinical manifestations (Fever (!>…
alimentary tract 2
Typhoid fever
typhoid means “typhus-like” and reflects the difficulty in differentiating the illness from epidemic typhus, another common cause of PROLONGED FEVER in Europe during the 19th century
Salmonella enterica subspecies enterica, typhi, paratyphi A, paratyphi B, paratyphi C, Enteric fever: Typhus and paratyphus
Epidemiology
S. typhi i S. paratyphi A and B: human-restricted pathogens
S. paratyphi C: pathogenic for animals as well as humans
S. Typhi excreted by acutely infected, chronic and convalescent carriers
Chronic carrier state: bacteria present in stools and / or urine >12 months after acute infection
Transmission
Ingestion of contaminated food or water
Direct contact, Anal intercourse
Flies, unsterile instruments
travelers returning from endemic zones
Pathogenesis
NTS and TS: distinct clinical course
Typhoid Salmonella cause prolonged bacteremia in immunocompetent hosts, typically without overwhelming sepsis or pyogenic foci of infection
penetration the epithelium of the small bowel, lymphoid tissue,
dissemination via the lymphatic and hematogenous route
Inflammatory diarrhea in 10-20% affected individuals
Intestinal lymphoid tissue is a predominant site of localized inflammation and persistent bacterial replication in cases of severe enteric fever
necrosis of intestinal lymphoid tissue, with mixed inflammatory infiltrates, including neutrophils and ulceration and
sloughing of overlying intestinal mucosa
hemorrhage and/or intestinal perforation, (major life-threatening complications of enteric fever)
Clinical manifestations
Symptoms are nonspeciphic
Infections caused by S. typhi and S. paratyphi A are clinically undistinguishable
most patients with enteric fever are diagnosed in the ambulatory setting, and up to 90% are treated as outpatients
classic descriptions of the features of enteric fever are derived from series of hospitalized patients with more severe disease
Disese lasted 3-4 weeks
Complications typically after 2 weeks of fever
Recurrence rate 10%
Fever
!>95%
May be the sole manifestation of enteric fever
onset of fever may be insidious
fever typically increase over the first week of illness
Symptomps
headache, anorexia, myalgias,
malaise may precede the onset of fever
diarrhoea / constipation, abdomianl pain
dry cough, mild confusion
Rose spots: 1- to 4-mm blanching pink macules, on the chest, back, and abdomen during the second week of fever.
pulse-temperature dissociation (relative bradycardia)
abdominal tenderness, hepatosplenomegaly
yellowish / brown coating of the tongue that spares the tongue’s edges
patients with uncomplicated enteric fever do not have leukocytosis, neutrophilia, or increased immature neutrophils
Severe ilness
descriptions are drawn from observations of hospitalized patients in the preantibiotic era
Mortality 10-15%, increasing fever over the first week of illness, followed by
increasing abdominal complaints and rash over the second week of illness, followed by
complications, including intestinal hemorrhage and perforation, or gradual resolution in the third and fourth weeks of illness
Complications
Gastrointestinal
Intestinal hemorrhage
Intestinal perforation
Neurologic
encephalopathy, encephalomyelitis
transverse myelitis, meningitis
ataxia, Guillain-Barré syndrome
Diagnosis
current culture-based, serologic and molecular diagnostic tests lack an optimal sensitivity and specificity
patients with suspected enteric fever should be treated with empirical antibiotic
The diagnosis of enteric fever should be considered in any person with fever, especially in those with fever lasting longer than 3 days and who have had an exposure in the last 1 to 6 weeks to an area where enteric fever is endemic
In endemic areas, other clinical factors that are associated with a higher likelihood of enteric fever include a temperature greater than 39° C, ill appearance, young age (<5 years), and any abdominal complaints, including abdominal pain, diarrhea, or constipation
Differential diagnosis
Miliary tuberculosis, Nontyphoidal Salmonella bacteremia
Dengue fever, malaria, leptospirosis, influenza, bartonellosis
riketsiosis, brucellosis, tularemia, Infective endocarditis
Viral haemorrhgic fevers
Noninfectious conditions (eg. Ymphoproliferative diseases, vasculitides)
Treatment
Chloramfenicol 14-21 dni
Amoxicillin po 3x1g, 14 dni
Ampicillin iv, 4x2g, 14 dni
TMP/SMX po, 960mg, 14 dni
other: ciprofloxacine, ceftriaxon, azithromicine
dexametasone iv in severe cases
Shigella
dysenteriae, flexneri, Boydii
Pathogenic exclusively for humans
Epidemiology
inoculum <100 CFU, high risk of secondary transmission
flies!, Indian Subcontinent, Bangladesh, Africa
in developed countries: fecal-oral spread from people with symptomatic infection
Fecal contamination during cultivation; raw vegetables are the most common mode of foodborne transmission
summertime
Transmission
fecal-oral route
direct person-to-person spread: hand transmission
contaminated food and water
outbreaks/secondary transmissions (e. g. households, cruise ships, nursing homes)
fecal excretion of the infecting strain generally lasts 1 to 4 weeks
Clinical manifestations
infection of the lower gastrointestinal tract
incubation period: 12 hours - 7 days
acute onset, high fever
abdominal cramps, bloody, mucoid and purulent diarrhea
Significant fluid loss is uncommon
secondary in sections after 1-3 days
constitutional symptoms: fever, anorexia, and malaise, abdominal cramps
watery diarrhea
subsequently may contain blood and mucus, tenesmus
Abdominal pain > Mucoid diarrhea > Bloody diarrhea > Watery diarrhea / Fever > Vomiting
Laboratory Findings
elevated / decreased / normal WBC
shift to the left
direct microscopic examination of a stained fecal smear: polymorphonuclear leukocytes
Treatment
Antibiotics are useful in the management of shigellosis
each patient with a positive stool culture or with known bacillary dysentery should be treated
3-day therapy: Ciprofloxacin, Azithromycin, Ceftriaxone
In a normal host, the course of disease is generally self-limited, lasting no more than seven days when left untreated.
mortality is unusual (except in malnourished children and older adults)
Complications
severe dehydration, febrile seizures, septicemia or pneumonia from coliform organisms, keratoconjunctivitis, immune complex acute glomerulonephritis, post-Shigella irritable bowel syndrome and reactive arthritis, and hemolytic uremic syndrome
Salmonella
typhoidal --> enteric fever
non-typhoidal=NTS --> foodborne disease / invasive disease
Nontyphoidal Salmonella infection
Epidemiology
major cause of diarrhea worldwide
animal reservoirs
Foodborne infection
Poultry, eggs, and egg products
Salmonellae can be passed transovarially from chickens to intact shell eggs
fresh produce, meat (including ground beef as well as dog food), fish, milk, nut butters, spices, and other
Animal contact
Reptiles and amphibians
Live poultry
Gastroenteritis
self-limiting disease with acute onset
8 to 72 hours following exposure
nausea / vomiting
nonbloody diarrhea (resolves within 4 to 10 days)
fever (resolves within 48 to 72 hours)
abdominal cramping, myalgia, headache
Diarrhea that persists for more than 10 days should suggest another diagnosis
megacolon toxicum, pseudoappendicitis
severe disease among the elderly, immunocompromised patients, including persons with HIV/AIDS or those who are receiving anti–tumor necrosis factor antibody
Bacteremia
among to 8% of patients with NTS gastroenteritis
variety of extraintestinal manifestations
suppurative endovascular focal infections
Extraintestinal focal infections
endocarditis (mortality 70%), CNS infections (mainly children)
osteomielitis, septis arthritis, pyelonephritis, cystitis
Muscle/soft tissue (abscesses, pyomyositis, mortality 33%)
Salmonellosis and HIV Infection
In developed countries during the pre-HAART era, NTS bacteremia occurred 20 to 100 times more commonly among those with HIV infection compared with the general population
associated with lower CD4 lymphocyte counts
among patients receiving antiretroviral therapy, the incidence of recurrent NTS bacteremia has declined up to 96%.
category C: recurrent Salmonella bacteremia
Chronic carrier state
persistence of Salmonella in stool or urine for more than 12 months after acute infection
asymptomatic
frequency higher in women and in persons with biliary abnormalities, gallstones, or concurrent bladder infection with Schistosoma haematobium
Treatment
Gastroenteritis
symptomatic
antimicrobials should not be used routinely to treat uncomplicated NTS gastroenteritis
antibiotics do not significantly decrease the length of illness
antibiotics increase risk of positive stool culture 1 month after treatment
Antimicrobial therapy should be considered for
neonates (probably up to 3 months of age)
patients older than 50 years with suspected atherosclerosis
persons with immunosuppression, cardiac valvular or endovascular abnormalities, or significant joint disease.
oral or intravenous antimicrobial administered for 48 to 72 hours or until the patient becomes afebrile: fluoroquinolone, TMP-SMX, or amoxicillin
Bacteremia
iv III gen cephalosoprine + fluoroquinolone 7-14 days
complete debridement and drainage of soft tissue or visceral foci of infection should be followed by a minimum of 3-6 weeks of antimicrobial therapy
Campylobacter jejuni
Campylobacter coli
Epidemiology
carried by a wide variety of wild and domestic animals, notably birds
C. coli is particularly associated with pigs
carcasses are contminated from gut contents at slaughter
food contamination from food-producing animals is a more significant problem
direct contact with animals
person-to-person: rare
Clinical manifestations
Gastroenteritis
incubation period: 3 days (1-7)
abrupt onset of abdominal pain and diarrhoea
fever, myalgia, headache
diarrhea after 12-24 hours, ranging from loose stools to massive bloody diarrhea
abdominal cramping, relieved by defecation
gradual resolution of symptoms over several days
colitis acuta
fever, abdominal cramping, bloody diarrhea lasting more than 7 days, tenesmus
megacolon toxicum
can mimic IBD
Diagnostics
suspected in the setting of severe abdominal pain with diarrhea
diagnosis is established by stool culture
Treatment
usually a mild, self-limited infection
rehydratation, correction of electrolyte abnormalities
antibiotics for patients with severe disease or risk for severe disease (high fever, bloody stools, > 8 stools/day
erythromycin, azytromycin, clarytromycin, ciprofloxacin
Cholera
Clinical Manifestations
Diarrhea
Spectrum: from asymptomatic colonisation, through mild, moderate and severe diarrhea
the volume of watery diarrhea can exceed 1 L/hr
In the initial stages, diarrhea may contain intestinal contents
as diarrhea progresses, it becomes more watery
eventually becoming clear, with flecks of white mucus (rice water stool) with a fishy odor
electrolyte disorders
Vomiting: common, Without fever: hypothermia
Abdominal cramping, ileus, Muscle pain adn spasms
dehydration
cholera gravis
lethargy, Sunken eyes
Decreased skin turgor
Cold and clammy skin
Dry mucous membranes
anuria
Lactic acidosis: Kussmaul breathing
hypoglycemia
severe hypoperfusion: stroke, acute tubular necrosis with renal dysfunction,
aspiration pneumonia
Diagnosis
Microbiologic analyses of stool samples permit confirmation of V. cholerae as well as determination of antimicrobial susceptibility profiles
In endemic countries such analyses usually are not necessary
Treatment
Fluid menagement
po / iv
ORS (oral rehydration solutions)
Antibiotics
Antibiotic indicated in moderate and severe dehydratation
reduce the volume of diarrhea by approximately 50%
shorten the duration of diarrhea
azithromycin, doxycycline, ciprofloxacin
Prevention
provision of safe water
adequate sanitation
Vaccine: Dukoral po, children >2 years and adults, 2 doses