Abdominal fever and other Salmonella infections; Flashcards
what is diarrhoea syndrome ?
3 or more stools daily
acute - <14 days
subacute 14-30 days
chronic- lasting more than 30 days
viral etiology of diarrhoea syndrome ?
rotavirus (transited through air)
adenovirus ?
norovirus - ?
bacterial etiology of diarrhea ?
shigella
vibrio cholera - most severe
ecoli
parasite etiology od diarrhea syndrome ?
lamblia giardia
what are the different types of diarrhea and their causes ?
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criteria for infectious diarrhea ?
watery diarrhea - rotavirus , vibrio cholera , salmonella
acute for 3 days and self limiting except for cholera - sever dehydration through rice stool - hypovolemic shock
bloody diarrhea / inflammatory - shigella , salmonella , enterohemrrhagic eccoli
lasts longer that watery diarrhea 2-7 days
and colon usually primary site
secretory diarrhea
D+V = s aureus , clostridium perfinges - 24hrs after ingestion
hospital acquired diarrhea
infants - rotavirus
adults - antibody associated diarrhea - clindamycin
travellers diarrhea
most cases 80 percent - enetrotoxigen related coli
shigella in contaminated food water
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criteria for infectious diarrhea ?
acute diarrhoea syndrome - lasting up to less than 14 days of diarrhoea
with the following symptoms - abdominal pain , nausea , vomiting , tenesmus
with
toxic infectious syndrome
EPIDEMIOLOGY of salmonella typhi ?
where there is the least amount of sanitation
east and southeast asia , africa
which SALMONELLA SPECIES CAUSES TYPHOID FEVER ?
Unlike other Salmonella species that primarily cause local intestinal inflammation
Salmonella Typhi and Paratyphi A, B, and C characteristically invade the gastrointestinal tract into the bloodstream, survive and reproduce within macrophages,
what is the RESERVOIR FOR SALMONELLA ENTERICA SEROTYPE TYPHI ?
and other salmonella species ?
only humans for salmonella enterica serotype typhi
other salmonella species have humans and animals as reservoirs - intestines , pigs , cows, chicken
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In typhoid fever and non
typhoidal salmonellosis, one important factor is important:
an asymptomatic
human carrier state exists for the agents of either form of the disease. The carrier state may last from
many weeks to years
.
what are the CHARACTERISTICS for salmonella ?
gram negative rod
hydrogen sulfide producing
facultative anaerobe
PERITICHOUS FLAGELLA
OXIdase negative
salmonella enterica serotype Enteritidis and typhimurium is resistant to gastric acid
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however S typhi High infectious dose required → NOT resistant against gastric acid
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typhoid toxin is exclusively produced by intracellular S. Typh
Salmonella cytolethal distending toxin (S-CDT), first described as the “typhoid toxin
DNA damage in eukaryotic cells.
TRANSMISSION in typhoid fever ?
fecal to oral - through contaminated stool
or through contaminated food and drink
what is the PATHOPHYSIOLOGY OF TYPHOID FEVER ?
oral uptake of a large number of organisms are needed to cause infection unlike shigella few as 10
migration to peyer patch at distal ileum
infection of macrophages - nd disseminates into organs of the mononuclear phagocyte system (e.g., lymph nodes, liver, spleen, bone marrow)
infected macrophages go int the blood stream - and this causessepticemia
what is the INCUBATION PERIOD FOR TYPHOID FEVER ?
5-30 days
after 3 weeks - chronic salmonella carriers
what are the CLINICAL SYMPTOMS IN TYPHOID FEVER ?
week 1
hyperthermia
STEP LADDER RISE IN TEMPERATURE (40-41°C) over 4 to 5
days, accompanied by headache
RELATIVE bradycardia - usually heart rate increases with rise in body temperature
but in typhoid fever this phenomena is significantly reduced (thats why it is relative bradycardia)
constipation
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week 2
fever -
no chills
and unresponsive to antipyretics
mild HEPATOSPLENOMEGALY
ROSE COLOURED SPOTS (rose coloured exanthema or rash) - in the upper chest and abdomen - mostly around navel
TYPHOID TONGUE - grey yellow coated tongue with red edges
abdominal pain and headache
diarrhea - YELLOW GREEN - pea soup - PURULENT BLOODY NECROSIS OF PEYER PATCHES
ILEUS BEcauses Peters patches become swollen
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weeks 3
all features of week 2
The patient will appear in the “TYPHOID STATE” which is a state of prolonged apathy,
toxemia,
delirium, disorientation and/or coma.
if left untreated high chance of gastrointestinal ulceration with bleeding and perforation - peritonitis
in rare cases - meningitis / myocarditis
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WEEK 4
RECOVERY
how is TYPHOID FEVER DIFFERENT FROM PARATYPHOID FEVER ?
Symptoms usually begin six to thirty days after exposure and are the same as those
of typhoid fever
Gradual onset of a high fever over several days
Without
treatment symptoms may last weeks or months.
DIAGNOSIS OF TYPHOID FEVER ?
lab anemia leukocytosis or leukopenia --absolute eosinopenia ! abnormal liver function
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detecting pathogen
blood culture - detectable in starting one week of clinical syndrome
stool culture - Cultures may be positive from weeks 2–3, but they are often negative despite active infection
bone marrow culture - might be positive even after antibiotic treatmnet
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Produces hydrogen sulfide (H2S) on TSI agar (Triple sugar iron agar)
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SEROLOGY - WIDAL TEST - WEEK 2 ONWARDS
agglutinating antibodies against the O and H antigens of S. Typhi.
TREATMENT of TYPHOID FEVER ?
fluroquinilones - ciprofloxacin
second line - azithromycin
third gen cephalosporins - ceftriaxone
however antibiotics prolong the fecal excretion of bacteria
persistent vomiting, diarrhea, or abdominal distention should be hospitalized
and treated with supportive therapy
COMPLICATION of TYPHOID FEVER ?
chronic salmonella carrier - positive stool culture 12 months after treating the disease
typically asymptomatic
however increased risk to gallbladder cancer
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if typhoid fever is left untreated high chance of gastrointestinal ulceration with bleeding and perforation - peritonitis
in rare cases - meningitis / myocarditis
PREVENTION of TYPHOID FEVER ?
vaccine not entirely effective - however recommended to those travelling to high risk areas
inactivated vaccine - IM 10 days before travelling
over 2 years of age
or
live attenuated vaccine - ORAL INGESTION of capsules
10 days before travel
for people over 5 years of
age
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and keeping basic hygiene
PEOPLE AT GREATEST RISK FOR NON TYPHOID SALMONELLOSIS ?
elderly - watery diarrhea → dehydration → circulatory collapse in elderly
immunocompromised -
meningitis in children
DD OF NON TYPHOID SALMONELLOSIS ?
Malaria, Dengue-fever
ETIOLOGY OF salmonellosis ?
salmonella enterica serotype enteritis and typhimurium
CHARACHTERISTIC OF SALMONELLA
gramnegative rods
enterobacteriaceae
// non sporing //
release endotoxin when killed
resistant to gastric acid
what is the TRANSMISSION of SALMONELLOSIS
food borne - through poultry , raw eggs and milk
PATHOPHYSIOLOGY of NON TYPHOID SALMONELLA?
bacteria is ingested by mouth
-> All virulent strains of Salmonella can survive gastric
acidity and penetrate intestinal mucosa and submucosa
///-> Hence they are facultative intracellular pathogens that enter cells via macropinosomes ////
After invading , they induce an acute inflammatory
response, which can cause ulceration.
but, unlike Shigella and invasive E.coli, they do not escape the phagosome in intestinal epithelial cells
-> so the extent of intercellular spread and
ulceration of the intestinal epithelium is
minimal
the organisms multiply intracellularly and then
spread to mesenteric lymph nodes throughout the body
; they are taken up by the reticuloendothelial cells-> The
reticuloendothelial system
confines and controls spread of the organism.
However, some organisms may infect the liver, spleen, gallbladder, bonemarrow, meninges, and other organs and thus are able to cause systemic disease and local organ damage
WHAT PART of the system does SALMONELLA AFFECT ?
stomach and small
intestine
INCUBATION PERIOD of SALMONELLOSIS ?
0-3 days
what is the CLINICAL FEATURE of SALMONELLOSIS ?
3-7 days duration fever - resolves within 2 days chills myalgia headache
SEVERE VOMITTING and inflammotry diarrhea - watery and bloody
TREATMENT OF SALMONELLOSIS ?
rehydration therapy
non typhoidal are self limited so rest
for symptomatic treatmnet
fluroquinilones first line - ciprofloxacin
alternative - TMP-SMX (Trimethoprim/sulfamethoxazole, also known as co-trimoxazole) / 3rd gen cephalosporins
antibiotics prolong bacterial feral excretion
COMPLICATIONS OF SALMONELLOSIS?
bacteremia
reactive arthritis
Systemic disease: osteomyelitis, meningitis, myocarditis
