2.
A collective term for the multisystemic illness caused by Salmonella Enterica serovars
that include Salmonella typhi and Salmonella paratyphi A, B and C
It’s a clinical syndrome that manifests with constitutional symptomatology such as
fever, malaise, leathargy together with abdominal complaints ie pain abdomen with or
without diarrhoea or constipation.
Although the clinical picture for all Salmonella serotypes is almost indistinguishable
yet, the most invasive clinical course has been observed with ailment secondary to
infection with serotype typhi , that is termed as typhoid fever.
If no complications occur, symptoms gradually improves over7-10 days.
INTRODUCTION
3.
Responsible for significant disease burden worldwide
It has been estimated that 33 million cases and 500,000 deaths occur annually
throughout the developing world due to typhoid fever with a worldwide incidence of
365 /100,000 and 540 /100,000 (0.5%) in the
developing world
Transmission takes place via feco-oral route
Bears a long and variable incubation period ranging from 6 to 30 days
Duration of sickness ranges from 14-35 days with a mean of 28 days
Complications occur in 30% of the untreated cases and account for 75% of the deaths
Frequency of relapse in 5% of the cases
Carrier rate is 3% on average
With emergence of XDR S.typhi especially in Middle East Asia and Pakistan, its
management has now become a challenge.
EPIDEMIOLOGY
4.
Infection begins with the organism invading the mucosal epithelial barrier of small gut.
Subsequently, The agents invade and replicate in the macrophages of Peyer patches,
mesenteric lymph nodes and spleen.
Bacteremia occurs, and infection dwells predominantly in Peyer patches
Proliferation ensues via recruitment of lymphocytes and macrophages in the Peyer
patches secondary to bacterial invasion, which may ultimately ulcerate that may lead
to dangerous hemorrhage and intestinal perforation.
Nontyphoidal Salmonella strains usually do not cause invasive disease owing to lack of
human specific virulence factors (typhoid toxin, Vi antigen etc)
PATHOPHYSIOLOGY
5.
Remittent fever, that begins low then rises gradually reaching as high as 104.9 degrees,
usually rises over the course of each day, dropping by subsequent morning. Takes
plateau after abuot 7-10 days. Sphygmothermal dissociation may occur
Dull frontal headache, more pronounced in younger age group
Coated tongue
Myalgias
Anorexia, upper GI upset
Diffuse abdominal pain and tenderness with or without constipation / diarrhoea. Pea
soup (foul smelling green colored) diarrhoea may also develop.
Salmon colored, blanching maculopapular rash on trunk, lesions are 1-4 cm wide and
usually less than 5 in number. Generally resolve within 2-5 days.
By the third week, apathy, confusion and psychosis may ensue (said typhoid state)
Intestinal perforation, secondary peritonitis and toxemia can take place
SIGNS & SYMPTOMS
6.
Blood culture is the investigation of choice, that is positive in 80 % of the patients
within the first week of illness. Rate of usefullness declines thereafter. Still positive in
25 percent of the cases by the 3rd week.
Bone marrow cultures may be occasionally positive when blood cultures are not, and
can be carried out. Stool cultures are however unreliable
Serological testing is also used but is obsolete and unreliable.
Full blood count typically reveals leucopenia, may reveal anemia and/or
thrombocytopenia, may also reveal elevated ESR.
Elevation of serum bilirubin and aminotransferases to twice the upper limit of normal
Mild hyponatremia / hypokalemia could also be there.
LABORATORY INVESTIGATIONS
7.
Might be rational in patients who’s symptoms do not resolve by the third week,
or who have severe constipation or in any way are suspects for intestinal
perforation.
Include X-RAY abdomen erect and supine and CT scan with IV Contrast.
SONOGRAPHIC IMAGING
10.
Treatment is aimed at shortening the due course of illness, relieving the
symptoms and preventing the complications.
Good nursing care should be offered
Vital signs, intake and output monitoring and according management
Fluid and electrolyte replacement as per customized scenario, adequate oral
intake
Antipyretics for fever
Symptomatic treatment such as anti emetics for nausea/vomiting, analgesics
for headache and myalgias
Antibiotics – empiric vs organism specific.
According management of complications if any.
MANAGEMENT
11.
General Considerations
Once enteric fever is suspected on clinical grounds, empiric antibiotic therapy
better be initiated on empiric basis. This is known to limit the complications
and shorten the course of illness.
Fluoroquinolones and third generation Cephalosporins , in general are the
antibiotics of choice against salmonella infections.
For suspected enteric fever, levofloxacin 500 mg once daily or Ciprofloxacin 750
mg twice daily for 5-7 days are quite effective.
Ceftriaxone 1-2 mg twice daily is also effective
Alternatively, using macrolide ie azithromycin 500 mg once daily for 5-7 days
is also effective
ANTIMICROBIAL THERAPY
12.
Geographical Considerations in Anti-biotic Selection
Resistance is being faced by ampicillin, co-trimoxazole and chloramphenicol in
treatment of typhoid globally
Strains have become increasingly resistant to quinolones in Middle East Asia
including Pakistan.
XDR strain of S typhi was isolated in Pakistan in 2016, that is resistant to
ceftriaxone but continues to maintain sensitivity to Azithromycin.
International sources recommend usage of carbapenepms (eg meropenem 1G
thrice daily) for complicated salmonella infections acquired in Pakistan,
ceftraxone 1-2 gram twice daily outside Pakistan and a quinolone (levofloxacin
500 mg once daily) outside South Asia, on empiric basis.
Certain antibiotic combinations eg cefixime-ofloxacin have shown better results
in background of increasing antibiotic resistance, especially in Asia.
CONTINUED..
13.
Guidelines by MMIDSP
The Medical Microbiology & Infectious Diseases Society of Pakistan 2019
Guidelines recommend empiric therapy with monoantibiotic which should be
as follows.
Cefixime 400 mg orally twice daily that could be changed to IV therapy if no
improvement is there for 5 days or there is emergence of complications
OR
Ceftriaxone intravenous in 1 gram twice daily dosage.
Once culture/sensitivity report is available, antibiotic should be adjusted
accordingly
CONTINUED..
14.
A chronic carrier is the one who continues to secrete S typhi in stool for more
than 1 year are considered carriers.
Ciprofloxacin 750 mg twice daily for 10-14 days is effective
TREATMENT FOR CARRIERS
15.
Despite of all the treatments, mortality rate is 2% in treated cases
Elderly pts with a number of co-morbids are likely to are likely to do worse
PROGNOSIS
16.
Maintaining good hygeine
Proper hand wash
Appropriate waste disposal
Vaccination should be considered for close contacts of typhoid patients
PREVENTION
17.
Current Medical Diagnosis and Treatment 2021
Center of Disease Control & Prevention- Typhoid fever & Paratyphoid fever >
symptoms and treatment
Available from Symptoms and Treatment | Typhoid Fever | CDC
Typhoid Management Guidelines – 2019 by MMIDS Pakistan. Available from
Typhoid Management Guidelines – 2019 – MMIDSP
Online sources – open access
References