Tuesday, February 26, 2013

Escherichia coli (E. Coli): A Detailed Information Best As Awareness campaign




Escherichia coli infection is an acute infectious disease mainly of early age children, caused by different pathogenic strains of Escherichia coli, and is characterized by localization of pathological process in Gastro-intestinal tract with development of toxic and diarrhea syndromes, rarer - defeat of other organs or generalization of the process up to sepsis or failure to thrive development.

Etiology: enterotoxigenic, enteropathogenic, enteroinvasive, enterohemorrhagic Escherichia Coli. Escherichia coli, a facultative anaerobic gram-negative bacillus, is a major component of the normal intestinal flora and ubiquitous in the human environment.
They well grow in ordinary  environments, ave a difficult antigen structure. Microbes contain a somatic 0-antigen, flagellate Н-antigen and superficial somatic O-antigen. Distinctions in a 0-antigen devide bacteria into number of 0-groups (serological groups) Different pathogenic effects, caused Е. coli, are conditioned by producted enthero-, cyto- and verotoxins, and also by the adhesive and invasive activity of bacteria.
Nowadays several categories of Е. coli that cause diarrhea are known: enterotoxigenic, enteropathogenic, enteroinvasive, enterohemorrhagic, enteroadgesive (enteroadherrent).

Epidemiology:

·       Source of infection – ill person or carrier;

·       Way of spreading – orally – Fecal (by water, milk, food); by direct contact;

·       Susceptible organism: children, especially before 2 years of old.

Pathogenesis:
1.     Invasion of bacteria in GIT
2.     Reproduction of bacteria, selection of toxins
·        EPE on the enterocytes surface
·        ETE on the enterocytes microvilli surface
·        EIE, EHE in the colon epithelial cells
3.     Local inflammatory process (EPE, EIE), toxemia (EPE, EIE)
4.     Violation of the surface and membrane digestion, absorption (EPE, EIE), hypersecretion, violation of water, and electrolytes absorption (ETE)
5.     Diarrhea
6.     In severe cases: bacteremia (sepsis)


Clinical features
Enteropathogenic diarrhea is usually self – limited in older children and adults. Nausea, vomiting, cramps and voluminous diarrhea without blood and mucus are common. Diarrhea lasting 2 weeks or longer in infants.
Enterotoxigenic diarrhea includes nausea, vomiting, cramps and frequent watery stools. There no fecal leukocytes in the stool. This syndrome is usually self – limited and lasts about 5 days.
Enteroinvasive strains are associated with a clinical picture comparable to those observed with shigella. Nausea and vomiting frequently accompany abdominal pain. The diarrhea is less in volume than that seen with ETEC strains and contains mucus and blood. Fever, headache, and myalgia are common.
Enterohemorrhagic escherichiosis is associated with severe abdominal cramps, low – grade fever, grossly bloody stools, nausea and vomiting. This organism also has been found in association with hemolytic uremic syndrome (HUS).
5. Enteroadgesive (enteroadherrent) Е. coli  were primary selected in 1985. They have not invasive activity, does not form cytotoxins and does not have a plasmide adhesive factor. The category of EAEC while is not represented by any serological group.

Enteropathogenic E.coli infection criteria
·        Latent period 5-8 days, in new-born, weakened - 1-2 days.
·        Accordingly: gradual or acute illness beginning.
·        The watery massive yellow-orange feces with the too-bit of mucus the green color admixtures sometimes (photo), up to 10-15 times per day.
·        Vomits, regurgitation from the disease beginning.
·        Gradual growth of symptoms up to 5-7 days.
·        subfebril temperature.
·        toxicosis with dehydration of 2-3 stage
·        Credible acute kidney or adrenal insufficiency, DIC-syndrome, infectious-toxic shock.
IMG_92
Massive yellow-orange feces

Enteropathogenic E.coli infection peculiarities in newborns
·        hospital infection caused by resistant cultures.
·        infection generalization with development of sepsis.
·        Frequent damage of brain-membranes, with development of the remaining phenomena
·        Rarely occurs diarrhea.
·        High lethality.

Enteroinvasive E.coli infection criteria
·        Latent period is 1-3 days.
·        Acute beginning with the severe toxic syndrome, fever (1-3 days), rarer vomits.
·        Diarrhea in the 1st day of the disease: feces with the admixtures of mucus and green, blood 3-5 times per day.
·        Abdomen is tender by the colon way, infiltrated sigmoid colon, tenesms are absent.
·        Rapid recovery, normalization of feces in 3-5 days.

Enteroinvasive E.coli infection peculiarities in infants
·        Gradual beginning.
·        severe toxic syndrome increases during 5-7 days.
·        enteritis, enterocolitic character of stools.
·        Dehydration develops often.
·        moderate or severe disease duration.
·        The fever lasts for 5-7 days, sometimes up to 2 weeks.
·        Normalization of feces delays to 1-2 weeks.

Enterotoxigenic E.coli infection criteria
·        Latent period from few hours up to 1-2 days.
·        Acute beginning from the repeated vomiting, watery diarrhea.
·        Intoxication is absent; body temperature is normal or subfebrile.
·        grumbling along thin intestine during palpation.
·        Feces 15-20 time per days, watery without pathological admixtures, of rice-water character.
·        Development of severe dehydration
·        Duration of the disease is not more than 5-10 days.

Enterohemorrhagic Е. coli  infection criteria
·        Latent period is 1-7 days, rarer 9-10 days.
·        A disease has moderate or severe course.
·        Acute beginning.
·        Crampy pain in epigastrium or in all abdomenm.
·        Development of secretory diarrhea in the first days.
·        Future signs of hemocolitis with frequent defecation, in severe cases up to 20-30 times per day.
·        Absence of febrile fever.
·        Complications:
o       hemolytic-uremic syndrome at 2-7%, at the end of the first - beginning of the second week of disease
o       acute kidney insufficiency,
o       hemolytic anaemia,
o       thrombocytopenia,
o       Cramps and other neurological disorders (up to blindness).
·        Laboratory features – in fecal test dissociation between large number of erythrocytes and less amount of leucocytes.
·        Letality is  1-2%. In HUS - 5-10%.

Enteroadgesive (enteroadherrent) escherichiosis is not good studied

Laboratory test
The examination of the stool (koprogram): inflammatory changes, intestinal enzymopathy
A culture of the stools
Serologic reaction (IHAR in dynamics with fourfold title increasing in 10-14 days) in children elder than 1 year if fecal culture is negative.


For more information, go to this link


References:
Main:      
1.      Ambulatory pediatric care/ edited by Robert A. Derchewitz; - 2nd ed. – Lippincot – Raven, 1992. – p. 404-411, P.425-429.
2.      Current therapy in pediatric infections disease – 2/ edited by John D. Nelson, M.D. – B.C. Decker Inc. Toronto, Philadelphia, 1988. – p.74-77, 80-81.
3.      Principles and Practice of Pediatric Infectious Diseases. / Edited by Saran S. Long, Larry K. Pickering, Charles G. Prober, PhiladelphiaPa: Churchill Livingstone; 1997. – 1921 p.

Additional:
1.                         Cleary TG: Yersinia. In: Behrman RE, Kliegman RM, Jenson HB, eds. Nelson Textbook of Pediatrics. 16th ed. Philadelphia: WB Saunders; 2000: 857-859.
2.                         Pickering L, ed: Yersinia enterocolitica and Yersinia pseudotuberculosis infections. In: Red Book: Report of the Committee on Infectious Diseases. 25th ed. Elk Grove VillageIllAmerican Academy of Pediatrics; 2000: 642-643.
3.                         Textbook of Pediatric Nursing.  Dorothy R. Marlow; R. N., Ed. D. –London, 1989.-661p.
4.                         Pediatrics ( 2nd edition, editor – Paul H.Dworkin, M.D.) – 1992. – 550 pp.
5.                         Behrman R.E., Kliegman R.M., Jenson H.B. Nelson nextbook of Pediatrics. - Saunders. - 2004. - 2618 p.
6.                         Castaneda C. Effects of Saccharomyces boulardii in children with Chronic Diarrhoea, Especially Due to Giardiasis // Revista Mexicana de Puericultura y Pediatria. - 1995. - V. 12. - P. 1462-1464.
7.                         Guidelines for control of shigellosis, icluding epidemics due to Shigella type 1/-World Health Organisation, 2005.
8.                         Implementing the New Recommendation on the Clinical Management of Diarrhoea. - World Health Organisation, 2006.
9.                         Klein J.D., Zaoutis T.E. Pediatric Infectious Disease Secrets. - Philedelphia: Hanley & Belfus Inc, 2003. - P. 142.

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