Difference between revisions of "Endamoeba coli: Dose Response Models"

From QMRAwiki
Jump to: navigation, search
m (Endamoeba coli)
Line 6: Line 6:
 
==='''Overview of ''Endamoeba coli'''''===
 
==='''Overview of ''Endamoeba coli'''''===
  
Amoebiasis is defined as infection with the protozoan parasite ''Entamoeba histolytica''. However there are several Endamebas species which are closely related to E''. histolytica'' such as ''E. dipar'' and ''E. coli''. (Anonymous 1997)
+
Amoebiasis is defined as infection with the protozoan parasite ''Entamoeba histolytica''. However there are several Endamebas species which are closely related to E''. histolytica'' such as ''E. dipar'' and ''E. coli''. <ref name=Entamoeba_taxonomy>Anonymous (1997). Entamoeba taxonomy. Bulletin of the World Health Organization 75.3: 291-292.[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2486954/pdf/bullwho00394-0118.pdf Full text]</ref>
  
 
''Entamoeba coli''are a non-pathogenic species of ''Entamoeba'' that frequently exists as a commensal parasite in large intestine of the human. Both cysts and trophozoites of the species are passed in stool and considered diagnostic (CDC 2009). Cysts are typically found in formed stool, whereas trophozoites are typically found in diarrheal stool.&nbsp; Colonization of the nonpathogenic amebae occurs after ingestion of mature cysts in fecally-contaminated food, water, or fomites(CDC 2009).  
 
''Entamoeba coli''are a non-pathogenic species of ''Entamoeba'' that frequently exists as a commensal parasite in large intestine of the human. Both cysts and trophozoites of the species are passed in stool and considered diagnostic (CDC 2009). Cysts are typically found in formed stool, whereas trophozoites are typically found in diarrheal stool.&nbsp; Colonization of the nonpathogenic amebae occurs after ingestion of mature cysts in fecally-contaminated food, water, or fomites(CDC 2009).  
Line 47: Line 47:
 
<references />
 
<references />
  
Anonymous (1997). "Entamoeba taxonomy." Bulletin of the World Health Organization '''75'''(3): 291-292.
 
  
 
CDC (2009). Intestinal Amebae. D. o. P. Diseases.
 
CDC (2009). Intestinal Amebae. D. o. P. Diseases.

Revision as of 02:13, 12 October 2012

Endamoeba coli

Author: Sushil Tamrakar


Overview of Endamoeba coli

Amoebiasis is defined as infection with the protozoan parasite Entamoeba histolytica. However there are several Endamebas species which are closely related to E. histolytica such as E. dipar and E. coli. [1]

Entamoeba coliare a non-pathogenic species of Entamoeba that frequently exists as a commensal parasite in large intestine of the human. Both cysts and trophozoites of the species are passed in stool and considered diagnostic (CDC 2009). Cysts are typically found in formed stool, whereas trophozoites are typically found in diarrheal stool.  Colonization of the nonpathogenic amebae occurs after ingestion of mature cysts in fecally-contaminated food, water, or fomites(CDC 2009).



Summary of data

Rendtorff, R. C. (1954) studied the Entamoeba coli exposure to human volunteers with a known numbers of cysts of E. coli were administered orally in capsules to volunteers to determine numbers of parasites necessary to establish the infection.


Experiment serial number Reference Host type Agent strain Route # of doses Dose units Response Best fit model Optimized parameter(s) LD50/ID50
45* [2] human From an infected human oral 5 Cysts infection beta-Poisson α = 1.01E-01 , N50 = 3.41E+02 3.41E+02
*This model is preferred in most circumstances. However, consider all available models to decide which one is most appropriate for your analysis.
Exponential and betapoisson model.jpg

Optimization Output for experiment 45

Humans model data [2]
Dose Infected Non-infected Total
1 1 7 8
10 3 7 10
100 2 2 4
1000 0 2 2
1E+04 2 0 2


Goodness of fit and model selection
Model Deviance Δ Degrees
of freedom
χ20.95,1
p-value
χ20.95,m-k
p-value
Exponential 27.8 22.8 4 3.84
1.81e-06
9.49
1.36e-05
Beta Poisson 5.04 3 7.81
0.169
Beta-Poisson fits better than exponential; cannot reject good fit for beta-Poisson.


Optimized parameters for the beta-Poisson model, from 10000 bootstrap iterations
Parameter MLE estimate Percentiles
0.5% 2.5% 5% 95% 97.5% 99.5%
α 1.01E-01 1.20E-03 2.60E-02 3.61E-02 2.12E-01 2.57E-01 3.08E-01
N50 3.41E+02 5.02E+00 1.73E+01 2.61E+01 1.48E+05 2.08E+06 1.19E+10


Parameter scatter plot for beta Poisson model ellipses signify the 0.9, 0.95 and 0.99 confidence of the parameters.
beta Poisson model plot, with confidence bounds around optimized model



Reference

  1. Anonymous (1997). Entamoeba taxonomy. Bulletin of the World Health Organization 75.3: 291-292.Full text
  2. 2.0 2.1 Rendtorff, R. C. (1954). "The Experimental Transmission of Human Intestinal Prozoan Parasites. I. Endamoeba coli Cyst Given in Capasules." American Journal of Hygien 59: 196-208.


CDC (2009). Intestinal Amebae. D. o. P. Diseases.

Rendtorff, R. C. (1954). "The Experimental Transmission of Human Intestinal Prozoan Parasites. I. Endamoeba coli Cyst Given in Capasules." American Journal of Hygien 59: 196-208.