CHOLERA Vibrio cholerae - PowerPoint PPT Presentation

Loading...

PPT – CHOLERA Vibrio cholerae PowerPoint presentation | free to download - id: 8455c0-YzZjZ



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

CHOLERA Vibrio cholerae

Description:

CHOLERA Vibrio cholerae Brenda Anna Kwambana Wangeci Kagucia History Origins in India, cases reported as early as 1563 About 8 pandemics to date 1817-`23: First ... – PowerPoint PPT presentation

Number of Views:110
Avg rating:3.0/5.0
Slides: 22
Provided by: Wange150
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: CHOLERA Vibrio cholerae


1
CHOLERAVibrio cholerae
  • Brenda Anna Kwambana
  • Wangeci Kagucia

2
History
  • Origins in India, cases reported as early as
    1563
  • About 8 pandemics to date
  • 1817-23 First Pandemic
  • 1829-50 Second Pandemic
  • 1852-60 Third Pandemic Pacini
  • 1863-79 Fourth Pandemic
  • 1881-96 Fifth Pandemic Koch
  • 1899-1923 Sixth Pandemic
  • 1961-? Seventh Pandemic
  • 1992-? Eighth Pandemic

3
History
  • First pandemic spreads from India to South,
    Central Asia, Middle East and Russia
  • Second pandemic reaches England
  • Pandemics in 1800s deadly
  • All pandemics reach Africa
  • First pandemic reaches Latin America in 1991

4
Distribution
5
Causative AgentDiscovery
  • 19th Century What is Cholera?
  • Miasma Theory
  • Blood Generation Theory
  • Germ Theory

6
Causative AgentDiscovery
  • John Snow (1813-1858)
  • Water borne transmission of Cholera (1855)

7
Discovery
  • Filippo Pacini (1812-1883)
  • 1854 Cholera reaches Florence, Italy. Pacini
    discovers causative agent
  • Publishes Microscopical Observations and
    Pathological Deductions on Cholera
  • 1965 Bacterium named Vibrio cholerae Pacini 1854

8
Discovery
  • Robert Koch (1843-1910)
  • 1884 Rediscovers Vibrio cholerae

9
Vibrio choleraeMorphology
  • Gram negative
  • Comma shaped
  • Sheathed, polar flagellum
  • 1.4-2.6µm x 0.5-3µm

10
Physiology
  • Facultative anaerobic
  • Asporogenous
  • Growth stimulated by NaCl
  • pH 6 - 10, Acid labile
  • Temperature 18 - 37ºC

11
Virulence Pathogenicity
  • Ingestion of V. cholerae
  • Resistant to gastric acid
  • Colonize small intestine
  • Virulence of Non-toxigenic V. cholerae O1 strain
    not well understood

12
  • Toxigenic V. cholerae Pathogenicity
  • Colonization factors (the TcpA pilus)
  • Production of enterotoxin
  • Associated outer membrane proteins on enterocytes
    e.g. adenylate cyclase

13
  • Secrete enterotoxin
  • Enterotoxin binds to intestinal cells
  • Chloride channels activated
  • Release Large quantities of electrolytes
    bicarbonates
  • Fluid hypersecretion
  • Diarrhea

14
Transmission
  • Fecal-oral route
  • Entry oral
  • Discharge fecal

15
Transmission
  • Humans only reservoirs
  • Bacterium transmitted via contaminated water,
    food
  • Carriers houseflies and other insects
  • Person to person transmission?

16
Symptoms
  • 1-3 day Incubation Period
  • Mild diarrhea Sudden severe
    diarrhea
  • Mucus and intestinal tissue visible in feces
  • Muscle cramps
  • Scaphoid abdomen
  • Vomiting
  • Loss of skin turgor
  • Weak pulse

17
Diagnosis
  • Clinical symptoms
  • Isolation of V. cholerae from stool
  • Live V. cholerae in stool (ca. 1.0 x 108 cells
    per ml)
  • Identification via dark-field microscopy
  • Measurement of serum antibodies using ELISA
  • Antibacterial antibodies vibriocidal assays
  • Antitoxin antibodies

18
Methods of Cure
  • Chemotherapeutic
  • Antibiotics (tetracycline)
  • Immunological
  • Local mucosal immune response to V. cholerae
  • Serological antivibrio antibodies
  • Antitoxin antibodies
  • To Ease Symptoms
  • Oral Rehydration
  • Intraveneous Rehydration

19
Prevention Control
  • Immunization
  • Active Immunity induced by
  • attenuated V. cholerae
  • Toxoid (not good antigen)
  • Preventing contamination of food and water e.g.
    boiling water, covering food
  • Education
  • Personal and domestic hygiene
  • Prevention of contamination of water supplies
  • Improvement of sewage systems

20
References
  • Wachsmuth, I., Blake, P. Olsvik. O (Eds.).
    Vibrio cholerae and Cholera Molecular to Global
    Perspectives. Washington, DC ASM Press (1994)
  • Drasar, B., Forrest, B. (Eds). Cholera and the
    Ecology of Vibrio cholerae. Bury St Edmunds,
    Great Britain Chapman Hall (1996)
  • Perry, J., Staley, J. Lory, S. Microbial Life.
    Sunderland, MA Sinauer Associates, Inc. (2002)
  • US Food and Drug Administration. Vibrio cholerae
    Serogroup 01. Stable URL http//vm.cfsan.fda.gov
    /MOW/chap7.html

21
References, contd.
  • Todar, K.V. cholerae and Asiatic Cholera (2002).
    Stable URL http//www.bact.wisc.edu/Bact330/lectu
    recholera
About PowerShow.com