leptospirosis, salmonellosis, swine flu and avian flu

1. LEPTOSPIROSIS, SALMONELLOSIS,SWINE AND
AVIAN FLU
UNIT-1
R.T.Vinodhini

2. • Leptospirosis is an infectious disease caused by pathogenic bacteria
called leptospires (transmitted directly or indirectly from animals to
humans)
• Human-to-human transmission occurs very rarely
• Leptospirosis is thought to be the most widespread zoonosis in the
world
LEPTOSPIROSIS

3. ◾ Humans cangetleptospirosis - Direct contact withurine frominfectedanimals or throughwater,soil
or food contaminated with their urine
◾ Animals – Cattle,pigs,horses,dogs,rodents, andother wildanimals
◾ Rodents are the most important reservoirs for maintaining transmission in most
settings. Infection in small rodents (eg, rats) usually occurs in utero, during birth,
or during infancy from environmental contamination of the nest.
◾ Once infected, rodents are asymptomatic carriers and shed the organism in their urine
intermittently or continuously throughout life, resulting in contamination of the
environment, particularly water
Distribution:

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Microbiology :

6. • Estimated case-fatality rates in different parts of the world have been
reported to range from <5% to 30%
• Seasonal – peak in summer, during rainy/monsoon season
Incidence:

7. Pathogenesis:

9. Symptoms:

10. DIAGNOSIS - LEPTOSPIROSIS
◾ ELISA:
◾ IgM antibodies against leptospires
◾ Genus specific
◾ PCR:
◾ Finding the genetic material of pathogen
◾ Microscopic agglutination test (MAT):
◾ Incubating patient serum with various serovars of leptospires
◾ Serovar that reacts with patient serum - Infecting serovar
DIAGNOSIS - LEPTOSPIROSIS

11. SALMONELLOSIS
◾ 1st isolated in 1884 in pigs – S.choleraesuis
◾ One of the common cause for food poisoning
◾ Affects gastrointestinal system (stomach & intestines)
◾ Gram negative bacteria
◾ Common types - S.typhimurium,S.Bongori & S.Enterica
◾ More than 2500 serotypes
◾ Many are zoonotic

12. SALMONELLOSIS
◾ Transmission:
◾ Fecal-oral (humans)
◾ Contaminated foods
◾ Close contact with infected animals

15. Symptoms:
• Diarrhea
• Fever
• Abdominal cramping
(last for 4-7 days)
• Occasionally long term illness (Reiter's syndrome)

16. DIAGNOSIS
◾ Diagnosis – Isolation of Salmonella organisms
◾ Serotyping & antimicrobial testing
O antigen – outer layer of cell
H antigen – filament portion of flagellum
V antigen – capsular polysaccharide
◾ PCR
◾ 90 % - Stool culture
◾ Blood
◾ Urine

17. SWINE FLU
◾ Commonly known as - H1N1 influenza virus
◾ H1 - Hemagglutinin & N1 – Neuraminidases
◾ Influenza viruses types –T
ype A, type B and type C
◾ InfluenzaA is the most common type and H1N1 is a
type of influenzaAm(has sub-types based on HA and
NA)
◾ Respiratory disease of pigs (cells have virus
receptors for both avian and mammalian influenza
strains

18. SWINE FLU
◾ Hemagglutinin‐ protein the virus uses to attach to
the host cells.
◾ Neuraminidase‐ enables the virus to be released
from the host cell.
◾ M2 Ion Channel - allows protons to move
through the viral envelope and is essential for the
virus replication process.
◾ RNP‐ Ribonucleoprotein containing the virus
RNA genome.

20. Influenza changes,
• By antigenic drift of HA and NA
• By cleavage of the HA
• By HA changing to bind to different receptors

21. DIAGNOSIS
◾ Respiratory specimen ((nasal/throat swab) - First 4 to 5 days of illness (when an
infected person is most likely to be shedding virus)
◾ However,some persons,especially children,may shed virus for 10 days or longer
.
◾ T
ests:
◾ RTPCR
◾ Rapid influenza diagnostic test
◾ Direct immunofluorescence assays

22. AVIAN FLU
◾ Bird flu or fowl plague
◾ InfluenzaA virus
◾ Categorized - Haemagglutinin (H 1-16) & Neuraminidase
(N1-9) subtypes
◾ Low pathogenicity avian influenza (LPAI) - H1-4,H6, H8-
16
◾ Low pathogenicity notifiable avian influenza (LPNAI) - H5
and H7
◾ Highly pathogenicity or highly pathogenic notifiable avian
influenza (HPNAI) only by mutated forms of H5 and H7
AVIAN FLU

23. DIAGNOSIS
◾ LP and HPAI viruses - oropharyngeal and cloacal swabs.
◾ AI viruses grow well -Allantoic sac of 9 to 11 day old
embryonating chicken eggs and they agglutinate RBCs
◾ rRT- PCR (Real Time Reverse Transcriptase PCR) -
preferred diagnostic test which gives result in 3 hours

24. THANK YOU