The document discusses various viruses affecting the central nervous system and respiratory system, focusing on Japanese Encephalitis (JE), SARS, and seasonal influenza. It outlines the transmission, clinical features, diagnosis, treatment, and prevention of these diseases, with emphasis on vaccination and vector control for JE. Additionally, it highlights the historical impact of influenza pandemics and the need for rapid response and international collaboration during outbreaks.

2. VIRUSES
1]Infecting CNS-Japanese encephalitis
2]Infecting RESPIRATORY SYSTEM
-SARS
-Pandemic influenza

3.  History
 Geographical distribution
 Transmission
 Clinical features
 Diagnosis and Treatment
 Prevention and Control

4.  Genus Flavivirus
 Name derived from
the Latin flavus meaning “yellow”
 Single stranded, enveloped RNA virus
 Morphology not well defined
 Different genotypes with single serotype
 Replication-Regional lymphnodes
 Invasion of CNS-via-Blood
 I.P-5 to 15 days

5.  1940 to 1978
› Disease spread with epidemics in China,
Korea, and India [Tamilnadu-1955]

6.  Endemic in
temperate and
tropical regions of
Asia
 Disease control by
vaccination
Japan
China
Korea
Indonesia
India Philippines

7.  The three southern states of Tamil Nadu
(TN), Andra Pradesh, Karnataka were
reporting higher incidence.
 JE is emerging as a public health
problem in Kerala
 In a few villages of Cuddalore district of
Tamil Nadu, a known JE-endemic area
(Chidambaram, Virudhachalam,
Thittakudi)

9.  Vector-borne
 Enzootic cycle
› Mosquitoes: Culex species
 Culex tritaeniorhynchus
› Reservoir/amplifying hosts
 Pigs, bats, Ardeid (wading) birds
 Possibly reptiles and amphibians
› Incidental hosts
 Horses, humans, others

10. Center for Food Security and Public Health, Iowa State University, 2011

11.  35,000-50,000 cases annually
 Most asymptomatic or mild signs
 Children and elderly
› Highest risk for severe disease
Center for Food Security and Public Health, Iowa State University, 2011

12. Prodromal stage: 1-6 days
 Acute encephalitis
› Headache, high fever, stiff neck, stupor
› May progress to paralysis, seizures,
convulsions, coma, and death
 Neuropsychiatric sequelae
› 45 to 70% of survivors
 In utero infection possible
› Abortion of fetus

13.  Laboratory diagnosis required
 Tentative diagnosis
› Antibody titer: HI, IFA, CF, ELISA
› JE-specific IgM in serum or CSF
 Definitive diagnosis
› Virus isolation: CSF, brain
 No specific treatment
› Supportive care

14.  Vector control
› Eliminate mosquito breeding areas
› Adult and larvae control
 Vaccination
› Equine, swine, humans
 Personal protective measures
› Avoid prime mosquito hours
› Use of repellants containing DEET
Center for Food Security and Public Health, Iowa State University, 2011

16. o Caused By- Varient of corona virus
o Emerging disease-2002-03
o Rapid spread in asian countries
o WHO-8422 cases
-916 deaths from 30 countries
o MOT-Respiratory droplets
o -Direct contact
-Possible fecal tranmission
o I.P-2 to 7 days

17. High fever

18.  Virus isolation: inoculate suitable cell
culture with patient specimens

19. When infected by SARS-CoV  antibodies
(e.g. IgM and IgG) are produced /
change in level
 Enzyme-linked immunosorbent assay
(ELISA)
 Immunofluorescence assay (IFA):

20.  Clinical history & observation
 Chest radiography: important role
› 70-80% patients have abnormal chest
radiographs

21. o Immunomodulatory therapy
-Corticosteroid
o Antiviral Agents
-Ribavirin
oProtease inhibitor
-Lopinavir-ritonavir co-formulation

22.  Principle: to break the chain of
transmission from infected to healthy
person
 3-step protocol of disease confinement
› Case detection
› Prompt isolation
› Contract tracing
 Daily health check
 Voluntary home isolation

23.  Creation of emergency operating center
 Institutional support
› Efficient quarantine measures
› Legislation
 International collaboration—WHO
› Travel alerts and restrictions
› Coordination for research
› Agreement of countries on containment
protocol

25. Seasonal Influenza
› A public health
problem each year
› Usually some immunity
built up from previous
exposures to the
same subtype
› Infants and elderly
most at risk
Influenza Pandemics
› Appear in the human
population rarely and
unpredictably
› Human population
lacks any immunity
› All age groups,
including healthy
young adults
Seasonal Epidemics vs. Pandemics

26. 1920 1940 1960 1980 2000
H1N1
H2N2
H3N2
1918: “Spanish Flu” 1957: “Asian Flu” 1968: “Hong Kong Flu”
20-40 million deaths 1-4 million deaths 1-4 million deaths

27. The new virus must be efficiently
transmitted from one human to another
A new influenza virus emerges to
which the general population has
little/no immunity
The new virus must be able to replicate
in humans and cause disease

28. Viral Re-assortment
Reassortment in pigs
Reassortment in
humans
Pandemic Influenza
Virus

29. Human Influenza
Type of infection Upper and lower respiratory
Fever Yes
Headache Yes
Cough Yes
Respiratory symptoms Varies; sore throat to difficulty
breathing
Gastrointestinal
symptoms
Uncommon, except children,
elderly
Recovery 2-7 days

30. Isolation Precautions

31. Source: Rosie Sokas, MD MOH UIL at
Chicago
Droplet precautions:
Surgical Masks

33. Personal Protective Equipment
(PPE)

36. Thank you