clinical manifestations of swine flu

1. SWINE FLU
SIDDHARTH
MEDICINE PG

2. TOPICS TO BE DISCUSSED
• INTRODUCTION
• EPIDEMIOLOGY
• RISK GROUPS
• ETIOLOGY
• PATHOGENESIS
• CLINICAL FEATURES
• COMPLICATIONS

3. INTRODUCTION
• It is caused by Influenza virus (H1N1)
• It is usually a mild and self limited respiratory
illness
• It has potential to cause significant morbidity
and mortality
• 2009 pandemic influenza A (H1N1) virus is
continued to co-circulate following years along
with seasonal influenza A and it cased significant
mortality among young people

4. EPIDEMIOLOGY
• Latest pandemic of swine flu was first noted in
Mexico in march 2009
• It spread worldwide affected nearly 195
countries and it ended in August 2010

6. • In India outbreak killed:
2009 - 981 2012 - 405
2010 - 1763 2013 - 699
2011 - 75 2014 - 218
• 2015 outbreak became wide spread throughout
India. Gujarat & Rajasthan were the worst affected
states
• 2009 pandemic strain is now responsible for the
periodic seasonal outbreaks of Influenza in India

9. • The average incubation period is 1-3 days
(maximum 7 days)
• Transmission through contact with large particle
respiratory droplets
• Other body fluids and fomites also play a role in
transmission
• Viral shedding begins the day prior to symptom
onset and often to persist for 5-7 days,
sometimes even longer in children & immuno
compromised

10. RISK GROUPS
• Age < 5 years & > 65 years
• Obese individuals
• Pregnancy
• Persons with Asthma/ COPD or other chronic
pulmonary diseases
• Immuno compromised and ppl receiving
Immuno suppressive therapy
• Sickle cell anemia and other
Hemoglobinopathies

11. • Long term aspirin therapy
• CKD
• Metabolic disease such as diabetes mellitus
• Persons with Neuromuscular disorders, seizure
disorders, cognitive dysfunction
• People working in Health care institutions

12. ETIOLOGICAL AGENT

14. • It’s a RNA virus belonging to the family of
Orthomyxoviridae
• Three main genera - Influenza A, Influenza B,
Influenza C
• Influenza A is further sub-typed into 16 distinct
H types & 9 distinct N types based on
Hemagglutinin & Neuroaminidase antigens on
the surface of the virus

15. • Every year new strains of influenza virus emerge
as its genes undergo point mutations leading to
‘Antigenic drift’
• This process helps the virus to evade host
defense mechanism
• Infuenza A virus has a 8 segmented genome with
eight single stranded RNA segments
• These genes get reassorted and produce a very
different strain altogether- “Antigenic shift”
• 2009 viral strain had undergone triple
reassortment and contain genes from the avian,
swine, and human viruses

17. PATHOGENESIS
• Virus particle may settle on nasopharyngeal,
tracheobronchial, conjuctival, or other
respiratory mucosal epithelial cells.
• H1N1 2009 strain can also additionaly bind to
the 2,3-linked sialic acid receptors that are
present in the lower respiratory tract and cause
diffuse alveolar damage and thereby causing
pneumonia in healthy individuals

20. COMMON CLINICAL FEATURES
• Fever
• Sore throat
• Rhinorrhea
• Myalgia & Arthralgia
• Headache
• Vomiting
• Diarrhoea

22. EXTRA PULMONARY MANIFESTATION
• CVS- Chest pain, hypotension
• CNS- Seizures, lethargy, altered mental status,
weakness or paralysis
• OTHERS- Decreased urine output, cyanosis,
dehydration

23. COMPLICATIONS
• PULMONARY - Progressive viral pneumonia,
Secondary bacterial pneumonia, ARDS
• CNS - Encephalitis, Encephalopathy, GBS,
ADEM
• CVS - Myocarditis, Pericarditis
• OTHERS – Renal failure, Rhabdomyolysis,
Ryes syndrome, Hemophagocytosis, Multi organ
failure syndrome

24. THANK YOU