1. Viruses causing respiratory infections. Influenza viruses
Viruses causing respiratory infections. Influenza viruses. Paramyxoviruses. Measles and mumps viruses.
Vinnitsa National Pirogov Memorial Medical University / Department of microbiology

2. Classification of an Orthomyxoviridae
Family Orthomyxoviridae includes three pathogenic for human species:
Influenza virus A
Influenza virus B
Influenza virus C

3. Influenza virus

5. Antigenic structure of influenza virus
Internal antigens (S-antigen)
Ribonucleoprotein (RNP)
M-protein from inner layer of envelope
External antigens (V-antigen)
Hemagglutinin (HA)
Neuraminidase (N)

6. Antigenic variation of influenza virus
Antigenic variability may be of two different types:
Antigenic drift
Antigenic shift

7. Epidemiology of the flu
The source of infection may be:
Infected person
Wild and domestic birds
Domestic animals
Characteristics of the viruses have caused the most famous pandemics:
In “Spanish flu” was caused by A (H1N1) virus
In 1957 “Asian flu” was caused by A (H2N2) virus
In 1968 “Hong Kong flu” was caused by A/Hong Kong (H3N2)
In 1977 “Red flu” was caused by A (H1N1)
From 1968 and 1977 pandemics both types (H1N1 and H3N2) have been circulated together

8. Endemic influenza annually in the US1
5% to 20% of the population gets the flu
More than 200,000 people are hospitalized from flu complications
About 36,000 people die from flu
Avian Influenza, cumulative data2
379 cases reported, 239 deaths (63%)
2008: 28 cases / 22 deaths
1http://
2APR 08, WHO

9. Avian Influenza, cumulative data2
379 cases reported, 239 deaths (63%)
2008: 28 cases / 22 deaths

10. Laboratory diagnostics
Collected samples are nasal or throat swabs, nasal or throat washing, sputum, nasal prints
Rapid tests are based on the demonstration of the virus antigens in the collected material. They include:
Direct immunofluorescence
Reversed indirect hemagglutination test (RIHA)
FLU OIA and QUICKVUE Influenza Test are based on detection of the viral antigens with monoclonal antibody
ZSTATFLU is based on detection of viral neuraminidase with colored substrate of the enzyme

11. Laboratory diagnostics
Microscopy
Isolation of the virus (culture or virological method)
Serology (serological method)

12. Laboratory diagnostics of the flu
Immunofluorescence
Virus inoculation into chicken embryo

13. Specific prophylaxis
Specific prophylaxis is immunization with subunit influenza vaccines 3-4 weeks before predictable onset of epidemic (Fluarix, Influvac, Vaxigrippe, Grippol and others).

14. Paramyxoviruses Family Paramyxoviridae
Subfamily Paramyxovirinae includes three genera:
Respirovirus (four serotypes of parainfluenza viruses)
Morbillivirus (measles virus)
Rubulavirus (mumps virus)
Subfamily Pneumovirinae contains one genus Pneumovirus (respiratory syncytial virus)

15. Structure of a paramyxovirus

16. Antigenic structure and biological features
Outer antigens: HN and F Inner antigens: RNP and M-protein

17. Epidemiology and pathogenesity
Parainfluenza viruses cause croup (acute laryngotracheo-bronchitis), laryngitis, brochiolitis and pneumonia in children and a disease resembling the common cold in adults. They are responsible for 50-80% of respiratory tract infections Measles virus causes measles Mumps virus causes mumps The source of infection is an ill person Paramyxoviruses are transmitted via respiratory droplets (airborne diseases)

18. Maculopapular rash (measles)

19. Laboratory diagnostics
Rapid tests:
Immunofluorescence test
Cytoscopy
Culture method
Serological investigation

20. Treatment and prophylaxis
Prophylaxis is made by immunization with alive attenuated vaccine For current prophylaxis in pregnant women, children with immunodeficiency anti-measles and normal human immunoglobulin are used

21. Mumps: clinical findings and immunity
Mumps is acute infectious disease commonly affecting children and characterized by nonsuppurative enlargement of parotid glands

22. Laboratory diagnostics
Virus isolation (culture method)
Serological tests
Prevention of mumps may be done with alive attenuated vaccine
Current prophylaxis is possible with either alone vaccine (active immunization) or normal human immunoglobulin (passive immunization)

23. Parainfluenza virus
Type 1 and type 2 cause croup ( acute laryngotracheobronchitis) in children
Type 3 cause tracheobronchitis, bronchiolitis and pneumonia in children before 5 years.
Type 4 provokes mild respiratory infections
Laboratory diagnosis is based on virus isolation from throat and nasal swabs.
Serological tests with paired sera can confirm diagnosis by 4-fold and greater rising of antibody titer