INFLUENZA A (H1N1) SWINE FLU : EVOLUTION OF THE PROBLEM

1
INFLUENZA A (H1N1) SWINE FLU EVOLUTION OF
THE PROBLEM

• BY
• DR ESSAM EL-GAMAL
• Professor of Chest Diseases
• Mansoura Faculty of Medicine
• Tuesday May, 5, 2009

2
Introduction

• Swine Influenza (swine flu) is a respiratory
  disease of pigs caused by type A influenza that
  regularly cause outbreaks among pigs.

3
Introduction

• Swine flu viruses do not normally infect humans,
• However, human infections with swine flu do occur
  affecting people who are around pigs.
• its possible for swine flu viruses to spread
  from person to person also.

4
Influenza Pandemics of thepast 100 years

• Year of Origin Sub-Type in Circulation
• 1890 H2N8
• 1900 H3N8
• 1918 H1N1 (Spanish Flu)
• 1957 H2N2 (Asian Flu)
• 1968 H3N2 (Hong Kong Flu)
• 1977 HIN1 (Russian Flu)
  

5
Spread in less than 30 days!
Source PBS, WGBH American Experience Influenza
1918 www.pbs.org/wgbh/amex/influenza/maps
6
Hospital Response

• Shifts are extended.
• Least ill are discharged.
• Urgent patients only are admitted.
• Severe shortages of linens, bedpans, gowns,
  mattresses.
• Offices, gymnasiums, warehouses, tent cities used
  to isolate and care for the sick.

Emergency Hospital During Influenza Epidemic,
Source National Museum of Health and Medicine
7
An Emergency Hospital for Influenza Patients 1918
8
Mass Burials
Source Crosby, Alfred W. Jr., Epidemic and
Peace 1918,
9
Why The Current Swine Flu is Terrible ???

• The 1918 flu pandemic (Spanish flu) that spread
  to every part of the world, was caused by a
  virulent and deadly Influenza A virus of the same
  strain (H1N1).
• It lasted from March 1918 to June 1920 and
  affected up to one billion people
• ( gt ½ world's population at that time).

10
Why The Current Swine Flu is Terrible ???

• It is cosidered to be the most devastating
  epidemic in recorded world history.
• Around 70 - 100 million people were killed
  worldwide (equivalent of ? of population of
  Europe) and gt double the No killed in World War I.

11
Swine Flu Outbreaks in USA

• An outbreak ccurred in New Jersey, 1976 and
  caused gt 200 cases with serious illness and one
  death.
• gt 40 million were vaccinated and 30 died as a
  direct result of vaccination.
• The program was stopped after over 500 cases of
  GPS, were reported.

12 human infections with swine flu were reported
(from 10 US states) between Dec 2005 - Feb 2009.
12
Current Situation in the US

• Now since March 2009, 160 of confirmed cases
  with one death from 21 States are reported.
• Virus is described as a new subtype of A/H1N1 not
  previously detected in swine or humans.
• Samples from Mexico outbreak match swine
  influenza isolates from patients in USA.

Source CDC
13
Current Situation in the US

• CDC has determined that this virus is contagious
  and is spreading from human to human.
• April 27, 2009 CDC recommends against all
  non-essential travels to Mexico.

Source CDC
14
MMRW Report, April 30, 2009

• April 23-24, in NYC 222 high school students
  visited the nursing office and left school
  because of illness.
• April 24 (Friday)
• Nasopharyngeal swabs were collected from 9
  newly symptomatic students

Source http//www.cdc.gov/mmwr/preview/mmwrhtml/m
m58d0428a2.htm
15
April 26, 2009 7 of 9 specimens collected were
positive for the new strain of influenza.

• April 27, School closed.

16
MMRW Report, April 30, 2009

• April 26-28, 2009
• 37 (88) of 42 specimens collected tested
  positive, bringing the total number of confirmed
  cases to 44 of which
• Median age was 15 years (range 14-21 ys)
• Thirty-one (70) were females.

17

• 5 patients reported travel outside NYC within US
  states in the week before symptom onset.
• None of the 44 patients reported recent travel to
  California, Texas, or Mexico.

• 5 May 2009 -- As of 0600 GMT
• USA has reported 286 lab confirmed human cases,
  including one death.

18
Current Situation in Mexico

• A total of 2,498 suspected cases,165 deaths and
  1311 hospitalizations (for pneumonia) have been
  reported in 31 of 32 Mexico States (Ministry of
  Health).
• 443 Lab confirmed
• 1st case discovered in Oaxaca, April 13, 2009, a
  woman died of pneumonia.

Source Mexican Ministry of Health, WHO, CDC,
PAHO ProMED
19
Current Situation in Mexico

• The illness outbreak in Mexico City prompted the
  country's health minister to
• - cancel classes in Mexico City.
• - advise students and adults to avoid crowded
  public places.

20
Current Situation in Mexico

• CDC's lab analyzed 14 samples from severely ill
  Mexican pts
• 7 of them had the same swine flu mix as the
  virus that infected the US patient.
• Canada's national lab has confirmed swine flu
  A/H1N1 in 18 isolates from Mexican pts 12 of
  which were identical to the swine flu viruses
  from California.

Source WHO, CDC ProMED
21
Current Situation in Mexico

• The virus in Mexico differs from seasonal
  influenza in that it affects otherwise healthy
  young adults, (20- 50 years) however, seasonal
  influenza typically affects the very young and
  very old (Ministry of Health).

22
MMWR, April 30, 2009

• March 2009
• Mexico experienced outbreaks of
  influenza-like illness (ILI).
• April 12, 2009
• the General Directorate of Epidemiology (DGE)
  reported an outbreak of ILI in a small community
  in the state of Veracruz to the Pan American
  Health Organization (PAHO)
• April 17, 2009
• a case of atypical pneumonia in Oaxaca State
  aroused enhanced surveillance throughout Mexico

Source CDC
23
MMWR, April 30, 2009

• April 23, 2009
• several cases of severe respiratory illness,
  lab confirmed as influenza A(H1N1) virus
  infection were communicated to the PAHO.
• Sequence analysis revealed that the patients were
  infected with the same strain detected in 2
  children living in California.
• April 30, 2009
• a total of 1,918 suspected cases were
  reported, including 286 probable and 97 confirmed
  cases including 7 persons who had died

24
MMWR, April 30, 2009

• Of the 24 patients for whom demographic and
  clinical information was available,
• 20 (83) were hospitalized, 3 were examined in
  outpatient settings, and 1 had illness that was
  not medically attended.
• 79 of patients aged 5 - 59 years.
• 62 (15 patients) were females.

Source CDC
25
Last News 5 May 2009 -- As of 0600 GMT

• 21 countries have officially reported 1124 cases
  of influenza A (H1N1) infection.
• Mexico has reported 590 laboratory confirmed
  human cases of infection, including 25 deaths.
• The United States has reported 286 laboratory
  confirmed human cases, including one death.
• Canada 140 confirmed cases, Spain 54 confirmed
  cases, UK 18 confirmed cases.

26
Situation in EGYPT

• Egypt started a mass slaughter of thousands of
  pigs in an effort to prevent swine flu spreading,
  although flu cannot be caught from eating pig
  meat, and there is no scientific rationale for
  slaughtering pig.

27
Situation in EGYPT

• The authorities have increased numbers of medical
  staff at Cairo airport to check passengers
  arriving from Mexico and will monitor them during
  their stay.
• Up till now, no cases of swine flu in Egypt.
  However, neighbouring Israel has 2 confirmed
  cases in humans.

28
(No Transcript)
29

• DOHMH New York City Department of Health and
  Mental Hygiene.
• CDC center of disease control and prevention.
• MMWR Morbidity and mortality weekly report.