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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. Introduction.
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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
Introduction Swine Influenza (swine flu) is a respiratory disease of pigs caused by type A influenza that regularly cause outbreaks among pigs.
Introduction • Swine flu viruses do not normally infect humans, • However, human infections with swine flu do occur affecting people who are around pigs. • it’s possible for swine flu viruses to spread from person to person also.
Influenza Pandemics of thepast 100 years Year of OriginSub-Type in Circulation 1890 H2N8 1900 H3N8 1918 H1N1 (Spanish Flu) 1957 H2N2 (Asian Flu) 1968 H3N2 (Hong Kong Flu) 1977 HIN1 (Russian Flu)
Spread in less than 30 days! Source: PBS, WGBH American Experience :Influenza 1918 www.pbs.org/wgbh/amex/influenza/maps
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
Mass Burials Source: Crosby, Alfred W. Jr., Epidemic and Peace 1918,
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 ( > ½ world's population at that time).
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 ⅓ of population of Europe) and > double the No killed in World War I.
Swine Flu Outbreaks in USA An outbreak ccurred in New Jersey, 1976 and caused > 200 cases with serious illness and one death. > 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.
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
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
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 MMRW Report, April 30, 2009 Source: http://www.cdc.gov/mmwr/preview/mmwrhtml/mm58d0428a2.htm
April 26, 2009 : 7 of 9 specimens collected were positive for the new strain of influenza. • April 27, School closed.
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.
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 06:00 GMT: USA has reported 286 lab confirmed human cases, including one death.
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
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.
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
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).
MMWR, April 30, 2009 March 2009 : Mexico experiencedoutbreaks of influenza-like illness (ILI). April 12, 2009 : the General Directorate of Epidemiology (DGE) reportedan 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
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
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
Last News : 5 May 2009 -- As of 06:00 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.
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.
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.
DOHMH : New York City Department of Health and Mental Hygiene. • CDC : center of disease control and prevention. • MMWR : Morbidity and mortality weekly report.