Avian Flu




Egypt new epicentre for
H5N1 infections


 

With 119 confirmed cases between March 2006 and December 2010, Egypt ranks second among countries reporting human H5N1 influenza virus infections. In 2009–2010, Egypt reported 68 new human cases and became the new epicentre for H5N1 infections.

Writing in PLoS One online open access journal, researchers from St Jude Children’s Hospital in Memphis and Egypt’s National Research Center in Cairo explore the epidemiology of H5N1 in Egypt and provide an analysis of some of the genetic isolates of the virus with a view to seeing if these mutations are responsible for the lower mortality rate in humans in Egypt compared to other countries where the virus is prevalent.

The authors write that there is some concern that because the Egyptian isolates seem to be less virulent than that elsewhere, they are becoming more adapted to humans.

Epidemiology

CIDRAP news summaries the epidemiology in the report as follows: Egypt had 119 human H5N1 cases from 2006 through 2010, with 40 deaths (CFR, 34%), the report says. In 2006 the cases peaked in the spring, and in the ensuing 4 years they peaked in the winter and spring. There were three family clusters totalling seven cases during that time.

Sixty-two per cent of the patients were under age 18, and 60% were female. The mean age for all patients was 10 years, with a range of 1 to 75 years. The young age distribution could reflect Egypt's demographics or children's level of contact with poultry, the authors say. They also note that women typically play the lead role in tending backyard poultry, perhaps explaining the burden of cases in females, but this needs corroboration.

Bird flu in Egypt – winter takes its toll

The following confirmed cases of human infection with avian influenza A (H5N1) virus in Egypt have been reported since January this year.

- A 26-year-old female from Dakahlia Governorate developed symptoms on 18 January and was hospitalised on 23 January. She recovered and was discharged on 7 February.

- FATAL: A 45-year-old male from Menofia Governorate developed symptoms on 20 January and was hospitalised on 26 January. He died on 5 February.

- A 32-year-old woman from Sharkia Governorate developed symptoms on 10 February and was hospitalised on 14 February. She died on 3 March.

- A 4-year-old male from Damiata Governorate developed symptoms on 14 February and was hospitalised on 16 February. He was reported in a stable condition.

- A 2-year-old boy from Kafr Elsheikh Governorate developed symptoms on 18 February and was hospitalised on 20 February. He was reported in a good general condition.

- FATAL: A 17-year-old girl from Dakahlia Governorate developed symptoms on 24 February and was hospitalised on 26 February. She died on 28 February.

- A 17-year-old girl from Behira Governorate developed symptoms on 27 February and was hospitalised on 1 March. She was reported in a stable condition.

- A 4-year-old male from Behira Governorate developed symptoms on 5 March and was hospitalised on 7 March. He recovered and was discharged on 12 March.

- A 28-year-old female from Giza Governorate developed symptoms on 8 March and was hospitalised on 10 March. She was reported in a stable condition.

- FATAL: A 32-year-old male from Suez Governorate developed symptoms on 8 March 2011, was hospitalised on 12 March and died on 13 March.

- FATAL: A 20-year-old female from Behaira Governorate developed symptoms on 14 March and was hospitalised on 19 March. She was in a critical condition and died on 28 March.

- A 55-year-old female from Behaira Governorate developed symptoms on 20 March and was hospitalised on 22 March. She recovered and was discharged on 5 April.

- A one-year-old male from Fayoum Governorate developed symptoms on 20 March and was hospitalised on 28 March. He was reported in a stable condition.

- A two-year-old female from Menofeya Governorate developed symptoms on 26 March and was hospitalised on 27 March. She was reported in a stable condition.

- FATAL: A 29-year-old man from Fayoum Governorate Wadi Elrian area, developed symptoms on 1 April and was hospitalised on 4 April. He died on 7 April.

- A one-and-a-half-year-old boy from Fayoum Governorate, Sennores District, developed symptoms on 9 April and was hospitalised on 11 Apr 2011. He was reported in a stable condition.

Of the 141 total cases confirmed to date (11 April 2011) in Egypt, 46 have been fatal.

The fatality rate increased with age and was three times as high in females as in males, the investigators found. The CFR ranged from 4% for children under 5 to 10% for 5- to 9-year-olds and 53% for 10- to 18-year olds. Adults up to age 49 had a 61% CFR, and the rate was 75% for older adults. The rate for females was 47%, versus 15% for males, a significant difference.

The CFR also varied considerably by year and was particularly low in 2009, at 10%, before bouncing up to 45% in 2010, the authors note. Most of the cases in 2009 were in children under age 5, but a regression analysis showed that mortality was significantly lower in 2009 than in other years even when the different age distribution was taken into account.

Early hospitalisation was found to be a key factor in survival. The CFR for patients who were hospitalised within the first 2 days was 8%, versus 54% for those who were hospitalised later, a significant difference.

The authors caution that the overall 34% CFR may be an overestimate, because the rate of unrecognised cases is unknown.

The researchers found that the pattern of H5N1 cases in humans tends to mirror the pattern in poultry, both in frequency and severity. “For instance, a decrease in human case-fatality rate in 2009 was accompanied by an observed decrease in mortality among poultry,” they write.

Genetics

The researchers say several genetic sublineages of H5N1 clade 2.2.1 have been found in Egypt. Three of these are still circulating. However it appears that no specific lineages are present only in humans. There has been no host-adaption mutation observed “which suggests that the main transmission route of H5N1 in Egypt is still contact with infected birds, just as observed in the rest of the world.”

The authors point out that they were not able to confirm that lower pathogenicity of the viruses is the main reason for increase or decrease in the mortality rate among humans in Egypt.

The researchers says they are concerned about the potential of H5N1 viruses circulating in Egypt to become more adapted to human-to-human transmission because these new viruses are less virulent and may be causing asymptomatic infections especially among adults.

They point out that there is an “urgent need to conduct more epidemiologic studies in Egypt and other endemic areas to enhance our understanding of incidence, prevalence, and determinants of human infections with avian influenza.”

Ref: Kayali G et al, The Epidemiological and Molecular Aspects of Influenza H5N1 Viruses at the Human-Animal Interface in Egypt, PLoS ONE 6(3): e17730.

doi/10.1371/journal. pone.0017730

 

Landmark agreement improves global preparedness for influenza pandemics

In a major breakthrough for the way the world deals with future influenza pandemics, the World Health Organisation has brokered an international agreement that will see the open sharing of vital information to ensure more effective and efficient access to essential influenza vaccines and medications, particularly for lower-income countries.

Following negotiations which began in November 2007 amid concerns that the avian influenza (H5N1) virus in South- East Asia could become a human pandemic, and after a final week of tough negotiations in April this year, an openended working-group meeting of WHO Member States successfully agreed upon a Framework that ensures that in any future influenza pandemic, virus samples will be shared with partners who need the information to take steps to protect public health.

The working-group meeting was convened under the authority of the World Health Assembly and coordinated by the World Health Organisation (WHO).

The new Framework includes certain binding legal parameters for WHO, national influenza laboratories around the world and industry partners in both developed and developing countries that will strengthen the effectiveness of how the world responds with the next flu pandemic. By making sure that the roles and obligations among key players are better established than in the past – including through the use of contracts – the Framework will help increase and expedite access to essential vaccines, antivirals and diagnostic kits, especially for lower-income countries.

In addition, the Framework will also put the world in a better position for seasonal influenza and potential pandemic threats such as the H5N1 virus, because some key activities will begin before the next pandemic, such as greater support for strengthening laboratories and surveillance, and partnership contributions from the industry.

During an influenza outbreak, knowing the exact makeup of the virus is critical for monitoring the spread of the disease, for knowing the potential of the virus to cause a pandemic and for creating the life-saving vaccines as well as other technological benefits. However, developing countries often have limited access to these vaccines for several reasons: they often do not have their own manufacturing capacity, global supplies can be limited when there is a surge in demand as is seen during pandemics, and vaccines can often be priced out of the reach of some countries.

The new Framework will help ensure more equitable access to affordable vaccines and at the same time, also guarantee the flow of virus samples into the WHO system so that the critical information and analyses needed to assess public health risks and develop vaccines are available.

“This has been a long journey to come to this agreement, but the end result is a very significant victory for public health,” said Dr Margaret Chan, director-general of the WHO. “It has reinforced my belief that global health in the 21st century hinges on bringing governments and key stakeholders like civil society and industry together to find solutions.”

The legal regimes will address clear roles and responsibilities of WHO, national labs and vaccine and pharmaceutical manufacturers.

“The framework provides a much more coherent and unified global approach for ensuring that influenza viruses are available to the WHO system for monitoring and development of critical benefits such as vaccines, antiviral drugs and scientific information while, at the same time, ensuring more equitable access to these benefits by developing countries,” said Dr Keiji Fukuda, assistant directorgeneral of Health Security and Environment at WHO.

The agreed upon framework will be presented to the World Health Assembly in May this year for its consideration and approval.


WHO document archive www.who.int/gb
WHO Pandemic Influenza Preparedness http://apps.who.int/gb/pip
 

 Date of upload: 10th Jul 2011

 

                                  
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