Are we prepared for Avian flu?
Michaela Freeland discusses the role of Cambridge scientists in tackling the threat posed by Avian flu, and Catherine Bosley outlines the measures taken to prepare Cambridge for an Avian flu epidemic
The word “flu” is used in many different contexts, from the predictable Fresher’s bout to the epidemic of the 1918 Spanish flu. But after the hospitalisation of a Suffolk cull vet with suspected bird flu on 6 February, a new kind of flu has been forced once more on the public attention.
Though the current threat is posed by “bird flu” in particular, the virus from which it derives is the same. Dr Paul Digard of the Department of Pathology argues that “all flu is avian at source, it’s just that some strains have adapted better to growing well in certain species”. Therefore, the study of the mechanisms of the virus and its transmission in any species provides invaluable knowledge to aid the prevention of bird flu. Cambridge academics are researching into a wide range of cases. Dr Debra Elton at Animal Trust runs a monitoring programme for equine influenza, and her group also keeps a close eye on Cambridge’s pigs, dogs and chickens.
But while most strains of avian and other animal flu are benign and commonly found on farms throughout Britain, the H5N1 strain responsible for the outbreak in Suffolk is distinctive for its capacity to bridge the species barrier and infect humans. Fears have been voiced that the genetic material of the virus could possibly mutate within other mammalian carriers such as cats. If so, it would have the potential to be transmitted from one human to another as opposed to through direct contact with infected birds. This development would increase the chance of a sweeping epidemic.
Influenza research at Cambridge seeks to combat the threat in two ways. While the Veterinary School and Zoology Department monitors animal health and possible outbreaks, the Department of Pathology conducts bio-chemical investigation at Addenbrooke’s. In the Department of Applied Maths & Theoretical Physics, the spread of infectious diseases is modelled mathematically. Cambridge Infectious Disease Consortium (CIDC), which oversees these different lines of enquiry, also includes an Education and Training Unit, training veterinary students to deal with potential pandemics in the future.
Cambridge is further involved in nationwide and international research. The Department of Zoology, which monitors outbreaks of influenza, plays a significant role in choosing the antigen composition of the World Health Organisation’s annual influenza vaccine.
The sharing of information and resources across institutions is important given that none of the laboratories in Cambridge meets the necessary requirements for biological containment facilities (“Biosafety Level 3” or above). As a result, University researchers cannot study highly pathogenic strains of the virus, and must work instead with non-infectious components.
Thus, rather than find ways to make it less infectious or harmful, researchers are studying the mechanisms by which the virus replicates. No virus can replicate on its own; it does so only inside the cells of the host organism. Understanding the mechanisms by which the virus manipulates the host to achieve this could lead to methods of disrupting this process. Further, to replicate its genetic material the influenza virus requires particular biological molecules that are not present in uninfected cells. Preventing their formation could halt the infection without damaging healthy cells. In any population, some individuals have natural immunity to infection. For eample, at the Vet School, researchers are studying those animals with genes that possess an “innate” resistance to influenza, so that vaccines would no longer be necessary.
Such novel methods are important since current vaccinations to prevent influenza remain ineffective. Like the other aspects of the influenza genome, the surface proteins of the virus to which antigens bind before destroying the infected cell are constantly mutating. This is why a new flu jab is needed each winter. Inherent genetic resistance may be an answer.
While the risk of an avian flu pandemic in Britain is minimal, the scientific study into combating the threat is essential. The better the understanding of biochemical action of the virus and the patterns in which it spreads, the more readily prevention measures can be transferred to other forms of influenza and animal-borne disease.
Historically, epidemics have contributed to scientific development. The last time the University was quarantined as a result of plague, Trinity mathematician Isaac Newton went home and returned with the theory of gravity.
The University of Cambridge is drawing up plans to deal with a future avian flu pandemic in the city following an outbreak the highly pathogenic H5N1 strain of avian flu on a turkey farm in Suffolk.
Government Departments have been frantically working over the past week to control the outbreak. The Department for Environment, Food and Rural Affairs (DEFRA) has undertaken the gassing of more than 150,000 poultry and set up a zone of restricted access that reaches 60 km of Cambridge. The NHS has stocked 14.6 million doses of Tamiflu, the drug used to treat flu cases. The Home Office along with several other agencies conducted a drill code-named “Winter Willow” to prepare for a possible large-scale flu outbreak.
Dr Mark Wormald, Senior Tutor at Pembroke College and chair of the Advisory Group on Communicable Diseases explained “There is a pandemic plan for the University, and we are in the process of conducting exercises across departments to test resilience.” He added “The Pa ndemic Planning Working Party and the Pandemic Emergency Planning sub-group have been meeting regularly and have drawn up guidelines for both the University as a whole and the colleges”.
At present, humans can only be infected with the avian flu virus through direct contact with infected birds. Since 2003, 166 individuals worldwide have died from the virus but transmission between humans is not possible. But should the virus mutate, enabling it to spread from person to person, a pandemic could ensue. The Centre for Disease Control, a US public health agency, warns that because students often live in close quarters in halls of residence, they could be particularly at risk.
The measure taken by the Univeristy include drawing up “avian influenza and pandemic flu guidelines”, details of which can be found on the university website. They are also working closely with the NHS and local GPs, and appointing a Pandemic Flu Liaison Nurse. Moreover, according to Dr Wormald, “the University has adopted quarantine guidelines”, although he did not disclose any details to Varsity. In the event of an outbreak, “The response… would be one of containment and isolation with appropriate medical support from trained and appropriately equipped staff. Provision for this is in place.”
In contrast, Harvard University has, in the past five years, undertaken emergency response planning including a new intranet for information sharing and fitting “front-line” staff with facemasks. Harvard has also conducted sessions in responding to a public health emergency for school staff and faculty members. One of the drills simulated the case of a student who had fallen sick after a trip to southern Africa. Drill-participants were linked via computer and given 15 minute deadlines to respond to unexpected developments, such as the unannounced appearance of television crews on campus and discussion of the student’s condition via internet chat groups.
Paul Parry, in charge of emergency planning for the evacuation plan in Cambri dge City Centre, has recently been participating in the Winter Willow exercise. Parry explained that he is currently in the process of “tweaking” the city’s emergency response plan, to “plug any gaps” left from the drawing board stage. One particular challenge he believes the City would face in the event of a pandemic outbreak would be allocating manpower. City employees would be pulled from their usual jobs to assist with the effort, but at the same time it would need to be ensured that basic services, such as trash collection, were functioning. Parry said he and his team were taking contingency planning for a flu pandemic “very seriously”. Successful planning required a response to public concerns and “not giving people a cold shoulder”, he contended.
At Addenbrooke’s hospital, spokeswoman Heather Munro told Varsity that if the flu were to emerge, response measures “would include ensuring that beds were available for those who really needed admission to hospital, [and] dealing with how we would run services in the event of increased staff absences”. Addenbrooke’s referred Varsity’s questions regarding the availability of Tamiflu to Cambridge students to the Health Protection Agency. The HPA, however, was unavailable to provide further details because its team members were busy dealing with the Suffolk flu outbreak.
Varsity also inquired with the Cambridgeshire County Council about what contingency plans had been drawn up and what sort of efforts were currently underway at the regional level. In response, the county council press office declined to comment.