Preventing spread of Influenza A - air transport angle

Ruwantissa Abeyratne

The Influenza A (H1N1) virus, formerly called the Swine flu virus, is a mutated strain of the common flu virus and therefore an infection caused by this virus cannot be treated by the seasonal flu vaccine administered in the latter part of the year in most countries.

However, two antivirals that appear to be effective in treating this illness are oseltamivir (Tamiflu) and zanamivir (Relenza). As at May 13, 2009, the World Health Organization (WHO) had recorded that 33 countries have officially reported 5,728 cases of influenza A(H1N1) infection.

According to WHO, Mexico has reported 2,059 laboratory confirmed human cases of infection, including 56 deaths. The United States has reported 3,009 laboratory confirmed human cases, including three deaths. Canada has reported 358 laboratory confirmed human cases, including one death.

Costa Rica has reported eight laboratory confirmed human cases, including one death.

Travel restrictions

Although the WHO does not advise travel restrictions and screening at the present time, it advises that it is prudent for people who are ill to postpone international travel and for people developing symptoms consequent upon undertaking international travel to seek medical attention, in line with guidance from national authorities.

The most important measure to be taken to ward off the virus is to wash hands thoroughly with soap and water on a regular basis. Should one develop flu like symptoms, which are reflective of an upper respiratory tract infection, coughing, high fever, severe fatigue and muscle strain (added to which could be headaches, nausea and vomiting) one should, according to WHO Guidelines, seek medical attention.

It is also a fact that there is no risk of infection from this virus from consumption of well-cooked pork and pork products.

The fundamental difference between the avian flu strain and the H1N1 strain is that the former was mainly transmitted within the bird population (with a rare case of human to human infection), the latter is transmitted from human to human, making it a stronger candidate for a pandemic (according to WHO, an influenza pandemic occurs when a new influenza virus capable of causing severe disease transmits easily among humans).

Therefore, with the Avian Flu, while we were at Phase 3 of the Pandemic Preparedness Alert of WHO - which is the phase where there is no general human to human transmission of the virus - we quickly went to Phase 4 on April 29, 2009 (which is the phase that recognizes that there is human to human transmission of the virus in a country of one WHO region resulting in death) to Phase 5 on April 29, 2009 (which is the phase that recognizes that there is human to human transmission in more than one State in a region and resultant deaths).

The last phase - Phase 6 - recognizes that there is a full blown influenza pandemic - and this phase occurs when there has been human to human transmission of the virus resulting in deaths in more than one WHO region).

The primary strategy of the WHO to mitigate the risks from a communicable disease is to contain the disease within the outbreak area. The main containment activities include heightened awareness of the public, mobilization of risk mitigation efforts by the community, including social distancing in the outbreak area (isolation and quarantine) and the application of prophylactic medication and vaccination.

To increase the effectiveness of this approach, the aviation sector can assist by reducing the likelihood of an individual with a communicable disease travelling outside the outbreak area.

This may require the establishment of traveller screening procedures at airports, medical assessment of travellers determined by screening as potentially infected by the disease in question and communication with the public, so that they are aware of the risks before setting out on their journey.

The H1N1 virus is clearly a communicable disease which is transmitted through air travel, in view of the fact that it has infected North America, Europe and Asia. It is therefore important to address pandemic preparedness from the perspective of air travel.

The International Civil Aviation Organization (ICAO) works closely with the WHO in this regard, particularly in view of the fact that the Convention on International Civil Aviation, an international treaty signed at Chicago in 1944, prescribes that member States of ICAO agree to take effective measures to prevent the spread by means of air navigation, certain communicable diseases as such States from time to time decide to designate.

Health issues

WHO, like ICAO, is a specialized agency of the United Nations. However, whereas WHO concentrates on health related issues, ICAO’s main area of interest concerns aviation. With respect to reducing the risk of spread of disease by air transport, neither organization can efficiently act alone, because detailed knowledge of relevant aspects of both health and aviation is required to develop an effective strategy.

ICAO and WHO work closely to complement each other in creating awareness of the risk of disease and its adverse effects.

Both organizations believe that, by jointly developing technical guidance and operational procedures, the aviation sector should be better prepared to respond to potential health risks which could spread through air transport and adversely affect the public health and aviation interests of different countries.

With regard to responding to the spread of communicable diseases by air transport, ICAO has reviewed its Standards and Recommended Practices (SARPs) of relevance to Article 14 of the Chicago Convention and has updated them in view of the contemporary risks to human health from communicable diseases.

New SARPs have been written that are in alignment with the latest revision of the WHO International Health Regulations. Although the SARPs describe the obligations on Contracting States, they do not explain in detail how they can be met.

Accordingly, ICAO has sought the assistance of specialist organizations such as the WHO, Centres for Disease Control and Prevention (CDC), Airports Council International (ACI) and the International Air Transport Association (IATA) in order to formulate guidelines for States that would assist them in developing their own, national, preparedness plans.

ICAO has advised States that National aviation authorities need to ensure that they are fully involved in the planning process to ensure that their expertise is available to the national public health authority. In this regard, it is believed that the chief medical officer of the national aviation authority is likely to be an important resource as he/she will have knowledge of most aspects of health and aviation operations that are relevant to developing a preparedness plan for aviation.

An area where specific expertise from the national aviation authority will be required is that of air traffic management.

Several issues will need to be considered, such as procedures to ensure flight safety when aircraft are diverted because of a suspected case on board, the reliable notification of the national public health authority by air traffic control after receiving information of a suspected case from a pilot, and how air traffic operations can be sustained when many personnel are simultaneously absent from work, possibly for several weeks.

In addition, the medical department of a national aviation regulatory authority is primarily concerned with ensuring that licence holders i.e. aircrew and air traffic controllers, are medically fit. However, because it has expertise in both aviation and health, such a department can play an important role in providing the link between public health and aviation interests.

Aviation sector

The regulatory authority’s medical department is well placed to ensure that health risks are managed in a consistent and proportionate manner across the airports in its State. Further, during public health emergencies the chief medical officer can be a valuable source of information for the national focal point with respect to the aviation sector, and can assist in the efficient management of such an emergency.

The main challenge to developing a management plan is to ensure that communication between the relevant stakeholders and partners is easy and rapid.

Traditionally, many organizations have worked in a vertical manner, meaning that inter-organizational communication links may not have been developed to the level necessary to adequately manage any health risk.

In particular, the national public health authority may not have developed efficient lines of communication with the national aviation authority (particularly with its medical department), with airport and airline operators, or with the media.

ICAO is working at an international level with the WHO to develop such communication links and is encouraging States to develop reliable communication networks between stakeholders and partners.

The writer is Acting Deputy Director, Air Transport at ICAO.