Influenza Pandemic: International Seminar

SPECIAL EDITORIAL

Influenza Pandemic: International Seminar

Maria Rita Donalísio

Membro da Comissão de Epidemiologia da ABRASCO e da FCM-Unicamp. Departamento de Medicina Preventiva e Social da Faculdade de Ciências édicas da Unicamp Caixa Postal 6111 Campinas - SP 13083-970 [e-mail]

Most human diseases originate from animals. It is estimated that 75% of emerging diseases are zoonotic. The existence of multiple reservoirs of the influenza virus in nature favors the recombination of human and animal viruses or mutations of the viral genome, increasing the likelihood of the emergence of new subtypes, to which the human population is susceptible.

Influenza epidemics, as well as other diseases, respond to social, cultural and ecological determinants that favor the dissemination of new strains and influence transmission dynamics in space and time. In the 20^th century, there were 3 major influenza pandemics: the Spanish Flu in 1918-19, the Asian Influenza in 1957-58, the Hong Kong Influenza in 1968-69, all in different historical and technological scenarios.

In 1997 in Asia, a highly pathogenic virus, influenza A H5N1, was transmitted from birds to humans setting the world on guard. After 2003, due to an economic and cultural situation of contact between birds and swine, there have been outbreaks of influenza in China, Vietnam, Korea, and Thailand, with severe clinical expression and high lethality. When virus A H5N1 was identified, there already were clear changes in its antigenic features, if compared to the 1997 strain, suggesting the occurrence of adaptive mutations in this strain.

Although the history of past influenza pandemics has taught us a few lessons, today no model can predict the exact magnitude, severity, and etiology of the next pandemic. The urban population has grown, there are a larger number of chronic and elderly patients, and there has been an increase in poverty and inequality in some regions, in addition to faster transportation that facilitates the circulation of pathogens around the world. At the same time, it is possible to produce vaccines in a large scale, to use prophylactic and therapeutic antiviral drugs, in addition to an improved clinical approach to support patients with severe diseases.

In face of the uncertainty, we are left with the challenge of getting ready for the unexpected by studying possible scenarios.

In many national and international forums, including the International Seminar on the Influenza Pandemic, held in November, in Rio de Janeiro, possible measures were discussed, like the readiness of institutions for the production of an appropriate vaccine in Brazil, a strategic national inventory of antiviral agents, criteria and priorities, the probable impact on hospitalizations and deaths, measures for individual and collective protection in the community and healthcare services, and epidemiological surveillance, and other issues. There is a consensus as to the need of working as a network and in partnerships, to prioritize the metropolitan approach, control the disease on its focus, reinforce virological and epidemiological surveillance in humans and animals, monitoring mutations and circulation of viruses, invest in therapeutic and laboratory resources. The Ministry of Health and the States have presented flexible contingency plans that may respond and adapt to unexpected versions of the diseases and transmission.

These are re-edited epidemics, old new diseases and new old diseases, which require flexibility and creativity, solidarity, and transparence from technicians to respond to the unexpected.

Publication Dates

• Publication in this collection
  11 June 2007
• Date of issue
  Dec 2005