Dengue in Cuba: research strategy to support dengue control
Original Text http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(09)61975-9/fulltext?_eventId=login
Maria G Guzm?n aEmail Address, Gustavo Kour? a
In recognition of the importance of research for human health, Cuba has been working hard to improve its capacity to face infectious diseases. Among these, dengue, an arthropod-borne disease caused by dengue viruses and transmitted by the Aedes aegypti mosquito, occupies a major position, when we consider that Cuba is surrounded by endemic countries and thus at risk of virus introduction.
The characteristics of the prevention programme for dengue, the continuous process of human-capacity building, and the development of basic and implementation research have been fundamental to keep the country free of dengue. Although sporadic epidemics have been reported, they were eliminated.1
Epidemiological, clinical, and virological studies have improved our knowledge about dengue. The role of secondary infection by a different dengue serotype, reported in Thailand and others countries2 as a risk factor for severe illness, has been confirmed in Cuba.1, 3, 4 Also, three important discoveries have been reported: the increase in disease severity corresponding to the longer interval between first and second dengue infections;3 the existence of a human dengue resistance gene (black people are highly resistant to severe dengue);4, 5 and a rapid increase in the severity of dengue disease as the epidemic advances.1, 4, 6
Early recognition of the role of the host, the virus, and the epidemiological conditions is important to explain epidemics of dengue haemorrhagic fever.4 Relevant factors are the report of some chronic diseases as risk factors for severity,1, 4 the recognition of warning signs for severe illness, and the association of some viral sequences with clinical outcome.7 Other scientific findings have implications for pathogenesis, case management, and vaccine development, such as dengue haemorrhagic fever 20 years after the primary dengue infection,1, 3, 7 the study of gene polymorphisms (such as HLA and FcγRIIa) and their association with susceptibility or resistance to dengue infection,8 and the role of humoral markers and cellular immune mediators in the course of the illness.9
Improvement of the diagnosis of dengue is another important research area. The serological and molecular diagnostic techniques that have been developed, including the Cuban ultramicro ELISA for specific IgM detection,10, 11 have allowed the country to be self-sufficient. The Cuban laboratory network with its serological capacity and the reference centre at the Institute of Tropical Medicine support the national laboratory surveillance.
For a vaccine, two recombinant candidates (chimeric protein domain III fused to p64k of Neisseria meningitidis and a fusion protein domain III capsid from dengue 2) were developed, and are at an advanced stage of preclinical evaluation with satisfactory results in terms of immunogenicity and protection after challenge. The results open a new window of opportunity for subunit vaccines.12
Presently, vector control is the only way for epidemic control and prevention. Cuba's efforts have been directed at the development and implementation of entomological research, such as the study of insecticide-resistance mechanisms, the monitoring of the efficacy of chemical and biological vector-control methods, and the development of new tools and strategies to identify the local environmental features that characterise A aegypti infestations.13 Investigations are also directed to measure and improve community involvement in dengue vector-control, in view of the fact that the presence of A aegypti depends on human behaviour. Results suggest that community-based environmental management embedded in the routine control programme is required for cost-effective and sustainable mosquito control.14
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Original Text http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(09)61975-9/fulltext?_eventId=login
Maria G Guzm?n aEmail Address, Gustavo Kour? a
In recognition of the importance of research for human health, Cuba has been working hard to improve its capacity to face infectious diseases. Among these, dengue, an arthropod-borne disease caused by dengue viruses and transmitted by the Aedes aegypti mosquito, occupies a major position, when we consider that Cuba is surrounded by endemic countries and thus at risk of virus introduction.
The characteristics of the prevention programme for dengue, the continuous process of human-capacity building, and the development of basic and implementation research have been fundamental to keep the country free of dengue. Although sporadic epidemics have been reported, they were eliminated.1
Epidemiological, clinical, and virological studies have improved our knowledge about dengue. The role of secondary infection by a different dengue serotype, reported in Thailand and others countries2 as a risk factor for severe illness, has been confirmed in Cuba.1, 3, 4 Also, three important discoveries have been reported: the increase in disease severity corresponding to the longer interval between first and second dengue infections;3 the existence of a human dengue resistance gene (black people are highly resistant to severe dengue);4, 5 and a rapid increase in the severity of dengue disease as the epidemic advances.1, 4, 6
Early recognition of the role of the host, the virus, and the epidemiological conditions is important to explain epidemics of dengue haemorrhagic fever.4 Relevant factors are the report of some chronic diseases as risk factors for severity,1, 4 the recognition of warning signs for severe illness, and the association of some viral sequences with clinical outcome.7 Other scientific findings have implications for pathogenesis, case management, and vaccine development, such as dengue haemorrhagic fever 20 years after the primary dengue infection,1, 3, 7 the study of gene polymorphisms (such as HLA and FcγRIIa) and their association with susceptibility or resistance to dengue infection,8 and the role of humoral markers and cellular immune mediators in the course of the illness.9
Improvement of the diagnosis of dengue is another important research area. The serological and molecular diagnostic techniques that have been developed, including the Cuban ultramicro ELISA for specific IgM detection,10, 11 have allowed the country to be self-sufficient. The Cuban laboratory network with its serological capacity and the reference centre at the Institute of Tropical Medicine support the national laboratory surveillance.
For a vaccine, two recombinant candidates (chimeric protein domain III fused to p64k of Neisseria meningitidis and a fusion protein domain III capsid from dengue 2) were developed, and are at an advanced stage of preclinical evaluation with satisfactory results in terms of immunogenicity and protection after challenge. The results open a new window of opportunity for subunit vaccines.12
Presently, vector control is the only way for epidemic control and prevention. Cuba's efforts have been directed at the development and implementation of entomological research, such as the study of insecticide-resistance mechanisms, the monitoring of the efficacy of chemical and biological vector-control methods, and the development of new tools and strategies to identify the local environmental features that characterise A aegypti infestations.13 Investigations are also directed to measure and improve community involvement in dengue vector-control, in view of the fact that the presence of A aegypti depends on human behaviour. Results suggest that community-based environmental management embedded in the routine control programme is required for cost-effective and sustainable mosquito control.14
[...]
