[New epidemiological aspects of dengue]

Area of Science:

• Tropical medicine
• Epidemiology
• Vector-borne diseases

Context:

• Dengue epidemics have escalated in the Pacific islands since the 1940s, with increasing severity.
• New Caledonia experienced its first identified dengue virus epidemic (DEN-1) in 1942-1943, followed by DEN-2 in 1972-1973.
• Multiple dengue serotypes (DEN-1, DEN-4, DEN-3) have circulated in New Caledonia since the mid-1970s, with co-circulation of different types observed from 1985.

Purpose:

• To analyze the historical trends and epidemiological characteristics of dengue epidemics in New Caledonia.
• To evaluate the efficacy of vector control measures, primarily aerial Ultra Low Volume (ULV) spraying.
• To identify potential contributing factors to the increasing dengue burden, including vector behavior and environmental changes.

Summary:

• The study details the timeline of dengue epidemics in New Caledonia, highlighting the emergence and re-emergence of various dengue virus serotypes.
• Aedes aegypti is identified as the primary vector, though other mosquito species were found to harbor dengue virus strains.
• Variable efficacy of vector control measures and increasing insecticide resistance in Ae. aegypti are noted challenges.
• Factors such as increased international travel, suburban expansion, and potential unknown transmission cycles are implicated in the escalating dengue problem.

Impact:

• Findings underscore the persistent threat of dengue in the Pacific and the need for adaptive vector control strategies.
• Highlights the complex interplay of environmental, social, and biological factors driving dengue epidemics.
• Suggests the possibility of novel transmission dynamics requiring further investigation to inform public health interventions.