Immune reactivity to dengue and Aedes albopictus mosquitoes in the population from Macao, China, before dengue occurrence

• Published in: In vivo (Athens) Vol. 25; no. 4; pp. 625 - 631
• Main Authors: De Carvalho, Isabel Lopes, Rocha, Diara Kady, Almeida, A Paulo G
• Format: Journal Article
• Language: English
• Published: Greece 01.07.2011
• Subjects: Adolescent; Adult; Aedes - immunology; Aged; Aged, 80 and over; Animals; Antibodies - blood; Antibodies - immunology; Antibodies, Viral - blood; Antibodies, Viral - immunology; Dengue - blood; Dengue - epidemiology; Dengue - immunology; Dengue Virus - immunology; Female; Humans; Immunoglobulin G - blood; Insect Vectors - immunology; Macau; Male; Mice; Middle Aged; Seroepidemiologic Studies; Young Adult; Macau
• ISSN: 1791-7549

A serological survey was conducted in Macao, China, in 753 individuals, with the objective of looking for antibodies to the mosquito, Aedes albopictus (Skuse 1894) (Diptera: Culicidae), and to dengue, before the occurrence of any autochthonous dengue cases. Blood samples were collected at several public health services, a questionnaire was answered, and enzyme-linked immunosorbant assay (ELISA) and Western blot techniques were performed with extracts of mosquito head and thorax (HT). Anti-Aedes albopictus IgG antibodies were present in titres 1:10(2)-1:10(3) in 9%, and in titres 1:10(4)-1:10(5) in 42% of the sera tested. This reactivity was more frequent (59%) in the population which had resided only in Macao in the 2 years previous to the survey, as opposed to those that had also resided in other areas (50%). From the 230 reactive sera selected for immunoblot, 48 (21%) reacted with a wide range of proteins from above 224 kDa to 21 kDa, with different patterns according to individual sera. Proteins in the intervals 35.3-28.7 kDa and 28.7-21.1 kDa were labelled by the greatest number of sera, 15 and 19 respectively. The presence of anti-Aedes albopictus antibodies presented a statistical relation to skin reaction to mosquito bites, but immunoblot patterns did not. Anti-dengue IgG antibodies were found in 48% of the subjects, with a higher proportion in people who had resided out of Macao, or who were nationals from dengue-endemic neighboring countries. Anti-dengue reactivity was in agreement with anti-mosquito reactivity in half of the population. It would be interesting to see if this proportion has changed since dengue became endemic in Macao in 2001.