Dengue virus infection: Incidence among Long Term Travelers

Transcription

1 Dengue virus infection: Incidence among Long Term Travelers Femke Overbosch 1, Janke Schinkel 2, Gerard Sonder 1 27 May Public Health Service Amsterdam 2 Academic Medical Center Amsterdam

2 Introduction WHO 2012: Over 2.5 billion people at risk for dengue virus infection Worldwide every year: million dengue virus infections - Hospitalisation of an estimated 500,000 people with severe dengue - 2.5% of those affected die.

3 Introduction (2) Incidence had increased 30-fold in last 50 years International travel markedly increased Rise in dengue diagnosis among ill returning European travelers from 2008 to 2012: Proportionate moribidity (PM) of 22/1000 to 36/1000 ill travelers * *Schlagenhauf et al. Lancet Infect Dis 2015; 15:55-64

4 Objectives What is the incidence rate of dengue virus infection among Dutch long term travelers? What are predictors for dengue virus infection?

5 Methods Prospective mono-centre study, Long term travelers (3-12 months) from the Netherlands to (sub)tropical countries 18 years and older Immunocompetent travelers

6 Methods (2) Travel starts 1st blood sample Return 2nd blood sample Time

7 Methods (3) Symptoms dengue like illness (DLI): Fever ( 38º C), together with: Retro-orbital pain, headache, muscle ache, joint pain, skin rash, vomiting and/or diarrhoea Variables: Sex, age, purpose of travel, previous travel, vaccination status, duration of travel, visited regions, use of DEET and symptoms

8 Methods (4) Blood samples: Immunoglobulines M (IgM) against dengue virus (DENV) antigen (IgM-capture ELISA) Immunoglobulines G (IgG) against DENV antigen serotypes 1, 2, 3 & 4 (indirect ELISA) previous DENV recent DENV recent DENV pretravel IgM IgG pos pretravel IgM neg IgG neg pos posttravel IgM IgG posttravel IgM neg/pos ratio 4:1 IgG pos pos

9 Results suggestive for previous DENV Total Previous dengue Multivariate analysis (OR (95%CI), p-value) N=600 % n=19 3.2% sex Male Age, y Country of birth Total duration at previous travel destinations, mth median 25 IQR < ( ) (0.6-11) Nondengue endemic < (1.3-34) > (1.0-25) Vaccination status (total of YF/JE/TBE vaccins)

10 Results suggestive for recent DENV Total recent dengue 6.5% N=600 % pm n=39 IR=13.7 sex male Purpose of travel Tourism Age, y median 25 IQR: Duration of travel median 20 IQR: Asia Visited regions Use of DEET, % Africa Latin America <

11 Results suggestive for recent DENV (2) Total recent dengue multivariate analysis (IRR (95%CI), p-value) N=600 % pm n=39 IR=13.7 Vaccination status (total of YF/JE/TBE vaccins) ( ) (3.7-26) DLI yes extended DLI no yes (1.6-11) 0.004

12 Conclusion Attack rate 6.5% Incidence rate of 13.7/1000 pm: comparable with previous research among (short) travelers 30/1000 pm, 10.2/1000 pm, 14.6/1000 pm, 11/1000 pm, 6.7/1000 pm respectively*) * (Cobelens et al; 1999, Ratnam et al; , Baaten et al; , Potasman et al; 1999, Leder 2013) Yellow book, CDC 2014; unpublished data, used with permission of Robert Steffen

13 Conclusion (2) Incidence rate Africa comparable to IR Asia/Latin America Vaccin status risk factor for recent DENV Cross-reactivity with other flavivirus vaccins? Or unknown risk factor of influence? Extended DLI seems a risk factor for recent DENV

14 Questions?