Search

Background: The impact of the spread of chikungunya virus (CHIKV) by autochthonous transmission and blood transfusion in nonendemic areas via travelers returning from CHIKV-affected locations is a concern., Methods: We analyzed the risks of potential CHIKV importation and transfusion transmission from Thailand to Europe via travelers visiting southern Thailand from 2008 through 2015, using the web-based European Up-front Risk Assessment Tool., Results: The risk of CHIKV importation by European travelers returning from Thailand from 2008 through 2015 varied depending on the year of travel, tourist destination, duration of stay, and time since last possible exposure. Specifically, the risks of acquiring CHIKV among travelers visiting Songkhla and Krabi for 1, 5, or 10-30 days during the highest epidemic activity in 2009 were estimated to be 74.40, 371.99, and 706.77 (Songkhla) and 1.82, 9.08, and 17.25 (Krabi) per 100,000 travelers, respectively. In contrast, such risks were estimated to be fewer than 0.099 per 100,000 travelers in nonepidemic years. The 2009 yearly average rates of expected incidence among 4,059,988 European travelers who stayed for 1 or 10-30 days in all six outbreak activity destinations were calculated to be, respectively, 4.01 × 10 -6 or 1.20 × 10 -4 cases per day, corresponding to the estimated rates of viremia and transfusion-transmitted CHIKV via traveling blood donations of 3.21 × 10 -5 and 0.61, and 9.62 × 10 -4 and 3.34, respectively. Additionally, it is probable that 18 (0.0004%) Europeans acquired CHIKV in Thailand, representing a maximum attack rate of 0.0023%., Conclusion: The extent of the expected risks and attack rates of CHIKV infection might reflect the travel preferences for popular destinations rather than the true risks of CHIKV transmission in travelers' home nonendemic countries. Nevertheless, preventive and blood-safety intervention measures may be applied to returning travelers at risk for infection to reduce CHIKV transfusion threats in their home countries., (© 2019 AABB.)

Background: Asymptomatic Chikungunya fever (CHIKF)-viremic blood donors could be a potential threat of spreading the disease unwittingly through contaminated blood transfusions. The relatively low prevalence of Chikungunya virus antibodies in the population and the records of more than 9000 suspected CHIKF cases raised concern about the potential transfusion-associated CHIKF during the 2009 epidemic. This study assessed the potential transfusion risk for CHIKF and the implementation of blood safety measures to mitigate this risk., Study Design and Methods: A probabilistic model using key variables obtained from local information was used to estimate the weekly risk of transfusion-associated CHIKF during the 2009 epidemic. In addition, other blood safety measure-based strategies involving screening for donors at risk, donor tracing, and a 7-day quarantine of blood components at risk were implemented at the time of the epidemic., Results: The risk of viremic donations per 100,000 ranged from 38.2 (95% confidence interval [CI], 36.5-39.8) to 52.3 (95% CI, 50.4-54.2). The potential risk of transfusion-associated CHIKF per 100,000 was estimated to be 1 in 2429 (0.04%; 95% CI, 1 in 6681 [0.02%]-1 in 1572 [0.06%]) to 1 in 1781 (0.06%; 95% CI, 1 in 3817 [0.03%]-1 in 1214 (0.08%]) donations. Among 26,722 donations, 11 (95% CI, 4-17) to 15 (95% CI, 7-22) donations were predicted to associate with transfusion risk. The implementation of blood safety measure-based strategies for this epidemic period suggested to deter 11 blood donations of transfusion risk., Conclusion: The interventions for blood safety measures applied in this study had mitigated the potential transfusion-associated CHIKF during the 2009 epidemic., (© 2014 AABB.)

Chikungunya virus (CHIKV) is responsible for large periodic epidemics in both endemic and nonendemic areas where competent mosquitoes are present. Transmission of CHIKV by transfusion during explosive outbreaks has never been documented, and the true impact of CHIKV infection on blood transfusion during an outbreak is unknown. Considerations include not only transfusions in the active outbreak areas but also returning travelers to nonendemic areas. Because there are no documented cases of transfusion-transmitted CHIKV, there are no standard guidelines regarding transfusion policies during a chikungunya fever outbreak. We review current information from studies during outbreaks with the goal of estimating the potential effect of different blood safety interventions (eg, querying donors for possible CHIKV exposure, chikungunya fever–related symptoms, screening for CHIKV RNA). • Current information regarding viral loads among presymptomatic, asymptomatic, and symptomatic CHIKV infected individuals is presented. • If transfusion is found to be a means of transmitting CHIKV, measures aimed at reducing the rate of transfusion transmission during an outbreak are reviewed. • Strategies regarding the return of traveling donors at risk for CHIKV infection are reviewed. [ABSTRACT FROM AUTHOR]