In-flight transmission of COVID-19 on flights to Greece: An epidemiological analysis.

BACKGROUND: The emergence in China in late 2019 and subsequent progression of a pandemic of a respiratory disease named coronavirus disease 2019 (COVID-19) was highly facilitated by international travel. We present 5 cases of probable in-flight transmission in Greece. METHODS: We studied international passengers arriving to or departing from Greece from February 26 through March 9, 2020. Contact tracing extended up to 4 days before the onset of symptoms and focused on close contacts. Close contacts were defined as persons sitting within a distance of <2 m for >15 min, including passengers seated two seats around the index case and all crew members and persons who had close contact with the index case. RESULTS: We investigated 18 international flights with 2224 passengers and 110 crew members. Main countries of departure included Northern Italy, Israel and the United Kingdom. In accordance with the national surveillance investigation, in these flights there were 21 index cases and 891 contact traced cases. Six index cases were symptomatic during the flight. Of the 891 contact traced cases, 4 passengers and 1 crew member developed laboratory-confirmed infection (3 with COVID-19 and 2 with asymptomatic infection); they travelled on the same flight with two COVID-19 cases. CONCLUSIONS: Air travel has played a central role in the progression of the COVID-19 pandemic. However, there are scarce data about in-flight transmission. Our extensive investigation showed five cases of probable in-flight transmission. Efforts should be placed in order to ensure the prompt implementation of appropriate infection control measures on board.

Vaccinations and Malaria Chemoprophylaxis of Adolescents Traveling From Greece to International Destinations: A Nine-Year Prospective Study.

BACKGROUND: There are few publications focusing on vaccination and malaria chemoprophylaxis in adolescent travelers. We assessed pretravel vaccinations and malaria chemoprophylaxis of adolescents 12-18 years old traveling from Greece to international destinations. METHODS: We prospectively studied 239 adolescents 12-18 years old during 2008-2016. A standard questionnaire was used to collect data. RESULTS: Adolescents sought pretravel services at a mean of 24.1 days before departure. Their main destinations were sub-Saharan Africa (79 adolescents; 33.1%), Latin America (56; 23.5%) and North America (26; 10.9%). Almost half (46.1%) of them planned to stay abroad for at least 3 months. Sixteen (7.4%) adolescents planned to visit friends and relatives. The yellow fever vaccine and the typhoid vaccine were the most frequently administered vaccines (74.1% and 20.5%, respectively), while the hepatitis A vaccine and the tetanus-diphtheria vaccine accounted for most routine vaccinations (18% and 14.2%, respectively). The rabies and the typhoid fever vaccines were administered inadequately to adolescents traveling to endemic areas. Malaria chemoprophylaxis should have been prescribed in many cases traveling to sub-Saharan Africa and the Indian subcontinent. CONCLUSIONS: Only a small number of adolescents from Greece traveling abroad seek pretravel counseling. We found significant gaps in typhoid fever and rabies vaccinations of adolescents traveling to endemic areas. We also found gaps in prescription of malaria chemoprophylaxis for those traveling to high-risk areas. There is a need to develop communication strategies to access adolescent travelers and improve appropriate vaccination and use of malaria chemoprophylaxis.

Vaccinations and malaria prophylaxis for long-term travellers travelling from Greece: a prospective, questionnaire-based analysis.

The purpose of this prospective, questionnaire-based study is to assess pre-travel vaccinations and malaria prophylaxis for long-term travellers who receive pre-travel advice in Greece. A total of 4721 travellers were studied from January 1, 2009 through December 31, 2012. Travellers sought pre-travel advice at a mean of 19.7 days (range: 0-349 days) before departure. Long-term travellers (≥ 1 month) accounted for 2205 (46.7%) of all travellers. Long-term travellers had a mean age of 34.5 years. The majority of them were men (79.8%). In terms of destinations, 84% were visiting malaria-endemic countries and sub-Saharan Africa was the most common destination (17.7%). Most long-term travellers pursued trips for work purposes (70%), visited urban areas (79.6%) and stayed in hotels (29.2%). Yellow fever, typhoid fever, hepatitis A and tetanus/diphtheria vaccines were administered to 1647 (74.7%), 741 (33.6%), 652 (29.5%), and 589 (26.7%) travellers, respectively. Yellow fever vaccine was administered to 339 (87%) and 132 (71%) of long-term travellers to sub-Saharan Africa and South America respectively, whereas typhoid vaccine to 119 (90.8%) and 330 (84.6%) of those travelling to the Indian subcontinent and sub-Saharan Africa respectively. Rabies vaccine was administered to 14 (0.6%) of them. Malaria prophylaxis was recommended to 446 (20%) of long-term travellers. Mefloquine was the most commonly (49%) prescribed agent, and was prescribed to 26.7% of long-term travellers to sub-Sahara Africa. In conclusion, this study revealed that recommendations for vaccine and malaria prophylaxis for long-term travellers to developing countries should be more selective, based on the assessment of all travellers' and travel characteristics, in order to provide adequate pre-travel preparation for this high risk group of travellers. More focused studies are suggested in order to understand the particular needs of long-term travellers. Increasing awareness of travellers and travel health consultants is very important.

Vaccination and Malaria Prevention among International Travelers Departing from Athens International Airport to African Destinations.

Background. International travel to Africa has grown dramatically over the last decade along with an increasing need to understand the health issues for travelers. The current survey aimed to assess vaccination and malaria prevention of travelers visiting Africa. Methods. A questionnaire-based survey was conducted from of November 1, 2011 to of April 30, 2013 at Athens International Airport. Results. A total of 360 travelers were studied; 68% were men. Their mean age was 39.9 years. Previous travel to tropical countries was reported by 71.9% of them. Most frequent destination was sub-Saharan Africa (60%). Most of them traveled for ≥1 month (62%). The main reason for travel was work (39.7%). Only 47% sought pretravel consultation. Hepatitis A, typhoid, and meningococcal vaccines were administered to 49.8%, 28%, and 26.6%, respectively, and malaria chemoprophylaxis to 66.8% of those who visited sub-Saharan Africa. A history of previous travel to a tropical country, elementary level of education, and traveling for visiting friends and relatives, and for short duration were significant determinants for not pursuing pretravel consultation. Conclusions. The current survey revealed important inadequacies in vaccine and malaria prophylaxis of travelers departing to Africa. Educational tools should be developed in order to improve awareness of travelers to risk destinations.

Ηepatitis A and enteric fever in Greece, 2004-2011: a cross-sectional analysis.

BACKGROUND: In Greece the number of international travellers has increased significantly the past decade. AIM: To study the impact of international travels on the epidemiology of hepatitis A and enteric fever in Greece. METHODS: We studied cases of hepatitis A and enteric fever notified through the National Surveillance System from January 1, 2004 through December 31, 2011. RESULTS: A total of 921 cases of hepatitis A and 106 cases of enteric fever were notified; of them, 88 (9.5%) and 46 (43.4%) were travel-associated, respectively. Travellers returning from Eastern Europe and the Middle East accounted for most imported cases of hepatitis A (37 (43.5%) and 14 (16.5%) cases, respectively). The Indian subcontinent was the prevalent area of acquisition of travel-associated enteric fever, followed by the Middle East (35 (83.3%) and 4 (9.5%) cases, respectively). Foreign-born travellers accounted for 43 (48.8%) and 39 (86.6%) cases of travel-associated hepatitis A and enteric fever, respectively. Children <15 years accounted for 65.1% of hepatitis A cases and 7.7% among foreign-born travellers. Greek Roma accounted for 270 (29.3%) of all hepatitis A cases notified. CONCLUSIONS: International travels have a significant impact on the epidemiology of enteric fever in Greece, affecting mainly foreign travellers. Hepatitis A carries a significant burden of morbidity among Greek travellers and children of foreign nationality. There is a need to improve travel medicine services for travellers travelling to developing countries.

Preparedness of paediatric international travellers departing from Athens, Greece: an 18-month airport-based survey.

AIM: The number of children who travel to tropical and subtropical areas has increased. This study aimed to assess the preparedness of children departing from Greece to Africa and Asia, in terms of vaccination and malaria chemoprophylaxis. METHODS: An 18-month airport-based study was conducted in Athens between November 2011 and April 2013. RESULTS: Of the 183 children studied, 122 (66.7%) had a foreign nationality. Their main destinations were the Indian subcontinent (43.2%), South-East Asia (30.6%) and sub-Saharan Africa (14.2%). Just under three-quarters (73.2%) of the children were travelling to visit friends and relatives. Forty (21.9%) children had received pretravel services. Children visiting friends and relatives sought pretravel services less frequently than those who were not (17.9% versus 32.7%; p = 0.033). Female children and Greek nationals were significantly more likely to seeking pretravel services than males and foreign nationals (p = 0.007 and <0.001, respectively). The rabies and the typhoid fever vaccines were administered inadequately to children travelling to endemic areas, but malaria chemoprophylaxis was generally justified. CONCLUSION: Travel medicine services for children in Greece should be improved. There is a particular need to communicate with the parents of children visiting friends and relatives.

Vaccinations for international travellers travelling from Greece.

The aim of this prospective, questionnaire-based study is to assess pre-travel vaccinations for international travellers who receive pre-travel advice in Greece. A total of 2494 travellers were studied from January 1, 2009 through December 31, 2010. Travellers sought pre-travel advice at a median of 16 days (range: 0-349 days) before departure. Sub-Saharan Africa was the most common destination (34.7%). Most travellers (60.8%) travelled for <1 month, for recreation purposes (58.9%), stayed in hotels (65.3%), and in urban areas (53.6%). Yellow fever, tetravalent meningococcal, typhoid fever, cholera, and rabies vaccines were administered to 1629 (65.3%), 666 (26.7%), 615 (24.7%), 28 (1.1%), and/or 12 (0.5%) travellers, respectively. Of those who received Yellow fever vaccine, 737 (45.2%) travelled to sub-Saharan Africa, 332 (20.4%) travelled to South America, 949 (58.3%) stayed for short term, and 762 (46.8%) stayed in urban areas. Of the 1629 travellers vaccinated against Yellow fever, 150 (9.2%) and 226 (13.8%) travelled to areas of sub-Saharan Africa and South America respectively, where the vaccine is not or generally not recommended. Of those travellers who received meningococcal vaccine, 327 (49.1%) travelled to the Middle East for the Hajj, 251 (29%) travelled to sub-Saharan Africa, 410 (61.6%) for short term, and 540 (64.4%) stayed in urban areas. Of those travellers who received typhoid vaccine, 241 (39.2%) travelled to sub-Saharan Africa, 78 (12.7%) to the Indian subcontinent, 234 (38%) for short term, and 419 (68.1%) stayed in urban areas. Regarding routine vaccines, tetanus-diphtheria, poliomyelitis, and measles-mumps-rubella vaccines were administered to 707 (28.3%), 639 (25.6%) and/or 149 (6%) travellers, respectively. Of those to whom poliomyelitis vaccine was recommended, 295 (46.2%) and 137 (21.4%) travelled to sub-Saharan Africa and the Middle East, respectively, and 362 (56.7%) travelled for short term. In conclusion, this study revealed that there is a need for more selective vaccine recommendations for travellers to developing countries, taking under consideration travellers and travel characteristics as well. Strategies to target travel health consultants should be developed in order to increase awareness in travel health issues.

Paediatric international travellers from Greece: characteristics and pre-travel recommendations.

The aim of this study was to describe the children who seek pre-travel advice in Greece. During 2008-2010, 4065 persons sought pre-travel services in the 57 Prefectures, including 128 (3.15%) children <15 years. Main travel destinations were sub-Saharan Africa (54 children; 42.2%), South America (18; 14.1%), the Middle East (16; 12.5%), the Indian subcontinent (12; 9.4%), and South East Asia (7; 5.5%). Seventy-six children (59.4%) stayed for <1 month, 34 (26.6%) for 1-6 months, and 10 (7.8%) for >6 months. Recreation was the main purpose of travel (81 children; 63.3%), followed by work (24; 18.8%), and to visit friends and relatives (VFRs) (14; 10.9%). Paediatric travellers VFRs stayed more frequently in local residences compared to non-VFR paediatric travellers (85.7% and 20.2%). Children stayed more frequently in local residences and travelled more frequently for recreational purposes or to VFRs (27.3%, 63.3%, and 10.9%, respectively), compared to older travellers (11.9%, 58.8%, and 4%, respectively). Malaria chemoprophylaxis was prescribed for 64.8% of children travelling to sub-Saharan Africa. This study demonstrated clearly that only a very small number of international paediatric travellers seek pre-travel services in Greece. Communication strategies to access paediatric travellers should be developed in order to improve travel medicine services for children in Greece.

Descriptive analysis of malaria prophylaxis for travellers from Greece visiting malaria-endemic countries.

International travel is changing the epidemiology of imported malaria. Our aim was to study malaria prophylaxis administered to travellers from Greece. The study was conducted during 2008-2009. Data were collected using a standardized form. A total of 2337 travellers were studied; prophylaxis was recommended to 60.2% of them. Of the 2337 travellers, 32.6% travelled to sub-Saharan Africa, 25.5% to South America, 11.8% to Indian subcontinent, 11.7% to Middle East, and 4.4% to Southeast Asia; prophylaxis was recommended to 77.4%, 64%, 80.6%, 4.8% and 73.5% of them, respectively. According to the purpose of travel, prophylaxis was recommended to 85.4% of those travelling for work, 75.2% of those visiting friends and relatives, and 62% of those travelling for recreation. Prophylaxis advised was provided to 68.5%, 66.2%, 61.5%, and 18.9% to those staying at a residence of local people, camping, hotels, and cruise ships, respectively. Regarding long-term travellers, malaria prophylaxis was recommended to 42.6%. Recommendation of malaria prophylaxis was significantly statistically in association with destination countries, purpose of travel, type of residence in endemic areas There is a need to improve recommendations for malaria prophylaxis for travellers from Greece, and to increase awareness and education of professionals providing travel health services in Greece.