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.

Meningococcal vaccination for international travellers from Greece visiting developing countries.

BACKGROUND: Meningococcal meningitis is a serious disease. Travel-associated infection for the general traveller is low; however regular epidemics in indigenous population, particularly in sub-Saharan Africa are responsible for significant morbidity and mortality. Our aim was to assess meningococcal vaccination for international travellers from Greece. METHODS: A prospective questionnaire-based study was conducted during 2009-2013. RESULTS: A total of 5283 travellers were studied (median age: 39.2 years); Meningococcal tetravalent vaccine (A,C,W135,Y) was delivered to 1150 (21.8%) of them. Of those who travelled to the Middle East and sub-Saharan Africa, 73.1% and 21.2% received meningococcal vaccine, respectively. Of those travellers who travelled to sub-Saharan Africa from November to June and from July to October, 22.1% and 20.6% were vaccinated with meningococcal vaccine, respectively. Of all travellers who travelled for <1 month and ≥1 month, 23.3%, and 20.5%, were vaccinated, respectively. Meningococcal vaccine was administered to 95.3% of pilgrims, 17.4% of those visiting friends and relatives (VFRs), 16.7% of those who travelled for recreation, and 13.8% of those who travelled for work. Of travellers who stayed in urban, in rural, and in urban and rural areas, 32%, 11.6% and 12.7% were vaccinated, respectively. Meningococcal vaccine was delivered to 29.2%, 21.1%, 19.4% and 5.1% of those who stayed in hotels, at local people's home, in camps, and on ships, respectively. The association of meningococcal vaccine administration with the destination, duration and purpose of travel, area of stay and type of accommodation was statistically significant. CONCLUSION: There is a need to improve meningococcal vaccine recommendations for travellers from Greece, particularly for high risk populations, such as VFRs, business travellers and those visiting sub-Saharan Africa especially during the dry season.

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.

Typhoid vaccination for international travelers from Greece visiting developing countries.

BACKGROUND: Typhoid fever is one of the most common diagnoses in returned international travelers. Our aim was to study the typhoid vaccine prescription practices for travelers from Greece visiting developing countries. METHODS: A prospective questionnaire-based study was conducted during 2009-2012 in 57 Public Health Departments, which are the only sources of typhoid vaccine in Greece. RESULTS: A total of 3,680 travelers were studied (median age: 38.1 years). Typhoid vaccine was delivered to 1,108 (30.1%) of them. Of those who traveled to sub-Saharan Africa, South America, the Middle East, the Indian subcontinent, Southeast Asia, South Africa, East Asia, North Africa, and Central America, 31.6, 17.1, 35, 44.2, 36.9, 31, 17.7, 31.6, and 36.8% received typhoid vaccine, respectively. Of travelers who stayed <1 month, 1 to <3 months, 3 to <6 months, and ≥6 months, 21.4, 63.1, 32.3, and 34.9% were vaccinated, respectively. According to the purpose of travel, typhoid vaccine was administered to 32.7% of those who traveled for leisure, to 28.8% of those who traveled for business, and to 24.1% of those visiting friends and relatives (VFRs). Of travelers who stayed in urban areas, rural areas, and urban and rural areas, 36.3, 30.1, and 26.8% were vaccinated, respectively. The majority of travelers who received the typhoid vaccine stayed in camps (62.9%) or at local residences (41%). Typhoid vaccine administration was statistically significantly associated with destination, duration of travel, purpose of travel, area of stay, and type of accommodation. DISCUSSION: There is a need to increase awareness of travelers and public health professionals for typhoid vaccination and particularly for high-risk groups of travelers, such as travelers to the Indian subcontinent and VFRs. Strategies for continuing professional education should be developed for travel health professionals.

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.