Dataset Information

Low transmission rate of 2009 H1N1 Influenza during a long-distance bus trip.

ABSTRACT:

Background

Current data on the risk of transmission of 2009 H1N1 Influenza in public transportation systems (e.g., public trains, busses, airplanes) are conflicting. The main transmission route of this virus is thought to be via droplets, but airborne transmission has not been completely ruled out.

Methods

This is a contact tracing investigation of a young woman subsequently diagnosed with the 2009 H1N1 Influenza virus who was symptomatic during a long-distance bus trip from Spain to Switzerland. Fever and cough had begun 24 h earlier, 2 h before she stepped onto a bus for a long-distance trip. After the 2009 H1N1 virus had been confirmed in the patient, the other bus travellers were contacted by telephone on day 7 and 10 after the bus trip.

Results

Of the 72 individuals travelling on the bus with the H1N1-infected young woman, 52 (72%) could be contacted. Only one of these 52 developed fever, with onset of symptoms 3 days after the bus trip, and rRT-PCR analysis of the nasopharyngeal swab showed the infection to be caused by the 2009 H1N1 virus. One other person complained of coughing 1 day after the bus trip, but without fever, and no further investigation was carried out. All other passengers remained without fever, coughing, or arthralgia. The risk of transmission was calculated as 1.96% (95% confidence interval 0-5.76%).

Conclusion

The transmission rate of 2009 H1N1 Influenza was low on a long-distance bus trip.

SUBMITTER: Piso RJ

PROVIDER: S-EPMC7099280 | biostudies-literature | 2011 Apr

REPOSITORIES: biostudies-literature

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Publications

Low transmission rate of 2009 H1N1 Influenza during a long-distance bus trip.

Piso R J RJ Albrecht Y Y Handschin P P Bassetti S S

Infection 20110222 2

<h4>Background</h4>Current data on the risk of transmission of 2009 H1N1 Influenza in public transportation systems (e.g., public trains, busses, airplanes) are conflicting. The main transmission route of this virus is thought to be via droplets, but airborne transmission has not been completely ruled out.<h4>Methods</h4>This is a contact tracing investigation of a young woman subsequently diagnosed with the 2009 H1N1 Influenza virus who was symptomatic during a long-distance bus trip from Spain ...[more]

PMID: 21340580

Similar Datasets

Project description:ObjectivesTo assess the risk of transmission of pandemic A/H1N1 2009 influenza (pandemic A/H1N1) from an infected high school group to other passengers on an airline flight and the effectiveness of screening and follow-up of exposed passengers.DesignRetrospective cohort investigation using a questionnaire administered to passengers and laboratory investigation of those with symptoms.SettingAuckland, New Zealand, with national and international follow-up of passengers.ParticipantsPassengers seated in the rear section of a Boeing 747-400 long haul flight that arrived on 25 April 2009, including a group of 24 students and teachers and 97 (out of 102) other passengers in the same section of the plane who agreed to be interviewed.Main outcome measuresLaboratory confirmed pandemic A/H1N1 infection in susceptible passengers within 3.2 days of arrival; sensitivity and specificity of influenza symptoms for confirmed infection; and completeness and timeliness of contact tracing.ResultsNine members of the school group were laboratory confirmed cases of pandemic A/H1N1 infection and had symptoms during the flight. Two other passengers developed confirmed pandemic A/H1N1 infection, 12 and 48 hours after the flight. They reported no other potential sources of infection. Their seating was within two rows of infected passengers, implying a risk of infection of about 3.5% for the 57 passengers in those rows. All but one of the confirmed pandemic A/H1N1 infected travellers reported cough, but more complex definitions of influenza cases had relatively low sensitivity. Rigorous follow-up by public health workers located 93% of passengers, but only 52% were contacted within 72 hours of arrival.ConclusionsA low but measurable risk of transmission of pandemic A/H1N1 exists during modern commercial air travel. This risk is concentrated close to infected passengers with symptoms. Follow-up and screening of exposed passengers is slow and difficult once they have left the airport.

Project description:BackgroundAs of June 11, 2009, a total of 17,855 probable or confirmed cases of 2009 pandemic influenza A (H1N1) had been reported in the United States. Risk factors for transmission remain largely uncharacterized. We characterize the risk factors and describe the transmission of the virus within households.MethodsProbable and confirmed cases of infection with the 2009 H1N1 virus in the United States were reported to the Centers for Disease Control and Prevention with the use of a standardized case form. We investigated transmission of infection in 216 households--including 216 index patients and their 600 household contacts--in which the index patient was the first case patient and complete information on symptoms and age was available for all household members.ResultsAn acute respiratory illness developed in 78 of 600 household contacts (13%). In 156 households (72% of the 216 households), an acute respiratory illness developed in none of the household contacts; in 46 households (21%), illness developed in one contact; and in 14 households (6%), illness developed in more than one contact. The proportion of household contacts in whom acute respiratory illness developed decreased with the size of the household, from 28% in two-member households to 9% in six-member households. Household contacts 18 years of age or younger were twice as susceptible as those 19 to 50 years of age (relative susceptibility, 1.96; Bayesian 95% credible interval, 1.05 to 3.78; P=0.005), and household contacts older than 50 years of age were less susceptible than those who were 19 to 50 years of age (relative susceptibility, 0.17; 95% credible interval, 0.02 to 0.92; P=0.03). Infectivity did not vary with age. The mean time between the onset of symptoms in a case patient and the onset of symptoms in the household contacts infected by that patient was 2.6 days (95% credible interval, 2.2 to 3.5).ConclusionsThe transmissibility of the 2009 H1N1 influenza virus in households is lower than that seen in past pandemics. Most transmissions occur soon before or after the onset of symptoms in a case patient.

Dataset Information

Low transmission rate of 2009 H1N1 Influenza during a long-distance bus trip.

Background

Methods

Results

Conclusion

Publications

Low transmission rate of 2009 H1N1 Influenza during a long-distance bus trip.

Similar Datasets

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