BACKGROUND: Clinical surveillance may have underestimated the real extent of the spread of the new strain of influenza A/H1N1, which surfaced in April 2009 originating the first influenza pandemic of the 21(st) century. Here we report a serological investigation on an influenza A/H1N1pdm outbreak in an Italian military ship while cruising in the Mediterranean Sea (May 24-September 6, 2009). METHODS: The contemporary presence of HAI and CF antibodies was used to retrospectively estimate the extent of influenza A/H1N1pdm spread across the crew members (median age: 29 years). FINDINGS: During the cruise, 2 crew members fulfilled the surveillance case definition for influenza, but only one was laboratory confirmed by influenza A/H1N1pdm-specific RT-PCR; 52 reported acute respiratory illness (ARI) episodes, and 183 reported no ARI episodes. Overall, among the 211 crew member for whom a valid serological result was available, 39.3% tested seropositive for influenza A/H1N1pdm. The proportion of seropositives was significantly associated with more crowded living quarters and tended to be higher in those aged <40 and in those reporting ARI or suspected/confirmed influenza A/H1N1pdm compared to the asymptomatic individuals. No association was found with previous seasonal influenza vaccination. CONCLUSIONS: These findings underline the risk for rapid spread of novel strains of influenza A in confined environment, such as military ships, where crowding, rigorous working environment, physiologic stress occur. The high proportion of asymptomatic infections in this ship-borne outbreak supports the concept that serological surveillance in such semi-closed communities is essential to appreciate the real extent of influenza A/H1N1pdm spread and can constitute, since the early stage of a pandemic, an useful model to predict the public health impact of pandemic influenza and to establish proportionate and effective countermeasures.
BACKGROUND: Clinical surveillance may have underestimated the real extent of the spread of the new strain of influenzaA/H1N1, which surfaced in April 2009 originating the first influenza pandemic of the 21(st) century. Here we report a serological investigation on an influenza A/H1N1pdm outbreak in an Italian military ship while cruising in the Mediterranean Sea (May 24-September 6, 2009). METHODS: The contemporary presence of HAI and CF antibodies was used to retrospectively estimate the extent of influenza A/H1N1pdm spread across the crew members (median age: 29 years). FINDINGS: During the cruise, 2 crew members fulfilled the surveillance case definition for influenza, but only one was laboratory confirmed by influenza A/H1N1pdm-specific RT-PCR; 52 reported acute respiratory illness (ARI) episodes, and 183 reported no ARI episodes. Overall, among the 211 crew member for whom a valid serological result was available, 39.3% tested seropositive for influenza A/H1N1pdm. The proportion of seropositives was significantly associated with more crowded living quarters and tended to be higher in those aged <40 and in those reporting ARI or suspected/confirmed influenza A/H1N1pdm compared to the asymptomatic individuals. No association was found with previous seasonal influenza vaccination. CONCLUSIONS: These findings underline the risk for rapid spread of novel strains of influenza A in confined environment, such as military ships, where crowding, rigorous working environment, physiologic stress occur. The high proportion of asymptomatic infections in this ship-borne outbreak supports the concept that serological surveillance in such semi-closed communities is essential to appreciate the real extent of influenza A/H1N1pdm spread and can constitute, since the early stage of a pandemic, an useful model to predict the public health impact of pandemic influenza and to establish proportionate and effective countermeasures.
Authors: R G Pebody; E McLean; H Zhao; P Cleary; S Bracebridge; K Foster; A Charlett; P Hardelid; P Waight; J Ellis; A Bermingham; M Zambon; B Evans; R Salmon; J McMenamin; B Smyth; M Catchpole; Jm Watson Journal: Euro Surveill Date: 2010-05-20
Authors: N Ikonen; M Strengell; L Kinnunen; P Osterlund; J Pirhonen; M Broman; I Davidkin; T Ziegler; I Julkunen Journal: Euro Surveill Date: 2010-02-04
Authors: Gabriel M Leung; Joseph S M Peiris; Benjamin J Cowling; Kwok Hung Chan; Vicky J Fang; Lincoln L H Lau; Hau Chi So; Rita O P Fung; Edward S K Ma; Alfred S K Kwong; Chi-Wai Chan; Wendy W S Tsui; Ho-Yin Ngai; Daniel W S Chu; Paco W Y Lee; Ming-Chee Chiu Journal: N Engl J Med Date: 2010-06-10 Impact factor: 91.245
Authors: Ted Ross; Shanta Zimmer; Don Burke; Corey Crevar; Donald Carter; James Stark; Brendan Giles; Richard Zimmerman; Stephen Ostroff; Bruce Lee Journal: PLoS Curr Date: 2010-02-24
Authors: Elizabeth Miller; Katja Hoschler; Pia Hardelid; Elaine Stanford; Nick Andrews; Maria Zambon Journal: Lancet Date: 2010-01-21 Impact factor: 79.321
Authors: Jose L Sanchez; Michael J Cooper; Christopher A Myers; James F Cummings; Kelly G Vest; Kevin L Russell; Joyce L Sanchez; Michelle J Hiser; Charlotte A Gaydos Journal: Clin Microbiol Rev Date: 2015-07 Impact factor: 26.132
Authors: Junxiong Pang; Jing Jin; Jin Phang Loh; Boon Huan Tan; Wee Hong Victor Koh; Sock Hoon Ng; Zheng Jie Marc Ho; Qiuhan Gao; Alex R Cook; Li Yang Hsu; Vernon J Lee; Mark I Cheng Chen Journal: BMC Infect Dis Date: 2015-07-25 Impact factor: 3.090
Authors: Delphis M Vera; Ricardo A Hora; Anarina Murillo; Juan F Wong; Armando J Torre; David Wang; Darbi Boulay; Kathy Hancock; Jacqueline M Katz; Mariana Ramos; Luis Loayza; Jose Quispe; Erik J Reaves; Daniel G Bausch; Gerardo Chowell; Joel M Montgomery Journal: Influenza Other Respir Viruses Date: 2014-02-10 Impact factor: 4.380
Authors: Ann-Christin Kordsmeyer; Natascha Mojtahedzadeh; Jan Heidrich; Kristina Militzer; Thomas von Münster; Lukas Belz; Hans-Joachim Jensen; Sinan Bakir; Esther Henning; Julian Heuser; Angelina Klein; Nadine Sproessel; Axel Ekkernkamp; Lena Ehlers; Jens de Boer; Scarlett Kleine-Kampmann; Martin Dirksen-Fischer; Anita Plenge-Bönig; Volker Harth; Marcus Oldenburg Journal: Int J Environ Res Public Health Date: 2021-05-13 Impact factor: 3.390
Authors: Tudor A Codreanu; Nevada Pingault; Edmond O'Loughlin; Paul K Armstrong; Benjamin Scalley Journal: Prehosp Disaster Med Date: 2021-07-09 Impact factor: 2.040
Authors: Zaheer Ahmad Nasir; Luiza Cintra Campos; Nicola Christie; Ian Colbeck Journal: Environ Sci Pollut Res Int Date: 2016-06-18 Impact factor: 4.223
Authors: Christina B Khaokham; Monica Selent; Fleetwood V Loustalot; Shauna Mettee Zarecki; Douglas Harrington; Eileen Hoke; Dennis J Faix; Ryan Ortiguerra; Bryan Alvarez; Nathaniel Almond; Kellie McMullen; Betsy Cadwell; Timothy M Uyeki; Patrick J Blair; Stephen H Waterman Journal: Influenza Other Respir Viruses Date: 2013-03-17 Impact factor: 4.380