Impact assessment of non-pharmaceutical interventions against COVID-19 and influenza in Hong Kong: an observational study

ABSTRACTBackgroundA range of public health measures have been implemented to delay and reduce local transmission of COVID-19 in Hong Kong, and there have been major changes in behaviours of the general public. We examined the effect of these interventions and behavioral changes on the incidence of COVID-19 as well as on influenza virus infections which may share some aspects of transmission dynamics with COVID-19.MethodsWe reviewed policy interventions and measured changes in population behaviours through two telephone surveys, on January 20-23 and February 11-14. We analysed data on laboratory-confirmed COVID-19 cases, influenza surveillance data in outpatients of all ages, and influenza hospitalisations in children. We estimated the daily effective reproduction number (Rt), for COVID-19 and influenza A(H1N1).FindingsCOVID-19 transmissibility has remained at or below 1, indicating successful containment to date. Influenza transmission declined substantially after the implementation of social distancing measures and changes in population behaviours in late January, with a 44% (95% confidence interval, CI: 34% to 53%) reduction in transmissibility in the community, and a 33% (95% CI: 24% to 43%) reduction in transmissibility based on paediatric hospitalization rates. In the two surveys we estimated that 74.5% and 97.5% of the general adult population wore masks when going out, and 61.3% and 90.2% avoided going to crowded places, respectively.ImplicationsContainment measures, social distancing measures and changes in population behaviour have successfully prevented spread of COVID-19. The social distancing measures and behavioural changes led to a substantial reduction in influenza transmission in early February 2020. However, it may be challenging to avoid fatigue and sustain these measures and population behaviours as COVID-19 continues to spread globally.FundingHealth and Medical Research Fund, Hong Kong

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Analysis of potential changes in seriousness of influenza A and B viruses in Hong Kong from 2001 to 2011

Epidemiology and Infection ◽

10.1017/s0950268814001472 ◽

2014 ◽

Vol 143 (4) ◽

pp. 766-771 ◽

Cited By ~ 3

Author(s):

J. Y. WONG ◽

P. WU ◽

E. GOLDSTEIN ◽

E. H. Y. LAU ◽

D. K. M. IP ◽

...

Keyword(s):

Hong Kong ◽

Influenza A ◽

Influenza Viruses ◽

Regression Coefficients ◽

Virus Infections ◽

Time Series Regression ◽

Respiratory Mortality ◽

Influenza A H1n1 ◽

Influenza Activity ◽

Ongoing Monitoring

SUMMARYContinued monitoring of the seriousness of influenza viruses is a public health priority. We applied time-series regression models to data on cardio-respiratory mortality rates in Hong Kong from 2001 to 2011. We used surveillance data on outpatient consultations for influenza-like illness, and laboratory detections of influenza types/subtypes to construct proxy measures of influenza activity. In the model we allowed the regression coefficients for influenza to drift over time, and adjusted for temperature and humidity. The regression coefficient for influenza A(H3N2) increased significantly in 2005. The regression coefficients for influenza A(H1N1) and B were relatively stable over the period. Our model suggested an increase in seriousness of A(H3N2) in 2005, the year after the appearance of the A/Fujian/411/2002(H3N2)-like virus when the drifted A/California/7/2004(H3N2)-like virus appeared. Ongoing monitoring of mortality and influenza activity could permit identification of future changes in seriousness of influenza virus infections.

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School absence data for influenza surveillance: a pilot study in the United Kingdom

Eurosurveillance ◽

10.2807/ese.15.03.19467-en ◽

2010 ◽

Vol 15 (3) ◽

Author(s):

W P Schmidt ◽

R Pebody ◽

P Mangtani

Keyword(s):

Primary Schools ◽

Influenza A ◽

School Age Children ◽

Influenza Surveillance ◽

Virus Infections ◽

The United Kingdom ◽

School Absence ◽

Influenza A H1n1 ◽

Respiratory Virus Infections ◽

Epidemiological Characteristics

School-age children are at a high risk of acute respiratory virus infections including the 2009 pandemic influenza A(H1N1). School absence records have been suggested as a tool for influenza surveillance. We analysed absence records from six primary schools (children aged from around five to 11 years) in London during the years 2005 to 2007 in order to provide baseline epidemiological characteristics of illness-related school absence, and to correlate school absence with seasonal influenza. The daily average prevalence of absence due to illness was 2.9%. The incidence was 1.3% per person-day. The mean duration of absence was 1.8 days (SD 1.8). Over 60% of absence episodes lasted for one day. Absence prevalence did not differ by sex. Prevalence was highest in the youngest children and then declined slightly, but was again high again in the oldest. Absence was slightly higher on Mondays and Fridays. In general, peaks of absenteeism coincided with peaks of influenza A and B (laboratory reports) but several high peaks were not associated with influenza. There was a better correlation between absence and laboratory reports and prevalence compared to incidence. School absence data may be useful for the detection of localised school outbreaks and as an additional surveillance tool but are limited by lack of data on weekends and during holidays.

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International Travelers as Sentinels for Sustained Influenza Transmission During the 2009 Influenza A(H1N1)pdm09 Pandemic

Journal of Travel Medicine ◽

10.1111/jtm.12025 ◽

2013 ◽

Vol 20 (3) ◽

pp. 177-184 ◽

Cited By ~ 5

Author(s):

Xiaohong M. Davis ◽

Kelly A. Hay ◽

D. Adam Plier ◽

Sandra S. Chaves ◽

Poh Lian Lim ◽

...

Keyword(s):

Influenza A ◽

Influenza A H1n1 ◽

Influenza Transmission

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Characterization of a Human H5N1 Influenza A Virus Isolated in 2003

Journal of Virology ◽

10.1128/jvi.79.15.9926-9932.2005 ◽

2005 ◽

Vol 79 (15) ◽

pp. 9926-9932 ◽

Cited By ~ 70

Author(s):

Kyoko Shinya ◽

Masato Hatta ◽

Shinya Yamada ◽

Ayato Takada ◽

Shinji Watanabe ◽

...

Keyword(s):

Hong Kong ◽

Avian Influenza ◽

Influenza A Virus ◽

Influenza A ◽

Mainland China ◽

Virus Infections ◽

Influenza A Viruses ◽

H5n1 Avian Influenza Virus ◽

H5n1 Influenza ◽

Avian Influenza A Virus

ABSTRACT In 2003, H5N1 avian influenza virus infections were diagnosed in two Hong Kong residents who had visited the Fujian province in mainland China, affording us the opportunity to characterize one of the viral isolates, A/Hong Kong/213/03 (HK213; H5N1). In contrast to H5N1 viruses isolated from humans during the 1997 outbreak in Hong Kong, HK213 retained several features of aquatic bird viruses, including the lack of a deletion in the neuraminidase stalk and the absence of additional oligosaccharide chains at the globular head of the hemagglutinin molecule. It demonstrated weak pathogenicity in mice and ferrets but caused lethal infection in chickens. The original isolate failed to produce disease in ducks but became more pathogenic after five passages. Taken together, these findings portray the HK213 isolate as an aquatic avian influenza A virus without the molecular changes associated with the replication of H5N1 avian viruses in land-based poultry such as chickens. This case challenges the view that adaptation to land-based poultry is a prerequisite for the replication of aquatic avian influenza A viruses in humans.

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In Vivo Influenza Virus-Inhibitory Effects of the Cyclopentane Neuraminidase Inhibitor RWJ-270201

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.45.3.749-757.2001 ◽

2001 ◽

Vol 45 (3) ◽

pp. 749-757 ◽

Cited By ~ 77

Author(s):

Robert W. Sidwell ◽

Donald F. Smee ◽

John H. Huffman ◽

Dale L. Barnard ◽

Kevin W. Bailey ◽

...

Keyword(s):

Influenza Virus ◽

Hong Kong ◽

Influenza A ◽

Arterial Oxygen Saturation ◽

Virus Titer ◽

Neuraminidase Inhibitor ◽

Arterial Oxygen ◽

Virus Infections ◽

Inhibitory Effects ◽

Lung Consolidation

ABSTRACT The cyclopentane influenza virus neuraminidase inhibitor RWJ-270201 was evaluated against influenza A/NWS/33 (H1N1), A/Shangdong/09/93 (H3N2), A/Victoria/3/75 (H3N2), and B/Hong Kong/05/72 virus infections in mice. Treatment was by oral gavage twice daily for 5 days beginning 4 h pre-virus exposure. The influenza virus inhibitor oseltamivir was run in parallel, and ribavirin was included in studies with the A/Shangdong and B/Hong Kong viruses. RWJ-270201 was inhibitory to all infections using doses as low as 1 mg/kg/day. Oseltamivir was generally up to 10-fold less effective than RWJ-270201. Ribavirin was also inhibitory but was less tolerated by the mice at the 75-mg/kg/day dose used. Disease-inhibitory effects included prevention of death, lessening of decline of arterial oxygen saturation, inhibition of lung consolidation, and reduction in lung virus titers. RWJ-270201 and oseltamivir, at doses of 10 and 1 mg/kg/day each, were compared with regard to their effects on daily lung parameters in influenza A/Shangdong/09/93 virus-infected mice. Maximum virus titer inhibition was seen on day 1, with RWJ-270201 exhibiting the greater inhibitory effect, a titer reduction of >104 cell culture 50% infective doses (CCID50)/g. By day 8, the lung virus titers in mice treated with RWJ-270201 had declined to 101.2 CCID50/g, whereas titers from oseltamivir-treated animals were >103CCID50/g. Mean lung consolidation was also higher in the oseltamivir-treated animals on day 8. Both neuraminidase inhibitors were well tolerated by the mice. RWJ-270201 was nontoxic at doses as high as 1,000 mg/kg/day. These data indicate potential for the oral use of RWJ-270201 in the treatment of influenza virus infections in humans.

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Mixed polysaccharides derived from shiitake mushroom, Poriacocos, Ginger and Tangerine peel prevent the H1N1 virus infections in mice

Bioscience Biotechnology and Biochemistry ◽

10.1093/bbb/zbab174 ◽

2021 ◽

Author(s):

Diqi Yang ◽

Minghua Hu ◽

Hongmei Zhu ◽

Jianguo Chen ◽

Dehai Wang ◽

...

Keyword(s):

Influenza A ◽

Clinical Symptoms ◽

H1n1 Virus ◽

Global Public Health ◽

Virus Infections ◽

Shiitake Mushroom ◽

Virus Challenge ◽

Influenza A H1n1 ◽

Public Health Challenges ◽

Cellular Immune

Abstract The pandemic influenza A (H1N1) virus spread globally and posed one of the most serious global public health challenges. The traditional Chinese medicine is served as a complementary treatment strategy with vaccine immunization. Here, we demonstrated the mixed polysaccharides (MPs) derived from shiitake mushroom, poriacocos, ginger and tyangerine peel prevent the H1N1 virus infections in mice. MPs pretreatment attenuated H1N1 virus-induced weight loss, clinical symptoms and death. The lymphocytes detection results showed the CD3+, CD19+ and CD25+ cell proportions were up-regulated in thymus under MPs pretreatment. Besides, MPs pretreatment reduced the inflammatory cell infiltration and increased the cell proportions of CD19+, CD25+ and CD278+ in lung. However, MPs treatment have no effective therapeutic effect after H1N1 virus challenge. The current study suggested that pretreatment with MPs could attenuate H1N1 virus-induced lung injury and up-regulate humoral and cellular immune responses in non- immunized mice.

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Seroepidemiology of pandemic influenza A (H1N1) 2009 virus infections in Pune, India

BMC Infectious Diseases ◽

10.1186/1471-2334-10-255 ◽

2010 ◽

Vol 10 (1) ◽

Cited By ~ 44

Author(s):

Babasaheb V Tandale ◽

Shailesh D Pawar ◽

Yogesh K Gurav ◽

Mandeep S Chadha ◽

Santosh S Koratkar ◽

...

Keyword(s):

Pandemic Influenza ◽

Influenza A ◽

Virus Infections ◽

Influenza A H1n1

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Dynamic interactions of influenza viruses in Hong Kong during 1998-2018

10.1101/19008987 ◽

2019 ◽

Cited By ~ 1

Author(s):

Wan Yang ◽

Eric H. Y. Lau ◽

Benjamin J. Cowling

Keyword(s):

Hong Kong ◽

Influenza A ◽

Vaccine Development ◽

Immune Escape ◽

Influenza Viruses ◽

Influenza Surveillance ◽

Influenza Epidemic ◽

Inference System ◽

Population Immunity ◽

Cross Immunity

AbstractInfluenza epidemics cause substantial morbidity and mortality every year worldwide. Currently, two influenza A subtypes, A(H1N1) and A(H3N2), and type B viruses co-circulate in humans and infection with one type/subtype could provide cross-protection against the others. However, it remains unclear how such ecologic competition via cross-immunity and antigenic mutations that allow immune escape impact influenza epidemic dynamics at the population level. Here we develop a comprehensive model-inference system and apply it to study the evolutionary and epidemiological dynamics of the three influenza types/subtypes in Hong Kong, a city of global public health significance for influenza epidemic and pandemic control. Utilizing long-term influenza surveillance data since 1998, we are able to estimate the strength of cross-immunity between each virus-pairs, the timing and frequency of punctuated changes in population immunity in response to antigenic mutations in influenza viruses, and key epidemiological parameters over the last 20 years including the 2009 pandemic. We find evidence of cross-immunity in all types/subtypes, with strongest cross-immunity from A(H1N1) against A(H3N2). Our results also suggest that A(H3N2) may undergo antigenic mutations in both summers and winters and thus monitoring the virus in both seasons may be important for vaccine development. Overall, our study reveals intricate epidemiological interactions and underscores the importance of simultaneous monitoring of population immunity, incidence rates, and viral genetic and antigenic changes.

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New influenza A(H1N1) virus infections in France, April – May 2009

Eurosurveillance ◽

10.2807/ese.14.21.19221-en ◽

2009 ◽

Vol 14 (21) ◽

Cited By ~ 11

Author(s):

Collective New influenza A(H1N1) investigation teams*

Keyword(s):

North America ◽

Active Surveillance ◽

Influenza A ◽

Clinical Characteristics ◽

H1n1 Virus ◽

Virus Infections ◽

Influenza A H1n1 ◽

Set Up

Since the emergence of a new influenza A(H1N1) virus in North America and its international spread, an active surveillance of cases of infection due to this virus has been set up in France in order to undertake appropriate measures to slow down the spread of the new virus. This report describes the epidemiological and clinical characteristics of the 16 laboratory confirmed cases diagnosed in France as of 20 May 2009.

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