Pandemic Influenza H1N1

Glass, Kathryn; Kelly, Heath; Mercer, G. N.

doi:10.1097/ede.0b013e31823a44a5

Cited by 17 publications

(8 citation statements)

References 73 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Using the excess degree of children and adults, the age specific R 0 can be estimated for both children and adults. We showed that R 0 for children is higher than that for adults (1.28 versus 1.08), which is consistent with other studies (see [19]). This implies that school-aged children likely contributed more infections than adults.…”

Section: 9supporting

confidence: 93%

Early real-time estimation of the basic reproduction number of emerging or reemerging infectious diseases in a community with heterogeneous contact pattern: Using data from Hong Kong 2009 H1N1 Pandemic Influenza as an illustrative example

Kwok¹,

Davoudi²,

Riley³

et al. 2015

PLoS ONE

View full text Add to dashboard Cite

Emerging and re-emerging infections such as SARS (2003) and pandemic H1N1 (2009) have caused concern for public health researchers and policy makers due to the increased burden of these diseases on health care systems. This concern has prompted the use of mathematical models to evaluate strategies to control disease spread, making these models invaluable tools to identify optimal intervention strategies. A particularly important quantity in infectious disease epidemiology is the basic reproduction number, R0. Estimation of this quantity is crucial for effective control responses in the early phase of an epidemic. In our previous study, an approach for estimating the basic reproduction number in real time was developed. This approach uses case notification data and the structure of potential transmission contacts to accurately estimate R0 from the limited amount of information available at the early stage of an outbreak. Based on this approach, we extend the existing methodology; the most recent method features intra- and inter-age groups contact heterogeneity. Given the number of newly reported cases at the early stage of the outbreak, with parsimony assumptions on removal distribution and infectivity profile of the diseases, experiments to estimate real time R0 under different levels of intra- and inter-group contact heterogeneity using two age groups are presented. We show that the new method converges more quickly to the actual value of R0 than the previous one, in particular when there is high-level intra-group and inter-group contact heterogeneity. With the age specific contact patterns, number of newly reported cases, removal distribution, and information about the natural history of the 2009 pandemic influenza in Hong Kong, we also use the extended model to estimate R0 and age-specific R0.

show abstract

Section: 9supporting

confidence: 93%

Early real-time estimation of the basic reproduction number of emerging or reemerging infectious diseases in a community with heterogeneous contact pattern: Using data from Hong Kong 2009 H1N1 Pandemic Influenza as an illustrative example

Kwok¹,

Davoudi²,

Riley³

et al. 2015

PLoS ONE

View full text Add to dashboard Cite

show abstract

“…Children are of particular importance due to the high attack rate among them and their known role in dispersing of the disease. This was indeed proven for the A(H1N1)pdm09 virus by Glass et al 26. These thresholds are important for policy makers to set minimum targets for vaccination coverage for novel influenza strain, as well as seasonal viruses.…”

Section: Discussionmentioning

confidence: 76%

The dynamics of infection and the persistence of immunity to A(H1N1)pdm09 virus in Israel

Weil

Shohat

Bromberg

et al. 2012

Influenza Resp Viruses

View full text Add to dashboard Cite

BackgroundInfluenza virus A(H1N1)pdm09 first appeared in Israel in late April 2009, disappeared in mid‐March 2010, and reappeared in late October 2010. Symptoms were mostly mild without need for medical care.ObjectivesTo provide targets for future pandemic preparedness and response by evaluating the dynamics and cumulative incidence of A(H1N1)pdm09 infection, the virus‐specific seroprevalence (HI antibody titer >1:40) at the height of the pandemic, during its decline and thereafter.MethodsA cross‐sectional seroepidemiological study was conducted on 6911 serum samples collected before, during, and after the pandemic.ResultsCumulative incidence of infection derived from the differences between post‐ and pre‐pandemic seroprevalence was 54·1%, 32·9%, 22·9%, 14·8%, and 6·3% in age‐groups 0–9, 10–19, 20–49, 50–79, and ≥80 years, respectively, and 28·5% for all age‐groups combined. Vaccination could have contributed at the most 4·6% to the post‐pandemic population seroprevalence. High pre‐pandemic immune response (47·4%) found in a cohort aged 15–18 year was strongly associated with birth years 1990–1993. Morbidity began to decline in mid‐November 2009 at 32·8% population seroprevalence (45% in ages 0–19 year) and stopped in March 2010 at 43·4% population seroprevalence in February 2010 (70% in ages 0–19 year). Between February and September 2010, seroprevalence declined by 12·2% allowing virus recirculation from October 2010.ConclusionsOur study provides targets for controlling future influenza pandemics in Israel. Vaccination should focus on the younger age‐groups (0–19 year) which played a key role in transmission of the A(H1N1)pdm09 due to lack of background immunity (ages 0–9 year) and high exposure rates (ages 10–19 year).

show abstract

“…Moreover, the completeness of the data could be affected by underreporting as some of the parents might have regarded measles as a kind of skin disease or might have confused it with other diseases that involve skin rashes. Apart from that, age-specific Rs are common to be used as a metric to identify appropriate age groups most responsible for transmission as for a target of interventions [10,12,13]. However, when determining the effort required to eliminate an infection, the interpretation of an age-specific R is different from that of an overall R in a heterogeneous population as using the original threshold of unity could lead to an underestimation of target population for interventions [16,17].…”

Section: Discussionmentioning

confidence: 99%

“…Nevertheless, some infectious diseases have been shown to be strongly age-specific, for example, measles. Age-specific R, defined as an average total number of secondary cases from all age groups generated by a single case with respect to his age group was recommended to study the differences in transmission potential taking account of social mixing [10][11][12][13][14][15]. Although a usual interpretation of age-specific R for gauging the control measures required to eliminate an infection is inappropriate [16,17], age-specific Rs provide valuable information on the underlying heterogeneous transmission between and within different groups of individuals.…”

Section: Introductionmentioning

confidence: 99%

Monitoring the age-specificity of measles transmissions during 2009-2016 in Southern China

Chong

Lau

et al. 2018

PLoS ONE

View full text Add to dashboard Cite

BackgroundDespite several immunization efforts, China saw a resurgence of measles in 2012. Monitoring of transmissions of individuals from different age groups could offer information that would be valuable for planning adequate disease control strategies. We compared the age-specific effective reproductive numbers (R) of measles during 2009–2016 in Guangdong, China.MethodsWe estimated the age-specific R values for 7 age groups: 0–8 months, 9–18 months, 19 months to 6 years, 7–15 years, 16–25 years, 26–45 years, and ≥46 years adapting the contact matrix of China. The daily numbers of laboratory and clinically confirmed cases reported to the Center for Disease Control and Prevention of Guangdong were used.ResultsThe peak R values of the entire population were above unity from 2012 to 2016, indicating the persistence of measles in the population. In general, children aged 0–6 years and adults aged 26–45 years had larger values of R when comparing with other age groups after 2012. While the peaks of R values for children aged 0–6 years dropped steadily after 2013, the peaks of R values for adults aged 26–45 years kept at a high range every year.ConclusionsAlthough the provincial supplementary immunization activities (SIAs) conducted in 2009 and 2010 were able to reduce the transmissions from 2009 to 2011, larger values of R for children aged 0–6 years were observed after 2012, indicating that the benefits of the SIAs were short-lived. In addition, the transmissions from adults aged between 26 and 45 years increased over time. Disease control strategies should target children and adult groups that carry high potential for measles transmission.

show abstract

Pandemic Influenza H1N1

Abstract: The difference between age-groups may help to explain high estimates of the reproduction number from outbreaks involving a large proportion of child cases.

Cited by 17 publications

References 73 publications

Early real-time estimation of the basic reproduction number of emerging or reemerging infectious diseases in a community with heterogeneous contact pattern: Using data from Hong Kong 2009 H1N1 Pandemic Influenza as an illustrative example

Early real-time estimation of the basic reproduction number of emerging or reemerging infectious diseases in a community with heterogeneous contact pattern: Using data from Hong Kong 2009 H1N1 Pandemic Influenza as an illustrative example

The dynamics of infection and the persistence of immunity to A(H1N1)pdm09 virus in Israel

Monitoring the age-specificity of measles transmissions during 2009-2016 in Southern China

Contact Info

Product

Resources

About