Browsing by Author "Cohen, Cheryl"
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- Distribution of influenza virus types by age using case-based global surveillance data from twenty-nine countries, 1999-2014Publication . Caini, Saverio; Spreeuwenberg, Peter; Kusznierz, Gabriela F.; Rudi, Juan Manuel; Owen, Rhonda; Pennington, Kate; Wangchuk, Sonam; Gyeltshen, Sonam; Ferreira de Almeida, Walquiria Aparecida; Pessanha Henriques, Cláudio Maierovitch; Njouom, Richard; Vernet, Marie-Astrid; Fasce, Rodrigo A.; Andrade, Winston; Yu, Hongjie; Feng, Luzhao; Yang, Juan; Peng, Zhibin; Lara, Jenny; Bruno, Alfredo; de Mora, Doménica; de Lozano, Celina; Zambon, Maria; Pebody, Richard; Castillo, Leticia; Clara, Alexey W.; Matute, Maria Luisa; Kosasih, Herman; Nurhayati, null; Puzelli, Simona; Rizzo, Caterina; Kadjo, Herve A; Daouda, Coulibaly; Kiyanbekova, Lyazzat; Ospanova, Akerke; Mott, Joshua A.; Emukule, Gideon O.; Heraud, Jean-Michel; Razanajatovo, Norosoa Harline; Barakat, Amal; El Falaki, Fatima; Huang, Sue Q.; Lopez, Liza; Balmaseda, Angel; Moreno, Brechla; Rodrigues, Ana Paula; Guiomar, Raquel; Ang, Li Wei; Lee, Vernon Jian Ming; Venter, Marietjie; Cohen, Cheryl; Badur, Selim; Ciblak, Meral A.; Mironenko, Alla; Holubka, Olha; Bresee, Joseph; Brammer, Lynnette; Hoang, Phuong Vu Mai; Le, Mai Thi Quynh; Fleming, Douglas; Séblain, Clotilde El-Guerche; Schellevis, François; Paget, John; Global Influenza B Study groupBackground: Influenza disease burden varies by age and this has important public health implications. We compared the proportional distribution of different influenza virus types within age strata using surveillance data from twenty-nine countries during 1999-2014 (N=358,796 influenza cases). Methods: For each virus, we calculated a Relative Illness Ratio (defined as the ratio of the percentage of cases in an age group to the percentage of the country population in the same age group) for young children (0-4 years), older children (5-17 years), young adults (18-39 years), older adults (40-64 years), and the elderly (65+ years). We used random-effects meta-analysis models to obtain summary relative illness ratios (sRIRs), and conducted meta-regression and sub-group analyses to explore causes of between-estimates heterogeneity. Results: The influenza virus with highest sRIR was A(H1N1) for young children, B for older children, A(H1N1)pdm2009 for adults, and (A(H3N2) for the elderly. As expected, considering the diverse nature of the national surveillance datasets included in our analysis, between-estimates heterogeneity was high (I2>90%) for most sRIRs. The variations of countries’ geographic, demographic and economic characteristics and the proportion of outpatients among reported influenza cases explained only part of the heterogeneity, suggesting that multiple factors were at play. Conclusions: These results highlight the importance of presenting burden of disease estimates by age group and virus (sub)type.
- Estimates of global seasonal influenza-associated respiratory mortality: a modelling studyPublication . Iuliano, A. Danielle; Roguski, Katherine M.; Chang, Howard H.; Muscatello, David J.; Palekar, Rakhee; Tempia, Stefano; Cohen, Cheryl; Gran, Jon Michael; Schanzer, Dena; Cowling, Benjamin J.; Wu, Peng; Kyncl, Jan; Ang, Li Wei; Park, Minah; Redlberger-Fritz, Monika; Yu, Hongjie; Espenhain, Laura; Krishnan, Anand; Emukule, Gideon; van Asten, Liselotte; Silva, Susana Pereira; Aungkulanon, Suchunya; Buchholz, Udo; Widdowson, Marc-Alain; Bresee, Joseph S.; Global Seasonal Influenza-associated Mortality Collaborator NetworkBACKGROUND: Estimates of influenza-associated mortality are important for national and international decision making on public health priorities. Previous estimates of 250 000-500 000 annual influenza deaths are outdated. We updated the estimated number of global annual influenza-associated respiratory deaths using country-specific influenza-associated excess respiratory mortality estimates from 1999-2015. METHODS: We estimated country-specific influenza-associated respiratory excess mortality rates (EMR) for 33 countries using time series log-linear regression models with vital death records and influenza surveillance data. To extrapolate estimates to countries without data, we divided countries into three analytic divisions for three age groups (<65 years, 65-74 years, and ≥75 years) using WHO Global Health Estimate (GHE) respiratory infection mortality rates. We calculated mortality rate ratios (MRR) to account for differences in risk of influenza death across countries by comparing GHE respiratory infection mortality rates from countries without EMR estimates with those with estimates. To calculate death estimates for individual countries within each age-specific analytic division, we multiplied randomly selected mean annual EMRs by the country's MRR and population. Global 95% credible interval (CrI) estimates were obtained from the posterior distribution of the sum of country-specific estimates to represent the range of possible influenza-associated deaths in a season or year. We calculated influenza-associated deaths for children younger than 5 years for 92 countries with high rates of mortality due to respiratory infection using the same methods. FINDINGS: EMR-contributing countries represented 57% of the global population. The estimated mean annual influenza-associated respiratory EMR ranged from 0·1 to 6·4 per 100 000 individuals for people younger than 65 years, 2·9 to 44·0 per 100 000 individuals for people aged between 65 and 74 years, and 17·9 to 223·5 per 100 000 for people older than 75 years. We estimated that 291 243-645 832 seasonal influenza-associated respiratory deaths (4·0-8·8 per 100 000 individuals) occur annually. The highest mortality rates were estimated in sub-Saharan Africa (2·8-16·5 per 100 000 individuals), southeast Asia (3·5-9·2 per 100 000 individuals), and among people aged 75 years or older (51·3-99·4 per 100 000 individuals). For 92 countries, we estimated that among children younger than 5 years, 9243-105 690 influenza-associated respiratory deaths occur annually. INTERPRETATION: These global influenza-associated respiratory mortality estimates are higher than previously reported, suggesting that previous estimates might have underestimated disease burden. The contribution of non-respiratory causes of death to global influenza-associated mortality should be investigated.
- The epidemiological signature of influenza B virus and its B/Victoria and B/Yamagata lineages in the 21st centuryPublication . Caini, Saverio; Kusznierz, Gabriela; Garate, Verònica Vera; Wangchuk, Sonam; Thapa, Binay; de Paula Júnior, Francisco José; Ferreira de Almeida, Walquiria Aparecida; Njouom, Richard; Fasce, Rodrigo A.; Bustos, Patricia; Feng, Luzhao; Peng, Zhibin; Araya, Jenny Lara; Bruno, Alfredo; de Mora, Doménica; Barahona de Gámez, Mónica Jeannette; Pebody, Richard; Zambon, Maria; Higueros, Rocio; Rivera, Rudevelinda; Kosasih, Herman; Castrucci, Maria Rita; Bella, Antonino; Kadjo, Hervé A.; Daouda, Coulibaly; Makusheva, Ainash; Bessonova, Olga; Chaves, Sandra S.; Emukule, Gideon O.; Heraud, Jean-Michel; Razanajatovo, Norosoa H.; Barakat, Amal; El Falaki, Fatima; Meijer, Adam; Donker, Gé A.; Huang, Q. Sue; Wood, Tim; Balmaseda, Angel; Palekar, Rakhee; Arévalo, Brechla Moreno; Rodrigues, Ana Paula; Guiomar, Raquel; Lee, Vernon Jian Ming; Ang, Li Wei; Cohen, Cheryl; Treurnicht, Florette; Mironenko, Alla; Holubka, Olha; Bresee, Joseph; Brammer, Lynnette; Le, Mai T.Q.; Hoang, Phuong V.M.; El Guerche-Séblain, Clotilde; Paget, John; Global Influenza B Study teamWe describe the epidemiological characteristics, pattern of circulation, and geographical distribution of influenza B viruses and its lineages using data from the Global Influenza B Study. We included over 1.8 million influenza cases occurred in thirty-one countries during 2000-2018. We calculated the proportion of cases caused by influenza B and its lineages; determined the timing of influenza A and B epidemics; compared the age distribution of B/Victoria and B/Yamagata cases; and evaluated the frequency of lineage-level mismatch for the trivalent vaccine. The median proportion of influenza cases caused by influenza B virus was 23.4%, with a tendency (borderline statistical significance, p = 0.060) to be higher in tropical vs. temperate countries. Influenza B was the dominant virus type in about one every seven seasons. In temperate countries, influenza B epidemics occurred on average three weeks later than influenza A epidemics; no consistent pattern emerged in the tropics. The two B lineages caused a comparable proportion of influenza B cases globally, however the B/Yamagata was more frequent in temperate countries, and the B/Victoria in the tropics (p = 0.048). B/Yamagata patients were significantly older than B/Victoria patients in almost all countries. A lineage-level vaccine mismatch was observed in over 40% of seasons in temperate countries and in 30% of seasons in the tropics. The type B virus caused a substantial proportion of influenza infections globally in the 21st century, and its two virus lineages differed in terms of age and geographical distribution of patients. These findings will help inform health policy decisions aiming to reduce disease burden associated with seasonal influenza.