Prevalence, Strain Circulation and Disease Burden Study of Seasonal Influenza A and B in Panama, Selected Countries of Central America and the Caribbean From the Year 2010 to 2015

The case definition of Influenza was any clinical specimen confirmed by a positive laboratory test. Cases were stratified by the following age categories: less than (<) 2 years; 2-4 years; 5-19 years; 20-39 years; 40-59 years; greater than of equal to (≥) 60 years and Unspecified age, instead of <1, 1-4, 5-9, 10-14, 15-19, 20-24, 25-44, 45-49, 50-59, 60-64 and ≥ 65 years, as initially described in the Protocol. Note that one specimen sample was positive for both influenza A and B so the number started still remains 1839.

The case definition of Influenza was any clinical specimen confirmed by a positive laboratory test. Cases were stratified by virus subtype (H1N1 and H3N2) and the following age categories: less than (<) 2 years; 2-4 years; 5-19 years; 20-39 years; 40-59 years; greater than of equal to (≥) 60 years. Note that one specimen sample was positive for both influenza A and B so the number started still remains 1839.

The case definition of Influenza was any clinical specimen confirmed by a positive laboratory test. Cases were stratified by lineage (Victoria and Yamagata) and the following age categories: less than (<) 2 years; 2-4 years; 5-19 years; 20-39 years; 40-59 years; greater than of equal to (≥) 60 years. Note that one specimen sample was positive for both influenza A and B so the number started still remains 1839.

The signs and symptoms assessed were: Fever, Cough, Sore throat, Rhinorrhea, Dyspnea, Vomiting, Diarrhea, Myalgias, Nausea, Headache, Wheezing, Apnea, Tachypnea, Polypnea, Arthralgia, Chest Pain, Convulsion, Hyporexia, Weakness, Irritability, Odynophagia, Abdominal pain, Conjunctivitis, Cyanosis and Chills. Each sign and symptom was assessed in four categories: yes = presence of sign/symptom; no = absence of sign/symptom; form not filled = no epi surveillance form available; and unspecified= no data on the Epi surveillance form. Analysis related to duration of the illness was not performed as the data was not collected. Note that one specimen sample was positive for both influenza A and B so the number started still remains 1839.

The outcomes were categorized as follows: Outpatient, Hospitalised, Dead or Unspecified (i.e. missing data on the epidemiology surveillance form). Note that one specimen sample was positive for both influenza A and B so the number started still remains 1839.

The cases were stratified by influenza type and Southern hemisphere Influenza seasonal period (May-October of each year 2011-2017). Note that one specimen sample was positive for both influenza A and B so the number started still remains 1839.

The cases were stratified by region. Regions were classified as follows: West, Central, Panama, Northeast, Unspecified (= region unknown). Note that one specimen sample was positive for both influenza A and B so the number started still remains 1839.

The cases were stratified by lineage (Victoria and Yamagata) and region. Regions were classified as follows: West, Central, Panama, Northeast, Unspecified (= region unknown). Note that one specimen sample was positive for both influenza A and B so the number started still remains 1839.

Comparison of characteristics of the influenza B-infection Victoria (V) or Yamagata (Y) as observed in the database and the B-strain included in the trivalent influenza vaccine expressed as the number of cases with B-lineage-level mismatch between trivalent seasonal influenza vaccines and circulating viruses observed during the study period. Categories are defined as follows: e.g. for the first category:"V.(B/Brisbane/60/2008)vsVictoria-May-Oct 2011" corresponds to Southern hemisphere influenza season of "May-Oct 2011" with vaccine recommendation: "Victoria (B/Brisbane/60/2008-like virus)" compared to circulating Influenza B lineages "Victoria". Note that one specimen sample was positive for both influenza A and B so the number started still remains 1839.