The national and provincial burden of medically attended influenza-associated influenza-like illness and severe acute respiratory illness in the Democratic Republic of Congo, 2013-2015

Abstract

Background: Estimates of influenza-associated outpatient consultations and hospitalizations are severely limited in low- and middle-income countries, especially in Africa.

Methods: We conducted active prospective surveillance for influenza-like illness (ILI) and severe acute respiratory illness (SARI) at 5 healthcare facilities situated in Kinshasa Province during 2013-2015. We tested upper respiratory tract samples for influenza viruses using a reverse transcription-polymerase chain reaction assay. We estimated age-specific numbers and rates of influenza-associated ILI outpatient consultations and SARI hospitalizations for Kinshasa Province using a combination of administrative and influenza surveillance data. These estimates were extrapolated to each of the remaining 10 provinces accounting for provincial differences in prevalence of risk factors for pneumonia and healthcare-seeking behavior. Rates were reported per 100 000 population.

Results: During 2013-2015, the mean annual national number of influenza-associated ILI outpatient consultations was 1 003 212 (95% Confidence Incidence [CI]: 719 335-1 338 050 - Rate: 1205.3; 95% CI: 864.2-1607.5); 199 839 (95% CI: 153 563-254 759 - Rate: 1464.0; 95% CI: 1125.0-1866.3) among children aged <5 years and 803 374 (95% CI: 567 772-1 083 291 - Rate: 1154.5; 95% CI: 813.1-1556.8) among individuals aged ≥5 years. The mean annual national number of influenza-associated SARI hospitalizations was 40 361 (95% CI: 24 014-60 514 - Rate: 48.5; 95% CI: 28.9-72.7); 25 452 (95% CI: 19 146-32 944 - Rate: 186.5; 95% CI: 140.3-241.3) among children aged <5 years and 14 909 (95% CI: 4868-27 570 - Rate: 21.4; 95% CI: 28.9-72.7) among individuals aged ≥5 years.

Conclusions: The burden of influenza-associated ILI outpatient consultations and SARI hospitalizations was substantial and was highest among hospitalized children aged <5 years.

Keywords: Democratic Republic of Congo; burden; influenza; influenza-like illness; severe acute respiratory illness.

Figure 1

Method used to estimate the numbers and rates of severe acute respiratory illness (SARI) and influenza‐associated SARI hospitalizations in the Democratic Republic of Congo, 2013‐2015. Data inputs steps are in light gray boxes, and data outputs are in dark gray boxes

Figure 2

Method used to estimate the numbers and rates of influenza‐like illness (ILI) and influenza‐associated ILI outpatient consultations in the Democratic Republic of Congo, 2013‐2015. Data inputs steps are in light gray boxes, and data outputs are in dark gray boxes

Figure 3

Monthly number of influenza‐positive specimens among patients with influenza‐like illness or severe acute respiratory illness from 5 surveillance sites in Kinshasa Province, Democratic Republic of Congo, 2013‐2015

Figure 4

Mean annual estimates of mild or severe respiratory illness and influenza‐associated mild or severe respiratory illness rates by age group, Democratic Republic of Congo, 2013‐2015. A, Influenza‐like illness (ILI); B, Severe acute respiratory illness (SARI)