Increase in detections of respiratory diseases in Argentina

In the recent National Epidemiological Bulletin No. 708, corresponding to Epidemiological Week (ES) 23 of the year 2024, relevant data on the situation of acute respiratory infections in the country have been presented.

During EW 23, 73 cases of COVID-19 and one related death were confirmed. In the period between EW 52 of 2023 and EW 4 of 2024, COVID-19 cases showed a significant increase, reaching a peak in EW 4 of 2024, although they subsequently decreased. This increase may be related to the greater movement of people and the return to work and school activities.

The Ambulatory Monitoring Units reported an increase in Influenza cases in the last 8 weeks, with 62 positive cases among 120 samples in the last EW. 6 cases of SARS-CoV-2 were also detected among 667 samples analyzed, with no detections of RSV (Respiratory Syncytial Virus).

In EW 23, 19 detections of SARS-CoV-2, 320 of Influenza and 137 of RSV were recorded in hospitalized patients. Influenza cases have shown an upward trend since EW 16, 2024, exceeding 200 weekly cases in the last 4 weeks. RSV detections have also increased since EW 16. SARS-CoV-2 cases remain at low levels.

The pressure on hospital systems has been manageable, but the increase in Influenza and RSV cases could put hospital capacity at risk if the trend continues. The authorities urge the population to get vaccinated against influenza and follow public health recommendations.

The respiratory virus network reported an increase in Influenza detections, going from 384 cases in EW 20 to 1,248 in EW 22. A slight increase was also observed in RSV detections, with more than 300 cases in the last three weeks. In EW 22, cases of SARS-CoV-2, parainfluenza, adenovirus and metapneumovirus were also detected.

This increase in detections suggests greater circulation of these viruses, possibly due to seasonal factors and the relaxation of some preventive measures. The medical community recommends strengthening vaccination campaigns and maintaining prevention measures, such as the use of masks and frequent hand washing.

In the first 23 weeks of 2024, 41 influenza-related deaths were reported. Regarding the SARS-CoV-2 variants, between EW 5 and 12 of 2024, the JN.1 variant was identified in 78.86% of cases, followed by BA.2.86* in 12.08% and EG.5 by 1.68%.

These variants are the subject of continuous study by experts, who monitor their impact on public health and the effectiveness of existing vaccines. Health authorities emphasize the importance of continuing with booster doses of COVID-19 vaccines to ensure optimal protection against emerging variants.

Influenza-like Illness (ILI)

Between epidemiological weeks (EW) 1 and 22 of 2024, 372,038 cases of Influenza-Type Illness (ILI) have been reported in Argentina, with a cumulative incidence rate of 790.4 cases per 100,000 inhabitants. Although this figure is lower compared to the years 2016-2017 and 2022-2023, it exceeds the notifications of the years 2015 and 2018-2021.

The highest number of ILI cases in the period 2015-2024 was recorded in 2022, with 528,389 cases. In 2024, an increase was observed in the first weeks of the year, reaching outbreak levels between EW 2 and EW 8, followed by a decrease to safe levels until EW 20, although with an upward trend in weekly notifications since EW 20. SE 10. In the last two weeks analyzed, the records were at alert levels.

During EW 1-22 of 2024, 47,471 cases of pneumonia were reported, with a cumulative incidence of 100.9 cases per 100,000 inhabitants. The year with the highest number of cases was 2022. Pneumonia notifications in 2024 are lower compared to most historical years, surpassing only the records of 2020 and 2018. Notifications remained in the security zone until EW 6 and showed a slightly upward trend starting in EW 10.

Between EW 1-22 of 2024, 37,810 cases of bronchiolitis were recorded, with a cumulative incidence rate of 2,602.6 cases per 100,000 inhabitants. The number of cases in 2024 is lower compared to historical records, surpassing only the notifications of 2020 and 2021. Notifications of bronchiolitis in children under 2 years of age remained within the expected limits in relation to historical records.

The number of confirmed cases of COVID-19 during 2023 and 2024 is lower compared to previous years. However, there was an increase in SARS-CoV-2 detections between EW 52/2023 and EW 4/2024, followed by a downward trend. Regarding deaths, an increase in notifications was observed in EW 5 of 2024, with a subsequent downward trend. During SE 23/2024, only one death was reported.

Surveillance in Outpatient Monitoring Units (UMA)

From the beginning of 2024 to EW 23, 7,896 samples studied by rt-PCR for SARS-CoV-2 were registered, of which 858 were positive, which represents a decrease of 21.64% compared to 2023. For influenza , 2,651 samples were studied, with 421 positive results, evidencing greater circulation of the virus in 2024 compared to 2023. Detections of Respiratory Syncytial Virus (RSV) were minimal, with only 12 positive cases in 2024.

Between EW 1 and EW 23 of 2024, 3,818 cases of SARS-CoV-2 were reported in hospitalized people, which represents an increase of 11.12% compared to the same period of the previous year. SARS-CoV-2 detections in hospitalized people showed a downward trend during the first nine weeks of 2023, followed by a new increase in cases.

Respiratory Virus Trends

2020: Marked decrease in respiratory virus cases due to the COVID-19 pandemic.

2021-2022: Resumption of the circulation of respiratory viruses. Unusual behavior of Influenza with peaks between SE 3-14 and SE 34-45. Significant increase in metapneumovirus between EW 16 and 26.

2023: Early seasonal activity of Respiratory Syncytial Virus (RSV) with a rapid increase in cases between EW 13 and 22. Higher number of parainfluenza detections compared to previous years, similar to 2017 and 2018. Adenovirus cases present throughout the year

National Epidemiological Bulletin… by El Litoral