Respiratory viral infections during Hajj seasons

Detection of COVID-19 incidence among attendees of the 2022 Hajj season

Objectives

This study investigated the presence of COVID-19 cases among pilgrims, health care workers (HCWs), and non-HCWs of Hajj 2022.

Methods

Nasopharyngeal samples were collected from 491 attendees of Hajj 2022. All participants received three doses of COVID-19 vaccines. Paired (n = 138; 69 participants) and unpaired (n = 422; 422 participants) nasopharyngeal swabs were subjected to reverse transcription-polymerase chain reaction targeting E gene of β-coronaviruses and RNA-dependent RNA polymerase of SARS-CoV-2. The results were linked to the participants' profiles, including role during Hajj, presence of respiratory symptoms or comorbidities, contact with symptomatic individuals, smoking status, and COVID-19 recovery.

Results

A total of 20 (20 of 560; 3.6%) samples tested positive for COVID-19. Most cases (18 of 20; 90%) were pilgrims and non-HCWs. Six (30%) samples belonged to participants with previous positive reverse transcription-polymerase chain reaction. A total of 12 (60%) samples belonged to participants with respiratory symptoms. Three (15%) cases were linked to participants who had contact with individuals with respiratory symptoms. All cases belonged to individuals with no comorbidities, apart from a single case who has a chronic sinusitis. Five (25%) cases were smokers. No significant association was found between positive COVID-19 test and participants' profiles.

Conclusions

Few COVID-19 cases were detected in this study. Sustainable surveillance of COVID-19 and other respiratory viruses during Hajj seasons remains necessary.

Descriptive analysis to assess seasonal patterns of COVID-19 and influenza in low-income and middle-income countries in Asia, the Middle East and Latin America

OBJECTIVES

Understanding disease seasonality can help predict the occurrence of outbreaks and inform public health planning. Respiratory diseases typically follow seasonal patterns; however, knowledge regarding the seasonality of COVID-19 and its impact on the seasonality of influenza remains limited. The objective of this study was to provide more evidence to understand the circulation of SARS-CoV-2, the virus responsible for COVID-19, in an endemic scenario to guide potential preventive strategies.

DESIGN

In this study, a descriptive analysis was undertaken to describe seasonality trends and/or overlap between COVID-19 and influenza in 12 low-income and middle-income countries using Our World in Data and FluMart data sources. Plots of COVID-19 and influenza cases were analysed.

SETTING

Singapore, Thailand, Malaysia, the Philippines, Argentina, Brazil, Mexico, South Africa, Morocco, Bahrain, Qatar and Saudi Arabia.

OUTCOME MEASURES

COVID-19 cases and influenza cases.

RESULTS

No seasonal patterns of SARS-CoV-2 or SARS-CoV-2/influenza cocirculation were observed in most countries, even when considering the avian influenza pandemic period.

CONCLUSIONS

These results can inform public health strategies. The lack of observed seasonal behaviour highlights the importance of maintaining year-round vaccination rather than implementing seasonal campaigns. Further research investigating the influence of climate conditions, social behaviour and year-round preventive measures could be fundamental for shaping appropriate policies related to COVID-19 and respiratory viral disease control in low-income and middle-income countries as COVID-19 variant data and epidemiologic patterns accrue over time.

Genetic diversity and molecular analysis of human influenza virus among pilgrims during Hajj

The risk of transmission of respiratory tract infections is considerably enhanced at mass gathering (MG) religious events. Hajj is an annual Islamic MG event with approximately 3 million Muslim pilgrims from over 180 countries concentrated in Makkah, Saudi Arabia. This study aimed to investigate the genetic diversity of influenza viruses circulating among pilgrims during the Hajj pilgrimage. We performed a cross-sectional analytical study where nasopharyngeal swabs (NPs) from pilgrims with respiratory tract illnesses presenting to healthcare facilities during the 2019 Hajj were screened for influenza viruses. Influenza A subtypes and influenza B lineages were determined by multiplex RT-PCR for positive influenza samples. The phylogenetic analysis was carried out for the hemagglutination (HA) gene. Out of 185 nasopharyngeal samples, 54 were positive for the human influenza virus. Of these, 27 were influenza A H1N1 and 19 H3N2, 4 were untypable influenza A, and 4 were influenza B. Phylogenetic analysis revealed that the H1N1 and H3N2 strains differentiated into different and independent genetic groups and formed close clusters with selected strains of influenza viruses from various locations. To conclude, this study demonstrates a high genetic diversity of circulating influenza A subtypes among pilgrims during the Hajj Season. There is a need for further larger studies to investigate in-depth the genetic characteristics of influenza viruses and other respiratory viruses during Hajj seasons.