Circulation of respiratory viruses among Grand Magal Pilgrims and villagers in rural Senegal

Respiratory symptoms and infections are common among pilgrims participating to the Grand Magal of Touba (GMT). In this study, we aim to investigate the transmission of respiratory viruses acquired by pilgrims on their return from the GMT to the population who remained at home in rural villages in South Senegal. Demographic and clinical data were collected from a cohort of pilgrims and a panel of respiratory viruses was detected by PCR. A total 191 participants were included in this study. Before the GMT, 16.8 % of participants had respiratory symptoms and 11.0 % reported fever with enterovirus (1.0 %) and PIV3 (0.5 %) the only respiratory viruses detected. After participating to the GMT, 38.8 % pilgrims reported respiratory symptoms and 23.8 % were febrile while 28.8 % pilgrim relatives and 15.0 % village controls reported respiratory symptoms after pilgrims returned to the villages with 21.2 % and 10.0 % being febrile. HRV (10.5 %), PIV1 (5.7 %), HCoV (2.9 %), SARS-CoV-2 (1.9 %), IAV (1.9 %), ADV (0.9 %), and MPV (0.9 %) were acquired by pilgrims. Among pilgrim relatives, 2 (3.0 %) acquired HRV. No virus was acquired by village controls. Pilgrims who participated to the GMT were more likely to develop respiratory symptoms and acquire respiratory viruses that villagers and they likely transmit rhinovirus within their families, on returning home.