High Prevalence of Viral Infections Among Hospitalized Pneumonia Patients in Equatorial Sarawak, Malaysia

Toh, Teck-Hock; Hii, King-Ching; Fieldhouse, Jane K; Ting, Jakie; Berita, Antoinette; Nguyen, Tham Thi; Wong, See-Chang; Wong, Toh-Mee; Lim, Wei-Honn; Ha, Siaw-Jing; Lau, Chuet-Zou; Kong, Sing-Ling; Bailey, Emily S; Warkentien, Tyler E; Husain, Tupur S; Gray, Gregory C

Sarawak, located on the northwest side of the island of Borneo, has an equatorial climate with a high relative humidity that rarely drops below 80% and temperatures ranging from 23°C to 32°C (see Supplementary Figure 2 ). Both Sibu (2.2873°N, 111.8305°E) and Kapit (1.9951°N, 112.9331°E) are approximately 2 degrees north of the equator (Supplementary Figure 1) . The rainy season in this region typically falls between November and February, with December to March seeing the most rain. A drier season typically falls between May and September, with June to August seeing the least rain. Our Previous studies have investigated the relationship between relative humidity or absolute humidity and influenza virus transmission, suggesting that increased levels of humidity are linked with decreased transmission efficiency; however, the prevalence of IAV in Sibu and Kapit Hospitals suggest the high humidity associated with the equatorial climate in this region may not constrain IAV transmission [15, 16] . Our findings regarding the prevalence of RSV support the existing literature that the 2 antigenic subgroups A and B can cocirculate but typically differ by season [17] . Unlike IAV, we saw seasonal variation of RSV-A and RSV-B during the drier months (see Supplementary Figure 3) .