Climate Anomalies and Spillover of Bat-Borne Viral Diseases in the Asia–Pacific Region and the Arabian Peninsula

Abstract

Climate variability and anomalies are known drivers of the emergence and outbreaks of infectious diseases. In this study, we investigated the potential association between climate factors and anomalies, including El Niño Southern Oscillation (ENSO) and land surface temperature anomalies, as well as the emergence and spillover events of bat-borne viral diseases in humans and livestock in the Asia–Pacific region and the Arabian Peninsula. Our findings from time series analyses, logistic regression models, and structural equation modelling revealed that the spillover patterns of the Nipah virus in Bangladesh and the Hendra virus in Australia were differently impacted by climate variability and with different time lags. We also used event coincidence analysis to show that the emergence events of most bat-borne viral diseases in the Asia–Pacific region and the Arabian Peninsula were statistically associated with ENSO climate anomalies. Spillover patterns of the Nipah virus in Bangladesh and the Hendra virus in Australia were also significantly associated with these events, although the pattern and co-influence of other climate factors differed. Our results suggest that climate factors and anomalies may create opportunities for virus spillover from bats to livestock and humans. Ongoing climate change and the future intensification of El Niño events will therefore potentially increase the emergence and spillover of bat-borne viral diseases in the Asia–Pacific region and the Arabian Peninsula.

One Health Surveillance Highlights Circulation of Viruses with Zoonotic Potential in Bats, Pigs, and Humans in Viet Nam

“…Bats are known to host some high consequence zoonotic pathogens and their progenitors within the CoV and PmV families, such as SARS-CoV-1, SARS-CoV-2, MERS-CoV, Nipah virus and Hendra virus [ 20 ]. However, the zoonotic spillover potential of the bat viruses identified in this study remain mostly unknown, as these viruses have not been fully characterized and their ability to jump species barriers has not been assessed.…”

“…Bats harbor a large diversity of CoVs belonging to the α-CoV and β-CoV genera [ 11 , 12 ] and have been identified as the evolutionary precursors of most CoVs infecting humans [ 13 ], including Severe Acute Respiratory Syndrome (SARS)-CoV-1 and SARS-CoV-2 [ 14 , 15 ], Middle East Respiratory Syndrome (MERS)-CoV [ 16 ], HCoV-NL63 [ 17 ], and HCoV-229E [ 18 ]. Paramyxoviruses (PmVs) also include several significant zoonotic pathogens in Southeast Asia, with a majority of them originating from bats [ 19 , 20 ].…”

Host–Pathogen Interactions Influencing Zoonotic Spillover Potential and Transmission in Humans

“…The bat breeding season seems to be associated with increased HeV and NiV shedding, because of a declining immunity level during this period. Despite most NiV outbreaks happening during the winter months in Bangladesh, serological survey suggests that NiV shedding by bats can occur at any time of the year and is cyclical rather than annual or seasonal [ 273 , 274 , 275 ]. Climatic factors were shown to determine HeV spillover patterns in horses, which could be linked to food shortage-related immune and behavioral changes in bats and horses [ 276 ].…”

“…Climate anomalies (in terms of temperature or rainfall patterns for example) and climate change more generally likely drive the emergence and spillover opportunities of bat viruses by altering numerous aspects of bat physiology and ecology (foraging, stress induced by climate variability and related immune changes or migrations, etc.) [ 275 , 279 ]. In particular, food shortage and the altered body condition of bats are associated with decreased immunocompetence and HeV seroprevalence [ 280 , 281 ].…”

Identifying weather patterns affecting household date palm sap consumption in Bangladesh, 2013-2016

“…One potential explanation is that humans drink more sap during the coldest days of the winter when sap is more abundant and they report that the sap is sweetest [12, 13] (Fig 1). More recently, lower precipitation in the month preceding the spillover event was also observed to be a predictor of spillover risk, along with El Niño Southern Oscillation cycles with a lag of three months [14]. One speculative explanation for this is that rain during the tapping process may dilute the sap, making it less sweet and less appealing to buyers.…”