Seasonal pulses of Marburg virus circulation in juvenile Rousettus aegyptiacus bats coincide with periods of increased risk of human infection.
Marburg virus (family Filoviridae) causes sporadic outbreaks of severe hemorrhagic disease in sub-Saharan Africa. Bats have been implicated as likely natural reservoir hosts based most recently on an investigation of cases among miners infected in 2007 at the Kitaka mine, Uganda, which contained a large population of Marburg virus-infected Rousettus aegyptiacus fruit bats. Described here is an ecologic investigation of Python Cave, Uganda, where an American and a Dutch tourist acquired Marburg virus infection in December 2007 and July 2008. More than 40,000 R. aegyptiacus were found in the cave and were the sole bat species present. Between August 2008 and November 2009, 1,622 bats were captured and tested for Marburg virus. Q-RT-PCR analysis of bat liver/spleen tissues indicated ~2.5% of the bats were actively infected, seven of which yielded Marburg virus isolates. Moreover, Q-RT-PCR-positive lung, kidney, colon and reproductive tissues were found, consistent with potential for oral, urine, fecal or sexual transmission. The combined data for R. aegyptiacus tested from Python Cave and Kitaka mine indicate low level horizontal transmission throughout the year. However, Q-RT-PCR data show distinct pulses of virus infection in older juvenile bats (~six months of age) that temporarily coincide with the peak twice-yearly birthing seasons. Retrospective analysis of historical human infections suspected to have been the result of discrete spillover events directly from nature found 83% (54/65) events occurred during these seasonal pulses in virus circulation, perhaps demonstrating periods of increased risk of human infection. The discovery of two tags at Python Cave from bats marked at Kitaka mine, together with the close genetic linkages evident between viruses detected in geographically distant locations, are consistent with R. aegyptiacus bats existing as a large meta-population with associated virus circulation over broad geographic ranges. These findings provide a basis for developing Marburg hemorrhagic fever risk reduction strategies.
Viral Special Pathogens Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
Brian R
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Amman
Serena A
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Carroll
Zachary D
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Reed
Tara K
TK
Sealy
Stephen
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Balinandi
Robert
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Swanepoel
Alan
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Kemp
Bobbie Rae
BR
Erickson
James A
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Comer
Shelley
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Campbell
Deborah L
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Cannon
Marina L
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Khristova
Patrick
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Atimnedi
Christopher D
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Paddock
Rebekah J Kent
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Crockett
Timothy D
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Flietstra
Kelly L
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Warfield
Robert
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Unfer
Edward
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Katongole-Mbidde
Robert
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Downing
Jordan W
JW
Tappero
Sherif R
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Zaki
Pierre E
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Rollin
Thomas G
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Ksiazek
Stuart T
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Nichol
Jonathan S
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Towner
D000818:Animals; D001483:Base Sequence; D059552:Caves; D002685:Chiroptera / Q000145:classification / Q000821:virology*; D004197:Disease Reservoirs; D005260:Female; D006801:Humans; D008297:Male; D008379:Marburg Virus Disease / Q000453:epidemiology* / Q000635:transmission*; D029024:Marburgvirus / Q000235:genetics / Q000302:isolation & purification*; D009687:Nuclear Proteins / Q000235:genetics; D010802:Phylogeny; D012367:RNA, Viral / Q000032:analysis; D012189:Retrospective Studies; D012621:Seasons; D017423:Sequence Analysis, RNA; D014454:Uganda / Q000453:epidemiology; D054334:Viral Regulatory and Accessory Proteins / Q000235:genetics
D009687:Nuclear Proteins; D012367:RNA, Viral; C080980:VP35 protein, filovirus; D054334:Viral Regulatory and Accessory Proteins