Studies of reservoir hosts for Marburg virus

Abstract

To determine reservoir hosts for Marburg virus (MARV), we examined the fauna of a mine in northeastern Democratic Republic of the Congo. The mine was associated with a protracted outbreak of Marburg hemorrhagic fever during 1998-2000. We found MARV nucleic acid in 12 bats, comprising 3.0%-3.6% of 2 species of insectivorous bat and 1 species of fruit bat. We found antibody to the virus in the serum of 9.7% of 1 of the insectivorous species and in 20.5% of the fruit bat species, but attempts to isolate virus were unsuccessful.

Figure 1

Marburg virus ELISA percent positivity (PP) values recorded on bat serum samples collected in 1999 in Durba, Democratic Republic of the Congo (n = 426), and from 1984 through 1994 in Kruger National Park, South Africa (n = 188). The cutoff PP value of 16.4 was fixed as 3 × (mean + 3 SD) of values observed in the Kruger National Park samples.

Figure 2

Phylogenetic analysis created by using a neighbor-joining algorithm (MEGA version 3.1, [3]) that related sequences of 302-nt fragments of Marburg viral protein 35 gene detected in 12 bats in Durba Mine (boldface) to sequences determined for isolates from human patients in the Durba plus previous outbreaks of the disease. Six bat-derived sequences were identical to sequences from human isolates during the outbreak; 1 corresponded to a 1975 human isolate from Zimbabwe, and the remaining 5 represented novel sequences, making a total of 15 distinct MARV sequences found to be in circulation during the Durba epidemic. Bootstrap values were determined by 500 replicates. DRC, Democratic Republic of the Congo; GER, Germany; KEN, Kenya; ZIM, Zimbabwe.