Browsing by Author "Salzer, Johanna S."

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    Effects of anthropogenic and demographic factors on patterns of parasitism in African small mammal communities
    (Parasitology, 2015) Salzer, Johanna S.; Carroll, Darin S.; Newkirk, Amanda Jo Williams; Lang, Stefanie; Peterhans, Julian Kerbis; Rwego, Innocent B.; Ockers, Sandra; Gillespie, Thomas R.
    Habitatdisturbance oftenresults in alterations in community structure of smallmammals.Additionally, the parasitesharboured by these small mammals may be impacted by environmental changes or indirectly affected by changes in available hosts. To improve our understanding of this interplay, we examined the patterns of parasitism in small mammal communities from a variety of habitats in forested Uganda. Small mammals were collected from areas experiencing variable habitat disturbance, host densityandspecies richness.The analysis focusedon3most abundant rodent species,Lophuromys aquilus,Praomys jacksoni and Hylomyscus stella, and a diverse group of parasites they harbour. The impact of various habitat and host community factors on parasite prevalence was examined using linear regression and Spearman’s rank-order correlation. We further investigated the parasite communities associated with each individual using correspondence analysis. We determined that, parasite prevalence and richness may be occasionally influenced by community and habitat factors, but taxonomy is a driving force in influencing the parasite community harboured by an individual host. Ultimately, applying general principles across a broad range of disturbance levels and diverse host communities needs to be approached with caution in complex communities.
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    Giardia sp. and Cryptosporidium sp. Infections in Primates in Fragmented and Undisturbed Forest in Western Uganda
    (Journal of Parasitology, 2007) Salzer, Johanna S.; Rwego, Innocent B.; Goldberg, Tony L.; Kuhlenschmidt, Mark S.; Gillespie, Thomas R.
    The molecular identification of species and genotypes of Giardia spp. infecting wild mammals represents the most reliable tool to understand the role played by these animals as reservoirs of cysts infectious for human and other animals. Of 139 fecal samples collected from fallow deer (Dama dama L.) hunted in a Natural Reserve of northern Italy, the prevalence of Giardia sp. was 11.5% (16 of 139 animals), and it was higher in fawns than in older animals. Fragments of the beta-giardin and triose phosphate isomerase (tpi) genes were successfully polymerase chain reaction amplified and sequenced from 8 isolates. No sequence variation was observed between isolates at the 2 genetic loci. Sequence and phylogenetic analyses identified a Giardia duodenalis subtype that clusters with assemblage A isolates and that shows homologies of 98 and 97% at the beta-giardin and tpi loci, respectively, compared with the A1 subtype. Because the G. duodenalis subtype found in fecal samples of fallow deer has never been detected previously, its role as a pathogen for humans and domestic animals is unknown, but, considering its genetic distinctiveness, it is likely to be low.
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    Impact of Anthropogenic Disturbance on Native and Invasive Trypanosomes of Rodents in Forested Uganda
    (EcoHealth, 2016) Salzer, Johanna S.; Pinto, C. Miguel; Grippi, Dylan C.; Newkirk, Amanda Jo Williams; Peterhans, Julian Kerbis; Rwego, Innocent B.; Carroll, Darin S.; Gillespie, Thomas R.
    Habitat disturbance and anthropogenic change are globally associated with extinctions and invasive species introductions. Less understood is the impact of environmental change on the parasites harbored by endangered, extinct, and introduced species. To improve our understanding of the impacts of anthropogenic disturbance on such host–parasite interactions, we investigated an invasive trypanosome (Trypanosoma lewisi). We screened 348 individual small mammals, representing 26 species, from both forested and non-forested habitats in rural Uganda. Using microscopy and PCR, we identified 18% of individuals (order Rodentia) as positive for trypanosomes. Further phylogenetic analyses revealed two trypanosomes circulating—T. lewisi and T. varani. T. lewisi was found in seven species both native and invasive, while T. varani was identified in only three native forest species. The lack of T. varani in non-forested habitats suggests that it is a natural parasite of forest-dwelling rodents. Our findings suggest that anthropogenic disturbance may lead to spillover of an invasive parasite (T. lewisi) from non-native to native species, and lead to local co-extinction of a native parasite (T. varani) and native forest-dwelling hosts.
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    Outbreak of Anthrax Associated with Handling and Eating Meat from a Cow, Uganda, 2018
    (Emerging Infectious Diseases, 2020) Kisaakye, Esther; Riolexus Ario, Alex; Bainomugisha, Kenneth; Cossaboom, Caitlin M. Ping Zhu; Lowe, David; Bulage, Lilian; Kadobera, Daniel; Sekamatte, Musa; Lubwama, Bernard; Tumusiime, Dan; Tusiime, Patrick; Downing, Robert; Buule, Joshua; Lutwama, Julius; Salzer, Johanna S.; Matkovic, Eduard; Joy Gary, Jana Ritter,; Zhu, Bao-Ping
    On April 20, 2018, the Kween District Health Office in Kween District, Uganda reported 7 suspected cases of human anthrax. A team from the Uganda Ministry of Health and partners investigated and identified 49 cases, 3 confirmed and 46 suspected; no deaths were reported. Multiple exposures from handling the carcass of a cow that had died suddenly were significantly associated with cutaneous anthrax, whereas eating meat from that cow was associated with gastrointestinal anthrax. Eating undercooked meat was significantly associated with gastrointestinal anthrax, but boiling the meat for >60 minutes was protective. We recommended providing postexposure antimicrobial prophylaxis for all exposed persons, vaccinating healthy livestock in the area, educating farmers to safely dispose of animal carcasses, and avoiding handling or eating meat from livestock that died of unknown causes.
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    Serologic Evidence For Circulating Orthopoxviruses In Peridomestic Rodents From Rural Uganda
    (Journal of wildlife diseases, 2013) Salzer, Johanna S.; Carroll, Darin S.; Rwego, Innocent B.; Li, Yu; Falendysz, Elizabeth A.; Shisler, Joanna L.; Karem, Kevin L.; Damon, Inger K.; Gillespie, Thomas R.
    The prevalence of orthopoxviruses (OPXV) among wildlife, including monkeypox virus (MPXV), remains largely unknown. Outbreaks of human monkeypox in central Africa have been associated with hunting, butchering, and consuming infected forest animals, primarily rodents and primates. Monkeypox cases have not been reported in east Africa, where human contact with wildlife is more limited. Whether this lack of human disease is due to the absence of MPXV in rodents is unknown. However, testing of wildlife beyond the known geographic distribution of human cases of monkeypox has rarely been conducted, limiting our knowledge of the natural distribution of MPXV and other OPXV. To improve our understanding of the natural distribution of OPXV in Africa and related risks to public health, we conducted a serosurvey of peridomestic rodents (Rattus rattus) in and around traditional dwellings in Kabarole District, Uganda, from May 2008 to July 2008. We tested for OPXV antibody in areas free of human monkeypox. Sera from 41%of the R. rattus individuals sampled reacted to OPXV-specific proteins from multiple, purified OPXV samples, but did not react by enzyme-linked immunosorbent assay. The specific OPXV could not be identified because poxvirus DNA was undetectable in corresponding tissues. We conclude that an OPXV or a similar poxvirus is circulating among wild rodents in Uganda. With the known geographic range of OPXV in rodents now increased, factors that dictate OPXV prevalence and disease will be identified.