Emerging Infectious Diseases of Wildlife and Species Conservation

The Occurrence and Meta-Analysis of Investigations on Intestinal Parasitic Infections Among Captive Wild Mammals in Mainland China

This study investigated the infection rates of intestinal parasites in captive wild animals from 2000 to 2024 and analyzed the associated risk factors using a meta-analysis. We retrieved 29 studies, with a total of 8421 captive wild mammals, published between 2000 and 2024. We used the DerSimonian-Laird model and calculated infection rate estimates with the variance stabilizing double arcsine transformation. The results revealed that the overall prevalence of gastrointestinal parasitic infections in captive wild mammals in mainland China was found to be 53.9%. The highest infection rate was observed for nematodes at 45.1%. Seasonal subgroup analysis revealed the highest incidence in summer at 61.8% and 61.6% in winter. In the class order Mammalia, the highest infection rate was found in the Primates at 66.5% and similarly high values were determined in several other orders like Artiodactyla (59%), Rodentia (57.1%), Carnivora (53.3%) and extremely low in Proboscidea (19.9%). The highest overall infection rate was recorded in summer. The infection rate of gastrointestinal parasites in captive wild mammals in mainland China is notably high. Additionally, parasitic infection rates in captive animals were found to be lower in economically developed regions of mainland China.

The wild cost of invasive feral animals worldwide

Invasive non-native species are a growing burden to economies worldwide. While domesticated animals (i.e. livestock, beasts of burden or pets) have enabled our ways of life and provide sustenance for countless individuals, they may cause substantial impacts when they escape or are released (i.e. become feral) and then become invasive with impacts. We used the InvaCost database to evaluate monetary impacts from species in the Domestic Animal Diversity Information System database. We found a total cost of $141.95 billion from only 18 invasive feral species. Invasive feral livestock incurred the highest costs at $90.03 billion, with pets contributing $50.93 billion and beasts of burden having much lower costs at $0.98 billion. Agriculture was the most affected sector at $80.79 billion, followed by the Environment ($43.44 billion), and Authorities-Stakeholders sectors ($5.52 billion). Damage costs comprised the majority ($124.94 billion), with management and mixed damage-management costs making up the rest ($9.62 and $7.38 billion, respectively). These economic impacts were observed globally, where Oceania, North America and Europe were the most impacted regions. Islands recorded a higher economic burden than continental areas, with livestock species dominating costs more on islands than mainlands compared to other feral species. The costs of invasive feral animals were on average twice higher than those of wild species. The management of invasive feral populations requires higher investment, updated regulations, and comprehensive risk assessments. These are especially complex when considering the potential conflicts arising from interventions with species that have close ties to humans. Effective communication to raise public awareness of the impacts of feral populations and appropriate legislation to prevent or control such invasive feral populations will substantially contribute to minimizing their socioeconomic and environmental impacts.

Detection of Leptospira spp. in Captive Broad-Snouted Caiman (Caiman latirostris)

Leptospira sp. is an important waterborne zoonotic bacterium, known to cause infection in animals and humans worldwide. The role of reptiles in the transmission of this microorganism is poorly understood and historically neglected. This study aimed to investigate the presence of anti-Leptospira spp. antibodies and leptospiral DNA in captive Caiman latirostris (broad-snouted caiman). Of the 23 reptiles studied by microscopic agglutination test (MAT), 22/23 (95.65%) were considered reactive (titers ≥ 100) and 1/23 (4.35%) non-reactive (titer < 100). The serogroup with highest occurrence was Grippotyphosa (68.18%, n = 15/22) followed by serogroup Djasiman (18.18%, n = 4/22). Specific amplification of Leptospira spp. gene lipL32 was observed in six (26.09%, n = 6/23) blood samples. Five of six samples, previously detected as pathogenic leptospira by PCR, were amplified and sequenced. All the samples corresponded to the pathogenic species Leptospira interrogans (presented 100% of identity) using the PCR targeting to secY gene. We demonstrated high detection of DNA of L. interrogans in crocodilians, and the authors suggest that further research is needed to elucidate the impact of Leptospira spp. infection in health broad-snouted caimans as well as the pathophysiology of leptospirosis in crocodilians.

Recurrent Anthrax Outbreaks in Humans, Livestock, and Wildlife in the Same Locality, Kenya, 2014-2017

Epidemiologic data indicate a global distribution of anthrax outbreaks associated with certain ecosystems that promote survival and viability of Bacillus anthracis spores. Here, we characterized three anthrax outbreaks involving humans, livestock, and wildlife that occurred in the same locality in Kenya between 2014 and 2017. Clinical and epidemiologic data on the outbreaks were collected using active case finding and review of human, livestock, and wildlife health records. Information on temporal and spatial distribution of prior outbreaks in the area was collected using participatory epidemiology. The 2014-2017 outbreaks in Nakuru West subcounty affected 15 of 71 people who had contact with infected cattle (attack rate = 21.1%), including seven with gastrointestinal, six with cutaneous, and two with oropharyngeal forms of the disease. Two (13.3%) gastrointestinal human anthrax cases died. No human cases were associated with infected wildlife. Of the 54 cattle owned in 11 households affected, 20 died (attack rate = 37%). The 2015 outbreak resulted in death of 10.5% of the affected herbivorous wildlife at Lake Nakuru National Park, including 745 of 4,500 African buffaloes (species-specific mortality rate = 17%) and three of 18 endangered white rhinos (species-specific mortality rate = 16%). The species mortality rate ranged from 1% to 5% for the other affected wildlife species. Participatory epidemiology identified prior outbreaks between 1973 and 2011 in the same area. The frequency and severity of outbreaks in this area suggests that it is an anthrax hotspot ideal for investigating risk factors associated with long-term survival of anthrax spores and outbreak occurrence.