GLOBAL RETROSPECTIVE REVIEW OF SEVERE ACUTE RESPIRATORY SYNDROME SARS COV-2 INFECTIONS IN NONDOMESTIC FELIDS: MARCH 2020-FEBRUARY 2021.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in nondomestic felids have been documented in North America, South America, Africa, Europe, and Asia. Between March 2020 and February 2021, at nine institutions across three continents, infection was confirmed in 16 tigers (Panthera tigris), 14 lions (Panthera leo), three snow leopards (Panthera uncia), one cougar (Puma concolor), and one Amur leopard cat (Prionailurus bengalensis euptilurus) ranging from 2 to 21 yr old (average, 10 yr). Infection was suspected in an additional 12 tigers, 4 lions, and 9 cougars. Clinical signs (in order of most to least common) included coughing, ocular and/or nasal discharge, wheezing, sneezing, decreased appetite, lethargy, diarrhea, and vomiting. Most felids recovered uneventfully, but one geriatric tiger with comorbidities developed severe dyspnea and neurologic signs necessitating euthanasia. Clinical signs lasted 1-19 d (average, 8 d); one tiger was asymptomatic. Infection was confirmed by various methods, including antigen tests and/or polymerase chain reaction (PCR) of nasal or oral swabs, tracheal wash, and feces, or virus isolation from feces or tracheal wash. Infection status and resolution were determined by testing nasal swabs from awake animals, fecal PCR, and observation of clinical signs. Shedding of fecal viral RNA was significantly longer than duration of clinical signs. Postinfection seropositivity was confirmed by four institutions including 11 felids (5 lions, 6 tigers). In most instances, asymptomatic or presymptomatic keepers were the presumed or confirmed source of infection, although in some instances the infection source remains uncertain. Almost all infections occurred despite using cloth facemasks and disposable gloves when in proximity to the felids and during food preparation. Although transmission may have occurred during momentary lapses in personal protective equipment compliance, it seems probable that cloth masks are insufficient at preventing transmission of SARS-CoV-2 from humans to nondomestic felids. Surgical or higher grade masks may be warranted when working with nondomestic felids.

Histologic lesions of giant African millipedes (Archispirostreptus gigas) from a zoological institution.

Histopathologic data of millipedes are scarce. Little is known about health and disease of these invertebrates despite their exhibition at zoological institutions and use in ecotoxicological studies. In a retrospective study of 69 zoo-housed giant African millipedes (Archispirostreptus gigas) submitted between 2018 and 2021, most deaths occurred during midwinter and in 2021. The most common lesion was inflammation (n = 55; 80%). Necrosis was seen concurrently in 31 (45%) millipedes and of these, bacteria (20; 29%) and fungi (7; 10%) were detected in lesions. Inflammation was seen in the head/collum (20; 29%), hemocoel (16; 23%), and appendages (9; 13%), specifically in perivisceral fat body (42; 61%), gut (16; 23%), tracheae (26; 38%), skeletal muscle (24; 35%), and ventral nerve (17; 25%). Inflammatory cell types and patterns included agranular hemocytes (61; 88%), granular hemocytes (39; 57%), and nodulation/encapsulation (47; 68%) often accompanied by melanization. The oral cavity or gut (ingestion), spiracles (inhalation), or cuticular defects were considered plausible routes of bacterial entry. Metazoan parasites (adult nematodes: 2, 3%; trematode ova: 2, 3%; and arthropods: 1, 1%) were associated with gut necrosis and inflammation in 5 millipedes. In addition, adult nematodes were noted in the gut of 4 millipedes without lesions. Neoplasia was not detected in any millipedes. Speculatively, environmental factors may have predisposed to disease, as most deaths occurred during winter months. Disease surveillance of millipedes is critical to optimize husbandry practices in zoo populations and investigate potential impacts of environmental degradation and climate change on wild millipedes.

Isolation of Leptospira kirschneri serovar Grippotyphosa from a red panda (Ailurus fulgens) after antimicrobial therapy: Case report.

A 1-year-old female red panda started showing symptoms of illness, including lethargy, anorexia, abdominal discomfort, and vomiting, shortly after transfer to a new zoo. Serum was tested for leptospirosis using the microscopic agglutination test, and a titer of 1:25,600 to serogroup Grippotyphosa was detected. Antimicrobial treatment with doxycycline was initiated. After completion of treatment and resolution of clinical symptoms, a urine sample was collected to ensure clearance of leptospires and cessation of urinary shedding prior to co-housing with other red pandas. A repeat serum sample taken 13 days later had a lower titer of 1:6,400 to serogroup Grippotyphosa. A sample of the animal's urine was cultured in HAN media and was culture positive for Leptospira. The recovered isolate was completely characterized by whole genome sequencing and serotyping with reference antisera, and the isolate was classified as Leptospira kirschneri serogroup Grippotyphosa serovar Grippotyphosa strain RedPanda1.

A topical microbicide gel formulation of CCR5 antagonist maraviroc prevents HIV-1 vaginal transmission in humanized RAG-hu mice.

For prevention of HIV infection many currently licensed anti-HIV drugs and new ones in the pipeline show potential as topically applied microbicides. While macaque models have been the gold standard for in vivo microbicide testing, they are expensive and sufficient numbers are not available. Therefore, a small animal model that facilitates rapid evaluation of potential candidates for their preliminary efficacy is urgently needed in the microbicide field. We previously demonstrated that RAG-hu humanized mouse model permits HIV-1 mucosal transmission via both vaginal and rectal routes and that oral pre-exposure chemo-prophylactic strategies could be tested in this system. Here in these proof-of-concept studies, we extended this system for topical microbicide testing using HIV-1 as the challenge virus. Maraviroc, a clinically approved CCR5 inhibitor drug for HIV treatment, was formulated as a microbicide gel at 5 mM concentration in 2.2% hydroxyl ethyl cellulose. Female RAG-hu mice were challenged vaginally with HIV-1 an hour after intravaginal application of the maraviroc gel. Our results showed that maraviroc gel treated mice were fully protected against vaginal HIV-1 challenge in contrast to placebo gel treated mice which all became infected. These findings highlight the utility of the humanized mouse models for microbicide testing and, together with the recent data from macaque studies, suggest that maraviroc is a promising candidate for future microbicide clinical trials in the field.