To provide more complete data on SARS-CoV-2 infections in dogs and cats in the U.S., we conducted a serosurvey on convenience serum samples from dogs ( n =1336) and cats ( n =956) collected from 48 states of the USA in 2020. An ELISA targeting the antibody against nucleocapsid identified eleven positive and two doubtful samples in cats, and five positive and five doubtful samples in dogs. A surrogate neutralization assay detecting antibodies blocking the attachment of the spike protein to ACE2 was positive with three of the ELISA positive and doubtful samples, and one of 463 randomly selected ELISA negative samples. These four positive samples were confirmed by SARS-CoV-2 virus neutralization testing. All were from cats, in New York, Florida, and New Jersey ( n =2). The serosurvey results, one of the largest yet completed on dogs and cats globally, support the OIE and CDC positions that currently there is no evidence that pets play a role in the spread of SARS CoV-2 in humans.

BackgroundRotavirus is the leading cause of severe diarrhea in infants and young children worldwide including Bangladesh. Unlike what was seen in high-income countries, the licensed rotavirus vaccines did not show high efficacy in Bangladeshi trials. We assessed rotavirus prevalence and genotypes in Bangladesh over six-year period to provide baseline information on the rotavirus burden and changing profile in the country.MethodsThis study was conducted from June 2006 to May 2012 in Matlab, Bangladesh. Group A rotaviruses were detected in stools collected from diarrhea patients by ELISA and genotyped using multiplex reverse transcription PCR followed by nucleotide sequencing.ResultsOf the 9678 stool samples, 20.3% were positive for rotavirus. The most predominant genotype was G1P[8] (22.4%), followed by G9P[8] (20.8%), G2P[4] (16.9%) and G12P[8] (10.4%). Mixed infections were detected in 14.2% of the samples. Emergence of an unusual strain, G9P[4] was documented during 2011–12. Several amino acid mismatches in the antigenic epitopes of VP7 and VP4 between Bangladeshi and the vaccine strains were identified.ConclusionsOur study provides important information on rotavirus genotypes that should be considered for the selection and introduction of rotavirus vaccines in Bangladesh.

Reverse transcription fluorescence resonance energy transfer-polymerase chain reaction (FRET-PCRs) were designed against the two most common mutations in severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) (A23403G in the spike protein; C14408T in the RNA-dependent RNA polymerase). Based on highresolution melting curve analysis, the reverse transcription (RT) FRET-PCRs identified the mutations in american type culture collection control viruses, and feline and human clinical samples. All major makes of PCR machines can perform melting curve analysis and thus further specifically designed FRET-PCRs could enable active surveillance for mutations and variants in countries where genome sequencing is not readily available.

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Background Heartworms, Dirofilaria immitis, are known to be widespread in dogs and cats in the USA, but there have been no country-wide prevalence studies performed to date. There have also been no large-scale studies to determine whether the closely related species, Dirofilaria repens, occurs in the USA. Methods To provide this large-scale data, we examined whole blood samples (n = 2334) submitted from around the USA to the Molecular Diagnostic Laboratory at Auburn University between 2016 and 2022. Quantitative PCRs for D. immitis (targeting 16S rRNA) and D. repens (targeting cytochrome c oxidase subunit 1 gene) were performed to determine the presence of Dirofilaria DNA. DNA sequencing was performed to confirm the results. Results Dirofilaria immitis DNA was found in 6.3% (68/1080) of the dogs from 17/39 states, and 0.3% (4/1254) of the cats from 4/42 states. None of the dogs or cats were positive for D. repens. The average 16S rRNA copy number of D. immitis in the dogs was 1,809,604 in 200 µl whole blood, while only a single copy was found in each of the four D. immitis-positive cats. The prevalence of D. immitis in dogs of different ages, sexes, and breeds did not differ significantly, but the prevalence in Southern states (7.5%, 60/803) was significantly higher than in the Western (1.7%, 1/58), Midwest (3.3%, 4/120), and Northeastern states (3.1%, 3/98) (P < 0.05). Dogs positive for D. immitis were identified in each study year (2016: 4.2%, 2/48; 2017: 9.8%, 4/41; 2018: 5.1%, 8/156; 2019: 4.9%, 15/306; 2020: 9.8%, 26/265; 2021: 4.9%, 13/264). Interestingly, dogs infected with Hepatozoon spp. (11.8%, 37/313) were significantly more likely to also be positive for D. immitis than dogs without evidence of Hepatozoon infection (3.9%, 30/760) (P < 0.0001). Conclusions To our knowledge, this is the first nationwide molecular survey of Dirofilaria spp. in dogs and cats in the USA, and the largest molecular survey of canine and feline dirofilariosis worldwide. Further studies are warranted to combine PCR with standard heartworm diagnostics to better understand the prevalence of Dirofilaria spp. and aid in determining the risks posed to dogs and cats in the USA. Graphical Abstract