Alma Roy
Interim Laboratory Director and Consultant Louisiana State University
Media
Areas of Expertise
Research Focus
West Nile Virus Ecology & Vaccine Development
Dr. Roy’s research focuses on West Nile virus ecology and control, spanning avian-mosquito transmission, equine and human disease, and vaccine development. She integrates viral immunology, serum-neutralization assays, and statewide vector-host surveillance with Louisiana health agencies to craft horse vaccines, track outbreaks, and guide zoonotic-disease prevention.
Media Appearances
Cases of West Nile Virus in Louisiana beginning to increase with the arrival of summer
Lou radio
2025-07-01
This is the time of year that West Nile Virus starts to ramp up, and Dr. Alma Roy, the director of LSU’s Vector-Borne Disease Diagnostic Lab, says this year could be a busy one.
“In our laboratory, we are seeing more positive mosquito pools currently than we did last year. So, it may be a very active season this year,” Roy said.
How LSU is tracking West Nile Virus in mosquitoes
WBRZ 2 tv
2025-06-30
"We are a testing lab where we do the surveillance on mosquito pools to understand how many are positive, where they are located," Lab Director Dr. Alma Roy said.
Articles
An outbreak of systemic chlamydiosis in farmed American alligators (Alligator mississippiensis)
Veterinary Pathology2022
Chlamydia spp are reported to causes systemic disease in a variety of hosts worldwide including few reports in crocodilians. Disease presentations vary from asymptomatic to fulminant disease, some of which are zoonotic. The aim of this study was to describe the pathological, immunohistochemical, and molecular findings associated with the occurrence of a previously unreported Chlamydia sp infection causing a major mortality event in farmed American alligators (Alligator mississippiensis). The outbreak presented with sudden death in juvenile alligators mainly associated with necrotizing hepatitis and myocarditis, followed by the occurrence of conjunctivitis after the initial high mortality event. The widespread inflammatory lesions in multiple organs correlated with intralesional chlamydial organisms identified via immunohistochemistry and confirmed by 23S rRNA-specific real-time quantitative polymerase chain reaction (qPCR) for Chlamydiaceae bacteria. By sequencing and phylogenetic analysis of the OmpA gene, this uncultured Chlamydia sp grouped closely with Chlamydia poikilothermis recently described in snakes. This study highlights the significance of such outbreaks in farmed populations. Enhanced epidemiological monitoring is needed to gain further insight into the biology of Chlamydia sp in alligators, disease dynamics, risk factors, and role of carrier animals.
Characterization, distribution, antimicrobial resistance and resistance risk factors in staphylococci isolated from cats from 2001 to 2014
Veterinary Medicine and Science2018
Relatively few studies have been published describing the patterns of staphylococcal isolation and antimicrobial resistance over time in cats. The objective of this retrospective study was to determine the frequency, location, characteristics and antimicrobial resistance profiles of staphylococci isolated by the Louisiana Animal Disease Diagnostic Laboratory between the years 2001 and 2014. All feline staphylococcal isolates were classified phenotypically. Isolates corresponding to known or possibly pathogenic species (Staphylococcus intermedius group (SIG) and Staphylococcus aureus (SA)) as well as Staphylococcus epidermidis (SE) and non‐speciated coagulase‐negative staphylococci (CNS) were further evaluated to determine antimicrobial resistance patterns. A total of 519 staphylococci were isolated. The largest percentage of isolates was CNS, representing 39.3% of the total, while SIG, SE, SA and non‐speciated coagulase positive staphylococci (CPS) represented 18.1%, 10.2%, 8.3% and 7.3%, respectively. Methicillin resistance (MR) was identified in 57.1% of SA and 20.5% of SIG. Resistance to 3 or more antimicrobial classes (multidrug resistance; MDR) was demonstrated in 54.5% of SA and 23.9% of SIG. The prevalence of MDR increased over time in both SIG and SA, while the prevalence of MR increased over time in SIG. An increase in mean antimicrobial resistance score over time was seen in SIG. This study demonstrates a high and increasing prevalence of MDR in SIG and SA, as well as increasing prevalence of MR in SIG isolated from cats. This retrospective study characterized the identity and antibiotic resistance profiles of staphylococci isolated from cats between 2001 and 2014. The results demonstrate a high and increasing prevalence of multi‐drug antibiotic resistance and an increasing prevalence of methicillin resistance in Staphylococcus intermedius group bacteria isolated from cats during this time.
Placentitis and Dystocia Attributed to Streptobacillus moniliformis in a Domestic Dumbo Rat (Rattus norvegicus)
Journal of Exotic Pet Medicine2017
A 12-week-old sexually intact female domestic Dumbo rat (Rattus norvegicus) was presented for dystocia. The animal had maloccluded incisors, muco-hemorrhagic vulvar discharge, and no evidence of obstruction of the pelvic canal. The animal was treated parenterally with calcium and oxytocin and provided supportive care. Controlled vaginal delivery under general anesthesia was unsuccessful. The animal was humanely euthanized and was diagnosed with bacterial placentitis on necropsy. Histopathologic examination revealed abundant filamentous, Gram-negative, Giemsa-positive bacteria associated with the placenta, endometrial surface and uterine vessels of the dam, and alveolar spaces of multiple fetuses. Aerobic bacterial culture of placental tissues revealed small pure gray colonies of Gram-negative, rod-shaped, filamentous bacteria. Polymerase chain reaction targeting the 16 S rRNA gene followed by sequencing identified the etiologic agent as Streptobacillus moniliformis, the causative agent of rat bite fever, a zoonotic disease that historically has been considered a non-pathogenic commensal organism of the rat. The current report documents placentitis attributed to S. moniliformis infection in a rat, is consistent with reports in mice and humans that this organism may be an opportunistic pathogen of the female reproductive tract, and suggests that S. moniliformis can cause primary disease in a rat.
