Amongst newly developed approaches to analyse molecular data, phylodynamic models are receiving much attention because of their potential to reveal changes to viral populations over short periods. This knowledge can be very important for understanding disease impacts. However, their accuracy needs to be fully understood, especially in relation to wildlife disease epidemiology, where sampling and prior knowledge may be limited. The release of the rabbit haemorrhagic disease virus (RHDV) as biological control in naïve rabbit populations in Australia in 1996 provides a unique dataset with which to validate phylodynamic models. By comparing the results obtained for RHDV1 with our current understanding of the RHDV epidemiology in Australia, we evaluated the performances of these recently developed models. In line with our expectations, coalescent analyses detected a sharp increase in the virus trajectory in the first few months after the virus release, followed by a more gradual increase. The phylodynamic analyses with a birth-death tree prior generated effective reproductive number estimates (the average number of secondary infections per each infectious case, Re) larger than one for most of the epochs considered. However, the possible range of the initial Re included estimates lower than one despite the known rapid spread of RHDV1 in Australia. Furthermore, the analyses that took into account the geographical structuring failed to converge. We argue that the difficulties that we encountered most likely stem from the fact that the samples available from 1996 to 2014 were too sparse with respect to geographic and within outbreak coverage to adequately infer some of the model parameters. In general, while these Bayesian analyses proved to be greatly informative in some regards, we caution that their interpretation may not be straight forward and recommend further research in evaluating the robustness of these models to assumption violations and sensitivity to sampling regimes.

Rabbit hemorrhagic disease virus 2 (RHDV2) is a newly emerging Lagovirus belonging to the family Caliciviridae. After its first discovery in 2010 in France, this highly pathogenic virus rapidly spread to neighboring countries and has become the dominant strain, replacing the classical RHDV1 strains. RHDV2 was first reported in North America in 2016 in Mont-Joli, Quebec, Canada and it was reported again in 2018 and 2019 on Vancouver, Island and the southeast mainland of British Columbia (BC). The whole genome sequence of the RHDV2 Quebec isolate resembled the RHDV-N11 isolate from Navarra, Spain identified in 2011 with 97% identity. The epidemiological investigation involved three hobby farms and one personal residence. In December and February 2018, high mortality was reported in first a private feral rabbit refuge and then, a large colony of feral rabbits on the Vancouver Island University Campus, Nanaimo, BC. The virus responsible showed only 93% identity to the Quebec RHDV2 isolate at the nucleotide level. Additional cases of RHDV2 on Vancouver Island and on the BC mainland affecting feral, captive domestic and commercial rabbits were reported subsequently. Vaccination was recommended to control the outbreak and an inactivated bivalent vaccine was made available to the private veterinary practices. In June 2019 an isolated RHDV2 outbreak was reported in an apartment building in Vancouver, BC. This virus showed only 97% identity to the RHDV2 isolate responsible for the BC outbreak in 2018 at the nucleotide level suggesting that it was an independent incursion. In October 2020, there are reports of partial recovery of the feral population in Nanaimo and to date there are no confirmed deaths of native rabbit species in BC.

Influenza viruses have been posing a great threat to public health and animal industry. The developed vaccines have been widely used to reduce the risk of potential pandemic; however, the ongoing antigenic drift makes influenza virus escape from host immune response and hampers vaccine efficacy. Until now, the genetic basis of antigenic variation remains largely unknown. In this study, we used A/swine/Guangxi/18/2011 (GX/18) and A/swine/Guangdong/104/2013 (GD/104) as models to explore the molecular determinant for antigenic variation of Eurasian avian-like H1N1 (EA H1N1) swine influenza viruses (SIVs), and found that the GD/104 virus exhibited 32~64-fold lower antigenic cross-reactivity with antibodies against GX/18 virus. Therefore, we generated polyclonal antibodies against GX/18 or GD/104 virus and a monoclonal antibody (mAb), named mAb102-95, targeted to the hemagglutinin (HA) protein of GX/18 virus, and found that a single amino acid substitution at position 158 in HA protein substantially altered the antigenicity of virus. The reactivity of GX/18 virus containing G158E mutation with the mAb102-95 decreased 8-fold than that of the parental strain. Contrarily, the reactivity of GD/104 virus bearing E158G mutation with the mAb102-95 increased by 32 times as compared with that of the parental virus. Structural analysis showed that the amino acid mutation from G to E was accompanied with the R group changing from -H to -(CH 2) 2-COOH. The induced steric effect and increased hydrophilicity of HA protein surface jointly contributed to the antigenic drift of EA H1N1 SIVs. Our study provides experimental evidence that G158E mutation in HA protein affects the antigenic property of EA H1N1 SIVs, and widens our horizon on the antigenic drift of influenza virus.

In the last decade, real time PCR has been increasingly adopted for bluetongue diagnosis with both broadly reactive and serotype-specific assays widely used. The use of these assays and nucleic acid sequencing technologies have enhanced bluetongue virus detection, resulting in the identification of a number of new serotypes. As a result, more than 30 different serotypes are proposed. Rapid identification of the virus serotype is essential for matching of antigens used in vaccines and to undertake surveillance and epidemiological studies to assist risk management. However, it is not uncommon for multiple serotypes to circulate in a region either concurrently or in successive years. It is therefore necessary to have a large suite of assays available to ensure that the full spectrum of viruses is detected. Nevertheless, covering a large range of virus serotypes is demanding from both a time and resource perspective. To overcome these challenges, real time PCR assays were optimised to match local virus strains and then combined in a panel of quadriplex assays, resulting in 3 assays to detect 12 serotypes directly from blood samples from cattle and sheep. These multiplex assays have been used extensively for bluetongue surveillance in both sentinel animals and opportunistically collected samples. A protocol to adapt these assays to capture variations in local strains of bluetongue virus and to expand the panel is described. Collectively these assays provide powerful tools for surveillance and the rapid identification of bluetongue virus serotypes directly from animal blood samples.

Leptospirosis is a zoonotic neglected disease of worldwide public health concern. Leptospira species can infect a wide range of wild and domestic mammals and can lead to a spectrum of disease, including severe and fatal forms. Herein, we report for the first time a fatal Leptospira interrogans infection in a free-ranging nonhuman primate (NHP), a black-tufted marmoset. Icterus, pulmonary hemorrhage, interstitial nephritis and hepatocellular dissociation were the main findings raising the suspicion of leptospirosis. Diagnostic confirmation was based on specific immunohistochemical and PCR assays for Leptospira species. Immunolocalization of leptospiral antigens and identification of pathogenic species ( L. interrogans species) were important for better understanding the pathogenesis of disease. One Health related implications of free-ranging NHPs in anthropized areas and transmission dynamics of human and animal leptospirosis are discussed.

The emergence of Zika virus (ZIKV) infection, which is unexpectedly associated with congenital defects, has prompted the development of safe and effective vaccines. The gram-positive enhancer matrix-protein anchor (GEM-PA) display system has emerged as a versatile and highly effective platform for delivering target proteins for vaccines. In this article, we developed a bacterium-like particle vaccine ZI-△-PA-GEM based on the GEM-PA system. The fusion protein ZI-△-PA, which contains the prM-E-△ protein of ZIKV (with a stem-transmembrane region deletion) and the protein anchor PA3, was expressed. The fusion protein was successfully displayed on the GEM surface, forming ZI-△-PA-GEM. Moreover, when BALB/c mice were immunized intramuscularly with ZI-△-PA-GEM combined with 201 VG and poly(I:C) adjuvants, durable ZIKV-specific IgG and protective neutralizing antibody responses were induced. Potent B cell/DC activation was also be stimulated early after immunization. Remarkably, splenocyte proliferation, the secretion of multiple cytokines, T/B cell activation and central memory T cell responses were elicited. These data indicate that ZI-△-PA-GEM is a promising bacterium-like particle vaccine candidate for ZIKV.

Bovine leptospirosis is a bacterial disease that affects cattle herds, causing economic losses due to reproductive problems, which require expensive treatments. The main source of transmission for cattle is still uncertain, but it has been described that rodents and bats can play an important role in the transmission cycle by being maintenance hosts for the pathogenic species of the bacterium and spreading it through urine. In this study, we characterize possible risk areas for bovine leptospirosis exposure in the state of Veracruz, Mexico, based on the geographical distribution of flying (bats) and terrestrial (rodents and opossums) wild hosts of Leptospira sp. reported in Mexico in addition with climatic, geographic, soil characteristics, land use and human activities variables (environmental variables). We used a generalized linear regression model (GLM) to understand the association between the frequency of anti- Leptospira sp. antibodies (a proxy of exposure to) in cattle herds exposed to Leptospira, the favorability of wild hosts of Leptospira as well as the environmental variables. The parameterized model explains 12.3% of the variance. The frequency of anti- Leptospira sp. antibodies exposoure in cattle herds was associated with elevation, geographic longitude, pH of the soil surface and environmental favorability for the presence of rodents, opossums, and bats. The variation in exposure is mainly explained by a longitudinal gradient (6.4% of the variance) and the favorability-based indices for wild hosts (9.6 % of the variance). Describing the possible risks for exposure to Leptospira in an important and neglected livestock geographical region, we provide valuable information to the selection of areas for diagnosis and prevention of this relevant disease.

The role of animal feed as a vehicle for the transport and transmission of viral diseases was first identified during the porcine epidemic diarrhea virus (PEDV) epidemic in North America. Since that time, various feed additives have been evaluated at the laboratory level to measure their effect on viral viability and infectivity in contaminated feed using bioassay piglet models. While a valid first step, the conditions of these studies were not representative of commercial swine production. Therefore, the purpose of this study was to evaluate the ability of feed additives to mitigate the risk of virus-contaminated feed using a model based on real-world conditions. This new model used an “ice-block” challenge, containing equal concentrations of porcine reproductive and respiratory syndrome virus (PRRSV), Seneca-virus A (SVA) and PEDV, larger populations of pigs, representative commercial facilities and environments, along with realistic volumes of complete feed supplemented with selected additives. Following supplementation, the ice block was manually dropped into designated feed bins and pigs consumed feed by natural feeding behavior. After challenge, samples were collected at the pen level (feed troughs, oral fluids) and at the animal level (clinical signs, viral infection, growth rate, and mortality) across five independent experiments involving 15 additives. In 14 of the additives tested, pigs on supplemented diets had significantly greater average daily gain (ADG), significantly lower clinical signs and infection levels, and numerically lower mortality rates compared to non-supplemented controls. In conclusion, the majority of the additives evaluated mitigated the effects of PRRSV 174, PEDV, and SVA in contaminated feed, resulting in improved health and performance.

Leishmaniasis is caused by protozoans of the Leishmania genus, which includes more than 20 species capable of infecting humans worldwide. In the Americas, the most widespread specie is L. braziliensis, present in 18 countries, including Bolivia. The taxonomic position of the L. braziliensis complex has been a subject of controversy, complicated further by the recent identification of a particular subpopulation named L. braziliensis atypical or outlier. The aim of this study was to carry out a systematic analysis of the L. braziliensis complex in Bolivia and to describe the associated clinical characteristics. Forty-one strains were analyzed by sequencing an amplified 1245 bp fragment of the hsp70 gene, which allowed its identification as: 24 (59%) L. braziliensis, 16 (39%) L. braziliensis outlier and one (2%) L. peruviana. In a dendrogram constructed, L. braziliensis and L. peruviana are grouped in the same cluster, whilst L. braziliensis outlier appears in a separate branch. Sequence alignment allowed the identification of five non-polymorphic nucleotide positions (288, 297, 642, 993 and 1213) that discriminate L. braziliensis and L. peruviana from L. braziliensis outlier. Moreover, nucleotide positions 51 and 561 enable L. peruviana to be discriminated from the other two taxa. A greater diversity, was observed in L . braziliensis outlier than in L. braziliensis- L. peruviana. The 41 strains came from 32 patients with tegumentary leishmaniasis, among which 22 patients (69%) presented cutaneous lesions (11 caused by L. braziliensis and 11 by L. braziliensis outlier) and ten patients (31%) mucocutaneous lesions (eight caused by L. braziliensis, one by L. braziliensis outlier and one by L. peruviana). Nine patients (28%) simultaneously provided two isolates, each from a separate lesion, and in each case the same genotype was identified in both. Treatment failure was observed in six patients infected with L. braziliensis and one patient with L. peruviana.

Mycobacterium bovis is the main causative agent of bovine tuberculosis (BTB) in cattle and it is also responsible for a proportion of human TB cases. The annual cost of BTB worldwide is estimated at US$3 billion. Zebu cattle are considered to be more resistant to some infectious diseases than Holstein-Friesian (HF) cattle, including BTB. However, epidemiological studies do not necessarily take into account usage differences of the two types of cattle. It could be argued that HF cattle suffer greater metabolic stress due to their mainly dairy use, whereas Zebu cattle are mainly used for beef production. However, in experiments comparing Zebu and European cattle, the number of animals has been too small to draw statistically robust conclusions on the differences in the level of resistance between these breeds of cattle. Here, we used a recently developed vaccination-and-BCG challenge model to compare the ability of naïve and vaccinated Zebu and HF cattle to control/kill mycobacteria. Young male cattle of both breeds with similar ages were housed in the same accommodation for the duration of the experiment; after correcting for multiple comparison, we found that there was a trend for vaccinated HF cattle to have lower cfu numbers than non-vaccinated HF cattle (ρ = 0.057). No such trend was observed between vaccinated and non-vaccinated Zebu cattle (ρ = 0.560); similarly, no difference was observed between naïve HF and Zebu (ρ = 0.862) cattle. In contrast, evaluation of antigen-specific IFNγ secretion indicated that Zebu and HF cattle differed in their response to mycobacteria. Thus, under the conditions used in this work, the data indicate that there are no differences between Zebu and HF cattle. Further experiments, using larger numbers of animals may be required to determine whether Zebu and HF cattle differ in their susceptibility to infection with M. bovis.

Rift Valley fever virus (RVFV) is a mosquito-borne pathogen with significant human and veterinary health consequences that periodically emerges in epizootics. RVF causes fetal loss and death in ruminants and in humans can lead to liver and renal disease, delayed-onset encephalitis, retinitis, and in some cases severe hemorrhagic fever. A live attenuated vaccine candidate (DDVax), was developed by the deletion of the virulence factors NSs and NSm from a clinical isolate, ZH501, and has proven safe and immunogenic in rodents, pregnant sheep and non-human primates. Deletion of NSm also severely restricted mosquito midgut infection and inhibited vector-borne transmission. To demonstrate environmental safety, this study investigated the replication, dissemination and transmission efficiency of DDVax in mosquitoes following oral exposure compared to RVFV strains MP-12 and ZH501. Infection and dissemination profiles were also measured in mosquitoes 7 days after feeding on goats inoculated with DDvax or MP-12. Hypothesis: DDVax should infect mosquitoes at significantly lower rates than other RVF strains and, due to lack of NSm, be transmission incompetent. Exposure of Ae. aegypti and Cx. tarsalis to 6-8 log 10 plaque forming units (PFU)/mL DDVax by artificial bloodmeal resulted in significantly reduced DDVax infection rates in mosquito bodies compared to controls. Plaque assays indicated negligible transmission of infectious DDVax in Cx. tarsalis saliva (1/140 sampled) and none in Ae aegypti saliva (0/120). Serum from goats inoculated with DDVax or MP-12 did not harbor detectable infectious virus by plaque assay at 1, 2, or 3 days-post-inoculation; infectious virus was, however, recovered from mosquito bodies that fed on goats vaccinated with MP-12 (13.8% and 4.6%, respectively), but strikingly, DDvax positive mosquito bodies were greatly reduced (4%, and 0%, respectively). Furthermore, DDVax did not disseminate to legs/wings in any of the goat-fed mosquitoes.  Collectively, these results are consistent with a beneficial environmental safety profile .

Classical swine fever (CSF) is caused by classical swine fever virus (CSFV) and has led to huge ecnomic losses for the pig industry worldwide. Although vaccination and other control measures have been carried out, it is essential to establish a rapid and valid method for CSF vaccination monitoring and clinical diagnosis. CSFV E2 protein has been well-known as a major antigen for antibody detection. It is significant to improve affinity between E2 protein and CSFV antibody for a better performance of detection method. In this study, a recombinant E2 extracellular protein (aa 1-331), which has a native homodimer conformation and has a high affinity with anti-CSFV-E2 monoclonal antibody WH303, was expressed using Bac-to-Bac baculovirus expression system. A novel immunochromatographic test strip based on the recombinant CSFV E2 protein was developed for CSFV antibody detection. The sensitivity of this strip for detecting CSFV standard positive serum was 1:102400, 4 times higher than that of the previously developed CnC2 test strip. No cross reaction with antibodies of other swine viruses was observed. The detection of clinical swine serum samples (n=138) demonstrated that the agreements of this E2 test strip with three commercial ELISA kits were 88.40% (122/138), 86.23% (119/138), and 96.38% (133/138), respectively. Our data indicated that a novel E2 test strip with higher sensitivity has been developed and can be applied for clinical sample detections, providing a new powerful and simple approach for CSFV antibody monitoring.

This study reports the development of multiplex real-time PCR assays for differential detection of capripoxvirus (CaPV), parapoxvirus (PaPV), and foot-and-mouth disease virus (FMDV) in sheep, goats and cattle. Three multiplex assays were developed, a capripox (CaP) rule-out assay for simultaneous detection and differentiation of CaPV and PaPV, a FMD rule-out assay for simultaneous detection and differentiation of FMDV and PaPV, and a FMD/CaP rule-out assay for simultaneous detection and differentiation of CaPV, PaPV and FMDV. All multiplex assays included -actin gene ACTB as an internal positive control to monitor PCR inhibition and accuracy of nucleic acid extractions. The optimized assays were highly specific to the target viruses (CaPV, PaPV, and FMDV) with no cross-reactivity against other differential viruses. Using positive control plasmids as template, the limit of detection (LOD) of the multiplex assays were estimated as 2 (CaPV), 7 (PaPV), and 15 (FMDV) copies per assay. The amplification efficiency (AE) and correlation co-efficient (R2), estimated from the standard curves (Ct vs. log10 template dilution), were 94-106% and >0.99, respectively, for CaP and FMD rule-out assays, 96-116% (AE) and >0.98 (R2), respectively, for CaP/FMD rule-out assays and 91-102% and >0.99, respectively, for the corresponding singleplex assays. The diagnostic sensitivity (DSe) of the multiplex assays was assessed on 35 (CaPV), 36 (PaPV) and 39 (FMDV) clinical specimens collected from experimentally (CaPV and FMDV) and naturally (PaPV) infected animals, and all tested positive (DSe 100%) except two FMDV specimens that were tested negative (37/39; DSe 95%). The newly developed multiplex assays offer a valuable tool for differential detection of clinically indistinguishable CaPV, PaPV, and FMDV in suspected animals and animals with mixed infections.

As global trade of live animals expands, there is increasing need to assess the risks of invasive organisms, including pathogens, that can accompany these translocations. The movement and release of live baitfish by recreational anglers has been identified as a particularly high-risk pathway for the spread of aquatic diseases in the United States. To provide risk-based decision support for preventing and managing disease invasions from baitfish release, we developed a hazard identification and ranking tool to identify the pathogens that pose the highest risk to wild fish via this pathway. We created a screening protocol and semi-quantitative stochastic risk ranking framework, combining published data with expert elicitation (n=25) and applied the framework to identify high-priority pathogens for the bait supply in Minnesota, USA. Normalized scores were developed for seven risk criteria (likelihood of transfer, prevalence in bait supply, likelihood of colonization, current distribution, economic impact if established, ecological impact if established, and host species) to characterize a pathogen’s ability to persist in the bait supply and cause impacts to wild fish species of concern. The generalist macroparasite Schizocotyle acheilognathi was identified as presenting highest overall threat, followed by the microsporidian Ovipleistophora ovariae, and viral hemorrhagic septicemia virus. Our findings provide risk-based decision support for managers charged with maintaining both the recreational fishing industry and sustainable, healthy natural resources. The ranking process, implemented here for a single state case study, provides a standardized conceptual framework that could be applied across jurisdictions to inform risk-based management of the live baitfish pathway.

African swine fever (ASF), is a serious global concern from an ecological and economic point of view. While it is well established that its main transmission routes comprise contact between infected and susceptible animals and transmission through contaminated carcasses, the specific mechanism leading to its long-term persistence is still not clear. Among others, a proposed mechanism involves the potential role of convalescent individuals, which would be able to shed the virus after the end of the acute infection. Using a spatially explicit, stochastic, individual-based model, we tested: 1) if ASF can persist when transmission occurs only through infected wild boars and infected carcasses; 2) if the animals that survive ASF can play a relevant role in increasing ASF persistence chances; 3) how hunting pressure can affect the ASF probability to persist. The scenario in which only direct and carcass-mediated transmission were contemplated had 52% probability of virus persistence 10 years after the initial outbreak. The inclusion of survivor-mediated transmission corresponded to slightly higher persistence probabilities (57%). ASF prevalence during the endemic phase was generally low, ranging 0.1-0.2%. The proportion of seropositive individuals gradually decreased with time and ranged 4.5 – 6.6%. Our results indicate that direct and carcass-mediated infection routes are sufficient to explain and justify the long-term persistence of ASF at low wild boar density and the ongoing geographic expansion of the disease front in the European continent. During the initial years of an ASF outbreak, hunting should be carefully evaluated as a management tool, in terms of potential benefits and negative side-effects, and combined with an intensive effort for the detection and removal of wild boar carcasses. During the endemic phase, further increasing hunting effort should not be considered as an effective strategy. Additional effort should be dedicated to finding and removing as many wild boar carcasses as possible.

African swine fever virus (ASFV) can survive in soy-based products for 30 days with T ½ ranging from 9.6-12.9 days in soybean meals and soy oil cake. As the US imports soy-based products from several ASFV-positive countries, knowledge of the type and quantity of these specific imports, and their ports of entry (POE), is necessary information to manage risk. Using the data from the International Trade Commission Harmonized Tariff Schedule website in conjunction with pivot tables, we analyzed imports across air, land, and sea POE of soy-based products from 43 ASFV-positive countries to the US during 2018 and 2019. In 2018, 104,366 metric tons (MT) of soy-based products, specifically conventional and organic soybean meal, soybeans, soy oil cake and soy oil were imported from these countries into the US via seaports only. The two largest suppliers were China (52.7 %, 55,034 MT) and the Ukraine (42.9%, 44,775 MT). In 2019, 73,331 MT entered the US and 54.7% (40,143 MT) came from the Ukraine and 8.4% (6,182 MT) from China. Regarding POE, 80.9% to 83.2% of soy-based imports from China entered the US at the seaports of San Francisco, CA and Seattle, WA, while 89.4% to 100% entered from the Ukraine via the seaports of New Orleans, LA and Charlotte, NC. Analysis of five-year trends (2015 to 2019) of the volume of soy imports from China indicated reduction over time (with a noticeably sharp decrease between 2018 and 2019), and seaport utilization was consistent. In contrast, volume remained high for Ukrainian soy imports, and seaport utilization was inconsistent. Overall, this exercise introduced a new approach to collect objective data on an important risk factor, providing researchers, government officials, and industry stakeholders a means to objectively identify and quantify potential channels of foreign animal disease entry into the US.

Wild boar is the main sylvatic reservoir of the genotype 3 of hepatitis E virus (HEV). The occurrence of HEV-3 human cases has been linked to the consumption of raw or undercooked pig and wild boar meat and liver. The zoonotic transmission of HEV-3 has been confirmed by sequencing identical or strictly related viral strains in humans, wild boar, and derived food. The HEV sequences classified within the HEV-3 genotype are highly variable, and although only one serotype has been identified so far, the observed differences allow for the further classification of the HEV-3 genotype into subtypes, named in alphabetical order. Compared to human and pig strains, an even higher heterogeneity is observed among strains infecting wild boar. In the present study, the genetic variability of eight HEV-3 strains detected in wild boars living in a small geographical area in central Italy (Lazio and Umbria regions) was investigated by full genome sequencing and phylogenetic analysis. The strains were classified within the HEV-3a, HEV-3c, HEV-3f subtypes and within two new recently proposed subtypes. Results demonstrate – despite the relatively small geographic area of origin – an unexpected divergence within HEV-3 strains hosted by the investigated wild boar population and highlights the need for extensive sequencing of HEV in reservoirs to fully understand diversity, geographical distribution and evolution of this group of viruses.

Host immune response as well as virulence factors are key in disease susceptibility. There are no known association studies of HLA class I and II alleles with chikungunya (CHIKV) infection in Latin American population. We aim to identify Human Leukocyte Antigen (HLA) alleles present in patients with CHIKV infection when compared to healthy controls, as well as allele association with the clinical spectrum of the disease. A cross-sectional analysis nested in a community cohort was carried out. We included patients 18 years and older with serological confirmation of CHIKV infection. HLA typing of HLA-A, HLA-B and HLA-DRB1 alleles was performed. Two-by-two tables were used to establish associations between allele presence and clinical characteristics. Data from 65 patients with confirmed CHIKV infection were analyzed for HLA typing. CHIKV infection was associated with the presence of HLA-A*68, HLA-B*35, HLA-DRB*01, HLA-DRB1*04 and HLA-DRB1*13 alleles with statistical significance when compared to healthy subjects. A statistically significant relationship was found between the presence of rash in the face or the abdomen and the presence of HLA-DRB1*04. Our study demonstrated that in our cohort, HLA type I as well as type II alleles are associated with CHIKV infection, and specifically an HLA type II allele with dermatological symptoms. Further research is needed to set a path for future investigation on genes outside the HLA system to improve knowledge in the pathophysiology of CHIKV infection and its host-pathogen interaction.