Rift Valley fever (RVF) is a zoonotic disease endemic in Africa and the Arabian Peninsula caused by the highly infectious Rift Valley fever virus (RVFV) that can be lethal to humans and animals and results in major losses in the livestock industry. RVF is exotic to the United States; however, mosquito species native to this region can serve as biological vectors for the virus. Thus, accidental or malicious introduction of this virus could result in RVFV becoming endemic in North America. Such an event would likely lead to significant morbidity and mortality in humans, and devastating economic effects on the livestock industry. Currently, there are no licensed vaccines for RVF that are both safe and efficacious. To address this issue, we developed two recombinant RVFV vaccines using vaccinia virus (VACV) as a vector for use in livestock. The first vaccine, vCOGnGc, was attenuated by the deletion of a VACV gene encoding an IFN-γ binding protein, insertional inactivation of the thymidine kinase gene, and expression of RVFV glycoproteins, Gn and Gc. The second vaccine, vCOGnGcγ, is identical to the first and also expresses the human IFN-γ gene to enhance safety. Both vaccines are extremely safe; neither resulted in weight loss nor death in severe combined immunodeficient mice, and pock lesions were smaller in baboons compared with the controls. Furthermore, both vaccines induced protective levels of antibody titers in vaccinated mice and baboons. Mice were protected from lethal RVFV challenge. Thus, we have developed two safe and efficacious recombinant vaccines for RVF.

Stray dogs are one of the main reservoirs of intestinal parasitic infections and some have zoonotic potential. An epidemiological survey was carried out between September 2017 and May 2018 in Mexicali Valley, this area sacrifices around 92,470 head of cattle monthly, which represents 27% of the national slaughter and has 71,307 hectares for crops. In this period the Municipal Animal Control Center during their routine visits to the Mexicali Valley captured 103 dogs. All the dogs were evaluated using copromicroscopic techniques to detect intestinal parasites. The general frequency of parasitic infections was 28.15% (29/103), the most frequent parasite being Dipylidium caninum 16.50% (17/103), followed by Taenia spp. 6.79% (7/103), Taenia hydatigena 2.91% (3/103), Taenia serialis 0.97% (1/103), Taenia pisiformis (0.97%), Toxocara canis 3.88% (4/103), Toxascaris leonina 1.94% (2/103), and Cystoisospora spp. 1.94% (2/103). No significant statistical associations were found between parasitic infections and the studied variables (sex, age, and size) however; there was a significant statistical association with the capture area. Most of the parasites found in this survey have potential to affect the human population and animal production.

Zoonotic parasitic infections are a major global public and veterinary health problem and widespread among stray dogs. The objective of this study was to establish the prevalence of intestinal parasites in stray dogs in the urban, rural and coastal areas of Mexicali County in northwest Mexico. In 2014, from January to December, 380 stray dogs were captured. The entire small intestine, cecum and faeces samples were collected and examined by using simple zinc sulfate flotation and Lugol’s solution staining. Data were statistically analysed. Overall, about 21.5% of examined dogs were found positive for intestinal parasites. Toxocara canis was the most frequent detected parasite, with a prevalence of 7.1%, followed by Toxascaris leonina (5.5%), Cystoisospora spp. (5.0%), Taenia spp. (3.9%) and Dipylidium caninum (2.8%). Dogs were more frequently found to be infected with a single genus of intestinal parasite (18.7%) than co-infected (2.8%). Intestinal parasites were more prevalent in samples from the coastal area (25%) than in those from the rural (24.4%) and urban (20.6%) areas, however, only statistical association was found between capture area and specific intestinal parasitic infection. There were significant differences in the prevalence of taeniasis among two age groups (P<0.01). A seasonal peak of prevalence for intestinal parasitic infections was found during spring (P<0.05), corresponding with a seasonal peak of prevalence of T. canis (P<0.05). The wide range of isolated parasites indicated that people residing in this area are at risk of exposure to these potentially hazardous zoonotic pathogens.

The prevalence of bovine cysticercosis was established using routine postmortem inspection of 52,322 feedlot cattle slaughtered at 1 Federal Inspection Type abattoir (TIF 301) located in the Mexicali Valley in Baja California, México. The study included 31,393 animals (60.0%) purchased and transported to Baja California from stocker operations located in 17 states of México and 20,929 animals (40.0%) native to Baja California. A total of 208 carcasses showed lesions suggestive of cysticercosis, and 109 were confirmed as positive for the parasite with a prevalence of 0.21%, equivalent to 2.1 cases/1000 carcasses inspected, 2.8 cases/1000 carcasses for cattle purchased in other states, and 1.0 cases/1000 carcasses for cattle native from Baja California. The sensitivity of the postmortem inspection, when compared to a gold standard of stereoscopic microscopy, was 52.4%. The prevalence of cysticercosis was 2.8 times higher in cattle from other states compared with those native to Baja California. Cysticerci were most frequently found in the heart, followed by liver and masseter muscles. In cattle from other states, 96.6% of cysticerci were classified as calcified and <4% as viable; in cattle native to Baja California, 29% of cysticerci were classified as calcified and 71% as viable. The prevalence of bovine cysticercosis established at TIF 301 was found to be 28% lower than a previous report for Baja California. However, given the sensitivity of the postmortem inspection calculated between 10% and 50%, it is possible that an undetermined number of carcasses pass as being free of cysticerci and that the meat reached both domestic and international wholesale markets, increasing the possibility of human infection and causing substantial economic loss through condemnation of infected meat and trade restrictions for endemic regions.

In many rural regions of Mexico, beekeeping is an important socioeconomic activity which is currently facing various health issues, being the main one the presence of infectious diseases. The aim of our study was to optimize a duplex Eva Green RT-PCR assay along with melting-curve analysis to detect and differentiate Nosema apis from Nosema ceranae infection in Apis mellifera. At four locations in Northwest Mexico 765 samples from 76 apiaries were tested using a RT-PCR and melting-curve analysis. Infection was detected in all the four geographical regions under study. Overall, 87.32% samples resulted positive for N. apis, 12.68% for N. ceranae and 10.20% resulted co-infected with both microsporidians. The Mexicali valley had the highest prevalence of N. apis with 56.68% positive apiaries, while in Ensenada the lowest prevalence was found with 7.89% positive apiaries. The highest prevalence of N. ceranae was detected in Mexicali (15.79%), while Tijuana and San Luis Rio Colorado showed the lowest prevalence with 1.32%, respectively. Our work indicates a wide spread of nosemosis in all the four geographical regions with a marked dominion of N. apis. The RT-PCR assay resulted highly specific and accurate for the detection of N. apis and N. ceranae and could provide a rapid and accurate diagnostic tool for the simultaneous detection and discrimination of both microsporidians. It can also be used for clinical diagnostics and disease surveillance and to evaluate the effectiveness of the measures for control and prevention of nosemosis in the Northwest corner of Mexico.