Francisco Miroslav Ulloa-Stanojlovic

Tilapia (genus Oreochromis ) contribute significantly to food security and aquaculture development in the Department of San Martín, an administrative region in the Peruvian Amazon. During the final quarter of 2024, an investigation was carried out following reports of infectious disease outbreaks associated with unusually high mortality in farmed tilapia located in the provinces of Mariscal Cáceres and Bellavista. A total of 153 samples were analysed, including 120 broodstock, 24 fry, and 9 juvenile specimens. PCR testing detected Streptococcus agalactiae in at least 1 juvenile sample from each of Farms A and B, representing the first confirmed cases of S. agalactiae associated with the outbreaks. In the hatchery, microbiological analysis of broodstock and fry samples yielded 6 bacterial isolates compatible with Streptococcus spp., which were subsequently confirmed as S. agalactiae by PCR. At Farm C, S. agalactiae was confirmed through PCR, and 3 bacterial isolates (P01, P02, and P03) were recovered and comprehensively characterized. Molecular analyses confirmed all isolates as S. agalactiae . Further characterization identified serotype Ia using conventional PCR and sequence type ST7 through multilocus sequence typing (MLST). Three representative isolates obtained from diseased juvenile tilapia were further characterized by whole-genome sequencing and MLST analysis, confirming their classification as S. agalactiae serotype Ia sequence type ST7. Clinical signs observed during the outbreaks included erratic swimming, lethargy, exophthalmos, fin erosion, and hepatic alterations, consistent with streptococcosis. This study represents the first molecular characterization of S. agalactiae serotype Ia ST7 associated with streptococcosis outbreaks in farmed tilapia in Peru.

The infectious pancreatic necrosis virus (IPNV) is a highly pathogenic virus that affects the aquaculture of rainbow trout (Oncorhynchus mykiss) and can cause mortality rates that exceed 90% in the juvenile stage. This study aims to know the distribution and frequency of IPNV presentation in trout production farms in the seven main producing states of the species in Peru. Prevalence values of IPNV have been identified in the states of Cusco (4.05%), Puno (3.81%), and Huancavelica (0.23%). These results showed the distribution and epidemiology of the IPNV that, until 2019, was absent in the country. Likewise, it represents the need to implement prevention and control measures against the virus to reduce the risk of dissemination to free states of IPNV. Finally, improving sanitary management against IPNV reduces its economic and productive impact on rainbow trout aquaculture in Peru.

Vampire bats became the main reservoir of rabies in Latin America, where the disease remains one of the most important viral zoonoses affecting humans and livestock. In Peru, the most affected livestock are cattle. The official data of 1,729 cases of bovine rabies were evaluated between 2003 and 2017 through a descriptive analysis, decomposition of the time series and spatiotemporal analyses. Although the cases did not present a defined seasonality, the trend seemed to increase for several years. The bovine rabies cases are more frequent in the inter‐Andean valleys than in other regions of the Amazon plains. The highest case density was observed in the regions of Ayacucho, Cuzco and Apurímac, all located in the Andes. It is necessary to review the current national program for the prevention and control of rabies in livestock, incorporating concepts of the ecology of vampire bats, as well as the prediction of the infection waves geographic and temporal spread. These approaches could improve the efficiency of other current prevention measures that have not shown the expected control effects, such as indiscriminate culling of vampire bats.

In Brazil, rabies surveillance is based on monitoring domestic and wild animals, although the most prevalent lineage of the rabies virus (RABV) currently diagnosed in Brazil is associated with bats, particularly non-haematophagous bats. Disease control is based on the mass vaccination of dogs and cats. We used data collected by the passive surveillance system of the city of Campinas from 2011 to 2015, to describe the temporal and geographic distributions of the bat specimens and RABV and discuss the current rabies surveillance with the advent of the declaration of canine and feline rabies-free areas in Brazil. We described the species, locations and health statuses of the collected bat specimens. Moreover, all samples were submitted for RABV diagnosis. Then, we performed a time series decomposition for each bat family. Additionally, we determined the spatiotemporal relative risk for RABV infection using the ratio of the kernel-smoothed estimates of spatiotemporal densities of RABV-positive and RABV-negative bats. From the 2537 bat specimens, the most numerous family was Molossidae (72%), followed by Vespertilionidae (14%) and Phyllostomidae (13%). The bat families behaved differently in terms of seasonal and spatial patterns. The distribution of bats varied geographically in the urban environment, with Molossidae and Phyllostomidae being observed downtown and Vespertilionidae being observed in peripheral zones. Concurrently, a significant relative risk of RABV infection was observed downtown for Vespertilionidae and in peripheral zones for Molossidae. No RABV-positive sample clusters were observed. As a result of the official declaration of RABV-free areas in southern Brazil, mass dog and cat vaccinations are expected to halt in the near future. This stoppage would make most dog and cat populations susceptible to other RABV lineages, such as those maintained by non-haematophagous bats. In this scenario, all information available on bats and RABV distribution in urban areas is essential. Currently, few studies have been conducted. Some local health authorities, such as that in Campinas, are spontaneously basing their surveillance efforts on bat rabies, which is the alternative in reality scenario of increased susceptibility to bat-associated RABV that is developing in Brazil.

A cross sectional study was carried out between May and November 2011 to investigate the epidemiological situation of bovine tuberculosis (bTB) in the state of São Paulo, Brazil. The state was divided into seven regions. Three hundred farms from each region, with reproductive activity, were randomly chosen and included as primary sample units. A fixed number of bovine females, older than 2 years of age, were randomly selected and tested, using the comparative cervical tuberculin test. An epidemiological questionnaire based survey was conducted in the selected farms. Our results show that in the state of São Paulo, the apparent prevalence of positive farms was 9% (95% confidence interval, 95% CI = 7.8 – 10.5%). The prevalence in the individual regions varied between 3.5% (95% CI = 1.7 ? 6.8%) and 13.9% (95% CI = 10.2 – 18.8%). The apparent prevalence of positive animals in the state was 1.3% (95% CI = 0.9 – 1.7%) and varied from 0.3% (95% CI = 0.2 – 0.6%) to 2.5% (95% CI = 1.4 – 4.5%) in the regions. The risk factors associated with tuberculosis in the state were (i) number of adult females in a herd is ? 24 (Odds ratio, OR = 1.91, 95% CI = 1.32 – 2.75), (ii) type of farm enterprise (dairy: OR = 2.70, 95% CI = 1.40 – 5.21; mixed: OR = 2.03, 95% CI = 1.08 – 3.82), (iii) milking process (milking parlor: OR = 4.12, 95% CI = 1.46 – 11.64; portable milking machine: OR = 2.94, 95% CI = 1.42 – 6.09), and (iv) pasture sharing (OR = 1.58, 95% CI = 1.07 – 2.33). The state of São Paulo should implement a structured surveillance system to detect and mitigate the disease. Further, an efficient animal health education program, which encourages the farmers to test replacement animals for bTB prior to introduction in their herds and to avoid pasture sharing with farms of unknown sanitary conditions should also be implemented.

The objectives of the study were to detect and genotype Cryptosporidium spp. and Giardia intestinalis in wastewater samples obtained from five cities with high transit of people in the State of São Paulo, Brazil, and at the entrance of a Wastewater Treatment Plant (WWTP) in Lima, Peru. Samples were collected and concentrated by centrifugation. The genomic DNA was extracted for molecular characterization by nested PCR for Cryptosporidium and double nested PCR for Giardia, followed by sequencing and phylogenetic analysis. G. intestinalis was found in 63.6 % of the samples, and the human assemblages A and B were identified. Cryptosporidium sp. was found in 36.4 % of the samples, and the species were corresponding to Cryptosporidium hominis, Cryptosporidium cuniculus, and Cryptosporidium muris. Results revealed the presence of human pathogenic Cryptosporidium species and G. intestinalis human pathogenic assemblages. Molecular tools highlight the importance to map the genetic diversity of these parasites, as well as to detect their epidemiological circulation pathway in the environment.

Feral pigeons (Columbia livia) live in close contact with humans and other animals. They can transmit potentially pathogenic and zoonotic agents. The objective of this study was to isolate and detect strains of diarrheagenic Escherichia coli and Campylobacter jejuni of urban feral pigeons from an area of Lima, Peru. Fresh dropping samples from urban parks were collected for microbiological isolation of E. coli strains in selective agar, and Campylobacter by filtration method. Molecular identification of diarrheagenic pathotypes of E.coli and Campylobacter jejuni was performed by PCR. Twenty-two parks were sampled and 16 colonies of Campylobacter spp. were isolated. The 100% of isolates were identified as Campylobacter jejuni. Furthermore, 102 colonies of E. coli were isolated and the 5.88% resulted as Enteropathogenic (EPEC) type and 0.98% as Shiga toxin-producing E. coli (STEC). The urban feral pigeons of Lima in Peru can act as a reservoir or carriers of zoonotic potentially pathogenic enteric agents.