Methods of macrophages activation and their modulation for the prospection of new antileishmania drugs: a review

Leishmaniasis are a group of parasitic zoonoses provoked by protozoa from Leishmania genus and belonging to the group of neglected tropical diseases. The search and development for new drugs is necessary not only to investigate the activity against only the parasite, but also to investigate the possible synergistic effect of new drugs with the immune response of the host. In the present review, macrophages are pointed out as potential targets of the investigation of new antileishmanial drugs, and some methodologies in order to assess their activation as response to Leishmania-infected cells are presented. Macrophages are an important role in the cellular immune response, since they are cells from mononuclear phagocytic system, the first line of defense of the host, against parasites from Leishmania genus. Phagocytic capacity, lysosomal activity, increase of nitric oxide and intracellular calcium levels are parameters regarding assessment of macrophages activation which allow them to be more hostile in order to solve the infection and lead the patient to cure. In this context, we bring 19 substances already investigated and that activate macrophages, what makes them promising in the antileishmanial treatment. Therefore, assessment of macrophages activation, are important tools for discovery of immunomodulatory compounds which have potential to act in synergism with host immune response. Such compounds might be promising as monotherapy in the treatment of leishmaniasis, as well as being used as adjuvants in vaccines and/or in combination with conventional drugs.

Prevalence of zoonotic potencial parasites in feces samples collected from public squares and beaches in São Lourenço do Sul, Rio Grande do Sul, Brazil / Prevalência de parasitos com potencial zoonótico em amostras fecais coletadas de praças e praias públicas de São Lourenço do Sul, Rio Grande do Sul, Brasil

In recent decades there has been a closer relationship between human beings and pets. Although this relationship is beneficial from several points of view, it also poses a risk to public health, as animals can transmit diseases to humans, called zoonoses. Among the main ones we can highlight the parasitic zoonoses, caused by helminths and protozoa, mainly transmitted via fecal-oral. Public squares and beaches are places with potential for the dissemination of parasitic zoonoses, as they are environments for mutual interaction between people and animals. The purpose of this study was to analyze the prevalence of parasites with zoonotic potential in samples of dog feces and sand collected from public squares and beaches in the municipality of São Lourenço do Sul, Rio Grande do Sul, Brazil. 204 samples of canine feces from the environment and 120 samples of sand were collected and submitted to coproparasitological techniques. Of the total, 57.84% of the fecal samples and 21.66% of the analyzed sand samples were contaminated with some parasitic genus. The contamination of the soil of public squares and beaches by parasites with zoonotic potential demonstrates that the population is at risk in these places, with the need to adopt sanitary measures to avoid human infection by zoonoses.

Epidemiological, Morphometric, and Molecular Investigation of Cystic Echinococcosis in Camel and Cattle From Upper Egypt: Current Status and Zoonotic Implications

Cystic echinococcosis has been considered one of the major parasitic zoonoses which is associated with severe economic losses. The present study was undertaken to investigate the occurrence, organ distribution, cyst fertility, and viability of cystic echinococcosis in slaughtered camels and cattle from various abattoirs in Assiut Governorate, Egypt. The work also involved morphological, morphometric, and molecular identification of the parasite. The occurrence of hydatid cysts was investigated in total number of 100 lungs of camels and 574 liver and lungs of cattle admitted to three slaughterhouses at Assiut Governorate, Egypt. Moreover, several individual variable factors, including organ involvement, age, sex, and hydatid cyst characteristics, were studied to identify their possible association with the occurrence of the disease. Genomic DNA was extracted from the hydatid cysts, followed by molecular identification of the parasite through amplification of ribosomal DNA internal transcribed spacer (ITS) regions. Hydatid cysts were found in 6 camels (6%) out of 100 inspected camels, while 5 hydatid cysts (0.87%) were detected in a total number of 574 cattle examined. The parasite was detected exclusively in lungs of camels, while lungs were the main organ infected by the parasite in cattle and one hydatid cyst was found in the liver (0.17%). In camel, 66.7, 16.65, and 16.65%of detected cysts were fertile, sterile, and calcified, respectively, while in cattle, these percentages were 60, 20, and 20%, respectively. None of the studied variable factors were significantly associated with the occurrence of the disease in camels, with the exception that all cysts were found in the lung. Conversely, we found a significant association (P < 0.05) between the age and sex of the slaughtered cattle and the occurrence of hydatid cysts. In this respect, the rate of infection was higher in female cattle and those cattle more than 5 years (P < 0.05). The morphological, morphometric, and molecular studies confirmed the presence of the parasite. Taken together, our results concluded that camels and cattle play a potential role in maintaining the transmission cycle of this zoonotic parasite.

DEMOGRAPHIC CHARACTERISTICS OF THE SEROPREVALENCE OF HUMAN TOXOCARIASIS AMONG THE POPULATION OF NORTH-EASTERN BULGARIA

Toxocariasis is a tissue zoonosis caused by Toxocara spp. and the exposure to these geohelminths varies in different parts of the population in a particular region. The purpose of the study is to reveal the seroprevalence of toxocariasis in North-eastern Bulgaria and to establish its demographic structure. Material/Methods: Within the scope of a broad seroepidemiological study, 701 individuals from North-eastern Bulgaria were tested for anti-Toxocara antibodies (ELISA) between 2017 and 2020. The results were stratified and analysed by age, gender, and place of residence. Results: The overall seroprevalence of human toxocariasis in North-eastern Bulgaria is 18.54%. Children (18.85%) and adults (18.30%) show similar levels of infection, but the stratified analysis by age in 5-years intervals revealed notable discrepancies. In younger children, the seroprevalence is higher than the observed for the entire population (0-4 years - 22.22%; 5-9 years - 22.22%), while in adolescents and adults is lower than average. In the elderly, the seroprevalence rises to its highest levels (60-64 years - 30.56% and over 65 years -31.67%). Although there are variations between males and females, gender is not a significant factor for the distribution of toxocariasis. Higher seroprevalence levels in residents of the smaller settlements of the region (children - 28.18%; adults -29.10%) correspond to a 2.5-fold increase in the odds of contracting toxocariasis in comparison to the ones living in Varna city. Conclusion: The overall seroprevalence of toxocariasis in North-eastern Bulgaria is alarmingly higher than the levels reported from other parts of the country, placing this unknown infection in a leading position among the parasitic zoonoses. The place of residence is the most significant factor driving the uneven distribution of the disease.

Prevalence of toxoplasmosis in semi-domesticated and pet cats within and around Bangkok, Thailand

Background Toxoplasmosis is one of the most common parasitic zoonoses worldwide. Cats become infected after ingesting infected tissue cysts. The objective of the present study was to compare the prevalence of toxoplasmosis in pet cats and semi-domesticated cats in the Bangkok metropolitan region. A survey of Toxoplasma infection was conducted in 260 cats (median age [range]: 3 years [10 months–10 years]; 155 females and 105 males) by collecting blood samples from 130 client-owned pet cats and 130 semi-domesticated cats within and around Bangkok during 2016–2017 using indirect fluorescence antibody tests. An IgG antibody to Toxoplasma antigen ratio of ≥1:100 was considered positive for Toxoplasma infection. Results The overall prevalence of T. gondii in cats was 6.5% (17/260). The prevalence of T. gondii in semi-domesticated cats and pet cats was 11.5 and 1.5%, respectively. Semi-domesticated cats aged 1–5 years (14.9%) had a higher prevalence of infection than domesticated cats (1.3%, p = 0.002) of the same age. The odds (95% confidence interval [CI]) of having T. gondii infection in semi-domesticated cats were 8.34 (1.86–76.29, p = 0.0017) times higher than in pet cats. Interestingly, there was an association between T. gondii infection according to city ​region (p = 0.002). The odds (95% CI) of having T. gondii infection in cats living in the inner city were 4.96 (1.03–47.16, p = 0.023) times higher than cats living in the suburb and the vicinity. Conclusions The present study identified a higher prevalence of Toxoplasma infection in semi-domesticated cats compared with pet cats. The semi-domesticated cats could serve as a zoonotic reservoir. Public health regulations should be implemented to prevent toxoplasmosis spread.

Towards an Integrated Approach for Monitoring Toxoplasmosis in Southern Italy

Toxoplasmosis is a widespread worldwide zoonotic infection caused by the intracellular protozoan Toxoplasma gondii. This protozoan infection is considered one of the most important food-borne parasitic zoonoses globally. Beyond its impact on public health, toxoplasmosis has also important veterinary implications, because it causes miscarriage or congenital malformations in livestock with negative economic impacts. An integrated monitoring programme aimed to deepen the epidemiological data on toxoplasmosis and to identify the risk factors that may favour T. gondii infections in animals and humans was conducted in an endemic area of southern Italy. The monitoring activities were based on the following tasks: (i) parasitological analysis and risk factors for T. gondii in livestock (sheep, goat, cattle and water buffalo) farms; (ii) serological and molecular monitoring at slaughterhouse in meat-producing livestock; (iii) analysis of hospital discharge records (HDRs); (iv) outreach activities (information, dissemination and health education) to farmers, vet practitioners and school-age children. The present study confirmed a very high seroprevalence of T. gondii infection in livestock farms (e.g., up to 93.1% in sheep farms) in southern Italy and highlighted the potentially significant public health risk in this area.

Low Prevalence of Cysticercosis and Trichinella Infection in Pigs in Rural Cambodia

Cysticercosis and Trichinella spp. infection are parasitic zoonoses prevalent among pigs in Southeast Asia, where pork is the most important source of meat. In rural Cambodia, many pigs are raised extensively in family backyards, and information regarding the prevalence in rural small-scale pig production is very limited. This study was conducted in four provinces in north-eastern Cambodia to determine the seroprevalence of porcine cysticercosis and Trichinella spp. infection in rural villages, and to identify possible risk factors. Only households with less than 10 pigs above three months old were eligible. In total, 139 households participated, and 242 blood samples were collected. Farmers were interviewed about food and hygiene habits, disease knowledge and practices. The serum samples were analysed by ELISA to determine antigens to Taenia spp. cysticerci or antibodies to Trichinella spp. muscle larvae. Positivity among the pigs was 11.2% (95% CI 7.5–15.8) for Taenia spp. cysts and 2.5% (95% CI 0.9–5.4) for Trichinella spp. Cysticerci were more common in the province Preah Vihear (p < 0.001) than in the other provinces. Risk factors associated with porcine cysticercosis were management systems for the pigs and access to human faeces (p < 0.001). Trichinella spp. infection in pigs was more common in the province Ratanakiri (p = 0.001). The main risk factor associated with Trichinella spp. transmission was feeding pigs with food waste (p = 0.048). More men had heard about cysticercosis than women (p = 0.002), and men also consumed undercooked pork meat to a greater extent (p = 0.004). Although the present study is relatively small, several risk factors could be identified for porcine infection with Taenia spp. and Trichinella spp., which can be used to guide future interventions to improve both porcine and human health in these provinces.

Zoonotic Parasitological Findings in a Puppy: The Course and Therapeutical Efficacy

Considering the close contact of companion animals and humans, gastrointestinal parasitic zoonoses are very widespread and represent a high risk of transmission with the potential of severe consequences affecting the digestive tract of both humans and other animals. In this study we focused on enteric zoonoses caused by Toxocara canis nematode, Dipylidium caninum tapeworm and Giardia duodenalis protozoa. Our primary aim was to observe Toxocara canis egg excretion within the 27 consecutive days before and after orally treatment (2 Caniverm® tablets) on Day 13 in a naturally infected puppy. An average egg per gram (EPG) of T. canis detected by coprological quantitative McMaster method was 4558.33 and 666.66, before and after treatment, respectively. The percentage of faecal egg count reduction (%FECR) in in vivo Faecal Egg Count Reduction Test (FECRT) has confirmed an 85.37 % efficacy against T. canis. Secondly, the efficacy of Caniverm® against the tapeworm Dipylidium caninum was also determined. No D. caninum proglottides were detected on Day 14. The data showed 100 % effectiveness of the anthelmintic treatment. Metrobactin® 250 mg has been tested as experimental therapy against Giardia duodenalis on Day 3. On day 10, no cysts were observed in the faeces after per os ¼ tablet administration twice a day for 7 days.