Journal of Zoonotic Diseases
Volume:8 Issue: 2, Spring 2024

Avian Influenza is a contagious zoonotic disease that can be transmitted from birds to mammals. In this study, we conducted a systematic review and meta-analysis to investigate and summarize the occurrence of avian influenza H9N2 in humans and other mammals in Iran. Data were collected systematically until July 1 2023 from four English and two Persian databases. According to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) and inclusion criteria, 14 eligible studies were obtained. Occurrences of AI H9N2 are reported in humans, dogs, and water buffaloes (Bubalus bubalis) in Iran. The pooled prevalence of AI H9N2 using a random model among humans was 0.15 (95% CI, 0.12-0.18). Pooled prevalence using the HI test was 0.16 (95% CI, 0.13-0.20). The pooled prevalence by different cut-offs for the HI test was equal to 0.34, 0.11, 0.02, and 0.01, respectively for cut-offs 1:20 to 1:160. Pooled prevalence using the HI test, among persons with possible exposure, hospitalized persons and hospital staff (0.20, 0.31, and 0.30) was higher than the prevalence in apparently healthy individuals (0.01). The group of individuals with possible exposure revealed the highest pooled prevalence of 0.25 (95% CI, 0.17-0.33) using the HI test. This was observed predominantly in slaughterhouse workers.  The pooled prevalence using the ELISA test was 0.27 (95% CI, 0.23-0.31). These results can help policymakers to create prevention and control programs for possible epidemics in the future and can help researchers to tailor the design and objectives of future studies in this area.

The most extensive monkeypox outbreak in history commenced in 2022 and has swiftly disseminated globally. This review aims to succinctly outline host immune reactions to orthopoxviruses, present an insight into available vaccines to counteract the epidemic, and delve into clinical research and animal studies examining induced immunity against monkeypox induced via the vaccinia virus-based monkeypox vaccines. It addresses current concerns about the outbreak and suggests optimal vaccine utilization as a control measure. During the 1980s, surveillance studies in Central Africa and subsequent outbreaks demonstrated that smallpox vaccines were approximately 85% effective against monkeypox. These findings are substantiated by numerous animal studies, primarily in primates, involving live virus challenges through different inoculation methods, consistently showcasing high levels of protection and immunity post-vaccination. Smallpox vaccines emerge as effective countermeasures for managing monkeypox outbreaks, although they do entail adverse effects, and second-generation, replicative vaccines have prohibited usage. Third-generation vaccines pose a challenge for rapid responses as they require 2 doses, which can be difficult for people with weak immunity.  Insights from the COVID-19 outbreak must guide our collective approach to addressing the monkeypox outbreak and future outbreaks.

Toxoplasmosis is a zoonotic disease caused by Toxoplasma gondii, which can infect humans through oocysts or undercooked meat. It can cause varying symptoms, including congenital toxoplasmosis. Early detection and treatment are beneficial, and antimicrobial treatment can prevent or resolve symptoms. The disease has a complex life cycle, with felids being the definitive host. Understanding the signaling pathways is crucial for effective therapeutic strategies. Toxoplasma invasion is regulated by the microtubule cytoskeleton, affecting macrophages and innate immunity cells. Calcium binding proteins and focal adhesion kinase-2 have been identified as key regulators of calcium signaling in Toxoplasma. Calcium signaling is crucial for parasite biology and drug development. The ERK pathway plays a significant role in host-parasite interactions and immune responses. This pathway plays a critical role in the spread of Toxoplasma by manipulating host cell migration. Toxoplasma infection can activate the ERK signaling pathway, leading to the inhibition of apoptosis in host cells. This inhibition of apoptosis is believed to have a positive effect on the survival and replication of the parasite in the host. The Akt signaling pathway, also known as the PI3K/Akt pathway, is crucial in parasitic diseases, modulating host immune responses and parasite survival. Host AKT activation is important for T. gondii proliferation which is related to reduction of ROS in host cells. More investigation is required to fully understand how these signals contribute to the pathophysiology of Toxoplasma infection and to identify possible therapeutic targets for the management of parasitic illnesses.

Rift Valley fever is a vector-borne zoonosis that can affect various species, including ruminants and camels. The present study reports the first serological detection of the Rift Valley fever virus in sheep and goats, along with an analysis of risk factors in Fars province, located in the south of Iran. The province of Fars was distributed into three climate zones, and three cities were accidentally chosen for each climatic zone. Two epidemiologic units were selected in each city, and samples of all the sheep and goats were collected from each unit. In total, 540 serum samples (391 from sheep and 149 from goats) were gathered and tested by a commercial ELISA kit. Out of 540 samples tested, 12 (2.2%) were found to be seropositive for the Rift Valley fever virus, with 10 from sheep and 2 from goats, indicating the presence of specific antibodies.  The correlation between seropositivity and risk factors such as age, sex, climate, animal type, and, history of abortion was not significant. In conclusion, the Rift Valley fever virus is not endemic in Fars province. Further studies are recommended to investigate the distribution of mosquito vectors and their genotype in Fars province, isolate the virus, and develop vaccines.

Toxoplasma is an intracellular parasite that can cause toxoplasmosis in humans and animals. In this disease, parasitic cysts of Toxoplasma gondii can remain present in various tissues such as the brain throughout the host's life. The potential role of toxoplasmosis should be considered in many neurological diseases with unknown mechanisms. In horses, behavioral disorders like crib-biting have multifactorial causes and may be due to neurophysiological dysfunction. This research aimed to determine the role of toxoplasmosis in the manifestation of crib-biting behavior in horses. A case-control study was conducted in horse riding clubs in Fars province, Iran, near the city of Shiraz. Ten horses with crib-biting behavior and 10 clinically healthy horses matched for sex, age, and breed were enrolled in the study. Blood samples were collected from cribbers and healthy horses, along with a thorough history-taking. An enzyme-linked immunosorbent assay (ELISA) was performed on sera to detect T. gondii-specific Immunoglobulin G (IgG) and Immunoglobulin M (IgM). The results of this study revealed that all horses were free of toxoplasmosis. It is concluded that this relation was not detected in the horse farms of Shiraz suburbs. Further research is required to explore more aspects of crib-biting behavior and its relationship with causative factors.

Wild and domestic ruminants become infected with Mycobacterium avium subsp. paratuberculosis (MAP) leads to chronic enteritis, known as Johne’s disease (JD). An eight-year-old male wild goat (Capra aegagrus) that lived in the wildlife breeding center in Chaharmahal and Bakhtiari province with symptoms of prolonged diarrhea that did not respond to antibiotic treatment was referred to a veterinary center. After a while, the animal died. JD was diagnosed after laboratory diagnosis (by acid-fast staining). The present study reported the incidence of JD in a wild goat in Iran for the first time. The economic losses and animal health should be considered. Since 2020, the wild goat (Capra aegagrus) has been classified in the category Near Threatened (NT) near treated on the list (International Union for Conservation of Nature) IUCN. Therefore, protecting the health of these species is essential. The importance of carrier animals and reservoirs in wildlife should be given special attention.