Background: Newly designed COVID-19 vaccines were approved and administrated worldwide. However,
the interaction between parasitic infections and COVID-19 vaccines and their efficacy is still obscure.
Objective: To correlate cytokines (TNF-α and IL-4) levels with COVID-19 vaccine administration in
patients with concomitant parasitic infections. A secondary objective is to assess the impact of parasitic
infections on COVID-19 efficacy.
Subjects and Methods: The study included 128 patients divided into 2 groups according to an answered
questionnaire, and routine laboratory investigations (stool, urine and blood film examination). Both
groups included vaccinated (received full doses of COVID-19 vaccine within 6 months of sample collection),
and non-vaccinated. A third matching group was recruited as control apparently health participants, i.e.,
neither parasitic infected nor received COVID-19 vaccines. Molecular detection of cytokines (TNF-α, and
IL-4) gene expression was performed for all study samples using real-time PCR.
Results: In comparison to the control group, there was up-regulation of TNF-α in patients with parasitic
infection, whether vaccinated or not. According to parasitism, IL-4 showed different gene expression.
In case of helminthic infections, it was up regulated in non-vaccinated patients, and down regulated in
vaccinated patients. Meanwhile, it was down regulated in patients with protozoal infections whether
vaccinated or not.
Conclusion: COVID-19 vaccinated patients with concomitant helminthic infections are susceptible to
reduced vaccine efficacy. Generally speaking, parasitism however, could provoke cytokine storm syndrome

ABSTRACT
Cats, as widely embraced companions in various settings, are at risk of significant health threats due to gastrointestinal infections. The current study investigates the prevalence of gastrointestinal parasitic infection in domestic cats from Tahta, Sohag Governorate, Egypt. Two hundred fecal samples were collected and examined using various techniques: direct smear examination, simple sedimentation, formal ether sedimentation, and flotation with Sheather's solution. The flotation method demonstrated the highest efficacy in isolating Toxocara spp. eggs and protozoan oocysts. The findings reveal a significant prevalence of gastrointestinal parasitic infections, with 71% of the cats examined carrying at least one species of parasite. The most frequently identified parasite was Toxocara leonine (47.5%), followed by Toxocara cati (10%) and mixed infections of both species (6.5%). Other less prevalent parasites included hookworm eggs (2%), Giardia spp. (2%), Cryptosporidium spp. (1%), Entamoeba spp. (1%), and Mite infections (1%). Notably, embryonation of Toxocara spp. eggs was achieved using a 0.01% sodium bicarbonate solution, resulting in embryonation of 60% of incubated eggs. The prevalence of parasitic infections showed no significant variation based on age or gender, however, seasonal factors significantly influenced the rate of infection (P ≤ 0.05). These findings underscore the high prevalence of gastrointestinal parasites among domestic cats in Sohag Governorate, highlighting the urgent need for effective parasite control strategies to safeguard feline and public health.

ABSTRACT
Background: Although ducks are pathogen-resistant, their preferred habitat is typically a
favorable home for parasites' survival and replication, especially in tropical and subtropical areas
like Egypt. Many parasites can exploit ducks using them as ultimate and intermediate hosts.
Methods: This study screened the prevalent intestinal parasites infecting domestic ducks [Native
breed and Muscovy ducks (Cairina moschata)] and their variability in Assiut, Egypt, from April
2023 to September 2024 to study. One hundred fresh intestinal samples were collected and
examined parasitologically using a light microscope. Some coccidia-positive samples were
histopathologically examined. Results: A total prevalence of 46% parasitic infection was
detected in examined ducks, categorized into single (30%) and mixed (16%). The recognized
parasites were verified into nematodes and protozoa. Nematodes included Ascaridia galli (6%)
and Trichuris spp. (2%) while protozoa oocysts were the oocysts of Cryptosporidium (42%) and
coccidian species (10%). The discriminated coccidian was identified as Eimeria anatis, Tyzerria
spp, Eimeria mullardi, and Wenyonella anatis. The histopathological examination revealed their
destructive effect on the intestinal tissue. Conclusion: the intestinal parasitic infection of
domesticated ducks is prevalent and variable in Assiut, Egypt. The current investigation is the
first report in Assiut showing the presence of Cryptosporidium infection in ducks, which could
contribute to assessing their possible role in the dissemination of Cryptosporidium species. Some
detected parasites are damaging to the intestinal tissue which may seriously cause loss of duck's
health and the nutritive value of their meat.
Keywords: Domestic duck, intestinal parasi