The human gut hosts a diverse and active community of bacteria that symbiotically support the physiology, metabolism, and immunity of the intestinal lining. Nevertheless, a dynamic community of parasites (helminths and protozoa) may share a habitat with gut-dwelling microbiota. Both microbiota and parasites can significantly change the physical and immunological environment of the gut, thus generating several mechanisms of interaction. Studying this field is crucial for understanding the pathogenesis of parasitic diseases. Additionally, intestinal microbiota and gut-dwelling parasites may interact with each other and with the host immunity to alleviate or exacerbate the disease. These interactions can alter the pathogenicity of both parasites and microbiota, thereby changing the infection outcomes and the overall disease profile. Parasites and microbiota interactions occur via several mechanisms, including physical alteration in both the gastrointestinal microenvironment and the adaptive and innate immune responses. By modulating the microbiota, treating parasitic infections and microbiota dysbiosis may be improved through knowing the mechanisms and consequences of the interactions between intestinal parasites and the microbiota. Thus, new biological tools of treatment including probiotics can be introduced, particularly with the emergence of drug resistance and adverse effects.

The presence of mosquitoes in a certain area is sufficient evidence of the transmission of diseases, in addition to the inconvenience and harassment they cause to the population. In order for mosquito control to be successful, there must be sufficient reports and information about the extent of the distribution and spread of the mosquito in this area. This study was conducted seasonally to calculate the distribution and abundance of mosquitoes and to initially detect hepatitis C virus in the most abundant species collected in some localities: Kafr Saqr (Hanot, El-Kodah, Abo Shokok, El-Hagarsa); Abo Kebeer (Manshat Radwan, Bane Aiat, Al-Rahmania, Horbat); Diarb Negm (Safor, El-Asaied, Karmot Sahbara, Saft Zreka); and El-Zakazik (Om El-Zein, Bany Amer, Al-Zankalon, Shanbrt El-Mimona) along Sharkia Governorate. According to the results, 12 mosquito species belonging to two genera were recorded in four stations (16 sites). The species Culex pipiens was found to be the most abundant across the majority of locations. It is reaching its peak in Al-Zankalon with a maximum count of 139 ± 7.61 individuals. C. antennatus exhibited a significant level of abundance (p < 0.001), especially in Al-Rahmania (82.5 ± 4.3). Species such as C. perexiguus and An. pharoensis were found in moderate-to-low numbers. The prevailing species is C. pipiens in all locations and seasons, especially during the summer. Other species like C. antennatus and An. pharoensis are also important, although their significance is somewhat less pronounced. Clusters of sites with similar features indicate that specific locations or species exhibit consistent patterns of activity or abundance throughout several seasons. These clusters represent groups of locations that share similar characteristics, as determined by the principal components. The findings of detecting hepatitis C virus in C. pipiens (the most abundant species) collected samples showed negative results for the presence of HCV during the summer season in Sharkia Governorate.