From October 2019 to February 2020, 987 stool samples were examined using the direct smear method (Lugol's Iodine, Normal Saline [0.9%]) for the detection of the following parasites: G. lamblia and E. histolytica, while using floatation methods and the Ziehl–Neelsen method (Malachite green) for detecting Cryptosporidium spp. by light microscope. Ninety-six positive samples from these were examined by PCR for patients with diarrhea (children and adults, males and females) who visited the Babylon Maternity and Children's Hospital, the Babylon Province's Specialized Marjan Hospital for Internal and Cardiac Diseases, primary health care centers, and private clinics. The ages ranged from less than a year to 31 years and up.

Infection with parasites that cause diarrhea was found in 47.3% of the cases (E. histolytica, G. lamblia, and Cryptosporidium spp.), with rates of 26.4%, 17.9%, and 3.7%, respectively, in the current investigation. These were analyzed using a direct smear approach to detect the parasites' trophozoite, cyst, and oocyst phases.

By microscopic examination, the rural area had the highest rate of infection at 67.2 percent, compared to 32.9 percent in the metropolis. Males had the greatest infection rate of 51.5 percent, compared to 41.2 percent for females. The highest infection rate was observed at 76.10 percent in the age group (16-20), while the lowest infection rate was documented at 22.80 percent in the age group (26-30). Significant differences in infection rates have been observed at (P ≤ 0.05).

In this study, 96 positive results in direct smear methods were employed to diagnose the major parasitic diarrhea agents using polymerase chain reaction (PCR). The total infection rate was 43.4 percent at the time (31.3 percent, 28.1 percent, and 2.1 percent, respectively). According to the PCR technique, males had the highest rates of infection (36.7 percent), while females had the lowest rates of infection (30.6 percent). In comparison to the rate of infection in urban regions, which was 25.9 percent, the highest rate of infection was found in rural areas (45.3 percent). In the current study, the highest rates of infection were found in the (16-20 years) age group (46.2 percent), while the lowest rates of infection were found in the (21-25 years) age group (16.7 percent).
 

Based on microscopic examinations and PCR methods, the new study indicated that parasites causing diarrhea are prevalent in Babylon province, and that rural areas had higher rates of infection compared to urban areas.

Key words : Microscopic inspection, PCR technique, E.histolytica, G.lamblia, and Cryptosporidium