ABSTRACT
Parasitic infection is still a serious public health problem in the world, especially in developing countries including Egypt. It represents a major cause of morbidity and mortality in childhood and among high-risk groups in most parts of the world. This study detected the prevalence of parasitic infection among school children in El-Wadi El-Gadded [the New Valley Governorate]. A total of randomly chosen 1615 students aged from 6-16 years, [771 males and 844 female] from 12 primary schools and 12 preparatory schools related to four centers [El Dakhala, El Farfra, Paris and Platt] from the New Valley Governorate. Each child was subject to: A questionnaire sheet, Urine examination through sedimentation methods, Stool examination using: Direct smear, Simple sedimentation method and Modified Ziehl-Neelsen Stain, Blood samples were collected randomly from 450 children and examined for Seropositivity of toxoplasmosis using [On-SiteToxoIgG/IgM Rapid Test-Cassette] and examination of hair and clothes for ectoparasites [lice]. The overall prevalence of parasites was [39.1%] among primary and preparatory school children. The helminthes were E. vermicularis [15.2% and 17. 1%]; A. lumbricoides [1.3% and 1.9%] and then H. nana [0.9% and 0.6%] and the protozoa were E. histolytica [14.1% and 13.2%], Giardia lamblia [3.8% and 309%], and then Cryptosporidium parvum [0.09%] and seropositivity of toxoplasmosis was in [3.0% and 2.7%] among primary and preparatory school children respectively. Mixed infection was in [0.4%] among primary school children. Head lice infestation was more prevalent among primary school children than preparatory school ones with a ratio [3.5% and 0.2%] respectively, was nil among males
ABSTRACT
Some snails of Biomphalaria alexandrina can resist the infection of Schistosoma mansoni so this study aimed to clearly this mechanism by using light and electron microscopy [EM] and determine the role of Nitric oxide in this mechanism. B. alexandrina snails used in this study were exposed individually to S. mansoni infection according to their response they were classified into susceptible group [shed cercariae] and resistant group [failed to shed cercariae]. Snails not exposed to infection were included in this study as control group. Nitric oxide [NO] level was assayed directly in the soluble fraction of B. alexandrina haemolymph supernatants collected from each group of B. alexandrina snails were subjected to NO assay by the Greiss reaction. The level of NO in haemolymph of infected snails was significantly increased [p<0.001] than both control and non infected snails groups, however, in non infected snails group had significantly [p<0.05] compared to control group. This study when correlated the changes recognized by EM with NO level the pro apoptotic effect of high level of NO on the haemocytes. Characterization and identification of cell shape of haemocytes in both haemolymph and tissue were examined by light and electron microscopy. Examination of B. alexandrina snail's haemocytes revealed three types of different cells classified according to their shape and granular contents. These cells are granulocytes, amoe-bocytes and hyalineocytes. Electron microscope Study also revealed the important role of granulocytes and amoebocytes as defense mechanism against snail infection. NO is considered an important anti parasite molecule; intra-molluscan stages of parasites switch off host NO defense response