Review of Giardiasis in Punjab, Pakistan

Introduction

The thired and the last class of microbial pathogens is protozoa that have been studied from extreme conditions like marine and fresh water, damp soils, dry sand etc (Kanwal K. ana Arslan M. 2016). Giardiasis is an illness caused by protozon Giardia lamblia.It is a gastrointestinal disease. It becomes sometime symptomatic as well as asymptomatic. It is epidemic and sporadic in its nature and cause malabsorption and diarrhea. It is a waterborne disease so called “swimming pool” disease. It encounters both the male and females of all age group. But mostly it was observed in infancy and childhood stages. It can affect the neonatal stage in 4th post-partum day. This infection is high in children and its rate reduce with the growing age. This parasitic infection is become a basic reason of death and develpmental deficiencies throughout the world. (Khan A.I. et al., 2010).

Giardia agilis, Giardia muris, Giardia duodenalis / Giardia lamblia . Giardia agilis infect the amphiboians like frogs. Giardia muris infect the birds and rodents. Giardia duodenalis infect the mammals including humans, dogs and rabbits (GILLON J. 1983).

Giardia lamblia is a zoonotic flagellate unicellular eukaroytic protozoanic Parasite in Diplomonadida order and family Hexamitidae. Giardia lamblia was firstly discovered by a scientist Antonie van Leeuwenhoek in 1861. He was famous as father of parasitology or Microbiology (Elmendorf G. H, et al.,2003). He was founded it into his own stool sample. Giardia ssp is consider a firstly emerging parasite that is able to cause gardiasis in mammals and livestock such as cattle sheep goats etc. It is pathogen of all vertebrate classes. It is a etiological agent. Giardia Lamblia live in digestive system reproduce and passed into stool (Oetega R. Y. and Adam D. R. 1997).

Giardia lamblia exist in two forms one is cyst and other is trophozoite. It has Four pairs of flagella two nuclei and a sucking disk on the ventral surface with which it absorbs nutrient from small intestine cause malabsorption by lashing movement of thread like flagella. Trophozoite is pear shape and 9.5 to 21um long and 5 to 15 um in width. Trophozoite form like tiny water droplets when see dorsally and swollen like a bowl from side appearance. The pattern of nuclei, median bodies and axonemes match to a mammal facial features. Trophozoite appear in liquid and soft stool. It is infectious form after excystion start to multiply by adhereing to the wall of small intestine.

Cyst is oval shape and have a thick resistant wall around itself due to which it can survive for a long period out of body. Cyst was 12um in length and 7-10 um in its width.Mature cyst has four nuclei curved median bodies and linear axonemes. It can survive in humidity and watery condition if a normal chlorine concentration was used for the purification of water upto 3 months at least. Cyst ingested cause excystation firstly in stomach and this go upto small intestine and produce two trophozoites. Giardia have five chromosomes that are polyploid in nature mitochondria, peroxisomes,smooth endoplasmic reticulm and various other cellular structures (Oetega R. Y. andzzz Adam D. R. 1997).

Giardia show some signs such as diarrhoea, abdominal cramps, bloating, weight loss or malabsorption, vomiting, nausea and iron deficiency and lack of appetite etc. These causes sever illness in human and sometime lead to the morbidity and mortility (Siddiqui H.M. et al., 2018).

Giardia have simple life cycle. It has two stages, one is infectious cyst stage and other is intestinal trophozoite stage. Cyst was ingested through the contaminated water, food and direct faecal contact. Excystation of ingested cyst cause the release of trophozoites in stomach and small intestine (Elmendorf G.H. et al., 2003). In stomach acidic pH gastric juice and in small intestine pancreatic juice causes the break down of inert hard resistance wall of cyst to produce vegetative form trophozoites. It increase its number asexually by the longitudinal binary fission in duodenum and early portion of jejunum. Encystation is a process in which a hard thick wall is wrap around the trophozoites to formation of round cyst structure. Some of the trophozoite trapped in villi and microvilli and cause illness and other go outside of the body through the stool (Oetega R.Y, and Adam D.R. 1997). Giardia genome have twenty seven clan CA cystein proteases gene regulate and controle the trophozoite producton and encystation. Two process are associated during life cycle of gardia lamblia Excystation and encystation. Excystation is a process in which ingested cyst wall is ruptured to free the trophozotic form that start illness by their replication and showing different symptoms. The encystation is a process in which the trophozoite change into cyst form again to release the cyst through the nitrogenous waste material so that an other host can ingest it to start another life cycle and so on. In which a hard thick wall is wrap around the trophozoites to formation of round cyst structure The encsytation intiate when trophozoites release a large number of secretory proteins called encystation- specific vesicles. These vesicles start to accumulate in the cell membrane of trophozoite to make a hard cyst wall. Cystein proteases was discovered in gardia that play a major role in the life cycle its survival and continuity of life cystein protease that degrade the surface proteins during excystation and breah the membrane of encystation –specific vesicles to release a copious amount of proteins that make the cyst wall (DuBois N. K et al 2008).

Giardia lamblia was transmitted through a varity of sources. As it is a waterborne disease so cyst of Giardia lamblia are mixed in ponds lake and water bodies resorces as human excrement through improper sewarge system. Water contaminated and drinking of such untreaded water cause a lot of water borne disease along with the giardiasis.Gardia lamblia also cause chronic diarrhea, malabsorption and growth retardation (Baldursson S. and Karanis P. 2011). This pathogen was also transmitted from person to person contact or through contaminated food or improper cooked food and raw vegetables. This caustive agent was also transmitted and prevaled through the unwashed hands contact indivdual to individual after toilt use or diapered change. Homsexual activties also included the oral-fecal involvement cause the transmisson of this disease. At least 10 cysts are enough to this infection ( WOLFE S.M. 1992).

The poverty, improper sewage system, poor personal conditions and poor sanitation. Limited and contaminated water resources, climate changes increasing population and food handlers these are some factors that related to distribution and prevalence of giardiasis in developing countries Pakistan also include. It was also observed during survey that finger nails of primary school going children also susceptible of Giardia lamblia up to 14.28% in Lahore district (Ghani J. J. et al., 2016). Study from worldwide areas show that different factors are associated in the prevalence of this disease. In Pakistan parasitic infections become one of the biggest issues to be solved out. Giardia lamblia was mostly infected the children with less educated mothers and those children which intake raw vegetables drinking pond spring water or water from open areas and eaten meal without hand washing (Khan W., Nisa U.N. and Khan.A. 2017).

For the epidemology of those infection stool sample was collected to detect ova and parasite detection. For this different fresh sample was collected in both developing and developed countries.The 2% to 5% industrialized and 20% to 30% in under developed countries. Mostly case was asyptomatic. Mostly was manifested in children upto 40%. Asymptomatic childrens are carriar of this pathogen and transmitted this infection their family and friends. This infection show symptoms within 1 – 2 weeks and some time several weeks or even upto months if infection is left untreated. Symptomatic patients have foul smelled stool with high fat deposition and high diarrheatic condition as loose motion. Stool of such patients does not contain blood (Ortega R.Y. and Adam D.R. 1997). Immunology include both humoral and cellular immune reaction to the Giardia lamblia which was generated the patient against infective agent. Antibodies are produce in a patient body against agent to eradicate it. The immunoglobulin A(IgA) and IgM. Both antibodies fight to the caustive agent and reduce its movement and attachment to the mucosal layer of small intestine (WOLFE S.M.1992).