Intestinal Parasites Among Unity Primary School Pupils, In Oraifite, Ekwusigo L.g.a., Anambra State, Southeastern Nigeria

The broad spectrum of activity, excellent safety profile and high therapeutic efficacy means that praziquantel is the current drug of choice for the treatment of schistosomiasis. Other drugs recommended in the treatment of schistosomiasis include metrifonate, which is active against S. haematobium and Oxaminoquine, which is effective against S. mansoni. Recently, however, the price of praziquantel has fallen considerably and because the price of oxaminoquine has not decreased, praziquantel is replacing it. The decreasing demand for oxaminoquine might stop oxaminoquine production, as it already has for metrifonate.

Metronidazole (flagyl) is an imidazole derivative. It is a well- tolerated and active anti-protozoan drug. Higher doses of metronidazole are required for its effectiveness (Wolfe, 1978). Some countries prefer Quinacrine to metronidazole because of its tolerance (Wolfe, 1978).

In recent research, Tinidazole has only recently been approved by the United State Food and Drug Administration (FDA) for the treatment of giardiasis, though it has been available in other parts of the world (Wiser, 2000). Tinidazole is very effective for the treatment of giardiasis - a single dose often cures the infection with very few side effects. It is an imidazole derivation and it is proven to be the drug of choice for giardiasis giving a reported cure rate of well over 90% in both adult and children.

Furazolidone is the only drug available as a suspension, making it particularly useful in young children, with a cure rate of approximately 80% (Wolfe, 1978). The dose for children is 6mg, four times daily for 10 days. For adults, the dose is 100mg, four times daily for 7 to 10 days (Wolfe, 1980). Hypersensitivity reaction may occur and it may stain the urine. Nausea, vomiting, haemolysis in patients with glucose-6- phosphate dehydrogenase (G6PD) deficiency are also observable (Horton, 2003). Furazolidone has caused mammary tumor in rats and its safety has been questioned by the Food and Drug Administration (Horton, 2003).

The major limitation of chemotherapy is that it provides only a short-term measure since rapid reinfection after chemotherapy is a common feature of intestinal parasitic transmission. For instance, a study in a highly endemic area of Tanzanian found that reinfection with hookworm among schoolchildren to pre-treatment levels occurred within 4-12 months (Albonico et al, 1995), whereas another study, conducted in Papua New Guinea, showed that reinfection following treatment occurred more slowly (Quinnell et al., 1993). The varying re-infection rates can be explained by population dynamic models of transmission which show that the rate of re-infection depends on treatment efficacy and coverage, and the intrinsic transmission potential of the parasite in the population (Anderson and Medley, 1985). The rate of re-infection is inversely correlated with the magnitudes of each of these factors. Thus, the high rates of re-infection observed in Tanzania are due, in part, to the high transmission potential and low population coverage of treatment.

Phytotherapy

Phytotherapeutic agents play a vital role in the natural management of intestinal parasites. Medicinal herbs can be used to both alleviate the symptoms of parasitic infections and clear the infection. For instance, Garlic (Allium sativa), has traditionally been used as an antiparasitic and antimicrobial agent (Ross, 2002). Recent research has substantiated its traditional uses and elucidated probable active constituents and possible mechanisms of action. Harris et al (2000) demonstrated antigiardial activity of both whole raw garlic and some of its constituents. Whole garlic extract demonstrated an LC50 (the concentration that inhibits growth of parasite by 50%) of 0.3mg/ml, while the allicin breakdown products diallyl disulfide, diallyl sulfide, and allyl mercaptan demonstrated LC50 values of 0.1, 1.3, and 0.037mg/ml, respectively. Other garlic constituents, such as allyl alcohol and dimethyl disulfide were also strongly inhibitory, with LC50 values of 0.007 and 0.2mg/ml respectively (Harris et al., 2000).

Berberine is an isoquinoline alkaloid found in a number of medicinal plants. Berberine-containing herbs have a long history of use in Chinese (Coptis chinensis), Western (Beberis vulgaris, Hydrastis Canadensis, Berberis aquifolium), and Ayurvedic herbal medicine (Berberis ariststa). Most of these herbs have been used in the treatment of gastrointestinal infections, intestinal parasites, and diarrhoea (Snow, 1997; Holmes, 1997; Willard, 1991). Berberine salts and extracts have demonstrated in vitro inhibitory activity against Giardia trophozoites (Kaneda et al., 1990). Berberine sulfate has been shown to induce morphological damage to trophozoites (Blumenthal et al., 2000).

Indian long pepper is a traditional Ayurvedic herb that has long been used for its anti-helminthic and carminative actions (Frawley and Lad, 1986).

Pippali rasayana is a traditional Ayurvedic formulation consisting of Piper longum and Butea monosperma (palash). It has traditionally been used in the treatment of chronic dysentery and worm infections. Agarwal et al (1994) recently investigated the antigiardial and immuno-stimulatory effects of Pippali rasayana.

2.4. DIAGNOSTIC METHODS

In the diagnosis of intestinal parasites, a lot of techniques exist. Each shows a considerable effectiveness in the diagnosis of intestinal protozoans and helmith parasites.

Fred Lumniano et al., (2005) compared the efficiency of Kato-Katz thick smear and thick smear techniques for the diagnosis of intestinal helminthes. The sensitivity of the tick smear technique was higher than that of the Kato-Katz method for the diagnosis of all helminthes except Schistosoma mansoni.

The merthiolate-iodine-formalin (MIF) technique to detect human intestinal parasites in feces was inefficient for the detection of hookworm and Trichuris trichiura eggs (Bawden, 1994). Addition of a saturated- brine flotation step increased recovery of hookworm eggs by 77% and Trichuris trichiura eggs by 87%. Recovery of Ascaris lumbricoides also was increased by 71%. This was a significant improvement in the sensitivity of the MIF technique for these 3 kinds of human parasite.

Amal et al., (2003) carried out a study on 168 patients suspected to be infected with Giardia lamblia. They were all subjected to direct stool microscopic examination, formol-ether concentration and by Parasep (faecal parasite concentrator). The result showed 14.3% of patients were positive for giardiasis by Parasep 10.7% were positive for giardiasis by formol-ether concentration and 5.35% of cases were positive by direct stool microscopic examination. Our results showed that the use of Parasep is an effective and convenient means for detection of G.lamblia cysts in faeces with disadvantage of highly cost-benefit respecting that the microscopic examination is the gold standard of giardiasis.

Radulovic and Jokovic (1981) in their study on new possibilities of diagnosing intestinal helminthiasis by floatation of ova in a honey medium noted that 446 stools of soldiers were examined by parallel flotation in honey and glycerine. By floatation in honey solution helminth eggs were found in 168 (37.6%) and by floatation in glycerin in 96 (21.5%), which made the difference of 72 (16.1%). The most commonly were found: Trichuris trichiura eggs in honey solution in 108 (24.2%) stools and in glycerin in 86 (15.2%); Ascaris lumbricoides eggs in honey solution in 39 (8.7%) stools and, in glycerin in 10 (2.2%); while eggs of other intestinal helminthes were rarely found and if they were found their number was approximately same obtained by both methods. Aqueous honey solution has shown to be a very suitable medium for flotation of intestinal helminth eggs, especially in cases when stools contain a small number of eggs and those mainly immature eggs of Ascaris lumbricoides, which can be hardly found by flotation in glycerin.

The formalin-tween sedimentation method was compared (Methanitikorn et al, 2004) with the formalin-ether sedimentation for parasitic detection. Of total 297 faecal specimens examined, 72.1% were positive. The formalin-tween technique was effective for ascertaining helminthes, particularly Ascaris lumbricoides, Trichuris trichiura and hookworm eggs; however it has less capability for protozoa detection. This method is simple, inexpensive, less time consuming and highly sensitive when detecting the parasitic infection, particularly when focusing on helminth eggs.

Rusell, (1991) speculated that in diagnosing pinworm (Enterobius vermicularis), proper knowledge of worm’s life cycle is required. He posited that the most effective means of diagnosing the infection is sampling from the anal verge in the morning, before stool is passed and before bath. Parents can also observe worms in children by putting them down to bed without underpants and examining the anus with flashlight at 12 am or 6am, depending on the child’s sleep pattern. Worms obtained by parents should be placed in alcohol or vinegar and brought to the clinic for confirmation.