Detection of acquired parasites in laboratory personnel at risk in Theodor Bilharz Research Institute

To evaluate the prevalence of intestinal parasitic infections and to investigate the possible associations of clinical status and laboratory findings with the different parasites found in stool samples in personnel at risk in TBRI. Microscopic examination of stool specimens is the cornerstone of detection of intestinal parasites in parasitology laboratories. Fresh, nonpreserved stool specimens are generally used for examination. Because intestinal parasites are shed intermittently, patients are asked to deliver multiple stool samples for examination. Three stool samples were collected in three consecutive days and three alternative days and were examined by direct smear, Merthiolate iodine formaldehyde concentration method [MIFC] and staining with Gimesa and Ziehl-Neelsen. The stool culture for bacteria was identified following standard procedures. Three sequential stool specimens are necessary for reliable detection of intestinal parasites in routine laboratory examinations. In a total of 208 cases [medical personnel, kitchen workers, animal house, Schistosome Biological Supply Centre and different laboratories] were examined, 47% were found infected with at least one parasite. The rates were as follows: Giardia lamblia 24%, E. histolytica 22.0%, E. coli 12%, E. vermicularis 10%, H.nana 7%, Dientamaeba fragils 7.0%, S.mansoni [6%], Fasciola spp [3%], and Ancylostoma duodenale [2%]. Of 5 patients who complained of diarrhoea, no intestinal parasites were detected from the samples of stool culture. Stool cultures revealed the isolation of Shigella species from one person. No other enteropathogenic bacteria were isolated from the stools. The data supports the value of standard fecal examinations. Periodic screening of medical personnel is recommended. Protection from passing intestinal parasites between workers and patients is necessary and the hand washing remains the most important contributes factor related to reduction of the frequency of acquired parasites in the lab

Potential relation ibetween the appearance of biomphalaria alexandrina- biomphalaria glabrata hybrid in the irrigation system and the evolution of resistance to praziquntel lyeatment in Egypt

In the last decade, partial resistance to Praziquantel [PZQ] in treatment of schistosomiasis appeared in some villages in Egypt. This happened following the invasion of the irrigation system by hybrid snails of the indigenous, vector snail Biomphalaria alexandrina and the introduced Biomphalaria glabrata. The objective of this study was to investigate if the distribution of the hybrid snails in the irrigation system represents a factor, between others, which is related to the appearance of [PZQ] resistance. Therefore, three groups of mice were infected with Schistosoma mansoni cercariae obtained from infected B. alexandrina, B.glabrata and hybrid snails. Six weeks later, the animals were treated with.the usual curative dose of PZQ [500mg/kg body weight for two consecutive days] and sacrificed two weeks post-treatment. The results showed that worms reduction in the group infected with cercariae from hybrid snails was significantly less than that in the other two groups 86.1% versus 95.1% and 92.8%, respectively. The number of dead ova in the same group was also less, being 81.5% versus 97.5%, and 95.1% respectively. The numbers of ova/g liver was 56.6%, in the same group while 64.2 and 70.9 in the other two groups. The reduction in numbers of ova/g intestine was 81.9% in this group versus 86.1% and 88.4% in the other two groups.The present results give indication that the appearance of PZQ resistance against schistosomiasis in Egypt may return at least partially to the wide distribution of the hybrid Biomphalaria snails in this country

Fascioliasis and bacterobilia in experimentally and naturally infected animals

Fascioliasis is a well known veterinary problem in sheep raising countries and is to date an important human disease. In Africa, the highest prevalence was recorded in Egypt especially in communities living in the Nile Delta. This study investigated the relationship between fascioliasis and presence of the pathogenic bacteria, and its effect on the liver and gall bladder. Six sheep were orally infected with 150 Fasciola metacercariae. Four months later, the sheep were slaughtered and number of worms, number of ova/gm feces and number of ova/mi bile solutions were estimated. Blood and bile samples from the infected sheep and 4 control non-infected sheep were collected for liver enzymes estimation and bile culture for microbiological pathogens. Meanwhile, 6 control non-infected and 14 naturally infected samples [blood and bile] from sheep and cattle were collected from the slaughter house at El-Warrak, Imbaba. Worm burden, number of ova/mi bile, liver enzymes and bile culture were estimated in the naturally infected and control non-infected cattle and sheep. Changes in liver and gall bladder tissues of all animals were examined by transmission electron microscope. In experimentally infected sheep, numbers of worm burden, ova/gm stool and ova/nil bile were 48+4.3, 473+89 and 4439+632 respectively and their bacteriological bile cultures revealed Eseherichia Coli only in 4 sheep. In the naturally infected sheep and cattle, worm burden was 107+6.2 and number of ova/mI bile was 9 176+870 and the bacteriological bile culture revealed E. co/i [50%], Klebsiella pneumonia [3 0%], Pseudomonas [8%], Proteus [5%], and 7% of bile cultures were with no growth. There was a significant increase in serum level of GPT, GOT and GGT and ALP in infected sheep and cattle when compared with uninfected control. Transmission electron microscopic examination revealed significant damage indicated by the appearance of collagen bundles, swollen mitochondria and fragmented condensed nuclear chromatin, especially on the irregular nuclear membrane when compared with uninfected control. This study is of value in endemic areas, where possibility of bacterial co-infection with Fasciola is a common occurrence

Evaluation of pyrimethamine and mefloquine antimalarial drugs for the treatment of albino mice co-infected with toxoplasma - gondii and Schistosoma mansoni

The mainstay of this work is to elucidate the prophylactic and curative effects of using two different antimalarial drugs [Pyrimethamine+ Mefloquine] in experimental Toxoplasma gondii infection on top of chronic schistosomiasis mansoni. A group of forty Swiss albino mice chronically infected [each with 80 S. mansoni cercariae and kept for seven weeks], was used in the experiment. This group was further subdivided into three subgroups. Subgroup I: control group which is further subdivided into two smaller subgroups. Subgroup I [A]: control infected untreated animals given S. mansoni cercariae by body immersion and kept for seven weeks [the time needed for the infection to become chronic]. Subgroup I [B]: included control doubly infected untreated animals. S. mansoni infected mice were given 100 tachyzoites of T. gondii via an intraperitoneal cannula seven weeks post schistosoma mansoni infection, then sacrificed four days later. Subgroup II: prophylactic group, included chronic S. mansoni infected mice [for 7 weeks], given the oral drug combination [Pyrimethamine 25 mg/Kg body weight + Mefloquine 100 mg/ Kg body weight] single daily dose for 14 successive days before Toxoplasma infection. Subgroup III: chronic S. mansoni infected mice for 7 weeks, treated 24 hours post Toxoplasma infection with the same oral drug combination [Pyrimethamine 25 mg/Kg body weight + Mefloquine 100 mg/Kg body weight] single daily dose for 14 successive days. Sacrifice was performed two weeks post Toxoplasma infection. The efficacy of both drugs was assessed by worm and tissue egg load and oogram pattern for schistosomiasis, and animal survival, and collecting peritoneal exudates from succumbing mice, then calculation at random for the presence of Toxoplasma gondii parasites. It was found that doubly infected [chronic seven weeks old Schistosoma mansoni followed by Toxoplasma gondii infections] untreated mice died between 6 and 8 days post Toxoplasma infection, while treatment markedly prolonged the survival time of experimental animals. Again, Daraprim and Mefloquine failed to significantly reduce the total number of worms when compared to the infected untreated control group. Moreover, there was complete absence of tachyzoites in the post infection treated group, in comparison with the control infected untreated animals. These data were less conspicuous in the group treated 14 days prior to Toxoplasma infection. This study may be of value in endemic areas, where double parasitic infestation with schistosomiasis and toxoplasmosis is a common occurrence