Giardia lamblia and chronic gastritis.

One hundred and two patients suffering from giardiasis and/or chronic gastritis were subjected for upper gastrointestinal endoscopy. Purified immune rabbit's serum against Giardia lamblia was used in ELISA and immunoperoxidase (IIP) techniques for detection of Giardia antigen in the stomach. Results showed that out of 70 cases with intestinal giardiasis, 8 (11.4%) by ELISA and 6 (8.6%) by IIP showed gastric giardiasis. Higher percentage of gastric giardiasis (14%) was encountered in cases with both giardiasis and chronic gastritis (50) than in cases with giardiasis alone (5%) but with statistically insignificant difference (P > 0.05). None of the cases with chronic gastritis alone (without giardiasis) was positive for gastric giardiasis. Dyspepsia was the main presenting symptom in cases with gastric giardiasis (P < 0.05) with significant (P < 0.05) association. Helicobacter pylori was encountered in 6 out of 8 cases (75%) with gastric giardiasis (P < 0.05) with significant (P < 0.05) association. Duodenogastric reflux was detected in 4 out of 8 cases (50%). Histopathological changes in antral mucosa were detected in all cases of gastric giardiasis. This study indicates that under abnormal circumstances most probably with decreased gastric acidity, gastric giardiasis can occur in concomitance with intestinal giardiasis. So, one has to search for Giardia in gastric biopsies, particularly those showing chronic atrophic gastritis and H. pylori. Also, one has to be aware of gastric giardiasis as a possible cause of upper gastrointestinal symptoms.

Isolation and concentration of microfilariae from peripheral blood of Wuchereria bancrofti infected patients by density gradient centrifugation.

A Ficoll-Hypaque gradient centrifugation technique was used for isolation and concentration of microfilariae from peripheral blood of 30 subjects with clinically and parasitologically diagnosed Wuchereria bancrofti infections. 86% of the microfilariae were found in the Ficoll-Hypaque layer. None were detected in the plasma, leucocyte layer or lower erythrocyte layer. 14% of microfilariae were identified on the top part of the erythrocyte layer. A 35 fold concentration and 88% quantitative recovery of parasites was achieved by conventional centrifugation of microfilariae-rich Ficoll-Hypaque layer. Following the centrifugation procedures, living motile microfilariae were separated. These results indicate that Ficoll-Hypaque centrifugation technique could be an effective method for the detection of low levels of microfilaraemia, and for obtaining relatively pure suspensions of living microfilariae for metabolic studies, production of antigen-rich excretory-secretory products and antigen analysis.

Antifilarial IgM versus IgG antibody determination in the diagnosis of Wuchereria bancrofti infection in Egyptians.

Circulating antifilarial IgM and IgG antibodies were assessed by indirect ELISA in 184 serum specimens from 80 patients with clinically and parasitologically diagnosed filarial infections (20 with acute filariasis 40 with chronic filariasis & 20 asymptomatic microfilaraemic subjects), 64 individuals with other parasitic infections, 20 parasitologically-free subjects from filariasis endemic areas and 20 normal healthy controls. A soluble surface membrane extract from Dirofilaria immitis worms was used as the antigen. Using a single serum dilution of 1:128 and optical densities (OD) at 492 nm, the respective cut off values for IgM and IgG were found to be 0.24 and 0.22. All healthy non-endemic controls were seronegative by IgM and IgG ELISAs. The highest antifilarial IgM OD492 values were obtained in 20 patients with acute filariasis (95% sensitivity), while the highest antifilarial IgG OD492 values were observed n 40 patients with chronic filariaisis (97.5% sensitivity). Asymptomatic microfilaraemic subjects gave IgM and IgG OD492 values which were significantly lower than those of other forms of clinical disease and endemic control subjects. The antifilarial IgM and IgG respective sensitivities in asymptomatic subjects were 75% and 70%. Endemic controls had positive antifilarial IgM (65%) and IgG (75%) levels. Of 64 subjects with other parasites only one with Ancylostoma duodenale had positive IgM level (98.4% specificity); while 9 patients with nematodal infections mainly had false positive antifilarial IgG antibody levels (85.9% specificity). These results suggest that measuring circulating antifilarial IgM antibody level may have some diagnostic advantage over measuring IgG antibody level for the detection of active filarial infection and consequently better management of the disease.