Tuberculosis/toxoplasmosis co-infection in Egyptian patients: A reciprocal impact.

OBJECTIVE: To assess the concurrent toxoplasmosis infection in Egyptian TB patients and the impact of each infection on the other in terms of increased severity of TB or reactivation of latent Toxoplasma infection. METHODS: Three hundred suspected pulmonary TB cases were initially screened for TB using direct Ziehl Neelsen staining and Lowenstein Jensen culture of their sputa. Rifampicin resistance was detected by Xpert MTB/RIF assay. Control group of 30 age and sex-matched healthy individuals negative for TB was included for comparison. All subjects were further assessed for serum levels of anti-Toxoplasma IgG antibodies and malondialdehyde (MDA). RESULTS: Forty three confirmed TB-infected patients including 10 (23.3%) rifampicin-resistant patients were detected. Associated toxoplasmosis was found to be significantly higher among TB patients (OR = 2.709; 95% CI: 1.034-7.099; P<0.05) and among rifampicin sensitive than rifampicin resistant TB patients (OR=0.213; 95% CI: 0.048-0.951; P < 0.05). Serum levels of anti-Toxoplasma IgG antibodies and MDA were significantly higher among TB patients than the control group. Furthermore, serum level of MDA was significantly higher among TB/Toxoplasma co-infected patients as compared to toxoplasmosis free-TB patients. Strong positive correlation was detected between serum levels of anti-Toxoplasma IgG and MDA in TB patients (r = 0.75, P = 0.001). CONCLUSIONS: Among pulmonary TB Egyptian patients, there is a considerable prevalence of toxoplasmosis. Severity of pulmonary tuberculosis could be increased by Toxoplasma co-infection.

Anti-Toxoplasma antibodies in Egyptian rheumatoid arthritis patients.

OBJECTIVE: To assess seroprevalence of anti-Toxoplasma gondii antibodies; both IgG and IgM in Egyptian rheumatoid arthritis (RA) patients versus a non-RA group and to compare anti-Toxoplasma antibodies seroprevalence among RA patients receiving traditional treatment and RA patients treated with biologic drug. METHODS: 60 RA patients and 60 healthy controls were enrolled in the study. Patients were categorized into two groups: one group included 30 patients receiving disease modifying anti-rheumatic drugs (DMARDs), while the other group included 30 patients receiving biologic agent, infliximab, a TNF-α antagonist. Serum samples of all investigated persons were examined for anti-Toxoplasma antibodies. RA activity markers including rheumatoid factor, anti-cyclic citrullinated protein antibodies, C reactive protein, ESR in addition to disease activity score 28 (DAS28) of RA patients were also evaluated to explore their association with Toxoplasma seropositivity. RESULTS: Anti-Toxoplasma IgG antibodies were detected among 46/60 RA patients (76.7%) versus 29/60 controls (48.3%), (p = 0.001). Anti-Toxoplasma IgG titre was higher among RA group [median, (range) = 232.940 (8.949-653.242) IU/ml] than among controls [median, (range) = 68.820 (2.450-318.945) IU/ml], (p < 0.001). No difference was detected among RA patients either on traditional or biologic treatment regarding anti-Toxoplasma IgG antibodies. No positive anti-Toxoplasma IgM was detected. A positive correlation was detected between anti-Toxoplasma IgG titre and disease activity markers. CONCLUSION: Higher seroprevalence of anti-Toxoplasma IgG antibodies among RA patients compared to controls reflects an association between latent Toxoplasma infection and RA. Our findings support previous studies and necessitate future large-scale studies to elucidate the exact role of Toxoplasma whether a trigger of autoimmunity in RA or an effect of immunosuppression.

In vitro activity of nitazoxanide against some metronidazole-resistant and susceptible Trichomonas vaginalis isolates.

Trichomonas vaginalis cases refractory to metronidazole (MTZ) treatment had been reported. This study aimed to the assessment of in vitro metronidazole resistance among Trichomonas positive cases with treatment failure by determination of metronidazole minimal lethal concentration (MLC), and to the evaluation of the in vitro efficacy of nitazoxanide (NTZ) as compared to metronidazole (MTZ) in both resistant and susceptible isolates. Drug testing was carried out by an aerobic tube assay where suspension of Trichomonas trophozoites was exposed for 24 and 48 h to serial dilution of metronidazole and nitazoxanide. In refractory isolates n = 30, median MLC conc. for MTZ was 100 µg/ml versus 50 µg/ml for NTZ (P < .0001). After 48 h median MLC conc. for MTZ was 25 µg/ml versus 12 µg/ml for NTZ (P < .0001). NTZ against resistant isolates was twice as active as MTZ at 24 h and increased to 2.5 times at 48 h while in susceptible isolates, NTZ was twice as active as MTZ at both 24 h and 48 h. MTZ was about 8 times more active in susceptible than in resistant isolates. So, high doses of metronidazole in resistant cases will likely increase side effects. The study proved the activity of NTZ against trichomoniasis especially in cases with MTZ resistance.

Giardia diagnostic methods in human fecal samples: a comparative study.

Several methods were tried for Giardia detection in stool. This study aimed to compare between the results of ordinary microscopy, direct immunofluorescence assay (DIF), and flow cytometry (FC) for the detection of Giardia cyst in human stool samples. The study included 84 children recruited from outpatient clinics of Mansoura University Children Hospital. Fecal samples were processed and examined for Giardia cysts using conventional microscopy, DIF, and FC. Among 84 fecal samples, 40 (47.6%) were diagnosed as Giardia-positive by saline wet mount, while DIF and FC detected 52 (61.9%), and 38 (45%) Giardia-positive cases, respectively. When compared with DIF as a gold standard method, ordinary microscopy had 76.9% sensitivity and 100% specificity while the FC had a sensitivity of 73.1% and 100% specificity, with statistically significant differences between DIF and the other two methods (P < 0.05). DIF was able to detect as few as 500 cysts/g of concentrated stool, yielding a threshold higher than ordinary microscopy (1,800 cyst/g) even after concentration. It is concluded that direct microscopic examination is reliable in Giardia diagnosis as a first choice test. DIF is an excellent technique in clinically suspected cases after negative microscopy. FC was found to be less sensitive to obtain accurate organisms' count but it could be an effective alternative method for the detection of Giardia cysts, especially for large-scale epidemiological studies or extensive surveillance programs as it has the beneficial attribute of speed and do not depend on an experienced microscope viewer. However, DIF remains the gold standard while FC still requires significant technical improvements before it can compete with DIF for Giardia diagnosis.