The lack of effectiveness of hyperbaric oxygenation as a treatment for Leishmania major in a mouse model.

We aimed to study the effectiveness of hyperbaric oxygen therapy (HOT) (100% oxygen at 2 ATA for 70 minutes each session for 20 consecutive days) on BALB/c male mice infected with Leishmania major. Fifty-one mice were assigned to six groups. Group 1 was treated with HOT from 1 day after the inoculation. In Groups 2-5, treatment began when the cutaneous lesions appeared. Group 2 received HOT only, Group 3 received topical therapy with Leshcutan only, Groups 4 and 5 received a combination of HOT and Leshcutan for 5 and 10 days respectively, and Group 6 did not receive any treatment (control group). When comparing the control group with Group 1, treatment with HOT in Group 1 did not significantly affect the time of the appearance of the lesions. In contrast, mice treated with Leshcutan demonstrated a significant difference in lesion size and spleen dimensions as compared to the rest of the mice (p<0.001). The results show that HOT treatment has no positive effect on the course of Leishmaniasis in a BALB/c mice model infected with Leishmania major. Further studies are needed with a mouse model closer to humans and with different HOT protocols.

Does co-infection with Giardia lamblia modulate the clinical characteristics of enteric infections in young children?

BACKGROUND: Giardia lamblia (G. lamblia) is a prevalent enteric pathogen causing both asymptomatic carriage and diarrheal illness among children worldwide. In this study we examined the hypothesis that G. lamblia may modulate the effect of other enteric pathogens during concurrent infection. METHODS: Bedouin (n = 238) infants were followed from birth to ages 18-23 months. Morbidity was ascertained by weekly home interviews and infant's stools were collected fortnightly. The risk for and severity of diarrheal disease were compared between episodes caused by enteric pathogens other than G. lamblia alone and G. lamblia-mixed episodes. RESULTS: In 59 of 293(20.1%) diarrhea episodes two or more pathogens were detected. In two thirds of the mixed episodes G. lamblia was involved. Neither the incidence of diarrhea nor the mean diarrheal episode duration differed between follow up months in which G. lamblia was or was not detected, when age specific or age adjusted values were compared. There were no differences in severity of episodes for single or G. lamblia-mixed infections except for rotavirus. Episodes with rotavirus alone were more severe as compared to episodes where co-infection with G. lamblia was found. CONCLUSIONS: The results of this study do not confirm the hypothesis that G. lamblia modulates the clinical effect of infection with other enteric agents. However, the findings of the change in severity of infection with rotavirus suggest that this question warrants further investigation.