First report of the lethal activity and synergism between deltamethrin, amitraz and piperonyl butoxide against susceptible and pyrethroid-resistant nymphs of Triatoma infestans.

In South America, Triatoma infestans (Hemiptera: Reduviidae) is the main vector of the parasite Trypanosoma cruzi, etiological agent of Chagas disease. The main strategy for vector control is to spray domestic structures with pyrethroids. Reports of populations of T. infestans with varying degrees of resistance to pyrethroids have made the search for alternative molecules for vector control necessary. In the first stage of this work we investigated the lethal activity of amitraz and deltamethrin against susceptible and pyrethroid-resistant nymphs of Triatoma infestans. Lethal dose at 50% (LD50) of susceptible nymphs were compared with those recorded in pyrethroid-resistant nymphs and the resistance ratio (RR50) was obtained. The RR50 of deltamethrin was approximately 300. In the case of amitraz, we observed similar triatomicidal activity in the two nymph populations (RR50: 0.7). In a second stage of the work, we determined the synergistic effect of amitraz and piperonyl butoxide (PBO) on the lethal activity of deltamethrin. The strong synergistic effect of PBO on the lethal activity of deltamethrin in resistant nymphs produced a decrease in RR50 to almost one third of the RR50 reported in absence of the synergist. Amitraz plus PBO lethal activity was similarly increased in pyrethroid susceptible and resistant nymphs. Our data indicate that deltamethrin synergism by amitraz was higher against resistant than to susceptible nymphs (Synergist ratio (SR50) of: 7.2- and 4.1-fold, respectively). In pyrethroid resistant nymphs, the highest level of synergism was obtained combining deltamethrin with amitraz and PBO (SR50: 26.7-fold). These results indicate that this combination could be considered an effective alternative for the control of T. infestans.

A survey of female genital schistosomiasis of the lower reproductive tract in the volta basin of Ghana.

OBJECTIVE: To determine the prevalence of female genital schistosomiasis in riparian communities in the Volta basin of Ghana, DESIGN: The study was a cross-sectional study conducted among women 15-49 years in the Volta Basin. Urinary schistosomiasis prevalence was determined using microscopy. A structured questionnaire was also administered to collect information on the demography, obstetric history and reproductive health experiences. Cervical punch biopsy was collected from women who consented to be screened for FGS. Descriptive statistics was used to determine frequency of occurrence, chi squared and logistic regression to identify associated variables RESULTS: Urinary schistosomiasis prevalence among the women was 24.8% while 10.6% of them diagnosed with FGS. More FGS diagnosed women (57.7%, p value =0.04%) were observed to report copious discharge, vaginal itch (80.8%, p=0.042) and lower abdominal pain (66.7%, p= 0.041) compared to FGS negative women. The predominant abnormal observation of the lower genital tract made was erythematous cervix (18.8%). CONCLUSION: The study confirms the reproductive health symptoms associated with FGS and recommends awareness creation on FGS among women in endemic communities to facilitate early treatment.

Treatment planning software for afterloading brachytherapy.

The subject of this short communication is to present the main features of an interactive treatment planning software package for brachytherapy. The program was initially developed in the Institute of Oncology in Warsaw and based on a minicomputer configuration by the Siemens treatment planning system. Since it was first introduced into clinical practice it has been constantly developed to meet the repractice it has been constantly developed to meet the requirements of a variety of brachytherapy techniques.