Comparison of sampling anopheline mosquitoes by light-trap and human-bait collections indoors at Bagamoyo, Tanzania.

The mosquito sampling efficiency of CDC miniature light-traps, relative to night-biting collections, was evaluated indoors at two sites in coastal Tanzania. We found that the total number of anophelines captured overnight by light-traps (hung beside a bednet in use) was 1.23 times the number of anophelines captured by human-bait collections. This relationship was not affected significantly by changes in the mosquito density, order of trapping method, date of sampling, or number of household occupants. Malaria sporozoite rates were twice as high among mosquitoes captured by light-trap as compared to those captured by night-biting collection. This was attributed to the tendency of light-traps to capture a larger proportion of gravid mosquitoes, which also had high sporozoite rates. The differences in sporozoites rates according to abdominal stage indicates that unfed mosquitoes captured by light-traps may define more precisely the human-biting activity and sporozoite rates as seen by night-biting collections. Our study shows that light-traps, when used in combination with night-biting collections, can be an effective and sensitive means for measuring human-biting activity and the sporozoite rate.

Congenital malformations and psychosocial development in children conceived by in vitro fertilization.

To determine whether in vitro fertilization (IVF) as a method of conception is associated with an increased risk for congenital malformations or developmental dysfunction, we performed a general physical examination for malformations, neurologic examination, developmental examination (Bayley Scales), echocardiography, electrocardiography, abdominal ultrasound study, and, when possible, cranial ultrasound examination on a cohort of 83 IVF children and 93 matched non-IVF children. Major malformations were found in two IVF and one non-IVF subject; the rates were not significantly different. The mean Mental Development Index scores for IVF subjects and the comparison group were 115 +/- 13 and 111 +/- 13, respectively (p = 0.12). The mean Psychomotor Development Index scores were 114 +/- 14 and 108 +/- 15 (p = 0.04). Based on these small numbers but extensive evaluation, we found no association between conception by IVF and an increased risk for congenital malformations. Likewise, children conceived by IVF showed no evidence of developmental delay. Their high average achievement on the Bayley tests probably resulted from the exceptional motivation of their parents ("wantedness") and their generally high socioeconomic status.