Evidence-based treatments for traumatized children and adolescents.

This article reviews recent advances in empirically supported psychotherapeutic treatments for children and adolescents experiencing trauma and provides a brief summary of available interventions, as well as a context for their use. We highlight the American Academy of Child and Adolescent Psychiatry's recent practice guidelines for trauma treatment and discuss their implications for clinicians, including the benefits of involving caregivers in treatment and the rationale for using practices that are specifically trauma-focused as first-line intervention. Finally, we discuss the status of research on the real-world implementation of these therapies and the need for further research, particularly regarding clinician knowledge and use of empirically supported practices, potential stepped-care approaches to trauma treatment, and the need to reduce attrition in child trauma research and practice.

Heritability and adaptive phenotypic plasticity of adult body size in the mosquito Aedes aegypti with implications for dengue vector competence.

Adaptive phenotypic plasticity is particularly important to organisms with developmental cycles that undergo ontogenetic niche shifts that differentially subject individual life stages to heterogeneous and often stressful environmental conditions. The yellow fever and dengue fever vector mosquito, Aedes aegypti, typically breeds in small water-filled containers that expose the developing aquatic larvae to competition for resources with conspecifics and high probabilities for habitat drying. Here we investigated the heritability (h(2)) and phenotypic plasticity among A. aegypti laboratory populations and field populations from Trinidad, West Indies. Heritability for body size was moderate or completely eroded among the laboratory populations, while field populations contained high genetic variation among both males and females. Norms of reactions based on optimum vs. deficient larval conditions for artificial sibling families representing Trinidad field populations suggested significant gene × environment interactions influence body size and that there may be sex specific differences in allocation of resources. Individuals reared under optimum laboratory conditions were significantly larger and showed much less variability in body size plasticity than their field reared cohorts, suggesting that exposure to environmental stress may be common for A. aegypti larval development and would undoubtedly impact other traits, including arbovirus vector competence among adult females, in a similar fashion. Broad genetic variance in body size and other characters is likely maintained by balancing selection. Our results also suggest the need for caution in translating conclusions from experiments with laboratory colonies to natural populations. These would likely be more informative to expected phenotypes under natural conditions if conducted over a range of conditions that simulate environmental stress.

Identification of quantitative trait loci for larval morphological traits in interspecific hybrids of Ochlerotatus triseriatus and Ochlerotatus hendersoni (Diptera: Culicidae).

Ochlerotatus triseriatus is the natural vector of La Crosse virus, a common cause of pediatric encephalitis in the United States; the closely related Ochlerotatus hendersoni transmits this virus at low frequency. Adults of these mosquito species are difficult to distinguish morphologically; however, the larval stages show species-specific differences in several characters. We identified genomic regions contributing to the differences between the larvae of these species through interspecific hybridizations. Quantitative trait loci (QTL) were identified by standard interval mapping techniques and by univariate marker association analyses. We examined 159 F(2) progeny from an Oc. hendersoni female by Oc. triseriatus male interspecific cross for variation in the number of saddle and siphon hair branches, attachment of the acus, and morphology of the anal papillae. At least one putative QTL was identified for each of the phenotypes examined. QTL most commonly mapped to linkage group (LG) III, although QTL were identified on LGI and LGII for three phenotypes each. Several of these QTL, and particularly those on LGIII, also map to genome regions controlling adult female body size and ability to orally transmit La Crosse virus. Further studies are required to elucidate the relationships among these traits and the impact they may have had on the ecological specialization and speciation of these mosquitoes.

Quantitative genetics of vector competence for La Crosse virus and body size in Ochlerotatus hendersoni and Ochlerotatus triseriatus interspecific hybrids.

La Crosse virus is a leading cause of pediatric encephalitis in the United States. The mosquito Ochlerotatus triseriatus is an efficient vector for La Crosse virus, whereas the closely related O. hendersoni transmits only at very low rates. Quantitative trait loci (QTL) affecting the ability to orally transmit this virus and adult body size were identified in 164 F(2) female individuals from interspecific crosses of O. hendersoni females and O. triseriatus males using a combination of composite interval mapping (CIM), interval mapping (IM) for binary traits, and single-marker mapping. For oral transmission (OT), no genome locations exceeded the 95% experimentwise threshold for declaring a QTL using IM, but single-marker analysis identified four independent regions significantly associated with OT that we considered as tentative QTL. With two QTL, an increase in OT was associated with alleles from the refractory vector, O. hendersoni, and likely reflect epistatic interactions between genes that were uncovered by our interspecific crosses. For body size, two QTL were identified using CIM and a third tentative QTL was identified using single-marker analysis. The genome regions associated with body size also contain three QTL controlling OT, suggesting that these regions contain either single genes with pleiotropic effects or multiple linked genes independently determining each trait.

Adult size and distribution of Aedes aegypti (Diptera: Culicidae) associated with larval habitats in Iquitos, Peru.

Adult mosquito size may be related to longevity, feeding frequency, and other factors that impact vectorial capacity. Various investigations have shown that characteristics of larval mosquito habitats influence adult size. We studied breeding container characteristics in relation to size and abundance of Aedes aegypti larvae and pupae in Iquitos, Peru, and compared these with the size of resulting adult females. During 22 May to 20 July 2000, immature mosquitoes were collected from 12,722 containers in 2,931 houses, of which 424 held > or =1 Ae. aegypti. A subsample of larvae and all 16,433 pupae detected was removed for study. Resting adult mosquitoes were also collected from the same houses as the immatures. Adult mosquito size was determined by measuring the wing lengths of 672 aspirated adults and 2,316 adult females that emerged from container-derived pupae. Immatures were most commonly found in rain-filled containers, located outside of houses, and without lids. The average wing length of females derived from pupae varied considerably (1.67-3.83 mm), with slightly less variation for females captured as adults (1.80-3.23 mm). Linear regression showed that average wing length of pupae-derived females was positively associated with presence of larvae, container-filling method, diameter of container, and density of females. Size of pupae-derived females was correlated with that of females captured in the same houses as adults. The geographic distribution of pupae and adults indicated that the spatial pattern for Ae. aegypti is heterogeneous, with areas of higher and lower abundance. These findings provide insight for more focused control efforts aimed at reducing Ae. aegypti-borne pathogens.