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Most autism has a genetic cause although post-encephalitis cases are reported. In a case-series (N = 20) from Tanzania, 14 met research criteria for autism. Three (M:F = 1:2) had normal development to age 22, 35, and 42 months, with onset of autism upon recovery from severe malaria, attended by prolonged high fever, convulsions, and in one case prolonged loss of consciousness. In four other cases (M:F = 3:1), the temporal relationship between onset of autism and severe infection was close, but possibly spurious since malaria is common in Tanzania and there were indications of abnormal development in the child or a family member. In seven cases, (M:F = 6:1) autism onset was unrelated to malaria. The excess of non-verbal cases (N = 10) is related to local diagnostic practice.

Determinants of elevational distribution of butterfly species richness and abundance in the tropics are poorly understood. Here we assess the combined effects, both additive and interactive, of seasonality and habitat structure on the elevational distribution of butterflies in the Uluguru Mountains, Tanzania. We sampled butterflies along a 1100 m elevational gradient that extended from 1540 to 2639 m using a time-constrained fixed-area method during the short to long rains and long to short rains transitions, and in habitat structure classified as closed or open. We used semi-parametric generalized linear mixed models to assess the relation between butterfly species richness or abundance, and seasonality, habitat structure, family and elevation. For all species combined, species richness declined with elevation in both open and closed habitats during the long to short rains transition. During the short to long rains transition, species richness displayed a mid-elevation peak across habitats. Among the three focal families (Nymphalidae, Papilionidae and Pieridae) similar patterns in the elevational distribution of species richness were observed. Species abundance declined or remained stable with elevation across seasons and habitat structure; the exception being species abundance in open habitat during the short to long rain transition and increased slightly with elevation. Abundance by family did not vary significantly by habitat structure or season. Our results indicate that seasonality and habitat structure shape species richness and abundance of butterflies along an elevational gradient in the Uluguru Mountains. These patterns are important for informing conservation actions because temperature as well as annual and seasonal variation in precipitation are predicted to increase in East Africa as a result of climate change, important determinants of seasonality, while habitat disturbance may increase due to a projected doubling in Tanzania's population over the next 27 years. [ABSTRACT FROM AUTHOR]