Detection and genetic characterization of diverse Bartonella genotypes in the small mammals of Singapore.

Bartonella species are arthropod-borne bacterial pathogens that infect numerous mammalian species. Small mammals play an important role as natural reservoirs of many Bartonella species, maintaining the greatest diversity of Bartonella described to date. Although Bartonella research has been conducted in Southeast Asia, no studies have been undertaken on small mammals in Singapore. Here, we report the detection and description of Bartonella in small mammals in Singapore during the period of November 2011 to May 2014. BartonellaDNA was detected in 20.8% (22/106) of small mammal spleens with a PCR amplifying the beta subunit of bacterial RNA polymerase (rpoB) gene. Commensal species Rattus norvegicus and Rattus tanezumi had the highest prevalence, 75% (3/4) and 34,5% (10/29), followed by Suncus murinus 30% (6/20), Tupaia glis 16,7% (1/6) and Mus castaneus 13.3% (2/15). Phylogenetic analysis of 18 rpoB gene sequences revealed five Bartonella genotypes circulating in the small mammals of Singapore. Bayesian tip-significance testing demonstrated strong structuring in the geographical signal, indicating that distribution of Bartonella species is correlated to the distribution of their hosts. Major deforestation and fragmentation in Singapore favour synanthropic species that traverse habitats and increase the possibility of spillover to incidental hosts.

High diversity of medically important gastrointestinal rodent-borne helminths in Singapore.

Small mammals are important reservoirs of zoonotic diseases and are definitive hosts for medically important parasitic helminths. Several rodent and shrew species are peridomestic, bringing them into close contact with both humans and the intermediate hosts that maintain the transmission cycle. Here, we screened DNA extracted from large intestine tissue homogenate from 108 individuals comprised of 10 species. We detected two species known to infect humans, Dicrocoelium dendriticum and Moniliformis moniliformis. We also report the first detection of a second Angiostrongylus species in Singapore. This study demonstrates the diversity of helminths that are parasitizing the small mammals in Singapore.

Place of residence by age, ethnicity, and level of retardation of the mentally retarded/developmentally disabled population of California.

California's data on their mentally retarded/developmentally disabled population, the largest set in the United States, were accessed to determine residency of clients by age, ethnicity, and level of retardation. Data on the desired variables were available for over 59,000 of the 64,000 clients in the records. Despite claims of excess institutional population and the availability of residential alternatives, 52.5% of all persons resided in their natural homes; small family care units held 14.2% of the population and institutions, 12.8%, these being the second and third among the eight types of residences identified by the state. The proportion of the population in the natural home decreased with age and level of retardation, dropping precipitously among profoundly and severely impaired persons. Anglo-white families kept fewer (44%) at home than did blacks, Latinos, and other ethnic groups combined.

Trends in maladaptive behavior of mentally retarded persons placed in community and institutional settings.

Changes in maladaptive behavior of retarded individuals referred and placed in institutional vs. community settings were examined. The results demonstrated that no significant time trend was present for either the institutional or community groups, regardless of clients' age and level of retardation. Placement, level of retardation, and age, however, were related to overall prevalence of maladaptive behavior among the individuals.