Biomedical subjects

James L Alexander

Publications and source records attributed to James L Alexander.

3 recordsLinked to original sources

PubMed2006

Human west nile virus neuroinvasive disease in Texas, 2003 epidemic: regional differences.

PURPOSE: Arboviral diseases, such as West Nile virus (WNV) epizootics, tend to be geographically unique because of the biomes that support the vector(s) and reservoir host(s). Understanding such details aids in preventive efforts. We studied the 2003 epidemic of human West Nile neuroinvasive disease (WNND) in Texas because it initially appeared that incidence was not uniform across regions of the state. METHODS: The epidemic was described by age, sex, and region of residence. These variables were used to compare age-specific incidence, standardized cumulative incidence, and age-adjusted relative risk (RR). We verified case data and used routine software, with population estimates from the US Census Bureau. RESULTS: Regardless of sex, risk increased with age. Males had the greater risk (RR, 1.69); however, males aged 5 to 17 years had the greatest RR. Of the five regions compared, two posed more (RRs, 7.98 and 2.14) and one posed less (RR, 0.40) risk than the remainder of the state. Proportions of Culex vector species differed significantly between regions. CONCLUSIONS: During 2003, the risk for WNND varied considerably across Texas. This suggests that various risks for WNV infection deserve additional research for preventive interventions to be regionally appropriate and effective.

Adolescent↗

PubMed2006

Screwworms.

New World and Old World screwworms pose threats to the livestock industry in the United States and other countries. Diligence on the part of veterinarians, physicians, and their respective staffs is essential to protect the livestock industry.

Animals↗

PubMed2006

Possible vector dissemination by swift foxes following a plague epizootic in black-tailed prairie dogs in northwestern Texas.

To determine whether swift foxes (Vulpes velox) could facilitate transmission of Yersinia pestis to uninfected black-tailed prairie dog (Cynomys ludovicianus) colonies by acquiring infected fleas, ectoparasite and serologic samples were collected from swift foxes living adjacent to prairie dog towns during a 2004 plague epizootic in northwestern Texas, USA. A previous study (1999-2001) indicated that these swift foxes were infested almost exclusively with the flea Pulex irritans. Black-tailed prairie dogs examined from the study area harbored only Pulex simulans and Oropsylla hirsuta. Although P. irritans was most common, P. simulans and O. hirsuta were collected from six swift foxes and a single coyote (Canis latrans) following the plague epizootic. Thus, both of these canids could act as transport hosts (at least temporarily) of prairie dog fleas following the loss of their normal hosts during a plague die-off. All six adult swift foxes tested positive for antibodies to Y. pestis. All 107 fleas from swift foxes tested negative for Y. pestis by mouse inoculation. Although swift foxes could potentially carry Y. pestis to un-infected prairie dog colonies, we believe they play only a minor role in plague epidemiology, considering that they harbored just a few uninfected prairie dog fleas (P. simulans and O. hirsuta).

Animals↗