Longitudinal survey of antibiotic stewardship practices in Wisconsin nursing homes, before and after a policy change.

The Centers for Medicare and Medicaid mandated that nursing homes implement antibiotic stewardship programs (ASPs) by November 2017. We conducted surveys of Wisconsin nursing-home stewardship practices before and after this mandate. Our comparison of these surveys shows an overall increase in ASP implementation efforts, but it also highlights areas for further improvement.

Vector Competence of Peruvian Mosquitoes for Two Orthobunyaviruses Isolated From Mosquitoes Captured in Peru.

We evaluated the potential for mosquitoes collected in the Amazon Basin, near Iquitos, Peru, to become infected with and transmit Murutucu (MURV) and Itaqui viruses (ITQV) (Order Bunyavirales, Family: Peribunyaviridae, Genus: Orthobunyavirus). Viremia levels in Syrian hamsters peaked 2 d after infection with either virus, and both viruses were highly lethal in hamsters with virtually all hamsters dying prior to 3-d postinfection. For almost all of the mosquito species tested some individuals were susceptible to infection and some developed a disseminated infection after oral exposure to either MURV or ITQV.

Complete genomic sequences of Venezuelan equine encephalitis virus subtype IIID isolates from mosquitoes.

Venezuelan equine encephalitis virus (VEEV) is an important pathogen of medical and veterinary importance in the Americas. In this report, we present the complete genome sequences of five VEEV isolates obtained from pools of Culex (Melanoconion) gnomatos (4) or Culex (Melanoconion) pedroi (1) from Iquitos, Peru. Genetic and phylogenetic analyses showed that all five isolates grouped within the VEEV complex sister to VEEV IIIC and are members of subtype IIID.

Comparison of the Potential for Different Genetic Forms in the Culex pipiens Complex in North America to Transmit Rift Valley Fever Virus.

Rift Valley fever virus (RVFV), a mosquito-borne virus, has been responsible for large outbreaks in Africa that have resulted in hundreds of thousands of human infections and major economic disruption due to loss of livestock and to trade restrictions. Culex pipiens was implicated as the principal vector of the Egyptian outbreak in 1977 that affected about 200,000 people. In the northern USA, Cx.

Rift Valley fever virus-infected mosquito ova and associated pathology: possible implications for endemic maintenance.

Background: Endemic/Enzootic maintenance mechanisms like vertical transmission (pathogen passage from infected adults to their offspring) are central in the epidemiology of zoonotic pathogens. In Kenya, Rift Valley fever virus (RVFV) may be maintained by vertical transmission in ground-pool mosquitoes such as . RVFV can cause serious morbidity and mortality in humans and livestock.

Potential for stable flies and house flies (Diptera: Muscidae) to transmit Rift Valley fever virus.

Rift Valley fever (RVF), a disease of ruminants and humans, has been responsible for large outbreaks in Africa that have resulted in hundreds of thousands of human infections and major economic disruption due to loss of livestock and to trade restrictions. As indicated by the rapid spread of West Nile viral activity across North America since its discovery in 1999 and the rapid and widespread movement of chikungunya virus from Africa throughout the Indian Ocean Islands to Asia and Europe, an introduced exotic arbovirus can be rapidly and widely established across wide geographical regions. Although RVF virus (RVFV) is normally transmitted by mosquitoes, we wanted to determine the potential for this virus to replicate in 2 of the most globally distributed and common higher flies: house flies, Musca domestica, and stable flies, Stomoxys calcitrans.

Susceptibility of Peruvian mosquitoes to eastern equine encephalitis virus.

Mosquitoes were collected in the Amazon Basin, near Iquitos, Peru, and used in experimental studies to evaluate their susceptibility to strains of eastern equine encephalitis virus (EEEV) that were isolated from mosquitoes captured within 20 km of Iquitos. When fed on hamsters or chickens with a viremia of 4105 plaque-forming units (PFU) of EEEV/ml, Culex pedroi Sirivanakarn and Belkin, Aedesfulvus (Wiedemann), Psorophora albigenu (Peryassu), and Psorophoraferox (Von Humboldt) were susceptible to infection, whereas none of the Aedes serratus (Theobald), Culex vomerifer Komp, Culex gnomatos Sallum, Huchings, and Ferreira, Culex portesi Senevet and Abonnenc, or Culex coronator Dyar and Knab became infected, even though they fed on the same viremic blood sources. When these mosquito species fed on animals with viremias of approximately 10(8) PFU/ml, Cx.

Viral nucleic acid stabilization by RNA extraction reagent.

In the collection of field materials to test for the presence of arboviruses, samples must be appropriately maintained to detect arboviral nucleic acids. In austere field conditions this is often difficult to achieve because, during routine specimen processing, storage, and shipping viral RNA degradation could result in detection failure. RNA extraction reagents, while used commonly for their intended purpose of stabilizing RNA during the extraction process, have not been assessed fully for their potential to stabilize RNA before extraction.

Experimental transmission of West Nile virus by Culex nigripalpus from Honduras.

As a result of concerns regarding the geographic spread of West Nile virus (WNV) to Central America, we evaluated the potential for Honduran Culex nigripalpus Theobald to transmit this virus. We tested individual mosquitoes captured in Olancho Province, Honduras, in September 2003. Mosquitoes were allowed to feed on 2- to 4- day-old chickens previously inoculated with a New York strain (Crow 397-99) of WNV.

Laboratory transmission of Japanese encephalitis, West Nile, and Getah viruses by mosquitoes (Diptera: Culicidae) collected near Camp Greaves, Gyeonggi Province, Republic of Korea 2003.

We conducted experimental studies to evaluate mosquitoes captured in Paju County, Gyeonggi Province, Republic of Korea, for their ability to transmit West Nile virus (family Flaviviridae, genus Flavivirus, WNV), Japanese encephalitis virus (family Flaviviridae, genus Flavivirus, JEV), and Getah virus (family Togaviridae, genus Alphavirus, GETV) under laboratory conditions. Both Culex pipiens pallens Coquillett and Culex tritaeniorhynchus Giles were highly susceptible to infection with WNV, with infection rates > 65% when allowed to feed on chickens with viremias of approximately 10(7) plaque-forming units (PFU) of virus/ml blood. In contrast, Cx.

Vector competence of Peruvian mosquitoes (Diptera: Culicidae) for a subtype IIIC virus in the Venezuelan equine encephalomyelitis complex isolated from mosquitoes captured in Peru.

We evaluated mosquitoes collected in the Amazon Basin, near Iquitos, Peru, for their susceptibility to a subtype IIIC strain of the Venezuelan equine encephalomyelitis complex. This virus had been previously isolated from a pool of mixed Culex vomerifer and Cx. gnomatos captured near Iquitos, Peru, in 1997.

Laboratory transmission of Japanese encephalitis and West Nile viruses by molestus form of Culex pipiens (Diptera: Culicidae) collected in Uzbekistan in 2004.

We evaluated the molestus form of Culex pipiens pipiens (L.) (hereafter referred to as "molestus") captured near Tashkent, Uzbekistan, for their ability to transmit Japanese encephalitis (family Flaviviridae, genus Flavivirus, JEV) and West Nile (family Flaviviridae, genus Flavivirus, WNV) viruses under laboratory conditions. These molestus were highly competent laboratory vectors of WNV, with infection and dissemination rates of 96 and 81%, respectively.

Isolation of viruses from mosquitoes (Diptera: Culicidae) collected in the Amazon Basin region of Peru.

As part of a comprehensive study on the ecology of arthropod-borne viruses in the Amazon Basin region of Peru, we assayed 539,694 mosquitoes captured in Loreto Department, Peru, for arboviruses. Mosquitoes were captured either by dry ice-baited miniature light traps or with aspirators while mosquitoes were landing on human collectors, identified to species, and later tested on Vero cells for virus. In total, 164 virus isolations were made and included members of the Alphavirus (eastern equine encephalomyelitis, Trocara, Una, Venezuelan equine encephalomyelitis, and western equine encephalomyelitis viruses), Flavivirus (Ilheus and St.

Pathogenesis of Rift Valley fever virus in mosquitoes--tracheal conduits & the basal lamina as an extra-cellular barrier.

Knowledge of the fate of an arbovirus in a mosquito is fundamental to understanding the mosquito's competence to transmit the virus. When a competent mosquito ingests viremic vertebrate blood, virus infects midgut epithelial cells and replicates, then disseminates to other tissues, including salivary glands and/or ovaries. The virus is then transmitted to the next vertebrate host horizontally via bite and/or vertically to the mosquito's offspring.

An update on the potential of north American mosquitoes (Diptera: Culicidae) to transmit West Nile Virus.

ABSTRACT Since first discovered in the New York City area in 1999, West Nile virus (WNV) has become established over much of the continental United States and has been responsible for >10,000 cases of severe disease and 400 human fatalities, as well as thousands of fatal infections in horses. To develop appropriate surveillance and control strategies, the identification of which mosquito species are competent vectors and how various factors influence their ability to transmit this virus must be determined. Therefore, we evaluated numerous mosquito species for their ability to transmit WNV under laboratory conditions.

Laboratory transmission of Rift Valley fever virus by Phlebotomus duboscqi, Phlebotomus papatasi, Phlebotomus sergenti, and Sergentomyia schwetzi (Diptera: Psychodidae).

We examined the potential for Phlebotomus papatasi (Scopoli), Phlebotomus duboscqi (Neveu-Lemarie), Phlebotomus sergenti (Parrot), and Sergentomyia schwetzi (Adler, Theodor, & Parrot) to transmit Rift Valley fever (RVF) virus. After feeding on hamsters that had been inoculated with RVF virus, P. papatasi, P.

Endemic Venezuelan equine encephalitis in northern Peru.

Since Venezuelan equine encephalitis virus (VEEV) was isolated in Peru in 1942, >70 isolates have been obtained from mosquitoes, humans, and sylvatic mammals primarily in the Amazon region. To investigate genetic relationships among the Peru VEEV isolates and between the Peru isolates and other VEEV strains, a fragment of the PE2 gene was amplified and analyzed by single-stranded conformation polymorphism. Representatives of seven genotypes underwent sequencing and phylogenetic analysis.

Virus inactivation by nucleic acid extraction reagents.

Many assume that common methods to extract viral nucleic acids are able to render a sample non-infectious. It may be that inactivation of infectious virus is incomplete during viral nucleic acid extraction methods. Accordingly, two common viral nucleic acid extraction techniques were evaluated for the ability to inactivate high viral titer specimens.

Isolation of Japanese encephalitis and Getah viruses from mosquitoes (Diptera: Culicidae) collected near Camp Greaves, Gyonggi Province, Republic of Korea, 2000.

As part of an evaluation of the ecology of arthropod-borne diseases in the Republic of Korea (ROK), we examined 8,765 mosquitoes captured in Paju County, Gyonggi Province, ROK, for the presence of viruses. Mosquitoes were captured in propane lantern/human-baited Shannon traps, Mosquito Magnet traps, or American Biophysics Corporation (East Greenwich, RI) miniature light traps with or without supplemental octenol bait and/or dry ice. Mosquitoes were identified to species, placed in pools of up to 40 mosquitoes each, and tested on Vero cells for the presence of virus.

Vector competence of Culex tarsalis from Orange County, California, for West Nile virus.

To evaluate the vector competence of Culex tarsalis Coquillett for West Nile virus (WN), females reared from larvae collected in Huntington Beach, Orange County, CA, were fed on 2-3-day-old chickens previously inoculated with a New York strain (Crow 397-99) of WN. The Cx. tarsalis mosquitoes were efficient laboratory vectors of WN, with estimated transmission rates of 81% and 91% for mosquitoes that ingested 10(6.

Experimental vertical transmission of West Nile virus by Culex pipiens (Diptera: Culicidae).

Despite the detection of West Nile (WN) virus in overwintering Culex pipiens L. in New York in February 2000, the mechanism by which this virus persists throughout the winter to initiate infections in vertebrate hosts and vectors the following spring remains unknown. After a blood meal, parous mosquitoes generally do not survive until spring and gonotrophic dissociation occurs in only a small percentage of the population.

Experimental transmission of eastern equine encephalitis virus by Ochlerotatus j. japonicus (Diptera: Culicidae).

We evaluated the potential for Ochlerotatus j. japonicus (Theobald), a newly recognized invasive mosquito species in the United States, to transmit eastern equine encephalitis (EEE) virus. Aedes albopictus (Skuse) and Culex pipiens (L.

Isolation of west nile and sindbis viruses from mosquitoes collected in the Nile Valley of Egypt during an outbreak of Rift Valley fever.

As part of an evaluation of potential vectors of arboviruses during a Rift Valley fever (RVF) outbreak in the Nile Valley of Egypt in August 1993, we collected mosquitoes in villages with known RVF viral activity. Mosquitoes were sorted to species, pooled, and processed for virus isolation both by intracerebral inoculation into suckling mice and by inoculation into cell culture. A total of 33 virus isolates was made from 36,024 mosquitoes.