For several years, there have been continuous reports of black flies in Mississippi with evidence of transmission of Leucocytozoon spp. This study was conducted to determine the presence and ...diversity of Leucocytozoon spp. in black flies captured throughout Mississippi. Thirty-three collections, consisting of 346 specimens, were made during the 2-yr period (2015–2016) at 10 locations around the state. In addition to these systematic biweekly collections, 46 specimens were taken in 10 collections at four additional sites from 2009 to 2014, as well as 388 specimens taken in 14 collections during a severe black fly outbreak during March and April of 2018. Out of 186 pooled samples, 21 samples were positive for haemosporidian DNA. Eighteen of those samples were identified as Leucocytozoon spp. A phylogenetic tree was constructed using the novel sequences along with existing sequences from the MalAvi database. Results showed several of the sequences constructed in this study had high divergence from the existing sequences from the database.
Container-breeding mosquitoes are increasingly important in public health due to recent outbreaks of Zika virus, chikungunya, and dengue. This paper documents seasonality of the most prevalent ...container-breeding mosquito species in Mississippi-Aedes albopictus. Ten sites in 5 counties in both northern and central Mississippi (20 sites, 10 counties total) were sampled by larval dipping and oviposition traps biweekly from September 2016 to June 2019, totaling 22 months and potentially yielding 440 egg or larval collections. However, 22 collections were missed due to inclement weather and personnel issues during the study period, so actually only 418 site visits were performed. Sites were chosen to maximize chances of finding Ae. albopictus. Of the total 1,310 mosquito larvae collected during the study period, 717 larvae and 50 positive egg papers belonged to Ae. albopictus. Aedes albopictus was found in all 10 northern and central counties. No eggs were collected at any of the sites from December through February, although larvae were occasionally collected during that time frame. This study demonstrates that Ae. albopictus is active in central and northern Mississippi beginning in March each year and continuing through November or December. There is little activity during the coldest months of the year (January and February). These data represent the first extensive analysis of Ae. albopictus seasonality in Mississippi, and as such, allow for better public health awareness of diseases transmitted by this species and design of more effective vector control programs.
Little is known of black fly species occurring in Mississippi, other than that provided in the historical work by Dr. George Bradley in the 1930′s. There has been a resurgence of black flies in the ...state over the past decade, prompting renewed interest in these blood-sucking pests. For this study, adult black flies were collected by hand netting from various locations throughout the state from 2015 through 2018. Samples were also periodically obtained/submitted from veterinarians and concerned citizens since 2009, and especially during outbreak years (2009, 2011, 2012, 2018). In addition, larval and adult specimens were found in the Mississippi State University Entomological Museum (MEM), which had been collected over several decades by a variety of entomologists and students. Data from approximately 14,771 black fly specimens were analyzed to compile a list of species from the state and to describe their seasonal and geographic distributions. Twenty-seven species of black flies were confirmed from Mississippi, including four new state records.
Not much information is available concerning economic impacts black flies have on humans and animals in Mississippi. The reemergence of black files in southern states has renewed interest in these ...pests to determine their economic impacts. In this study, effects of black flies were assessed using a four-tiered approach: 1) a literature search of recent reports concerning human health effects from black flies in Mississippi, 2) a query of local mosquito personnel at the annual Mississippi Mosquito Vector Control Association meeting from 2015--2016 to assess prior or current complaints of black flies in their local municipality, 3) a request to the Mississippi State Department of Health for ICD-9 (International Classification of Diseases) data for outpatient hospital discharge data for patients in Mississippi diagnosed with insect bites/stings, both with and without infection, and lastly, 4) a survey (questionnaire) of Mississippi back-yard poultry owners assessing effects, if any, of black flies on poultry flocks or other livestock. Results revealed four recent medical and popular press articles about black flies since 2011; one city (Greenville) reported aerial spraying during a black fly outbreak in June 2011; Health Department ICD-9 data codes for the years 2010-11 revealed a total of 13,760 outpatient discharge cases for bites/stings in counties across the state. Statistical analysis of biting incidence data from counties known to have black fly problems versus counties without black fly problems showed no significance or clear patterns. Lastly, the survey of backyard poultry owners yielded 33 responses out of 522 questionnaires mailed. Poultry owners reported attacks on their birds and other livestock during known years of black fly outbreaks in the state, and also during known months of peak black fly activity. Forty-five poultry reportedly were killed by black flies and one olivestocko death (type or species unknown).
For several years, there have been continuous reports of black flies in Mississippi with evidence of transmission of Leucocytozoon spp. This study was conducted to determine the presence and ...diversity of Leucocytozoon spp. in black flies captured throughout Mississippi. Thirty-three collections, consisting of 346 specimens, were made during the 2-yr period (2015-2016) at 10 locations around the state. In addition to these systematic biweekly collections, 46 specimens were taken in 10 collections at four additional sites from 2009 to 2014, as well as 388 specimens taken in 14 collections during a severe black fly outbreak during March and April of 2018. Out of 186 pooled samples, 21 samples were positive for haemosporidian DNA. Eighteen of those samples were identified as Leucocytozoon spp. A phylogenetic tree was constructed using the novel sequences along with existing sequences from the MalAvi database. Results showed several of the sequences constructed in this study had high divergence from the existing sequences from the database. Key words: black flies, Leucocytozoon, Simuliidae, leucocytozoonosis, Simulium
Although there are at least 27 reported species of black flies in Mississippi, little is known about which of these are the primary pest species occurring in the state. The resurgence of black flies ...in Mississippi over the past decade prompted renewed interest in these blood-sucking pests. The purpose of this study was to survey black flies occurring in Mississippi and analyze their seasonality, distribution, and possible relationship of activity versus various meteorological conditions. Black fly adults were collected by hand netting at ten sites around the state for two years. Upon each visit, data was recorded including date, time, temperature, humidity, sky conditions, and wind speed. A total of 350 adult black flies were collected, returned to the lab, and identified. The two main species collected were Simulium jenningsi group (248 specimens) and Simulium meridionale (98 specimens). Three other species were rarely collected (4 specimens): S. parmatum and S. tribulatum and S. johannseni. Simulium jenningsi was found predominantly from February through July each year, mostly in central, south, and eastern Mississippi, while S. meridionale was found from March through July, mostly in the northern Delta region. Analysis of meteorological data indicated that temperature, relative humidity, and sky condition were the main factors affecting black fly flight activity. This study suggests that there are two main pest species of black flies encountered in Mississippi.
Little is known about black fly pest species in Mississippi, other than research from the 1930s. A better understanding of the pest species that occur in Mississippi is important for human and animal ...health. My research focused on what species of black flies occur in Mississippi, their seasonality and distribution, and a detailed systematic survey of the primary pest species. Lastly, I attempted to quantify nuisance effects and economic impacts of black flies on people, backyard poultry, and livestock. I examined scientific literature and records of black flies occurring in the southeastern U.S., and particularly Mississippi. This search revealed several unpublished manuscripts by Dr. George H. Bradley on the biology, ecology, and control of black flies in the Mississippi Delta during the 1930s. These publications were curated and made available to the scientific community. I identified and compiled an annotated list of larval, pupal, and adult stages of black flies occurring in Mississippi, derived from specimens housed in the Mississippi State University Entomological Museum (MEM). These specimens had been collected over several decades by a variety of entomologists, students, and the public. In addition, I included data from thousands of black flies collected during this project. To assess seasonality and relative abundance of the primary pest black fly species in Mississippi, I systematically collected adult black fly specimens for two years, documenting species present, seasonality, adult emergence patterns, and associated meteorological conditions. These ten sites were selected based on Dr. George Bradley's extensive work and complaints from local county extension agents, veterinarians, and municipal public works personnel. For economic, human, and animal health impacts of black flies, I employed a four-tiered approach: 1) a survey of lay and medical literature for reports of human health problems from black fly bites, 2) a query of city and county public works personnel concerning black fly nuisance effects, 3) an analysis of statewide hospital outpatient International Classification of Diseases-9 (ICD-9) discharge data and lastly, 4) a statewide survey of backyard poultry owners to ascertain animal health and monetary impacts from black flies.
Convalescent plasma has been one of the most common treatments for COVID-19, but most clinical trial data to date have not supported its efficacy.
Is rigorously selected COVID-19 convalescent plasma ...with neutralizing anti-SARS-CoV-2 antibodies an efficacious treatment for adults hospitalized with COVID-19?
This was a multicenter, blinded, placebo-controlled randomized clinical trial among adults hospitalized with SARS-CoV-2 infection and acute respiratory symptoms for < 14 days. Enrolled patients were randomly assigned to receive one unit of COVID-19 convalescent plasma (n = 487) or placebo (n = 473). The primary outcome was clinical status (disease severity) 14 days following study infusion measured with a seven-category ordinal scale ranging from discharged from the hospital with resumption of normal activities (lowest score) to death (highest score). The primary outcome was analyzed with a multivariable ordinal regression model, with an adjusted odds ratio (aOR) < 1.0 indicating more favorable outcomes with convalescent plasma than with placebo. In secondary analyses, trial participants were stratified according to the presence of endogenous anti-SARS-CoV-2 antibodies ("serostatus") at randomization. The trial included 13 secondary efficacy outcomes, including 28-day mortality.
Among 974 randomized patients, 960 were included in the primary analysis. Clinical status on the ordinal outcome scale at 14 days did not differ between the convalescent plasma and placebo groups in the overall population (aOR, 1.04; one-seventh support interval 1/7 SI, 0.82-1.33), in patients without endogenous antibodies (aOR, 1.15; 1/7 SI, 0.74-1.80), or in patients with endogenous antibodies (aOR, 0.96; 1/7 SI, 0.72-1.30). None of the 13 secondary efficacy outcomes were different between groups. At 28 days, 89 of 482 (18.5%) patients in the convalescent plasma group and 80 of 465 (17.2%) patients in the placebo group had died (aOR, 1.04; 1/7 SI, 0.69-1.58).
Among adults hospitalized with COVID-19, including those seronegative for anti-SARS-CoV-2 antibodies, treatment with convalescent plasma did not improve clinical outcomes.
ClinicalTrials.gov; No.: NCT04362176; URL: www.
gov.
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