An annotated list of the ticks (Ixodidae and Argasidae) of Mississippi.
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Animals↗
Biomedical subjects
Jerome Goddard
Publications and source records attributed to Jerome Goddard.
New ways of looking at memory function: certain traumatic memories function like viruses, replicating themselves.
By the process of natural selection, life on earth spreads in all directions, finding niches favorable for survival. Some niches are harmful to another plant or animal (parasitism). This universal survival strategy applies to all living things, and apparently even non-living things such as viruses and prions. The same pattern may occur with immaterial entities such as memories. Traumatic memories mimic virus behavior in many ways such as infecting, spreading, occasionally becoming latent, and even reproducing themselves. Patients with past traumatic experiences are still "infected" with pathogenic memories. The experience remains ever-present in the patient's neural pathways and may even grow via a feedback loop in which each episode of remembering produces a stress hormone response. Under this model, doctors might view and treat patients with a history of trauma as persons infected with latent memories which periodically break out and cause new damage.
Biomimetics↗
Personal protection measures against fire ant attacks.
BACKGROUND: Fire ant stings lead to significant morbidity and mortality each year. Virtually no information exists in the scientific literature about the effectiveness of personal protection measures against these ants. OBJECTIVES: To quantify the level of protection from ant stings by socks and cotton tights and to evaluate the efficacy of repellents and other chemicals in preventing stings. METHODS: Commercially obtained infant socks were fitted on a plastic doll's foot, which was touched to fire ant mounds in a series of controlled experiments. Socks and cotton tights were stretched over a human finger and placed in a fire ant mound to test the ability of ants to sting through fabric. Assays were developed to screen chemical substances for their ability to stop or prevent fire ant stings. RESULTS: Socks of any type reduced the number of fire ants that reached the skin and delayed the time required for ants to reach the skin above the sock level. Fire ants were unable to sting through all socks tested. Ants successfully stung both paper towels and human skin, regardless of chemical substance or repellent applied to them. CONCLUSIONS: Socks provide some degree of protection from fire ant stings; therefore, children living in fire ant-infested areas should wear them. Fire ants appear unable to sting through many commercially available socks. Cotton tights may be useful in protecting the lower extremities of children. Fire ants are not deterred from stinging by a wide variety of insect repellents and chemical substances.
Animals↗
Observations on distribution and seasonal activity of the Gulf Coast tick in Mississippi.
Medical importance of the Gulf Coast tick, Amblyomma maculatum Koch, has been highlighted with the recent discovery of a new rickettsial pathogen associated with this tick. Accordingly, distribution and seasonal collection records of A. maculatum were assessed in Mississippi by using three sources of data: sampling of experimental field plots, national tick collection records, and Mississippi Department of Health human tick biting records. A. maculatum was collected in 17/82 (21%) Mississippi counties, mostly in central and southern regions. Estimates of seasonal activity were made using collection data for 2,217 adult, 11 nymphal, and 426 larval specimens. Adult A. maculatum were collected during March through November, with a peak during late July through early August. Nymphs were collected during February through August, and larvae were collected once during each of June, September, and October. Small sample sizes of the immature stages precluded determination of their peak activity.
Animals↗
New, recent, and questionable mosquito records from Mississippi.
Enhanced mosquito surveillance in Mississippi has confirmed the presence of Mansonia titillans and Ochlerotatus trivittatus, which represent new state records for Mississippi. Recent records of Aedes albopictus, Anopheles maverlius, An. quadrimaculatus, An. smaragdinus, and Ochlerotatus hendersoni, and questionable records of Ochlerotatus dorsalis, Oc. stimulans, and Psorophora pygmaea are reviewed.
Aedes↗
Fire ant attacks on patients in nursing homes: an increasing problem.
We review the medical reports of fire ant attacks on residents of nursing homes in the context of the medical entomology of these insects, and present recommendations to prevent and manage future attacks. Two reports were recent cases, while a computer-assisted search yielded four other similar cases of attacks by foraging fire ants in the last 10 years. One patient experienced an anaphylactic reaction and 4 patients died within 1 week of the attack. Ants were usually noted in health care facilities days before the attacks. The presence of fire ants around immobile, often cognitively impaired, patients seems to be the primary risk factor for massive fire ant attacks. Health care providers and administrators in fire ant endemic areas must be aware that the presence of fire ants in hospitals and nursing homes represents a hazard. Fire ant infestation can lead to sting attacks on patients, causing respiratory tract obstruction, worsening of pre-existing medical conditions, or frank anaphylaxis. All the attacks reported here have resulted in legal action involving physicians and health care facilities.
Animals↗
Rickettsia parkeri: a newly recognized cause of spotted fever rickettsiosis in the United States.
Ticks, including many that bite humans, are hosts to several obligate intracellular bacteria in the spotted fever group (SFG) of the genus Rickettsia. Only Rickettsia rickettsii, the agent of Rocky Mountain spotted fever, has been definitively associated with disease in humans in the United States. Herein we describe disease in a human caused by Rickettsia parkeri, an SFG rickettsia first identified >60 years ago in Gulf Coast ticks (Amblyomma maculatum) collected from the southern United States. Confirmation of the infection was accomplished using serological testing, immunohistochemical staining, cell culture isolation, and molecular methods. Application of specific laboratory assays to clinical specimens obtained from patients with febrile, eschar-associated illnesses following a tick bite may identify additional cases of R. parkeri rickettsiosis and possibly other novel SFG rickettsioses in the United States.
Adult↗
Implications of presumptive fatal Rocky Mountain spotted fever in two dogs and their owner.
A dog was examined because of petechiation, an inability to stand, pale mucous membranes, a possible seizure, and thrombocytopenia. Tick-borne illness was suspected, but despite treatment, the dog died. Eight days later, a second dog owned by the same individual also died. The dog was not examined by a veterinarian, but Rocky Mountain spotted fever (RMSF) was suspected on the basis of clinical signs. Two weeks after the second dog died, the owner was examined because of severe headache, fever, nausea, vomiting, decreased appetite, lethargy, and a fine rash on the body, face, and trunk. Despite intensive treatment for possible RMSF, the owner died. Although results of an assay for antibodies to Rickettsia rickettsii were negative, results of polymerase chain reaction assays of liver, spleen, and kidney samples collected at autopsy were positive for spotted fever group Rickettsia spp. These cases illustrate how dogs may serve as sentinels for RMSF in humans and point out the need for better communication between physicians and veterinarians when cases of potentially zoonotic diseases are seen.
Animals↗
Allergic reactions to Triatoma bites.
BACKGROUND: Triatoma bugs are best known in the medical community as vectors of trypanosomiasis (Chagas disease). However, bites of Triatoma bugs are a cause of local cutaneous reactions and anaphylaxis, mainly in the western and southwestern United States. The reactions typically occur at night during sleep, and the bite may not be recognized. There is continuing public interest in medical complications of bites of these bugs, although the scope of the problem remains undefined. OBJECTIVE: To review the relevant medical literature, identify present knowledge, and determine future research goals for allergy to Triatoma. DATA SOURCES: Computerized databases were used to search the medical literature for articles in the English language on Triatoma bites, allergy and entomology, and Chagas disease. STUDY SELECTION: Almost all identified articles on Triatoma allergy were used. Only selected articles on Triatoma bites and entomology were pertinent to the objectives. Articles on Chagas disease were limited to cases in the United States. RESULTS: Bites of Triatoma bugs have been known to cause anaphylaxis for more than a century. These insects inhabit a large area of the United States, but to date most reports of allergic reactions to their bites have originated in the West and Southwest. The reactions typically occur at night during sleep following a bite on uncovered skin and may be unrecognized. Procalin has been identified as the major salivary allergen of Triatoma protracta and was recently cloned and expressed through recombinant technique. Allergenic reactivity has been demonstrated to salivary gland extracts of 2 species. The extracts of these 2 species have not shown immunologic cross-reactivity. Immunotherapy using a salivary gland extract appeared to be beneficial in a small number of patients; however, no commercial testing or treatment allergen is available. CONCLUSIONS: Triatoma bites appear to be an important cause of anaphylaxis, especially in the western and southwestern United States. Because exposure to these insects often occurs during sleep, the incidence of allergic reactions to them is unclear. An epidemiologic study should be performed to determine the incidence, prevalence, and range of allergic responses to the bites of these insects. The lack of commercial antigen limits diagnostic and treatment capabilities. The development of an allergen under the Orphan Drug Act should be encouraged.
Animals↗
Seasonality of delusions of parasitosis.
Delusions of parasitosis (DOP) is an emotional disorder in which patients are convinced that they are infested with tiny, almost invisible, mites or insects. Despite sample examination by entomologists and repeated doctor visits, no evidence of a real infestation can be found. Previous studies of DOP patients have described epidemiological features such as age, race, and gender. This is the first report of an apparent link between season of the year and DOP.
Animals↗
Experimental infection of lone star ticks, Amblyomma americanum (L.), with Rickettsia parkeri and exposure of guinea pigs to the agent.
The maculatum agent, Rickettsia parkeri (a member of the spotted fever group rickettsiae), was inoculated into a colony of the lone star tick, Amblyomma americanum, and followed for two tick generations. In addition, guinea pigs were exposed to the agent by direct injection and by feeding infected ticks on them. Eighty (53%) of 150 nymphal A. americanum that were inoculated with suspensions of R. parkeri were positive by hemolymph test and fluorescent antibody test for rickettsial infection when examined as adults. One-month survival of R. parkeri-infected ticks was similar to that of control (noninfected) ticks. Transstadial and transovarial transmission of R. parkeri in the laboratory was demonstrated in A. americanum. When guinea pigs were exposed to the maculatum agent by either direct injection of Vero cell-grown R. parkeri, injection of homogenates of infected ticks, or by feeding of infected ticks, they developed mild fevers and occasional scrotal reactions. These data indicate that R. parkeri can remain viable in lone star ticks for two generations and suggest that guinea pigs may become infected, displaying mild clinical signs.
Animals↗
Survey of ticks collected in Mississippi for Rickettsia, Ehrlichia, and Borrelia species.
From November 1999 through October 2000, we tested ticks collected from vegetation as well as from deer, dogs, and humans for spotted fever group (SFG) rickettsiae, Ehrlichia chaffeensis, and Borrelia spp. spirochetes. A total of 149 adult ticks representing four species was collected from 11 collection sites from southwestern to northern Mississippi. Amblyomma americanum was most commonly collected (n=68), followed by Ixodes scapularis (n=53). The bird tick, Ixodes brunneus (usually rare), was the third most commonly collected tick (n=17). Eleven Dermacentor variabilis were also collected. Ticks were cut longitudinally to make smears on three microscope slides. The remaining body parts were frozen at -65 degrees C for additional testing. Tick smears were stained by direct immunofluorescence assays (DFA) for Rickettsia spp. and Borrelia spp., while indirect immunofluorescence assays (IFA) were used for Ehrlichia spp. The corresponding tick for each positive smear was evaluated using PCR analysis. None of the 149 ticks tested was DFA positive for Borrelia spp. However, smears of 30 (20%) and 32 (22%) ticks reacted with anti-E. chaffeensis sera and anti-R. rickettsii conjugate (known to react with several members of the spotted fever group), respectively. None of the ticks staining with the IFA for Ehrlichia was positive for E. chaffeensis using PCR. However, 23 (72%) of 32 FA-positive ticks for SFG rickettsiae yielded amplicons of the appropriate size when tested using a PCR assay for SFG rickettsiae, corresponding to an overall infection rate with SFG rickettsiae among the collected ticks of 15%. Smears of 12 (71%) of 17 I. brunneus revealed abundant bacilliform bacteria. PCR amplification of DNA from a single I. brunneus containing these bacteria was performed using universal primers for the 16S rRNA gene as well as Borrelia-specific primers. The predominant sequence obtained using the universal primers did not match any sequence in GenBank, but it showed 91% identity with an endosymbiont of Acanthoamoeba. Other sequences represented in the top 50 Basic Local Alignment Search (BLAST) scores were primarily from soil bacteria, although some similarity to several Anaplasma species and Ehrlichia risticii was indicated. The significance of this finding remains undetermined.
Animals↗
A ten-year study of tick biting in Mississippi: implications for human disease transmission.
To determine exactly which tick species bit people in Mississippi, information was gathered on ticks involved in human biting cases for the ten-year period, January 1, 1990-December 31, 1999. Specimens were identified by the author and, in most cases, confirmed by personnel at the Institute of Arthropodology and Parasitology, Georgia Southern University. A total of 119 ticks were recovered from 73 humans during the study period. Seven tick species were represented; most common included the lone star tick, Amblyomma americanum, the gulf coast tick, A. maculatum, the American dog tick, Dermacentor variabilis, and the black-legged deer tick, Ixodes scapularis. Interestingly, no immature Ixodes scapularis were collected. there were several unusual records. Twelve larvae of Amblyomma tuberculatum, a species associated with the gopher tortoise, were removed from a patient. Two Dermacentor albipictus larvae were collected from an elderly woman with no travel history except her backyard. One Dermacentor sp. nymph, removed from a man in central MS, was not even a North American species. One adult female Dermacentor variabilis was involved in a clinical case of tick paralysis. These findings indicate that, although we know which tick species are common human biters, unusual/unreported tick-human interactions may be more common than we think.
Journal Article↗
Recommendations for prevention and management of fire ant infestation of health care facilities.
The range of imported fire ants now includes most of the southeastern United States, parts of the Southwest, portions of the East and West Coasts, and Puerto Rico. Increasingly, fire ant attacks on patients in health care facilities have been reported. In this paper, we provide recommendations for fire ant control in and around health care facilities that should help prevent building infestation and further attacks. In addition, we provide algorithms detailing fire ant prevention strategies (indoors and outdoors) and patient management after fire ant stings. Physicians in areas endemic for fire ants should be aware of the possibility that patients may be harmed by these insects, and also should be generally familiar with measures used to control fire ants.
Algorithms↗
Community-wide medical entomology training for medical practitioners.
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Curriculum↗