James H. Diaz

Autochthonous Transmission of Trypanosoma cruzi, Louisiana

Autochthonous transmission of the Chagas disease parasite, Trypanosoma cruzi, was detected in a patient in rural New Orleans, Louisiana. The patient had positive test results from 2 serologic tests and hemoculture. Fifty-six percent of 18 Triatoma sanguisuga collected from the house of the patient were positive for T. cruzi by PCR.

Epidemiology and outcome of postural headache management in spontaneous intracranial hypotension

Background and Objectives Spontaneous intracranial hypotension is a postural headache syndrome unrelated to dural puncture. Due to the apparent failure of epidural blood patch to relieve headache in spontaneous intracranial hypotension, we investigated the epidemiologic features and treatment outcomes of this condition. Methods The clinical findings and management of 22 cases (21 published + 1 reported) of spontaneous intracranial hypotension were analyzed retrospectively. The study population was stratified by age and sex; continuous variables were compared for differences by t-tests; categorical variables were compared by Fisher exact tests. Significant differences were identified by P values of .05 or less. Results The mean age of the study population was 43 [plusmn] 16 years, with a female:male ratio of 3.4:1.0. Females with spontaneous intracranial hypotension were younger (P = .050) than males. Men presented with tinnitus (P = .021) and visual field defects (P = .009) more often than women. Meningeal enhancement on contrast magnetic resonance imaging was the most consistent radiographic finding. Radionuclide cisternography showed thoracolumbar dural leaks in 7 of 9 patients. Cerebrospinal fluid opening pressure was low in all patients (33.13 [plusmn] 31.02 mm H2O). Epidural blood patch was performed in 8 patients, repeated in 3 patients, failed in 3 patients, and offered only transient improvement in 5 patients. Conclusions Spontaneous intracranial hypotension was more common in women than men, was not uniformly responsive to epidural blood patch, and had significant comorbidities. The management of postural headache in spontaneous intracranial hypotension by other techniques to restore cerebrospinal fluid dynamics and prevent its leakage should be investigated.

Intranasal ketamine preinduction of paediatric outpatients

A double‐blinded, placebo‐controlled study compared the outcomes of intranasal ketamine premedication with placebo in outpatients. Forty paediatric outpatients were assigned randomly in a prospective fashion to one of two separate study groups of equal size (20 patients per group). A placebo group received 2 ml of intranasal saline, 1 ml per naris. The study group received intranasal ketamine, 3 mg·kg−1, diluted to 2 ml with saline, 1 ml per naris. Using a cooperation index, a play therapist scored resistance to nasal instillation, separation of the child from parents at ten min, and acceptance of anaesthesia monitors and face mask at 15 min. Differences in age, weight, episodes of vomiting, recovery and discharge times among the two groups were not significant. Intranasal ketamine, 3 mg·kg−1, was asssociated with a significantly better (P=0.013) cooperation index than intranasal placebo. Intranasal ketamine, permitted pleasant and rapid separation of children from their parents, cooperative acceptance of monitoring and of mask inhalation induction, and did not cause prolonged postanaesthetic recovery or delayed discharge home.

Skin and Soft Tissue Infections Following Marine Injuries and Exposures in Travelers

BACKGROUND Bacterial skin and soft tissue infections (SSTIs) in travelers often follow insect bites and can present a broad spectrum of clinical manifestations ranging from impetigo to necrotizing cellulitis. Significant SSTIs can also follow marine injuries and exposures in travelers, and the etiologies are often marine bacteria. METHODS To meet the objectives of describing the pathogen-specific presenting clinical manifestations, diagnostic and treatment strategies, and outcomes of superficial and deep invasive infections in travelers caused by commonly encountered and newly emerging marine bacterial pathogens, Internet search engines were queried with the key words as MESH terms. RESULTS Travel medicine practitioners should maintain a high index of suspicion regarding potentially catastrophic, invasive bacterial infections, especially Aeromonas hydrophila, Vibrio vulnificus, Chromobacterium violaceum, and Shewanella infections, following marine injuries and exposures. CONCLUSIONS Travelers with well-known risk factors for the increasing severity of marine infections, including those with open wounds, suppressed immune systems, liver disease, alcoholism, hemochromatosis, hematological disease, diabetes, chronic renal disease, acquired immunodeficiency syndrome, and cancer, should be cautioned about the risks of marine infections through exposures to marine animals, seawater, the preparation of live or freshly killed seafood, and the accidental ingestion of seawater or consumption of raw or undercooked seafood, especially shellfish. With the exception of minor marine wounds demonstrating localized cellulitis or spreading erysipeloid-type reactions, most other marine infections and all Gram-negative and mycobacterial marine infections will require therapy with antibiotic combinations.

Comparison of two immunochromatographic assays and the indirect immunofluorscence antibody test for diagnosis of Trypanosoma cruzi infection in dogs in south central Louisiana

Two rapid tests evaluated in dogs considered to be of high risk of infection with the Chagas parasite Trypanosoma cruzi using two immunochromatographic assays: Trypanosoma Detect for canine, InBios, Seattle, WA and CHAGAS STAT-PAK assay, Chembio Diagnostic Systems, Medford, NY, in south central Louisiana. For this purpose a serological survey was carried out in a total of 122 dogs and a serum bank was created. These 122 animals were first tested by IFAT that was used as the standard test. From the serum bank 50 samples were tested using the two rapid Chagas assays and results compared to the standard test IFAT. The serological survey using IFAT showed a prevalence of T. cruzi infection in 22.1% of the tested dogs. In the immunochromatographic assays, 13 and 11 animals were positive on rapid assay: Trypanosoma Detect for canine, InBios and CHAGAS STAT-PAK, Chembio Diagnostic Systems, respectively compared to 11 positive by IFAT. These two immunochromatographic tests have shown high susceptibility and specificity compared to our standard method IFAT. The rapid, easy and accurate screening assays used in conjunction with confirmatory tests, would be an excellent tool for veterinarians to diagnose T. cruzi infection. Early detection of T. cruzi infection may prevent complications through an effective treatment. Greater awareness by veterinarians of the risk, clinical findings, history along with diagnostic methods will contribute greatly to an understanding of the true prevalence of Chagas disease in dogs in Louisiana.

The Evaluation, Management, and Prevention of Stingray Injuries in Travelers

Although sharks may attack man without warning, stingrays are docile, usually nonaggressive, and do not attack man unless disturbed, by coastal waders or divers or caught or netted by fishermen. Because stingrays are ubiquitous in all temperate and tropical oceans worldwide, and even occur in many tropical freshwater river systems, human stingray injuries are common but rarely fatal. In the United States alone, 750 to 2,000 stingray injuries are reported each year compared with more than 300 scorpionfish envenomings annually, many in home aquarists, and thousands of catfish‐inflicted spine injuries, most of which are not reported.1–6 On very rare occasions, stingrays have launched off surface waters and into anchored or speeding motorboats, inflicting fatal human injuries. Several fatalities from penetrating thoracic stingray injuries and septic stingray wounds have now been reported.1–4,7 Although not as common as injuries caused by other venomous fish, stingray injuries are an important group of, mostly preventable, marine envenomings.1–4 Since the 1950s, stingray injuries treated in emergency departments and/or reported to poison control centers have only been described retrospectively and, often, incompletely. To date, no prospective multicenter collaborative investigations by coastal medical centers have been conducted to verify the frequencies and fatal and nonfatal outcomes of stingray injuries. Nevertheless, as more vacationing travelers spend more leisure time exploring seacoasts and tropical reefs, often in isolated island areas without immediate access to advanced health care services, there will be greater potential for stingray injuries with poor outcomes. A retrospective meta‐analysis of the descriptive epidemiology of stingray injuries, the mechanisms of stingray envenoming, the multiple clinical presentations of stingray injuries, and the management strategies for stingray injuries is now indicated and may improve the clinician’s ability to better manage and to prevent stingray injuries in travelers. To describe the epidemiology, pathophysiology, presenting manifestations, and any … Corresponding Author: James H. Diaz, MD, MPH&TM, DrPH, Program in Environmental and Occupational Health Sciences, Schools of Public Health and Medicine, Louisiana State University Health Sciences Center in New Orleans, 2021 Lakeshore Drive, Suite 200, New Orleans, LA 70122, USA. E‐mail: jdiaz{at}lsuhsc.edu

Paragonimiasis Acquired in the United States: Native and Nonnative Species

SUMMARY Paragonimiasis is a parasitic lung infection caused by lung flukes of the genus Paragonimus, with most cases reported from Asia and caused by P. westermani following consumption of raw or undercooked crustaceans. With the exception of imported P. westermani cases in immigrants, in travelers returning from areas of disease endemicity, and in clusters of acquired cases following consumption of imported Asian crabs, human paragonimiasis caused by native lung flukes is rarely described in the United States, which has only one indigenous species of lung fluke, Paragonimus kellicotti. Clinicians should inquire about the consumption of raw or undercooked freshwater crabs by immigrants, expatriates, and returning travelers, and the consumption of raw or undercooked crayfish in U.S. freshwater river systems where P. kellicotti is endemic when evaluating patients presenting with unexplained fever, cough, rales, hemoptysis, pleural effusions, and peripheral eosinophilia. Diagnostic evaluation by specific parasitological, radiological, serological, and molecular methods will be required in order to differentiate paragonimiasis from tuberculosis, which is not uncommon in recent Asian immigrants. All cases of imported and locally acquired paragonimiasis will require treatment with oral praziquantel to avoid any potential pulmonary and cerebral complications of paragonimiasis, some of which may require surgical interventions.

Chemical and Plant-Based Insect Repellents: Efficacy, Safety, and Toxicity

Most emerging infectious diseases today are arthropod-borne and cannot be prevented by vaccinations. Because insect repellents offer important topical barriers of personal protection from arthropod-borne infectious diseases, the main objectives of this article were to describe the growing threats to public health from emerging arthropod-borne infectious diseases, to define the differences between insect repellents and insecticides, and to compare the efficacies and toxicities of chemical and plant-derived insect repellents. Internet search engines were queried with key words to identify scientific articles on the efficacy, safety, and toxicity of chemical and plant-derived topical insect repellants and insecticides to meet these objectives. Data sources reviewed included case reports; case series; observational, longitudinal, and surveillance studies; and entomological and toxicological studies. Descriptive analysis of the data sources identified the most effective application of insect repellents as a combination of topical chemical repellents, either N-diethyl-3-methylbenzamide (formerly N, N-diethyl-m-toluamide, or DEET) or picaridin, and permethrin-impregnated or other pyrethroid-impregnated clothing over topically treated skin. The insecticide-treated clothing would provide contact-level insecticidal effects and provide better, longer lasting protection against malaria-transmitting mosquitoes and ticks than topical DEET or picaridin alone. In special cases, where environmental exposures to disease-transmitting ticks, biting midges, sandflies, or blackflies are anticipated, topical insect repellents containing IR3535, picaridin, or oil of lemon eucalyptus (p-menthane-3, 8-diol or PMD) would offer better topical protection than topical DEET alone.

Postoperative quadriplegia after spinal fusion for scoliosis with intraoperative awakening

Neurologic complications, although rare, may follow scoliosis correction by spinal fusion (1,2). The incidence of acute neurologic complications during spine fusion may vary, with the population treated and the procedure performed, from 0.7% to 5.0% (2,3). The etiology of cord damage during spinal fusion remains unclear, but may involve vascular compromise associated with mechanical deformation (1,4-6). Intraoperative monitoring of spinal cord function during scoliosis correction has been recommended as a means of detecting early neurologic deficits that can be reversed by reduction of vertebral distraction or removal of supporting rods (3,6-11). Wake-up techniques and recording of somatosensory evoked potentials (SSEPs) are the only current means for monitoring spinal cord integrity during scoliosis surgery (3,6-12). Recently, postoperative paraplegia has been observed despite the recording of normal intraoperative SSEPs. As SSEP monitoring continues to be a research tool that is not universally available, intraoperative awakening has remained an important modality for testing cord integrity after scoliosis correction since its introduction in 1973 (11). Permanent quadriplegia after successful intraoperative awakening during spine fusion for scoliosis is now reported.

Croup and epiglottitis in children: the anesthesiologist as diagnostician.

The techniques for early diagnosis and management of airway obstruction in children with croup (laryngotracheobronchitis) and epiglottitis remain controversial. Epiglottitis or, more appropriately, supraglottitis, is an acute fulminant bacterial inflammation of supraglottic structures including epiglottis, arytenoids, aryepiglottic folds, and uvula (1,2) (Fig. 1). Croup, on the other hand, is a more insidious viral syndrome causing progressive inflammation and edema of the entire subglottic tracheobronchial tree (3-5) (Fig. 1). Epiglottitis quickly produces rapid inspiratory airway obstruction, while croup results in gradually worsening inspiratory stridor progressing to fatigue and respiratory failure. Early differentiation of croup and epiglottitis avoids the catastrophic consequences of sudden complete supraglottic airway obstruction associated with acute epiglottitis, and permits proper management of subglottic airway obstruction in croup to reduce the likelihood of developing subglottic granulomas, tracheomalacia, and subglottic stenosis. This review compares the etiology, epidemiology, pathology, and clinical findings of croup and epiglottitis, which should aid physicians in developing a practical approach to rapid differential diagnosis and early appropriate therapeutic intervention based on anatomic and physiologic principles.