Risk factors for tick exposure in suburban settings in the Northeastern United States.

Prevention of tick-borne diseases requires an understanding of when and where exposure to ticks is most likely. We used an epidemiologic approach to define these parameters for residents of a Lyme-endemic region. Two persons in each of 500 Connecticut households were asked to complete a log each night for one week during June, 2013. Participants recorded their whereabouts in 15min increments (indoors, outdoors in their yard, outdoors on others' private property, or outdoors in public spaces) and noted each day whether they found a tick on themselves. Demographic and household information was also collected. Logs were completed for 934 participants in 471 households yielding 51,895 time-place observations. Median participant age was 49 years (range 2-91 years); 52% were female. Ninety-one participants (9.8%) reported finding a tick during the week, with slightly higher rates among females and minors. Household factors positively associated with finding a tick included having indoor/outdoor pets (odds ratio (OR)=1.7; 95% confidence interval (CI): 1.1-2.9), the presence of a bird feeder in the yard (OR=1.9; CI:1.2-3.2), and presence of an outdoor dining area (OR=2.2; CI:1.1-4.3). Individual factors associated with finding a tick on a given day were bathing or showering (OR=3.7; CI:1.3-10.3) and hours spent in one's own yard (OR=1.2, CI:1.1-1.3). Nineteen participants found ticks on multiple days, more than expected assuming independence (p<0.001). Participants who found ticks on multiple days did not spend more time outdoors but were significantly more likely to be male than those finding ticks on a single day (p<0.03). Our findings suggest that most tick exposures in the study area occurred on private property controlled by the respective homeowner. Interventions that target private yards are a logical focus for prevention efforts.

Use of sindbis/eastern equine encephalitis chimeric viruses in plaque reduction neutralization tests for arboviral disease diagnostics.

Eastern equine encephalitis virus (EEEV) is a highly virulent, mosquito-borne alphavirus that causes severe and often fatal neurological disease in humans and horses in eastern North American, the Caribbean, and Mexico and throughout Central and South America. EEEV infection is diagnosed serologically by anti-EEEV-specific IgM detection, with confirmation by the plaque reduction neutralization test (PRNT), which is highly specific for alphaviruses. Live virus is used in the PRNT procedure, which currently requires biosafety level 3 containment facilities and select agent security in the case of EEEV. These requirements restrict the ability of public health laboratories to conduct PRNTs. Sindbis virus (SINV)/EEEV recombinant constructs have been engineered to express the immunogenic structural proteins from 2 wild-type EEEV strains in an attenuated form. These SINV/EEEVs, which are not classified as select agents, were evaluated as alternative diagnostic reagents in a PRNT using human, equine, and murine sera. The results indicate that the chimeric viruses exhibit specificity comparable to that of wild-type EEEV, with only a slight reduction in sensitivity. Considering their benefits in increased safety and reduced regulatory requirements, these chimeric viruses should be highly useful in diagnostic laboratories throughout the Americas.

Digital processing of equine exercise electrocardiograms.

We have developed and used a system for recording and analyzing the electrocardiogram (ECG) of the horse during exercise. The system consists of a commercial ECG transmitter telemetering a Z lead (base-apex) ECG from an exercising horse. The received data are then remodulated at an audio frequency and stored on a audio cassette recorder. Exercise protocols of up to 10 minutes are digitized using a Macintosh II computer. For rhythm analysis, a computer program to identify the various waves of the ECG uses a modification and refinement of the integrated-squared-derivative (ISD) technique. This technique consists of frequency selective digital filtering and differentiation followed by integration of the squared derivative. The waves of the ECG are identified using adaptive thresholding of the ISD and the derivative of the ECG. Thus far, we have been able to successfully identify the Q, R, and the end of T in ECGs severely contaminated by exercise artifact. The system can place the absolute time of occurrence of the Q, R, and end of T in a text file for export to other analysis programs such as spreadsheets and statistics packages.

Genitourinary rhabdomyosarcoma in children.

Although rhabdomyosarcoma of the genitourinary tract occurs infrequently in children, it presents a challenging problem to the surgeon, radiotherapist, and oncologist. Thirty-six children with genitourinary rhabdomyosarcoma were treated at our institutions from 1957 to 1985. The primary site of tumor involved the bladder, prostate, or both in 15 patients, the paratesticular structures in 12, and female reproductive organs in nine. Although treatment modalities and philosophies of care varied over the past 27 years, the majority of patients were treated with a combination of surgery, chemotherapy, and radiation therapy. The event-free survival for all patients is 74%. Patients with paratesticular tumors had the best prognosis (88% event-free survival). Regional nodal radiation therapy is not necessary in this favorable group if the retroperitoneal lymph node dissection is negative. Of 15 children with bladder/prostate tumors nine had initial conservative surgery. Of these nine six are long-term survivors, but only three patients have intact bladders. The girls with tumors of the reproductive organs had an event-free survival of 63%; all patients in this group had hysterectomies. Chemotherapy and radiotherapy have not substituted for radical surgical procedures in most children with bladder or prostate rhabdomyosarcomas. Innovative therapeutic approaches are necessary for this group of patients.

Weekly high-dose methotrexate and doxorubicin for osteosarcoma: the Dana-Farber Cancer Institute/the Children's Hospital--study III.

Weekly high-dose methotrexate with leucovorin rescue and vincristine (HDMTX) and doxorubicin was administered as adjuvant postoperative therapy to 46 patients with a diagnosis of conventional high-grade nonmetastatic osteosarcoma of an extremity between July 1976 and December 1981. The primary lesions were managed by wide or radical amputation (26 patients) or by limb-sparing resection in 20 selected patients. The margins of the resections were retrospectively classified as marginal in three, wide in 16, and radical in one. The 5-year relapse-free survival (RFS) for all patients is 59% (95% confidence interval [CI], 43%, 74%) and overall survival is 78% (95% CI, 65%, 91%). The RFS for patients initially having a limb resection procedure is 55% (95% CI, 32%, 77%) compared with 62% (95% CI, 43%, 81%) for those initially having amputations (P = .52). Using multivariate analysis, the only significant prognostic variables that predicted RFS of greater than or equal to 3 years, were the presence of moderate to marked lymphocytic infiltration of the primary tumor (P less than .002), primary site outside of the proximal humerus (P less than .005), and the absence of a predominance of osteoblastic pattern in the primary tumor (P less than .03).

Prognostic factors in childhood acute myelogenous leukemia.

The prognostic significance of initial clinical and laboratory parameters was evaluated in 125 children with acute myelogenous leukemia (AML) treated on two consecutive protocols (VAPA and 80-035). Both protocols used an anthracycline with cytosine arabinoside (ara-C) for induction therapy followed by 12 to 14 months of intensive sequential postremission chemotherapy. Results are similar for the two treatment regimens. Seventy-two percent of patients achieved a complete remission, with 42% projected 5-year disease-free survival for the complete responders. Monocytic or myelomonocytic leukemic subtype (French-American-British [FAB] types M4 and M5), WBC count less than 100,000/microL, and age less than 2 years at diagnosis all predicted increased risk of relapse and decreased overall survival in univariate analyses. FAB subtype and high white count continued to predict for an increased risk of relapse in multivariate analyses and only M5 leukemic subtype independently predicted for poor survival. Patients with M4 or M5 leukemic subtype had a higher incidence of initial relapses in the CNS. The addition of intrathecal cytosine arabinoside in the second protocol, 80-035, decreased the percentage of patients with initial failure in the CNS, but did not improve overall survival. Improved CNS prophylaxis, better systemic therapy, and/or different treatment strategies are needed to improve therapy in these high-risk patients.

The medical and surgical management of typhlitis in children with acute nonlymphocytic (myelogenous) leukemia.

The treatment of acute leukemia in childhood has been increasingly successful. Infectious complications are the major cause of morbidity and mortality among these patients receiving aggressive chemotherapy. In particular, neutropenic enterocolitis or typhlitis has had a reported mortality of 50% to 100%. The authors reviewed a series of 77 previously untreated patients with acute myelogenous leukemia begun on treatment from March 1976 to June 1984 to better define the characteristics of typhlitis and its optimum management. Twenty-five patients had episodes of typhlitis, characterized by fever, abdominal pain, and tenderness, occurring during periods of neutropenia. Ten of these patients had watery diarrhea as a major additional symptom, and nine patients had a significant episode of gastrointestinal bleeding. In seven instances, blood culture results were positive, all for intestinal flora. The episodes of typhlitis occurred most frequently during the induction therapy (19 patients). Five patients experienced typhlitis during maintenance therapy, and one patient had acute appendicitis. Two patients had typhlitis during their reinduction therapy, and of note, one had had abdominal symptoms during her initial induction. All patients were treated initially with broad-spectrum antibiotics and bowel rest. Four criteria have been used for surgical intervention: (1) persistent gastrointestinal bleeding after resolution of neutropenia and thrombocytopenia and correction of clotting abnormalities; (2) evidence of free intraperitoneal perforation; (3) clinical deterioration requiring support with vasopressors, or large volumes of fluid, suggesting uncontrolled sepsis; and (4) development of symptoms of an intra-abdominal process, in the absence of neutropenia, which would normally require surgery. Using these criteria, five patients required surgical intervention for typhlitis or its sequelae and one for acute appendicitis. There was one perioperative death resulting from miliary tuberculosis. Among the 21 patients managed medically, there was 1 death resulting from typhlitis in a patient in whom surgery was deferred because of her multiple failures to enter remission.

Prognostic significance of complete surgical resection of pulmonary metastases in patients with osteogenic sarcoma: analysis of 32 patients.

Between 1972 and 1981, 93 patients with extremity osteogenic sarcoma without detectable metastatic disease were treated with surgery and adjuvant chemotherapy. Fifty-two patients remain continuously free of disease. Thirty-two of the 41 patients who relapsed had pulmonary metastases only and 26 underwent thoracotomy to remove all metastatic disease. Complete resection was possible in 11 of 26 patients as defined by the removal of all macroscopic disease, no microscopic disease at resection margins, and no histologic evidence of pleural disruption by tumor. Nine of 11 patients are currently free of disease with a median duration of most recent remission of 42 months (range, 3-72 months). Four of these nine patients have had only one relapse. Only two of 15 patients with incomplete resection of metastatic disease defined by the above criteria are currently free of disease for 57 and 101 months. A significant difference in survival from initial relapse for patients made surgically free of disease using this stringent criteria was observed even when the result is stratified for time to first relapse and number of pulmonary nodules (p = 0.005). A subgroup of patients within the group undergoing thoracotomies who can be expected to have an improved survival has been defined.