Mexico City during and after the September 19, 2017 earthquake: Assessment of seismic resilience and ongoing recovery process.

Mexico City was severely affected by the September 19, 2017 Puebla-Morelos earthquake (M w = 7.1). City authorities confirmed that more than 12,000 structures for all uses were damaged as a consequence of this earthquake. In this paper, the focus of attention is devoted to trying to quantify in a simple manner how resilient the built environment in Mexico City was during the September 19, 2017 earthquake. Global statistics compiled for the severity of damage observed during this seismic event from detailed information gathered from well-documented and detailed damage surveys were used for this purpose. Also, an update is provided on how the seismic reconstruction and recovery processes of the built environment in Mexico City have been after this earthquake. This adaptive resilience has been assessed from reliable information and statistics of the ongoing reconstruction process of the affected built environment in Mexico City. The implementation of structural health monitoring programs for typical, representative buildings within the city would be germane to detect and correct potential structural deficiencies on time before the next strong earthquake may strike, then helping to improve the seismic resilience of the built environment.

Drug-induced fever due to diltiazem.

To our knowledge, drug-induced fever has not been reported with the use of diltiazem hydrochloride, a commonly prescribed calcium channel blocker. We describe a patient in whom this was the primary manifestation of drug hypersensitivity. A 67-year-old man was admitted for management of a diabetic foot ulcer. His hospital course was complicated by a non-Q-wave myocardial infarction, for which diltiazem was prescribed. On the seventh day of therapy, he experienced fever, with temperatures as high as 38.8 degrees C. Despite an extensive evaluation, which included a gallium scan, a technetium bone scan, and abdominal ultrasound, a source could not be found. On the 16th day of therapy, however, relative eosinophilia developed, and 2 days later a pruritic maculopapular rash appeared. Diltiazem therapy was discontinued, leading to resolution of fever within 48 hours. Drug-induced fever should be considered in patients who have unexplained high temperatures during diltiazem therapy.

Regulation and characterization of the interferon-alpha present in patients with advanced human immunodeficiency virus type 1 disease.

To examine a possible association between plasma viremia and interferon-alpha (IFN-alpha) in patients with the acquired immunodeficiency syndrome (AIDS), we performed IFN plasma immunoadsorption by apheresis (IFN-alpha apheresis) in four volunteers with AIDS who had sustained levels of endogenous plasma IFN-alpha. IFN-alpha apheresis with two plasma volume exchanges was performed daily for 5 days. Clinical signs and symptoms and hematologic, virologic, and immunologic parameters were monitored. Two subjects developed anemia from phlebotomy, and one had a catheter++-associated bacteremia. The IFN-alpha apheresis was effective only in transiently removing IFN-alpha: depletion of IFN-alpha led only to its rapid reconstitution. Cell-associated HIV-1 was unchanged, but three of four subjects had a modest decrease in culturable plasma virus burden following the procedures. The recovery of in vivo HIV-1-related IFN-alpha by apheresis allowed its biologic and biochemical characterization. The HIV-1 IFN-alpha showed characteristics on ELISA, western blot, and biologic assays similar to two subspecies of the natural protein. The natural, recombinant, and HIV-1-induced IFN-alpha s demonstrated nearly identical antiviral activities. The HIV-1 IFN-alpha eluted from the column was not acid labile. The inability of large amounts of plasma IFN-alpha found in some patients with AIDS to affect viral burden likely reflects properties of the virus or of host factors independent of IFN-alpha.

Central nervous system lesions in liver transplant recipients: prospective assessment of indications for biopsy and implications for management.

BACKGROUND: Precise diagnosis of central nervous system (CNS) lesions in liver transplant recipients remains problematic. Brain biopsies are often not feasible as a result of coagulopathy. We sought to determine whether selected clinical or radiologic characteristics can predict the likely etiology of CNS lesions in liver transplant recipients and thus obviate the need for diagnostic brain biopsies. METHODS: A 4-year prospective, observational, cohort study was conducted at liver transplant centers at four geographically diverse medical institutions. A total of 1730 consecutive liver transplant recipients were evaluated for CNS lesions; 60 patients with radiologically documented CNS lesions comprised the study sample. RESULTS: Vascular events (52%, 31/60), infections (181%, 11/60), immunosuppressive associated leukoencephalopathy (12%, 7/60), central pontine myelinolysis (8%, 5/60), and malignancy (3%, 2/60) were the predominant etiologies of CNS lesions. CNS lesions were most likely to occur within 30 days of transplantation (43%, 26/60); central pontine myelinolysis, subdural hematoma, acute infarcts, and Aspergillus brain abscesses were the predominant etiologies during this time. All brain abscesses were fungal; 73% (8/11) of these patients concurrently had documented extraneural (pulmonary) infection as a result of the same fungal pathogen. Thus, a diagnostic brain biopsy is not warranted in these patients. Patients on dialysis were more likely to have ischemic or infectious CNS lesions (P=0.03). Vascular events were more likely to occur in repeat transplant recipients (P=0.03). Twenty-five percent (15/60) of the CNS lesions occurred more than 1 year after transplantation; small vessel ischemic lesions, malignancy, or non-Aspergillus fungal brain abscesses accounted for all such lesions. CONCLUSIONS: A presumptive etiologic diagnosis can be established in a vast majority of CNS lesions in liver transplant recipients based on identifiable presentation that includes time of onset, unique risk factors, and neuroimaging characteristics. Empiric therapy of brain abscesses in liver transplant recipients should include antifungal and not antibacterial agents.

A pilot study of antibiotic cycling in a hematology-oncology unit.

OBJECTIVE: To determine the safety and treatment efficacy of cycling antibiotic regimens for prophylaxis or treatment of patients with profound neutropenia. DESIGN: A prospective, nonrandomized, observational trial. SETTING: A 20-bed adult hematology-oncology inpatient unit at a university referral hospital. PATIENTS: Hospitalized adult patients with chemotherapy- or radiation-induced neutropenia (absolute neutrophil count less than 500 cells/mm3). INTERVENTION: Between July 1994 and January 1996, 295 hospitalized patients were evaluated on an intent-to-treat basis for the cycling protocol. Of these, 271 were eligible and assigned to one of four antibiotic regimens being used at the time of enrollment: (1) ceftazidime+vancomycin; (2) imipenem; (3) aztreonam+cefazolin; (4) ciprofloxacin+clindamycin. Data on infection rates and types, and antibiotic resistance patterns, toxicity, and effectiveness were collected. RESULTS: Twenty-four patients were excluded. Of the 271 evaluable patients, 123 (42%) were able to complete treatment on the assigned regimen. Of the 148 patients (50%) unable to do so, the reasons for failure included persistent fever (79%), breakthrough bacteremia (14%), and drug toxicity (7%). The antibiotic susceptibility profiles over the study period showed no increase in resistance. However, there was a marked increase in enterococcal infections. CONCLUSIONS: Our data show no significant increase in side effects or decrease in efficacy while cycling antibiotics among neutropenic patients and thus support further study of its role.

Pneumococcal vaccination: work to date and future prospects.

In our opinion, the conclusion from all these studies is that pneumococcal polysaccharides in the form in which they have been administered are relatively poor immunogens when compared, for example, to certain proteins such as tetanus toxoid. Had pneumococcal vaccination been the success that might reasonably have been predicted, there would be no argument, this many years later, over its merits. Although polysaccharide vaccines appear to have been effective in mass vaccination programs and in epidemic situations where presumably healthy adults have been involved, it has been more difficult to document their efficacy in individuals who are most in need of them, namely those with aberrant or senescent immune systems. There seems to be no disagreement that antibody at some concentration (the precise level remains to be determined) will, in general, be associated with protection, although in any one individual, for a variety of reasons, infection with a vaccine serotype might still occur. Thus, the clear direction for the future should be not to argue further the merits of currently available vaccine preparations, but rather to work rapidly and efficiently to develop and test new and more effective polysaccharide antigens. Studies in the past 10 years have shown that the polyribosyl ribitolphosphate (PRP) of Haemophilus influenzae type b is a far more effective antigen when conjugated to diphtheria toxoid. For example, in a study in our laboratory, vaccination of healthy young adults with PRP-conjugated diphtheria toxoid yielded serum antibody levels 10- to 100-fold higher than after PRP alone. Responses may be even better if other proteins are used.(ABSTRACT TRUNCATED AT 250 WORDS)

[Origin of surgical metastatic bone disease]. / Origen de la enfermedad ósea metastática quirúrgica.

BACKGROUND: Metastatic bone disease should be considered as a public health problem. The alterations it may cause include pain that is refractory to medical treatment, metabolic instability, pathologic fractures and spinal disorders. MATERIAL AND METHODS: The primary tumor site that led to the need for surgery was investigated in a series of patients with a diagnosis of metastatic bone disease. The bone involved and the histology of the lesions were also studied. RESULTS: Kidney cancer was the one that most frequently required a surgical procedure; it was followed by breast and prostate cancer. The primary tumor was not found in 6.36% of cases. The bones affected by the lesions studied were as follows in order of occurrence: femur, spine, humerus and pelvis. Adenocarcinoma was the most frequent histological diagnosis. DISCUSSION: The diagnosis of metastatic bone disease should always be considered in patients over forty years of age with skeletal lesions, preferably lytic. CONCLUSIONS: In this study, kidney cancer, the proximal limbs and adenocarcinomas were the variables that most frequently produced metastatic bone lesions that warranted a surgical procedure.

Adoption of thermometry into clinical practice in the United States.

Technologic advances in thermometer design and conceptual advances in the understanding of homeostasis between 1700 and 1850 led to recognition of the usefulness of measuring body temperature in human disease. These advances took place in Europe and Great Britain, culminating in the publication in 1868 of the seminal work on fever in human disease by Carl Wunderlich. In the United States thermometry was popularized by a number of distinguished American physicians who used European data that had appeared in British and American journals even before 1868. Thus Edward Seguin and Austin Flint included fever curves and vital signs in articles that appeared in 1866. Flint and Jacob DaCosta added sections on thermometry to their medical textbooks in 1866-1867, and Edouard Seguin (the father of Edward) encouraged the use of thermometry by the public at large in a series of articles in the medical and lay press. Within just two decades thermometry became recognized as an indispensable medical tool, which it remains to the present time.

Comparison of rapid diagnostic techniques for respiratory syncytial and influenza A virus respiratory infections in young children.

We performed virus isolation tests for respiratory viruses on combined nasal wash-throat swab specimens collected from infants and children with acute respiratory illnesses presenting to a hospital clinic during a 3-month period of concurrent epidemics of respiratory syncytial virus (RSV) and influenza A virus (Flu A) infections. Virus isolation results were used to assess the utility of commercially available rapid diagnostic kits for these two viruses. The kits employed direct immunofluorescence (IF) of cells (Imagen for RSV and Flu A), indirect IF of cells (Baxter Bartels Microscan), and enzyme immunoassay (EIA) (Becton Dickinson Directigen for RSV and Flu A and Abbott TestPack for RSV). All testing was completed on 81 specimens from 80 subjects. Of the 81 specimens, 53 (65%) yielded a virus: RSV, 28%; Flu A, 25%; rhinovirus, 6%; and enterovirus, cytomegalovirus, herpes simplex virus, and adenovirus, 2 to 4% each. Among the tests, Bartels Microscan and Directigen Flu-A exhibited the highest sensitivities (87 and 75%) and efficiencies (94 and 94%) for RSV and Flu A, respectively. All the tests exhibited high specificity. Thus, optimal detection of RSV and Flu A among infants and children who presented to a hospital clinic required two different detection methods (IF and enzyme immunoassay) and kits from two different companies (Baxter [Bartels Microscan] and Becton Dickinson [Directigen]).

Comparison of reverse transcription-PCR with tissue culture and other rapid diagnostic assays for detection of type A influenza virus.

We applied a reverse transcription (RT)-PCR assay for influenza A virus to combined nasal wash-throat swab specimens previously obtained from an outpatient pediatric population with acute respiratory illness during concurrent epidemics of influenza A virus and respiratory syncytial virus. The results of the RT-PCR assay were compared with those previously reported with virus cultivation and commercially available rapid diagnostic kits (E.A. Dominguez, L.H. Taber, and R.B. Couch, J. Clin. Microbiol. 31:2286-2290, 1993). With virus cultivation as the "gold standard", the RT-PCR assay had a sensitivity, specificity, and efficiency of 95, 98, and 97%, respectively, compared with 75, 100, and 93%, respectively, for the best diagnostic kit (Becton Dickinson Directigen). RT-PCR is an effective alternative to virus isolation for the detection of influenza A virus in clinical specimens.

Infective endocarditis in solid organ transplant recipients.

Infective endocarditis, defined as pathologically or clinically definite by the Duke criteria, was observed in 14 transplant recipients at our institutions. In addition, we reviewed 32 previously reported cases in solid organ transplant recipients. The spectrum of organisms causing infective endocarditis was clearly different in transplant recipients than in the general population; 50% of the infections were due to Aspergillus fumigatus or Staphylococcus aureus, but only 4% were due to viridans streptococci. Fungal infections predominated early (accounting for six of 10 cases of endocarditis within 30 days of transplantation), while bacterial infections caused most cases (80%) after this time. In 80% (37) of the 46 cases in transplant recipients, there was no underlying valvular disease. Seventy-four percent (34) of the 46 cases were associated with previous hospital-acquired infection, notably venous access device and wound infections. Three patients with S. aureus endocarditis had had an episode of S. aureus bacteremia > 3 weeks prior to the diagnosis of endocarditis and had received treatment for the initial bacteremia of < 14 days' duration. The overall mortality rate was 57% (26 of 46 patients died), with 58% (15) of the 26 fatal cases not being suspected during life. Endocarditis is an underappreciated sequela of hospital-acquired infection in transplant recipients.

An outbreak of vancomycin-resistant Enterococcus faecium in liver transplant recipients.

Vancomycin-resistant Enterococcus faecium (VREF) has become a significant nosocomial pathogen for immunosuppressed patients. During a 5-month period in 1993, 8 cases of invasive infection with VREF (7 with bacteremia) were identified in liver transplant recipients, half of whom were adults. Epidemiology and microbiology studies were designed to identify the source and to determine the risk factors for this infection. Overall mortality was 50% (3 adults and 1 child). Mortality in bacteremic patients was 57%. A case-control study showed that cases were more likely to have been treated with a third-generation cephalosporin or vancomycin and to have undergone more than four biliary tract procedures. Environmental surveillance cultures yielded only one VREF isolate from a rectal temperature probe, but this device was used in only 2 of the cases. Cultures from all surgery and radiology suites were negative. All VREF isolates were genotyped by contour-clamped homogenous electric field electrophoresis of chromosomal DNA restriction fragments. These studies showed that a single clone was responsible for the outbreak, although other clones could be detected in the hospital. After implementing strict contact isolation on the liver transplant unit, only 1 additional patient with VREF was identified during this outbreak. In conclusion, it was found that antibiotic use and biliary tract manipulation were risk factors for developing invasive infections with VREF after liver transplantation. Optimal treatment is still unclear but most likely includes a combination of two or more antibiotics. Prompt institution of infection control measures can preclude rapid spread of this nosocomial pathogen.

Development and application of an enzyme immunoassay for coronavirus OC43 antibody in acute respiratory illness.

Study of coronavirus OC43 infections has been limited because of the lack of sensitive cell culture systems and serologic assays. To improve this circumstance, we developed an indirect enzyme immunoassay (EIA) to detect serum antibody to OC43. Antigen (100 ng) prepared by polyethylene glycol precipitation provided optimal results without a postcoat procedure. Evaluation of intraplate variation indicated that a > or = 2.5-fold increase in serum titer was significant. Sixteen of 18 (89%) paired serum samples with previously identified, reproducible increases in the level of hemagglutination inhibition (HAI) antibody to OC43 also showed significant increases as detected by EIA. Specificity for the EIA was established with paired sera obtained from persons given influenza immunizations or experiencing a respiratory infection. No rise in antibody titers occurred among 33 persons with documented coronavirus 229E infection. EIA was then performed on each of 419 paired serum samples from ambulatory chronic obstructive pulmonary disease patients and healthy older adults, from asthmatic adults presenting for emergency room treatment, and from persons hospitalized with acute respiratory symptoms. Twenty-three antibody rises to OC43 were detected; only nine of these were detected by the HAI test, and the HAI test did not detect any increases in antibody titers that were not detected by EIA. Nineteen of 25 coronavirus OC43 infections for which a month of infection could be assigned occurred between November and February. Overall, 4.4% of acute respiratory illnesses in the studied populations were associated with a coronavirus OC43 infection.

An epidemic of pneumococcal disease in an overcrowded, inadequately ventilated jail.

BACKGROUND: In the United States many correctional facilities now operate at far over capacity, with the potential for living conditions that permit outbreaks of respiratory infections. We investigated an outbreak that was identified in an overcrowded Houston jail after two inmates died of pneumococcal sepsis on the same day. Outbreaks of pneumococcal disease have been rare in the era of antibiotics. METHODS: We assessed risk factors for pneumococcal disease in both a case-control and a cohort study. Ventilation was evaluated by measuring carbon dioxide levels and air flow to the living areas of the jail. The extent of asymptomatic infection was determined by culturing pharyngeal specimens from a random sample of inmates. Type-specific immunity was determined with an enzyme immunoassay. RESULTS: Over a four-week period, 46 inmates had either acute pneumonia or invasive pneumococcal disease due to Streptococcus pneumoniae serotype 12F. The jail's capacity had been set at 3500 inmates, but it housed 6700 at the time of the outbreak; the inmates had a median living area of only 34 ft2 (3.2 m2) (interquartile range, 28 to 56 ft2 [2.6 to 5.2 m2]) per person. There were significantly fewer cases of disease among inmates with 80 ft2 (7.4 m2) per person or more (P = 0.030). Carbon dioxide levels ranged from 1100 to 2500 ppm (acceptable, < 1000), and the ventilation system delivered a median of only 6.1 ft3 of outside air per minute per person (interquartile range, 4.4 to 8.5 ft3; recommended, > or = 20 ft3). The attack rate was highest among inmates in cells with the highest carbon dioxide levels and the lowest volume of outside air delivered by the ventilation system (relative risk, 1.94; 95 percent confidence interval, 1.08 to 3.48). Of underlying medical conditions, intravenous drug use was most strongly associated with disease (odds ratio, 4.50). The epidemic strain (serotype 12F) was cultured from 7 percent of the asymptomatic inmates. Of 11 case patients tested with the enzyme immunoassay, 9 (82 percent) lacked preexisting immunity to this strain. CONCLUSIONS: Severe overcrowding, inadequate ventilation, and altered host susceptibility all contributed to this outbreak of pneumococcal disease in a large urban jail.