Infection prevention and control measures and tools for the prevention of entry of carbapenem-resistant Enterobacteriaceae into healthcare settings: guidance from the European Centre for Disease Prevention and Control

Background

Infections with carbapenem-resistant Enterobacteriaceae (CRE) are increasingly being reported from patients in healthcare settings. They are associated with high patient morbidity, attributable mortality and hospital costs. Patients who are “at-risk” may be carriers of these multidrug-resistant Enterobacteriaceae (MDR-E).

The purpose of this guidance is to raise awareness and identify the “at-risk” patient when admitted to a healthcare setting and to outline effective infection prevention and control measures to halt the entry and spread of CRE.

Methods

The guidance was created by a group of experts who were functioning independently of their organisations, during two meetings hosted by the European Centre for Disease Prevention and Control. A list of epidemiological risk factors placing patients “at-risk” for carriage with CRE was created by the experts. The conclusions of a systematic review on the prevention of spread of CRE, with the addition of expert opinion, were used to construct lists of core and supplemental infection prevention and control measures to be implemented for “at-risk” patients upon admission to healthcare settings.

Results

Individuals with the following profile are “at-risk” for carriage of CRE: a) a history of an overnight stay in a healthcare setting in the last 12 months, b) dialysis-dependent or cancer chemotherapy in the last 12 months, c) known previous carriage of CRE in the last 12 months and d) epidemiological linkage to a known carrier of a CRE.

Core infection prevention and control measures that should be considered for all patients in healthcare settings were compiled. Preliminary supplemental measures to be implemented for “at-risk” patients on admission are: pre-emptive isolation, active screening for CRE, and contact precautions. Patients who are confirmed positive for CRE will need additional supplemental measures.

Conclusions

Strengthening the microbiological capacity, surveillance and reporting of new cases of CRE in healthcare settings and countries is necessary to monitor the epidemiological situation so that, if necessary, the implemented CRE prevention strategies can be refined in a timely manner. Creating a large communication network to exchange this information would be helpful to understand the extent of the CRE reservoir and to prevent infections in healthcare settings, by applying the principles outlined here.

This guidance document offers suggestions for best practices, but is in no way prescriptive for all healthcare settings and all countries. Successful implementation will result if there is local commitment and accountability. The options for intervention can be adopted or adapted to local needs, depending on the availability of financial and structural resources.

Electronic supplementary material

The online version of this article (10.1186/s13756-017-0259-z) contains supplementary material, which is available to authorized users.

Influenza A(H1N1)pdm09 vaccination policies and coverage in Europe

In August 2010 the Vaccine European New Integrated Collaboration Effort (VENICE) project conducted a survey to collect information on influenza A(H1N1)pdm09 vaccination policies and vaccination coverage in the European Union (EU), Norway and Iceland. Of 29 responding countries, 26 organised national pandemic influenza vaccination and one country had recommendations for vaccination but did not have a specific programme. Of the 27 countries with vaccine recommendations, all recommended it for healthcare workers and pregnant women. Twelve countries recommended vaccine for all ages. Six and three countries had recommendations for specific age groups in children and in adults, countries for specific adult age groups. Most countries recommended vaccine for those in new risk groups identified early in the pandemic such as morbid obese and people with neurologic diseases. Two thirds of countries started their vaccination campaigns within a four week period after week 40/2009. The reported vaccination coverage varied between countries from 0.4% to 59% for the entire population (22 countries); 3% to 68% for healthcare workers (13 countries); 0% to 58% for pregnant women (12 countries); 0.2% to 74% for children (12 countries). Most countries identified similar target groups for pandemic vaccine, but substantial variability in vaccination coverage was seen. The recommendations were in accordance with policy advice from the EU Health Security Committee and the World Health Organization.

Multidrug-resistant, extensively drug-resistant and pandrug-resistant bacteria: an international expert proposal for interim standard definitions for acquired resistance

Many different definitions for multidrug-resistant (MDR), extensively drug-resistant (XDR) and pandrug-resistant (PDR) bacteria are being used in the medical literature to characterize the different patterns of resistance found in healthcare-associated, antimicrobial-resistant bacteria. A group of international experts came together through a joint initiative by the European Centre for Disease Prevention and Control (ECDC) and the Centers for Disease Control and Prevention (CDC), to create a standardized international terminology with which to describe acquired resistance profiles in Staphylococcus aureus, Enterococcus spp., Enterobacteriaceae (other than Salmonella and Shigella), Pseudomonas aeruginosa and Acinetobacter spp., all bacteria often responsible for healthcare-associated infections and prone to multidrug resistance. Epidemiologically significant antimicrobial categories were constructed for each bacterium. Lists of antimicrobial categories proposed for antimicrobial susceptibility testing were created using documents and breakpoints from the Clinical Laboratory Standards Institute (CLSI), the European Committee on Antimicrobial Susceptibility Testing (EUCAST) and the United States Food and Drug Administration (FDA). MDR was defined as acquired non-susceptibility to at least one agent in three or more antimicrobial categories, XDR was defined as non-susceptibility to at least one agent in all but two or fewer antimicrobial categories (i.e. bacterial isolates remain susceptible to only one or two categories) and PDR was defined as non-susceptibility to all agents in all antimicrobial categories. To ensure correct application of these definitions, bacterial isolates should be tested against all or nearly all of the antimicrobial agents within the antimicrobial categories and selective reporting and suppression of results should be avoided.

Multidrug-resistant, extensively drug-resistant and pandrug-resistant bacteria: an international expert proposal for interim standard definitions for acquired resistance

Many different definitions for multidrug-resistant (MDR), extensively drug-resistant (XDR) and pandrug-resistant (PDR) bacteria are being used in the medical literature to characterize the different patterns of resistance found in healthcare-associated, antimicrobial-resistant bacteria. A group of international experts came together through a joint initiative by the European Centre for Disease Prevention and Control (ECDC) and the Centers for Disease Control and Prevention (CDC), to create a standardized international terminology with which to describe acquired resistance profiles in Staphylococcus aureus, Enterococcus spp., Enterobacteriaceae (other than Salmonella and Shigella), Pseudomonas aeruginosa and Acinetobacter spp., all bacteria often responsible for healthcare-associated infections and prone to multidrug resistance. Epidemiologically significant antimicrobial categories were constructed for each bacterium. Lists of antimicrobial categories proposed for antimicrobial susceptibility testing were created using documents and breakpoints from the Clinical Laboratory Standards Institute (CLSI), the European Committee on Antimicrobial Susceptibility Testing (EUCAST) and the United States Food and Drug Administration (FDA). MDR was defined as acquired non-susceptibility to at least one agent in three or more antimicrobial categories, XDR was defined as non-susceptibility to at least one agent in all but two or fewer antimicrobial categories (i.e. bacterial isolates remain susceptible to only one or two categories) and PDR was defined as non-susceptibility to all agents in all antimicrobial categories. To ensure correct application of these definitions, bacterial isolates should be tested against all or nearly all of the antimicrobial agents within the antimicrobial categories and selective reporting and suppression of results should be avoided.

Multidrug-resistant, extensively drug-resistant and pandrug-resistant bacteria: an international expert proposal for interim standard definitions for acquired resistance

Many different definitions for multidrug-resistant (MDR), extensively drug-resistant (XDR) and pandrug-resistant (PDR) bacteria are being used in the medical literature to characterize the different patterns of resistance found in healthcare-associated, antimicrobial-resistant bacteria. A group of international experts came together through a joint initiative by the European Centre for Disease Prevention and Control (ECDC) and the Centers for Disease Control and Prevention (CDC), to create a standardized international terminology with which to describe acquired resistance profiles in Staphylococcus aureus, Enterococcus spp., Enterobacteriaceae (other than Salmonella and Shigella), Pseudomonas aeruginosa and Acinetobacter spp., all bacteria often responsible for healthcare-associated infections and prone to multidrug resistance. Epidemiologically significant antimicrobial categories were constructed for each bacterium. Lists of antimicrobial categories proposed for antimicrobial susceptibility testing were created using documents and breakpoints from the Clinical Laboratory Standards Institute (CLSI), the European Committee on Antimicrobial Susceptibility Testing (EUCAST) and the United States Food and Drug Administration (FDA). MDR was defined as acquired non-susceptibility to at least one agent in three or more antimicrobial categories, XDR was defined as non-susceptibility to at least one agent in all but two or fewer antimicrobial categories (i.e. bacterial isolates remain susceptible to only one or two categories) and PDR was defined as non-susceptibility to all agents in all antimicrobial categories. To ensure correct application of these definitions, bacterial isolates should be tested against all or nearly all of the antimicrobial agents within the antimicrobial categories and selective reporting and suppression of results should be avoided.

Differences in national influenza vaccination policies across the European Union, Norway and Iceland 2008-2009

In 2009 the second cross-sectional web-based survey was undertaken by the Vaccine European New Integrated Collaboration Effort (VENICE) project across 27 European Union (EU) member states (MS), Norway and Iceland (n=29) to determine changes in official national seasonal influenza vaccination policies since a survey undertaken in 2008 and to compare the estimates of vaccination coverage between countries using data obtained from both surveys. Of 27 responding countries, all recommended vaccination against seasonal influenza to the older adult population. Six countries recommended vaccination of children aged between six months and <18 years old. Most countries recommended influenza vaccination for those individuals with chronic medical conditions. Recommendations for vaccination of healthcare workers (HCW) in various settings existed in most, but not all countries. Staff in hospitals and long-term care facilities were recommended vaccination in 23 countries, and staff in out-patient clinics in 22 countries. In the 2009 survey, the reported national estimates on vaccine coverage varied by country and risk group, ranging from 1.1% - 82.6% for the older adult population; to between 32.9% -71.7% for clinical risk groups; and from 13.4% -89.4% for HCW. Many countries that recommend the influenza vaccination do not monitor the coverage in risk groups. In 2008 and 2009 most countries recommended influenza vaccination for the main risk groups. Hovewer, despite general consensus and recommendations for vaccination of high risk groups many countries do not achieve high coverage in these groups. The reported vaccination coverage still needs to be improved in order to achieve EU and World Health Organization goals.

Low coverage of seasonal influenza vaccination in the elderly in many European countries

In May 2003, the 56th World Health Assembly (WHA) recommended influenza vaccination for all people at high risk defined as the elderly and persons with underlying diseases [1]. The WHA countries, including all European Union (EU) Member States, also committed to the goal of attaining vaccination coverage of the elderly population of at least 50% by 2006 and 75% by 2010 and to having mechanisms for monitoring the uptake [1]. To date there has been no published survey on how successful European countries have been in implementing this WHA resolution.

Antioxidants and free radical scavengers for the treatment of stroke, traumatic brain injury and aging

The overproduction of reactive oxygen species (ROS) and reactive nitrogen species (RNS) is a common underlying mechanism of many neuropathologies, as they have been shown to damage various cellular components, including proteins, lipids and DNA. Free radicals, especially superoxide (O(2)*-), and non-radicals, such as hydrogen peroxide (H(2)O(2)), can be generated in quantities large enough to overwhelm endogenous protective enzyme systems, such as superoxide dismutase (SOD) and reduced glutathione (GSH). Here we review the mechanisms of ROS and RNS production, and their roles in ischemia, traumatic brain injury and aging. In particular, we discuss several acute and chronic pharmacological therapies that have been extensively studied in order to reduce ROS/RNS loads in cells and the subsequent oxidative stress, so-called "free-radical scavengers." Although the overall aim has been to counteract the detrimental effects of ROS/RNS in these pathologies, success has been limited, especially in human clinical studies. This review highlights some of the recent successes and failures in animal and human studies by attempting to link a compound's chemical structure with its efficacy as a free radical scavenger. In particular, we demonstrate how antioxidants derived from natural products, as well as long-term dietary alterations, may prove to be effective scavengers of ROS and RNS.

Effect of flue gas desulfurization residue on plant establishment and soil and leachate quality

Effects on soil quality and crop establishment after incorporation of flue gas desulfurization by-product (FGD) into soil as an amendment was assessed in a mesocosm study. Mesocosm units received applications equivalent to 0, 2.5, 5.0, 7.5, and 10% FGD residue [0, 25, 50, 75, and 100 tons acre(-1)]. Germination, biomass production, and elemental composition of corn (Zea mays L. var. Dekalb DK-683), soybean [Glycine max (L.) Merr. var. Haskell Pupa 94], radish (Raphanus sativus L. var. Sparkler), and cotton (Gossypius hirsutus L. var. Deltapine 51) were determined. The quality of leachates and soil were also determined periodically. Flue gas desulfurization residue did not affect germination and all application rates stimulated aboveground biomass. Plants grown in FGD-amended soil contained significantly elevated tissue concentrations of As, B, Se, and Mo. The FGD residue elevated surface soil pH from 5.5 (Control) to 8.1 (at 10% FGD). Leachate pH was unaffected by FGD, but salinity rose sharply with increasing application rates of FGD. Leachates contained higher concentrations of B, with small increases in Se and As. Flue gas desulfurization residue application caused an increase in total B, As, Mo, Se, and extractable Ca in the soil, but decreased Mn and Zn. Using FGD residues could have beneficial effects on crop establishment without detrimental effects on soil or leachate quality, at an optimum rate of approximately 2.5%. This material could alleviate surface acidity, and B and Mo deficiencies in plants.

Influence of fly ash on soil physical properties and turfgrass establishment

A field study (1993-96) assessed the benefits of applying unusually high rates of coal fly ash as a soil amendment to enhance water retention of soils without adversely affecting growth and marketability of the turf species, centipedegrass [Eremochloa ophiuroides (Munro) Hack.]. A Latin Square plot design was employed that included 0 (control, no ash applied), 280, 560, and 1120 Mg ha-1 application rates of unweathered precipitator fly ash. The fly ash was spread evenly over each plot area, rototilled, and allowed to weather under natural conditions for 8 mo before seeding. High levels of soluble salts, indicated by the electrical conductivity (EC) of soil extracts, in tandem with an apparent phytotoxic effect from boron (B), apparently inhibited initial plant establishment as shown by substantially lower germination counts in treated soil. However, plant height and rooting depth were not adversely affected, as were the dry matter (DM) yields throughout the study period. Ash treatment did not significantly influence water infiltration rate, bulk density, or temperature of the soil, but substantially improved water-holding capacity (WHC) and plant-available water (PAW). Enhanced water retention capacity improved the cohesion and handling property of harvested sod.

Traumatic injury of cortical neurons causes changes in intracellular calcium stores and capacitative calcium influx

Using an in vitro traumatic injury model, we examined the effects of mechanical (stretch) injury on intracellular Ca2+ store-mediated signaling in cultured cortical neurons using fura-2. We previously found that elevation of [Ca2+](i) by the endoplasmic reticulum Ca2+-ATPase inhibitor, thapsigargin, was abolished 15 min post-injury. In the current studies, pre-injury inhibition of phospholipase C with neomycin sulfate maintained Ca2+-replete stores 15 min post-injury, suggesting that the initial injury-induced store depletion may be due to increased inositol trisphosphate production. Thapsigargin-stimulated elevation of [Ca2+](i) returned with time after injury and was potentiated at 3 h. Stimulation with thapsigargin in Ca2+-free media revealed that the size of the Ca2+ stores was normal at 3 h post-injury. However, Ca2+ influx triggered by depletion of intracellular Ca2+ stores (capacitative Ca2+ influx) was enhanced 3 h after injury. Enhancement was blocked by inhibitors of cytosolic phospholipase A2 and cytochrome P450 epoxygenase. Since intracellular Ca2+ store-mediated signaling plays an important role in neuronal function, the observed changes may contribute to dysfunction produced by traumatic brain injury. Additionally, our results suggest that capacitative Ca2+ influx may be mediated by both conformational coupling and a diffusible messenger synthesized by the combined action of cytosolic PLA2 and P450.

Traumatic injury of cultured astrocytes alters inositol (1,4,5)-trisphosphate-mediated signaling

Our previous studies using an in vitro model of traumatic injury have shown that stretch injury of astrocytes causes a rapid elevation in intracellular free calcium ([Ca2+]i), which returns to near normal by 15 min postinjury. We have also shown that after injury astrocyte intracellular calcium stores are no longer able to release Ca2+ in response to signal transduction events mediated by the second messenger inositol (1,4,5)-trisphosphate (IP3, Rzigalinski et al., 1998). Therefore, we tested the hypothesis that in vitro injury perturbs astrocyte IP3 levels. Astrocytes grown on Silastic membranes were labeled with [3H]-myo-inositol and stretch-injured. Cells and media were acid-extracted and inositol phosphates isolated using anion-exchange columns. After injury, inositol polyphosphate (IPx) levels increased up to 10-fold over uninjured controls. Significant injury-induced increases were seen at 5, 15, and 30 min and at 24 and 48 h postinjury. Injury-induced increases in IPx were equivalent to the maximal glutamate and trans-(1S,3R)-1-amino-1,3-cyclopentanedicarboxylic acid-stimulated IPx production, however injury-induced increases in IPx were sustained through 24 and 48 h postinjury. Injury-induced increases in IPx were attenuated by pretreatment with the phospholipase C inhibitors neomycin (100 microM) or U73122 (1.0 microM). Since we have previously shown that astrocyte [Ca2+]i returns to near basal levels by 15 min postinjury, the current results suggest that IP3-mediated signaling is uncoupled from its target, the intracellular Ca2+ store. Uncoupling of IP3-mediated signaling may contribute to the pathological alterations seen after traumatic brain injury.

Alterations in calcium-mediated signal transduction after traumatic injury of cortical neurons

Calcium influx and elevation of intracellular free calcium ([Ca2+]i), with subsequent activation of degradative enzymes, is hypothesized to cause cell injury and death after traumatic brain injury. We examined the effects of mild-to-severe stretch-induced traumatic injury on [Ca2+]i dynamics in cortical neurons cultured on silastic membranes. [Ca2+]i was rapidly elevated after injury, however, the increase was transient with neuronal [Ca2+]i returning to basal levels by 3 h after injury, except in the most severely injured cells. Despite a return of [Ca2+]i to basal levels, there were persistent alterations in calcium-mediated signal transduction through 24 h after injury. [Ca2+]i elevation in response to glutamate or NMDA was enhanced after injury. We also found novel alterations in intracellular calcium store-mediated signaling. Neuronal calcium stores failed to respond to a stimulus 15 min after injury and exhibited potentiated responses to stimuli at 3 and 24 h post-injury. Thus, changes in calcium-mediated cellular signaling may contribute to the pathology that is observed after traumatic brain injury.

A bioactive peptide from the transmembrane 5-intracellular loop 3 region of the human 5HT1a receptor

15 amino acid peptide from the transmembrane 5-intracellular loop 3 region of the human 5HT1a receptor produced concentration-dependent decreases in agonist binding. This result is consistent with a competitive interaction between peptide, receptor, and G protein at the receptor-G protein interface. Bombesin and a 13 amino acid peptide from the carboxyl terminus region of the receptor were inactive. Additionally, the peptide decreased forskolin-mediated cAMP elevation. Overall, these results suggest that amino acid residues from this region of the receptor are involved in receptor-G protein coupling and that G protein is activated by the receptor.

Effect of HIV reporting by name on use of HIV testing in publicly funded counseling and testing programs

CONTEXT

Policies requiring confidential reporting by name to state health departments of persons infected with the human immunodeficiency virus (HIV) have potential to cause some of them to avoid HIV testing.

OBJECTIVE

To describe trends in use of HIV testing services at publicly funded HIV counseling and testing sites before and after the implementation of HIV reporting policies.

DESIGN AND SETTING

Analysis of service provision data from 6 state health departments (Louisiana, Michigan, Nebraska, Nevada, New Jersey, and Tennessee) 12 months before and 12 months after HIV reporting was introduced.

MAIN OUTCOME MEASURE

Percent change in numbers of persons tested at publicly funded HIV counseling and testing sites after implementation of confidential HIV reporting by risk group.

RESULTS

No significant declines in the total number of HIV tests provided at counseling and testing sites in the months immediately after implementation of HIV reporting occurred in any state, other than those expected from trends present before HIV reporting. Increases occurred in Nebraska (15.8%), Nevada (48.4%), New Jersey (21.3%), and Tennessee (62.8%). Predicted decreases occurred in Louisiana (10.5%) and Michigan (2.0%). In all areas, testing of at-risk heterosexuals increased in the year after HIV reporting was implemented (Louisiana, 10.5%; Michigan, 225.1 %; Nebraska, 5.7%; Nevada, 303.3%; New Jersey, 462.9%; Tennessee, 603.8%). Declines in testing occurred among men who have sex with men in Louisiana (4.3%) and Tennessee (4.1%) after HIV reporting; testing increased for this group in Michigan (5.3%), Nebraska (19.6%), Nevada (12.5%), and New Jersey (22.4%). Among injection drug users, testing declined in Louisiana (15%), Michigan (34.3%), and New Jersey (0.6%) and increased in Nebraska (1.7%), Nevada (18.9%), and Tennessee (16.6%).

CONCLUSIONS

Confidential HIV reporting by name did not appear to affect use of HIV testing in publicly funded counseling and testing programs.

Invasive cervical cancer in human immunodeficiency virus-infected and uninfected hospital patients

OBJECTIVE

To compare the prevalence of invasive cervical cancer in women with, and in women without, human immunodeficiency virus (HIV) infection, so as to evaluate the inclusion of invasive cervical cancer in the AIDS surveillance case definition.

METHODS

The Sentinel Hospital Surveillance System for HIV Infection collected data and serum specimens that remained after clinical testing of persons who received inpatient or outpatient care at 14 hospitals with high HIV prevalence. We analyzed data on invasive cervical cancer obtained from medical record review and HIV serostatus from white, black, and Hispanic women in the age groups 20-34, 35-44, and 45-54 years.

RESULTS

In 1994 and 1995, 2684 (6.6%) of the 40,524 women sampled were HIV infected. Of the HIV-positive women, 28 had invasive cervical cancer (10.4 per 1000 women) and of the HIV-negative women, 236 had invasive cervical cancer (6.2 per 1000 women, relative risk [RR] 1.7, 95% confidence interval [CI] 1.1, 2.5). The prevalence of invasive cervical cancer was higher for HIV-positive than for HIV-negative black women aged 20-34 (RR 3.8; CI 1.7, 8.5) and Hispanic women aged 20-34 (RR 7.3; CI 1.4, 37.1) and 35-44 (RR 3.9; CI 1.1, 14.7) years. Twenty-six of the 28 cases of invasive cervical cancer in HIV-positive women were in women known to be HIV-positive during admission.

CONCLUSION

The prevalence of invasive cervical cancer was higher for women who were HIV positive than for women who were HIV negative. This lends support to the inclusion of invasive cervical cancer in the revision of the surveillance case definition for AIDS in 1993.

Intracellular free calcium dynamics in stretch-injured astrocytes

We have previously developed an in vitro model for traumatic brain injury that simulates a major component of in vivo trauma, that being tissue strain or stretch. We have validated our model by demonstrating that it produces many of the posttraumatic responses observed in vivo. Sustained elevation of the intracellular free calcium concentration ([Ca2+]i) has been hypothesized to be a primary biochemical mechanism inducing cell dysfunction after trauma. In the present report, we have examined this hypothesis in astrocytes using our in vitro injury model and fura-2 microphotometry. Our results indicate that astrocyte [Ca2+]i is rapidly elevated after stretch injury, the magnitude of which is proportional to the degree of injury. However, the injury-induced [Ca2+]i elevation is not sustained and returns to near-basal levels by 15 min postinjury and to basal levels between 3 and 24 h after injury. Although basal [Ca2+]i returns to normal after injury, we have identified persistent injury-induced alterations in calcium-mediated signal transduction pathways. We report here, for the first time, that traumatic stretch injury causes release of calcium from inositol trisphosphate-sensitive intracellular calcium stores and may uncouple the stores from participation in metabotropic glutamate receptor-mediated signal transduction events. We found that for a prolonged period after trauma astrocytes no longer respond to thapsigargin, glutamate, or the inositol trisphosphate-linked metabotropic glutamate receptor agonist trans-(1S,3R)-1-amino-1,3-cyclopentanedicarboxylic acid with an elevation in [Ca2+]i. We hypothesize that changes in calcium-mediated signaling pathways, rather than an absolute elevation in [Ca2+]i, is responsible for some of the pathological consequences of traumatic brain injury.

An outbreak of Brainerd diarrhea among travelers to the Galapagos Islands

In 1992, an outbreak of chronic diarrhea occurred among passengers on a cruise ship visiting the Galapagos Islands, Ecuador. Passengers (548) were surveyed, and stool and biopsy specimens from a sample who reported chronic diarrhea were examined. On completed questionnaires, returned by 394 passengers (72%), 58 (15%) reported having chronic diarrhea associated with urgency (84%), weight loss (77%), fatigue (71%), and fecal incontinence (62%). Illness began 11 days (median) after boarding the ship and lasted 7 to >42 months. Macroscopic and histologic abnormalities of the colon were common, but extensive laboratory examination revealed no etiologic agent. No one responded to antimicrobial therapy. Patients were more likely than well passengers to have drunk the ship's unbottled water or ice before onset of illness and to have eaten raw sliced fruits and vegetables washed in unbottled water. Water handling and chlorination on the ship were deficient. Outbreaks of a similar illness, Brainerd diarrhea, have been reported in the United States. Although its etiology remains unknown, Brainerd diarrhea may also occur among travelers.

Trends in HIV seropositivity in publicly funded HIV counseling and testing programs: implications for prevention policy

INTRODUCTION

We describe trends in seropositivity among clients attending publicly funded HIV counseling and testing sites across the United States and discuss implications for prevention policy.

METHODS

The present analysis used client-level data from 1990 through 1994 for 26 of 65 state, territorial, and local health departments receiving Centers for Disease Control and Prevention funds. Logistic regression was used to predict the proportion of HIV tests that were positive. Curves were created representing adjusted HIV seropositivity trends for 1990 through 1994.

RESULTS

HIV seropositivity rates were higher before 1992. Throughout, rates were higher among men, most racial/ethnic minorities tested, and persons 30 years or older. Although rates for men remained higher than those for women, the gap has narrowed in recent years. For both men and women, rates remained low for those reporting heterosexual activity as their only potential risk for HIV. Over time, more high-risk seronegatives are being repeatedly tested.

CONCLUSIONS

Lower, stabilized seropositivity rates after 1992 reflect large increases in testing volume, increasing frequency of repeat testing, and fewer asymptomatic-infected persons entering this public system. Various program innovations including enhanced outreach, improved access, rapid testing, and client-centered counseling should be considered as strategies to increase the number of infected persons who learn their serostatus early and enter into medical care.

Presence of human immunodeficiency virus (HIV) type 1 subtype A infection in a New York community with high HIV prevalence: a sentinel site for monitoring HIV genetic diversity in North America. Centers for Disease Control and Prevention-Bronx Lebanon HIV Serosurvey Team

To determine whether US residents are infected with subtypes of human immunodeficiency virus (HIV) type 1 other than subtype B (Western), the predominant North American subtype with a unique GPGR genetic sequence in the V3 loop, viruses from 22 HIV-infected adults were serotyped and subtyped. Twenty patients had subtype B (Western), of whom 15 had serotype B (Western), 3 had serotype A/C, 1 had serotype B (Thai), and 1 had a nontypeable serotype. Two had subtype A, both serotype A/C. Both subtype A-infected patients, only 1 of whom had been outside the United States, reported sex with persons traveling abroad, suggesting possible acquisition in the United States. Because US residents are infected with non-subtype B (Western) strains, US surveillance for HIV-1 diversity is needed to elucidate subtype-specific transmission patterns and pathogenesis and to guide evaluation and development of HIV diagnostic tests and vaccines.

Tumor necrosis factor-alpha: a neuromodulator in the CNS

In the central nervous system (CNS), the cytokine tumor necrosis factor-alpha (TNF alpha) is produced by both neurons and glial cells, participates in developmental modeling, and is involved in many pathophysiological conditions. There are activity-dependent expressions of TNF alpha as well as low levels of secretion in the resting state. In contrast to the conventional view of a cytotoxic effect of TNF alpha, accumulating evidence suggests a beneficial effect when TNF alpha is applied at optimal doses and at specific periods of time. The bimodal effect is related to subtypes of receptors, activation of different signal transduction pathways, and the presence of other molecules that alter the intracellular response elements such as immediate-early genes. TNF alpha may be an important neuromodulator in development of the CNS, diseases of demyelination and degeneration, and in the process of regeneration. It could induce growth-promoting cytokines and neurotrophins, or it could increase the production of antiproliferative cytokines, nitric oxide, and free radicals, thereby contributing to apoptosis.

Activity of Parthenolide at 5HT2A receptors

Parthenolide displaces [3H]ketanserin from 5HT2A receptors from rat and rabbit brain and cloned 5HT2A receptors. Ki's are in the 100-250 microM range. These results suggest that parthenolide may be a low-affinity antagonist at 5HT receptors; it is unlikely that the entire mechanism of action can be explained by its modest 5HT2A receptor affinity.

Publicly funded HIV counseling and testing in the United States, 1992-1995

Data are collected and reported through the Centers for Disease Control and Prevention (CDC) Counseling and Testing System (CTS) on episodes of publicly funded counseling and HIV testing in the Unites States. The objective of this analysis is to describe testing data reported from 1992 through 1995. In 1992, 2,689,056 tests were performed, and 55,024 (2.0%) were positive; in 1995, 2,491,434 tests were performed, of which 40,605 (1.6%) were positive. Among tests reported with client-level data, the proportion of tests of men and women at higher risk for HIV infection remained stable or declined; the proportion of tests of persons who had been previously tested increased each year; and in 1995, the proportion of tests that included posttest counseling was 86% for anonymous and 70% for confidential tests. Although information collected through CTS could be improved by changing the system so that individuals could be distinguished from testing episodes, the CTS does provide important monitoring information to local and state health departments.

Rabbit cerebral cortex 5HT1a receptors

Selective 5HT1a agonist binding to membranes from rabbit cerebral cortex was concentration-dependent and saturable; the Kd was 1.1 nM and Bmax of 480 fmols/mg protein. Scatchard as well as Hill plots were linear; the Hill coefficient was 0.96, suggesting a single, non-interacting binding site. Agonist binding was inhibited in a concentration-dependent fashion by gamma S GTP, a result consistent with the coupling of this binding site to the G protein signal transduction system. In competition experiments involving agonist and a series of agents with known affinities and specificities at 5HT1a receptors, a rank order relationship was found consistent with this binding site being a 5HT1a binding site. Direct comparisons of agonist and antagonist binding at rat cerebral cortex 5HT1a receptors and cloned human 5HT1a receptors also suggested that the rabbit binding site belongs to the 5HT1a class. The only rank order anomalies were with methiothepin in rabbit cerebral cortex, where a comparatively high Ki was observed and with buspirone in cloned human 5HT1a receptor, where a low Ki was determined; these anomalies bear further study in light of the comparative pharmacology of 5HT1a receptors. Finally, the natural product parthenolide was tested for affinity in the rabbit, rat, and human systems, where it uniformly was unable to displace agonist, suggesting that the 5HT1a receptor is not a target for this compound. Overall, these results suggest that a functional 5HT1a receptor exists in rabbit cerebral cortex.

Performance characteristics of a rapid HIV antibody assay in a hospital with a high prevalence of HIV infection. CDC-Bronx-Lebanon HIV Serosurvey Team

BACKGROUND

The delay between collection of blood samples and availability of test results may be as long as 3 weeks and is one barrier to the acceptance of voluntary testing for human immunodeficiency virus (HIV) infection. Serologic tests that provide results rapidly could overcome this barrier, but the accuracy and reliability of rapid tests have not been well characterized in the United States.

OBJECTIVE

To evaluate, in a "real world" setting, the performance characteristics of a rapid HIV assay that reduces the need for patients to return for counseling after the test.

DESIGN

Testing of HIV antibodies by rapid and nonrapid assays and survey about risk behaviors for HIV.

SETTING

A hospital in Bronx, New York, with a high prevalence of HIV-seropositive patients.

PATIENTS

837 patients who were not known to be infected with HIV, had not been admitted for conditions related to the acquired immunodeficiency syndrome, and agreed to participate in HIV testing and an interview.

MEASUREMENTS

Sensitivity and specificity of a rapid HIV antibody assay based on comparisons with nonrapid assay and Western blot assay.

RESULTS

According to nonrapid assays, 5.4% of patients were infected with HIV. The rapid assay was highly accurate in this sample overall: its sensitivity was 1.00, its specificity was 0.991, its positive predictive value was 0.865, and its negative predictive value was 1.00. The assay was also highly accurate in various subgroups.

CONCLUSIONS

Accurate, rapid tests for HIV infection may enhance testing programs by preventing the need for delayed counseling of seronegative patients and by providing preliminary results to seropositive patients. These preliminary results may encourage patients to return for confirmatory test results and to adopt risk-reducing behaviors sooner.

Experience with the use of an investigational F(ab')2 heptavalent botulism immune globulin of equine origin during an outbreak of type E botulism in Egypt

During an outbreak of type E foodborne botulism in Cairo in 1991, an investigational equine F(ab')2 "despeciated" heptavalent botulism immune globulin (dBIG) was provided to the Egyptian Ministry of Health by the U.S. Army. Of 54 patients known to have been treated with antitoxins, 4 received commercially available trivalent antitoxins, 45 received dBIG, and 5 received both commercial antitoxin and dBIG. Physicians recorded side effects in 10 (22%) of 45 patients who received dBIG; in nine cases, reactions were considered "mild," and in one case they were believed to be serum sickness. In contrast, possible serum sickness during hospitalization was recorded for two of four patients who were receiving commercial antitoxins. No complications of therapy were noted for any patient who was receiving both antitoxin types. In a separate study, 31 patients were contacted about their reactions to the antitoxin by telephone after discharge from the hospital. Seven (54%) of 13 patients attributed symptoms that they experienced while they were hospitalized to receipt of dBIG, while four (44%) of nine patients who indicated that they had received commercial antitoxins and one (20%) of five who received both commercial antitoxin and dBIG reported side effects before discharge. Data on the efficacy of the antitoxins were not obtained. In our experience, equine dBIG was at least as safe as commercially available antitoxins in treating type E foodborne botulism.

Absence of human immunodeficiency virus type 2 infection among patients in a hospital serving a New York community at high risk for infection. Centers for Disease Control and Prevention/Bronx-Lebanon Hospital Center HIV Serosurvey Team

BACKGROUND

Although human immunodeficiency virus type 2 (HIV-2) infection among United States residents is considered rare, there are US populations at high risk. Few studies have surveyed these populations with a high likelihood of infection, that is, those with high percentages of persons from HIV-2-endemic areas and high prevalences of behaviors that would allow for transmission.

STUDY DESIGN AND METHODS

Patients (n = 832) enrolled in a confidential HIV serosurvey at a hospital that serves a community with a relatively high percentage of West African immigrants, drug injectors, and persons who practice high-risk sexual activity were evaluated. Sera were tested for HIV type 1 (HIV-1) and HIV-2 by rapid enzyme immunoassays, standard enzyme immunoassays and Western blots.

RESULTS

Eight of 832 patients were weakly reactive to HIV-2 on rapid assay, but none was confirmed to be infected when tested by standard immunoassay and Western blot. Five of these eight were reactive to HIV-1.

CONCLUSION

Weak reactivity to HIV-2 antibody on the rapid assay is best explained by cross-reactivity with HIV-1 antibody; thus, even in this population at high risk for infection, false-positive reactions are more likely than true infections. The finding that HIV-2 is absent in this population at potentially high risk for infection corroborates the findings of other studies that HIV-2 infection is rare among US residents. These results support previous recommendations that, in settings other than blood collection facilities, HIV-2 testing should be selectively offered to persons with epidemiologic risk factors.

The first reported outbreak of diarrheal illness associated with Cyclospora in the United States

OBJECTIVE

To investigate and characterize the epidemiology of a diarrheal outbreak associated with a potentially new pathogen, Cyclospora species (previously referred to as Cyanobacteria [blue-green algae]-like bodies).

DESIGN

Three retrospective cohort studies supported by laboratory studies, environmental investigation, and community surveillance.

SETTING

A hospital in Chicago.

PARTICIPANTS

Housestaff physicians and hospital administrative staff.

MEASUREMENTS

Identification of clinical features associated with illness and potential risks for acquisition of infection.

RESULTS

Illness was characterized by watery diarrhea, abdominal cramping, decreased appetite, and low-grade fever. Symptoms typically occurred in a distinctive cycle of remissions and exacerbations lasting up to several weeks. Stool cultures and examinations for known ova and parasites were negative. Microscopic examination of stool specimens from 11 ill persons showed many spherical bodies, 8 to 10 microns in diameter, that were identified as Cyclospora organisms. The organisms disappeared by 9 weeks after onset of illness in the 7 patients from whom follow-up specimens were obtained. Epidemiologic studies implicated tap water from a physicians' dormitory as the most likely source of the outbreak. Environmental investigation suggested that stagnant water in a storage tank may have contaminated the water supply after a pump failure.

CONCLUSIONS

This is the first reported outbreak of diarrhea associated with Cyclospora in the United States. Cyclospora may be a human enteric pathogen able to produce bouts of acute and relapsing diarrhea, and it should be considered in assessments of patients with unexplained, prolonged diarrheal illness.

New treatments for Chlamydia trachomatis genital infection

To provide information for the formulation of treatment guidelines, we review recently published articles and abstracts on advances in the treatment of Chlamydia trachomatis genital infection. We ask specific questions about new treatments that are answered on the basis of the results of clinical trials and efficacy studies. New, potentially effective treatments for C. trachomatis genital infection include azithromycin and ofloxacin. Clinical studies indicate that the efficacy of these agents is equivalent to that of the current recommended agent doxycycline. Both azithromycin and ofloxacin are substantially more expensive than doxycycline. Azithromycin has the advantage of being given as a single dose, while doxycycline and ofloxacin are administered for 1 week. Issues of compliance, cost, and toxicity for specific patients should be considered when deciding whether to treat C. trachomatis genital infections with these agents.

Synaptic morphology of substance P terminals on catecholamine neurons in the commissural subnucleus of the nucleus tractus solitarii in the rat

The ultrastructure of substance P-containing nerve terminals synapsing on catecholamine neurons in the rat commissural subnucleus of the nucleus tractus solitarii (NTScom) was studied using a double immunocytochemical labeling technique. Although there were numerous tyrosine hydroxylase-immunoreactive (TH-I) somata present, substance P immunoreactive (SP-I) cell bodies were only occasionally found in the NTScom. At the light microscopic level, many SP-I terminals were seen closely associated with TH-I dendrites and somata. At the electron microscopic level, SP-I terminals synapsing on TH-I structures were also readily encountered. SP-I terminals contained small, clear, and predominantly spherical vesicles (32 +/- 4 nm diameter), as well as large dense-cored vesicles approximately 100 nm in diameter. Postsynaptic TH-I dendritic profiles of various calibers and somata were encountered. These postsynaptic TH-I structures often showed postsynaptic densities. The morphological features of the SP-TH synapses in the present study, that is, the size of synaptic vesicles and the presence of postsynaptic densities, are quite different from those of central carotid sinus afferent synapses reported in our previous study [Chen et al. (1992), J. Neurocytol., 21:137-147]. Therefore, most of the SP terminals of the SP-TH synapses in the NTScom appear not to originate from the carotid sinus afferents. SP-I second-order neurons of the carotid sinus afferent pathway [Chen et al. (1991), J. Auton. Nerv. Syst., 33:97-98] may be one of the possible sources of such terminals.

Synaptic connections of central carotid sinus afferents in the nucleus of the tractus solitarius of the rat. II. Connections with substance P-immunoreactive neurons

A combined transganglionic transport and immunocytochemical technique was used to study the synaptic morphology of central carotid sinus afferents and substance P-immunoreactive neurons in the commissural subnucleus of the nucleus of the tractus solitarius in rats. A large population of substance P-immunoreactive neurons (88.32%) were seen in close association with central carotid sinus afferents by light microscopy. However, many labelled central carotid sinus afferents appeared not associated with substance P-immunoreactive neurons in the nucleus of the tractus solitarius. Substance P-immunoreactive neurons were spindle, pear, or oval-shaped with a short axis ranging from 5 to 11 microns. Their long axis was oriented predominantly in a lateral-medial direction along the path of the central carotid sinus afferents from the solitary tract to the midline. Synaptic contacts between central carotid sinus afferents and substance P-structures, including dendritic profiles of different calibers and somas, were readily found by electron microscopy. Many central carotid sinus afferents were also found in synaptic contact with non-immunoreactive dendrites and somas. Appositions between central carotid sinus afferents and unlabelled axon terminals were common, but only in a few cases were morphological manifestations of synapses revealed. In the latter, the substance P-immunoreactive terminals appeared mostly presynaptic but postsynaptic ones were also encountered. Our data provide the evidence that some of the substance P-immunoreactive cells in the nucleus of the tractus solitarius are 2nd order neurons of the carotid sinus afferent pathway. The possibility that some of the substance P-immunoreactive neurons in the nucleus of the tractus solitarius may be interneurons and mediate carotid sinus afferent inputs to catecholaminergic neurons in the nucleus of the tractus solitarius is considered. Our findings also provide an anatomical substrate for a possible presynaptic modulatory role of central carotid sinus afferents on the inputs from other brain centers to the substance P-neurons in the nucleus of the tractus solitarius.

Cholera in the United States, 1965-1991. Risks at home and abroad

OBJECTIVE

To assess risks for cholera in the United States.

DESIGN

Review of published reports of cholera outbreaks and sporadic cases and Centers for Disease Control and Prevention (CDC) memoranda and laboratory reports.

PATIENTS

Persons with symptomatic laboratory-diagnosed cholera treated in the United States and territories.

RESULTS

From 1965 through 1991, 136 cases of cholera were reported. Fifty-three percent of the patients were hospitalized and three persons died (case-fatality rate, 0.02). Ninety-three infections were acquired in the United States and 42 overseas; for one case the source was unknown. Domestically acquired cholera was largely related to the endemic Gulf Coast focus of Vibrio cholerae 01 (56 cases). The major domestic food vehicle was shellfish, particularly crabs harvested from the Gulf of Mexico or nearby estuaries. In 1991, 14 (54%) of 26 domestically acquired cases were caused by food from Ecuador (n = 11) and Thailand (n = 3). During 1991, the first cases of cholera in travelers returning from South America were reported. In 1991, the rate of cholera among air travelers returning from South America was estimated as 0.3 per 100,000; among air travelers returning from Ecuador, 2.6 per 100,000.

CONCLUSIONS

Cholera remains a small but persistent risk in the United States and for travelers. An endemic focus on the Gulf Coast, the continuing global pandemic, and the epidemic in South America make this likely to continue for years to come. Physicians should know how to diagnose and treat cholera and should report all suspected cases to their state health departments.

The neurotrophins and their receptors: structure, function, and neuropathology

The neurotrophins are a family of polypeptides that promote differentiation and survival of select peripheral and central neurons. Nerve growth factor, brain-derived neurotrophic factor, neurotrophin-3, neurotrophin-4, and neurotrophin-5 are included in this group. In recent years, tremendous advances have been made in the study of these factors. This has stimulated our review of the field, characterizing the neurotrophins from initial isolation to molecular analysis. The review also discusses their synthesis, localization, and responsive tissues, in both the periphery and CNS. The complex receptor interactions of the neurotrophins are also analyzed, as are putative signal transduction mechanisms. Discussion of the observed and postulated involvement in neuropathological disorders leads to the conclusion that the neurotrophins are involved in the function and dysfunction of the nervous system.

Epidemic cholera in Ecuador: multidrug-resistance and transmission by water and seafood

To determine risk factors for cholera in an epidemic-disease area in South America, a case-control investigation was performed in Guayaquil, Ecuador, in July 1991. Residents > 5 years old who were hospitalized for treatment of acute, watery diarrhoea and two matched controls for each were interviewed regarding sources of water and food, and eating, drinking, and hygienic habits. Interviewers inspected homes of case-patients and controls to document water treatment, food-handling, and hygienic practices. Faecal specimens and shellfish were cultured for Vibrio cholerae O 1. Isolates were tested for susceptibility to a variety of antimicrobial agents. Drinking unboiled water (odds ratio [OR] = 4.0, confidence interval [CI] = 1.8-7.5), drinking a beverage from a street vendor (OR = 2.8, CI = 1.3-5.9), eating raw seafood (OR = 3.4, CI = 1.4-11.5), and eating cooked crab (OR = 5.1, CI = 1.4-19.2) were associated with illness. Always boiling drinking water at home (OR = 0.5, CI = 0.2-0.9) was protective against illness. The presence of soap in either the kitchen (OR = 0.3, CI = 0.2-0.8) or bathroom (OR = 0.4, CI = 0.2-0.9) at home was also protective. V. cholerae O 1 was recovered from a pooled sample of a bivalve mollusc and from 68% of stool samples from case-patients. Thirty-six percent of the isolates from stool specimens were resistant to multiple antimicrobial agents. Specific prevention measures may prevent transmission through these vehicles in the future. The appearance of antimicrobial resistance suggests the need for changes in current methods of prevention and treatment.

The opiate system in invertebrates

The presence in diverse species of a similar mode of communication, that of a soluble messenger binding to a receptor, raises the question as to whether the specific components of this system are equally widespread. Do invertebrates use the same hormones and receptors as vertebrates do? Invertebrates ranging from unicellular organisms to insects have been shown to contain opiate-like peptides and binding sites, and they exhibit biological responses to opiates. However, critical genetic data are lacking. It is not known how signal systems arise phylogenetically, but it is conceivable that signal molecules that are already present cause the formation of their own receptors from membrane proteins.

Chemoarchitectonic subdivisions of the visual pulvinar in monkeys and their connectional relations with the middle temporal and rostral dorsolateral visual areas, MT and DLr

The organization of the inferior pulvinar complex (PI) in squirrel monkeys was studied with histochemical localization of the calcium binding proteins calbindin-D28k and parvalbumin, and of cytochrome oxidase. With each of these markers, the inferior pulvinar complex can be subdivided into four distinct regions. Calbindin-D28k immunoreactivity is densely distributed in cells and neuropil within PI, except for a distinct centromedially located gap. This calbindin-poor zone, termed the medial division of the inferior pulvinar (PIM), corresponds precisely to a region that contains elevated cytochrome oxidase activity and parvalbumin immunostaining. The PIM extends slightly above and behind the classically defined limit of the inferior pulvinar, the corticotectal tract. Regions of inferior pulvinar with intense immunostaining for calbindin-D28k were the posterior division of the inferior pulvinar (PIP, medial to PIM) and the central division (PIC, lateral to PIM). A newly recognized lateral region, PIL, adjoins the lateral geniculate nucleus and stains more lightly for calbindin and parvalbumin immunoreactivity and for cytochrome oxidase. Staining patterns for calbindin, parvalbumin, and cytochrome oxidase in the pulvinar of rhesus monkeys closely resemble those shown in squirrel monkey inferior pulvinar, suggesting that a common organization exists in all primates. In order to examine cortical connection patterns of the histochemically defined compartments in the inferior pulvinar, injections of up to five neuroanatomical tracers (wheat germ agglutinin conjugated to horseradish peroxidase and fluorescent retrograde tracers) were placed in the same cerebral hemisphere. Single injection sites were in the middle temporal area (MT), and several separate injections were placed in a strip corresponding to the rostral subdivision of the dorsolateral area (DLr). Injections that involved only DLr and not MT labeled principally the PIC, and more sparsely PIP and PIL. DLr connections occupied a "shell" region dorsal to PIM that extended from PIC into the lateral and medial divisions of the pulvinar, PL and PM. Injection sites that included MT or were largely restricted to MT produced dense label in PIM and moderate label in PIC and PIL. The retinotopic organization within the inferior pulvinar was inferred from patterns of connections. Connections with cortex related most closely to central vision were found posteriorly in PIM and in adjacent portions of PIC as it wraps around the caudal pole of PIM. Cortex related to more peripheral locations in the lower visual field connected with more rostral PIM and PIC. Patterns of label within the portions of PL and PM that were immediately adjacent to PIM roughly paralleled those in PIM and PIC.(ABSTRACT TRUNCATED AT 400 WORDS)

An outbreak of diarrhea and hemolytic uremic syndrome from Escherichia coli O157:H7 in fresh-pressed apple cider

OBJECTIVE

Escherichia coli O157:H7 causes hemorrhagic colitis and the hemolytic uremic syndrome. In the fall of 1991, an outbreak of E coli O157:H7 infections in southeastern Massachusetts provided an opportunity to identify transmission by a seemingly unlikely vehicle.

DESIGN

Case-control study to determine the vehicle of infection. New England cider producers were surveyed to assess production practices and determined the survival time of E coli O157:H7 organisms in apple cider.

RESULTS

Illness was significantly associated with drinking one brand of apple cider. Thirteen (72%) of 18 patients but only 16 (33%) of 49 controls reported drinking apple cider in the week before illness began (odds ratio [OR], 8.3; 95% confidence interval [CI], 1.8 to 39.7). Among those who drank cider, 12 (92%) of 13 patients compared with two (13%) of 16 controls drank cider from cider mill A (lower 95% CI, 2.9; P < .01). This mill pressed cider in a manner similar to that used by other small cider producers: apples were not washed, cider was not pasteurized, and no preservatives were added. In the laboratory, E coli O157:H7 organisms survived for 20 days in unpreserved refrigerated apple cider. Addition of sodium benzoate 0.1% reduced survival to less than 7 days.

CONCLUSIONS

Fresh-pressed, unpreserved apple cider can transmit E coli O157:H7 organisms, which cause severe infections. Risk of transmission can be reduced by washing and brushing apples before pressing, and preserving cider with sodium benzoate. Consumers can reduce their risk by only drinking cider made from apples that have been washed and brushed.

Wound botulism in a patient with a tooth abscess: case report and review

We describe a case of wound botulism associated with a tooth abscess in a 5-year-old boy. We reviewed the literature and reports to the Centers for Disease Control and Prevention (Atlanta) of laboratory-confirmed cases of wound botulism. From 1943 through 1990, 47 cases were reported. Type A botulinus toxin was identified in 32 cases, type B in 13, types A and B in 1, and an unknown type in 1. Botulism was associated with wounds from trauma, use of injectable drugs, and surgery. Sinusitis after use of intranasal cocaine has also been associated with botulism. Treatment for wound botulism includes prompt debridement of the wound for eliminating anaerobic conditions, intensive care, and treatment with antitoxin.

A massive outbreak of type E botulism associated with traditional salted fish in Cairo

In April 1991, 91 hospitalized patients in Cairo were reported to the Egyptian Ministry of Health with botulism intoxication. To define the spectrum of illness and identify a food vehicle, 45 patients were interviewed and a case-control investigation was conducted among families of 5 hospitalized patients. Clinical specimens and specimens of implicated food were tested for toxin and cultured for Clostridium botulinum. Hospitalized patients had symptoms consistent with botulism; 18 (20%) of 91 reported patients died. Illness was associated with eating faseikh (uneviscerated, salted mullet fish; lower 95% confidence limit of odds ratio = 6.6, P < .001). All 5 case-families purchased faseikh from one shop. Very high levels of type E botulinal toxin were detected in faseikh reported to be purchased from the implicated shop; C. botulinum type E was isolated from cultures of clinical specimens and from the faseikh. This is the first documented outbreak of botulism in Egypt and the largest type E outbreak ever reported.

Modulation of chloride secretion in the rat colon by intracellular bicarbonate

Extracellular HCO3- stimulates colonic net Cl- absorption in part by inhibiting basal Cl- secretion. This inhibition was investigated by measuring serosal-to-mucosal Cl- flux across short-circuited colonic segments from Sprague-Dawley rats. Mucosal intracellular pH and bicarbonate were estimated using the pH-sensitive dye BCECF. When extracellular [HCO3-] ([HCO3-]e) was increased from 0 to 39 mmol/L at PCO2 33 mm Hg, mucosal intracellular [HCO3-] ([HCO3-]i) increased to 25.3 mmol/L and serosal-to-mucosal Cl- flux decreased from 13.0 to 7.1 microEq.cm-2.h-1. When PCO2 was increased to 72 mm Hg at [HCO3-]e 39 mmol/L, [HCO3-]i increased to 29.8 mmol/L and serosal-to-mucosal Cl- flux decreased to 5.9 microEq.cm-2.h-1. In Ringer's solution containing 21 mmol/L HCO3- and 20 mmol/L Cl- (but not 100 mmol/L Cl-), increasing PCO2 from 21 to 70 mm Hg increased [HCO3-]i to 22.6 mmol/L and decreased serosal-to-mucosal Cl- flux from 3.0 to 1.7 microEq.cm-2.h-1. Overall, serosal-to-mucosal Cl- flux was inversely related to [HCO3-]i on either side of an [HCO3-]i plateau of 9-18 mmol/L at which flux was stable. These data suggest that [HCO3-]i is an important modulator of basal Cl- secretion in rat distal colon.

Synaptic connections of central carotid sinus afferents in the nucleus of the tractus solitarius of the rat. I. An electron microscopic study

A transganglionic transport technique was used to study the synaptic connections of the central carotid sinus afferents in the nucleus of the tractus solitarius of the rat by electron microscopy. The caudal part of the nucleus was profusely innervated. Labelled fibres extended to the contralateral nucleus, and to the ipsilateral dorsal motor nucleus of the vagus nerve, nucleus ambiguus, spinal nucleus of the trigeminal nerve and the area postrema. The labelled terminals were densely packed with clear, predominantly spherical vesicles about 50 nm in diameter and a few often swollen mitochondria. The terminals synapsed on dendrites of various calibres, spindle- or pear-shaped somal profiles with short axes lesser than 8 microns, and axon terminals. In axo-axonal synapses, most labelled terminals appeared to be presynaptic. Frequently, profiles of labelled terminals were in direct apposition with one another. The latter may represent the morphological substrate of the interaction between baro- and chemoreceptor inputs in the nucleus of the tractus solitarius and warrants further study. The present results indicate that in addition to direct inputs, the carotid sinus afferents are able to influence second-order neurons in the nucleus of the tractus solitarius indirectly through presynaptic modulation.

Liposarcoma of the esophagus

Presented here is a report on an unusual liposarcoma of the esophagus. A 66-year-old-woman was treated successfully by surgical excision without removal of the esophagus. Thirty months after surgery and radiation she presented with neither complaint nor recurrence.

The parabigeminogeniculate projection: connectional studies in eight mammals

Anterograde and retrograde tracing methods have been used to analyze the origin and distribution of parabigeminogeniculate axons in the gray squirrel, the gopher, the rat, the opossum, the cat, the greater bushbaby, the squirrel monkey and the macaque monkey. Our findings reveal that parabigeminogeniculate axons most heavily innervate regions of the lateral geniculate that are also targeted by axons arising from the superior colliculus (tectogeniculate). These geniculate layers and zones of parabigeminal and tectal overlap contain small cells, and in several species are associated with the small W cell retino-geniculocortical pathway. In addition to the dense input to small-celled layers and zones, parabigeminal axons in several species also innervate regions of the lateral geniculate nucleus that are relatively free of tectogeniculate axons and that are associated with the medium (X) and large (Y) cell streams. Finally, our data reveal that the laterality of parabigeminogeniculate pathways varies across mammals, being primarily crossed in the gray squirrel, the gopher, the rat, and the opossum, bilateral in the cat, and primarily ipsilateral in the three primates.

Neuroanatomical studies of the nigrotectal projection in the cat

We have used retrograde and anterograde transport methods to analyze the nigrotectal projection in the cat. This projection arises from both pars reticulata (SNr) and pars lateralis (SNl) and distributes to all cellular laminae of the superior colliculus. This extensive nigrotectal innervation is not a simple, single circuit. Rather it appears to consist of several parallel channels, with each taking origin from a particular zone of the substantia nigra and terminating within specific collicular laminae and/or sublaminae. For instance, only neurons within the SNl project to the stratum griseum superficiale; such neurons also project diffusely to all other tectal laminae. Cells in the most lateral portion of the SNr project to a horizontal, patchy tier in the interface region between the stratum opticum and the stratum griseum intermediate (SGI). Finally, more medially placed neurons within the SNr project to a horizontal patchy tier within the middle of the SGI and to a wedge-shaped locus in the stratum griseum profundum. Our findings provide an anatomical substrate for electrophysiological data (Karabelas and Moschovakis: J. Comp. Neurol. 239: 309-329, '85) showing a widespread distribution of nigrorecipient tectal neurons in the cat.