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* Context.-Induced sputum sampling has an approximate 70% sensitivity for detection of Pneumocystis jiroveci in human immunodeficiency virus (HIV) patients. Bronchoalveolar lavage sampling has greater than 90% sensitivity but is a far more invasive procedure. Therefore, bronchoalveolar lavage testing is often recommended as a follow-up after a negative induced sputum. In HIV-negative patients, the utility of induced sputum testing is still not well defined.

Objective.-To determine whether repeat induced sputum sampling increases diagnostic yield and might thereby reduce the need for follow-up bronchoalveolar lavage sampling. To determine the utility of induced sputum sampling in HIV-negative patients.

Design.-A 2-year retrospective review of the utility of repeat induced sputa testing in patients with previous first and/or second negative induced sputa. Retrospective review of induced sputa detection in HIV-negative patients.

Results.-Repeat testing of induced sputa for Pneumocystic jirovecii did not significantly increase diagnostic yield. Furthermore, in HIV-negative patients, induced sputum testing was diagnostically insensitive.

Conclusions.-Bronchoalveolar lavage testing should be performed initially in HIV-negative patients and after a first negative induced sputum in HIV-positive patients.

(Arch Pathol Lab Med. 2007;131:1582-1584)

Pneumocystis jiroveci (formerly Pneumocystic carinii) causes a severe pneumonia in immunocompromised patients. Direct fluorescent antibody testing is a sensitive and standard method for detection of P jiroveci in clinical samples.1 However, optimal sensitivity requires adequate sampling of lower respiratory secretions. In prior studies in human immunodeficiency virus (HIV)-positive patients, induced sputum and bronchoalveolar lavage (BAL) sampling generally yield sensitivities of roughly 70% and greater than 90%, respectively.2,3 Because induced sputum collection is less invasive, induced sputum has often been favored as the initial specimen in HIV-positive patients.1

In a retrospective review of data from a large tertiary care teaching hospital, 2 issues were addressed. The first was whether repeat induced sputum collection increases diagnostic yield and thereby decreases the need for follow- up BAL procedures in HIV-positive patients. The second was the utility of induced sputum collection in HIVnegative patients, a population in which organism burden is lower4 and in which a diagnostic algorithm optimized for HIV-positive patients might not be similarly applicable.

METHODS

Sample Processing

Induced sputa were collected by respiratory therapists after inhalation of nebulized 3% NaCl. Specimens were deemed insufficient that (1) did not appear to be induced as judged by the microbiology technologist; (2) were of poor quality, that is, did not have any cellular material; or (3) were less than 2 mL. Insuf- ficient specimens were excluded from our analysis. Bronchoalveolar lavage samples were similarly assessed for sufficiency by criteria 2 and 3. For each induced sputum or BAL sample, 2 cytospin preparations were made, stained with the MONOFLUO Pneumocystis carinii IFA Test Kit (Bio-Rad, Hercules, Calif) according to the manufacturer’s instructions, and screened for infection.

Data Acquisition

Electronic medical records were reviewed to ascertain relevant laboratory data and clinical history. This study was approved by our institutional review board and conducted according to institutional guidelines.

RESULTS

Diagnostic Yield of Multiple Induced Sputa

Pneumocystis testing results from samples submitted to our microbiology laboratory during a 2-year period from 2004 to 2005 were reviewed. During this time, 687 patients submitted 666 induced sputum specimens and 393 BAL specimens. Among these patients, 615 had known HIV status.

Data are summarized in the Table. Notably, testing of the first induced sputum in HIV-positive patients demonstrated a positivity rate of 11.8%. In contrast, testing of a second induced sputum after a first negative induced sputum yielded only a single additional positive result or a 3.3% yield, whereas testing a third induced sputum after 2 negative induced sputa yielded no additional positives. This contrasts with a 23.8% yield obtained with BAL after a negative induced sputum or a 7.2-fold relative increase in detection. Therefore, repeat induced sputum testing does not significantly increase diagnostic yield.

In contrast to initial high sensitivity for HIV-positive patients, only a single HIV-negative patient of 211 was diagnosed by induced sputum testing. Furthermore, no additional cases were detected after second or third induced sputum. However, testing of BAL fluid after a negative induced sputum led to a 7.4% diagnostic yield or a 13- fold relative increase in detection. Interestingly, those tested initially by BAL sampling had a lower positivity rate of 1.5%. Therefore, in the HIV-negative patient population, clinicians preferentially chose a much less sensitive method for initial testing, that is, induced sputum sampling, in those at greatest risk for Pneumocystis pneumonia.

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Around the world, there has been an increase in epidemiological surveillance of bloodborne infections.1-3 This is due to the fact that blood transfusion has served as a prominent route for transmission of such infections; however, prevalence varies from one region to another.4-7 In order to prevent the transmission of these infections through blood transfusion, plans, policies and procedures have been put in place to screen prospective blood donors in Nigeria.

Although a variety of agents are transmissible through blood, hepatitis B (HBV), hepatitis C (HCV) and human immunodeficiency virus (HIV) rank high on the list of frequently screened infectious agents because of their pathological course.8-10 Routine screening of blood donors for HBV and HIV is now carried out by most blood banks in Nigeria, but only a few centres11 routinely screen for HCV. In West Africa, prevalence of HCV among blood donors is 1.1-6.7%,12-15 but there is no national policy for screening donors for HCV in Nigeria.

The aim of this study is to estimate the seroprevalence and possible co-infections of HBV, HCV and HIV among prospective blood donors attending the authors’ institution.

A total of 2496 asymptomatic prospective blood donors (voluntary and replacement) attending the blood bank at Ladoke Akintola University Teaching Hospital between July 2004 and December 2005 were recruited to the study. Informed consent was obtained from each participant. A 5 mL clotted sample of venous blood was obtained from each donor, and the serum was stored at -20° C until tested.

Hepatitis A surface antigen (HBsAg) was detected by a sandwich immunoassay test strip (Clinotech Diagnostics, Canada) in which monoclonal and polyclonal antibodies are employed. The strip was dipped into the serum for 2-3 sec and read for visibility of one test line and one procedural control line after 10-20 min. The limit of sensitivity provided by the manufacturer was 5 ng/mL. Antibody to HCV was detected using a recombinant double antigen sandwich immunoassay (Clinotech Diagnostics, Canada), following a procedure similar to that adopted for HBsAg.

Antibodies to HIV-1, HIV-2 and HIV-I O subtypes were detected using the HIV1/2/O Tri-line HIV rapid test device, which is a qualitative immunochromatographic assay employing a membrane strip precoated with recombinant HIV antigens in the test lines, T1 (HIV-1 and subtype O) and T2 (HIV-2) regions, and a procedural control line C (relative sensitivity: 99.9%, relative specificity: 99.6%, relative accuracy: 99.7%, correlation with HIV enzyme-linked immunosorbent assay [ELISA]: 99.7%).

All 2496 prospective donors, comprising 1988 (79.6%) males and 508 (20.4%) females (male:female ratio 3.9:1) in the study were screened. Age ranged from 18 to 65 years, and the majority (68.3%) were in the 21-40 age group (Table 1).

Table 2 shows the prevalence of HBV, HCV and HIV infection among the group of blood donors studied, and Table 3 shows the age/gender distribution. No gender differences were seen in the distribution of single HBV, HCV and HIV infections (odds ratio [OR] 0.7986,1.219 and 1.023, respectively).

Apparently healthy blood donors have been a constant source of transfusion-related infection, especially in the developing world where facilities for screening blood before transfusion are inadequate.

In the present study, the prevalence of 19.9% for HBsAg, a marker of chronic HBV infection is high when compared to values reported from other regions of Nigeria6 and from other countries around the world.4,8-10,15-17 However, the level reported here is less than the 21.3% reported in Ibadan,18 which is in the same geographical zone. This indicates that there is a high prevalence of HBV infection in south-west Nigeria, which may be due to the socio-cultural practices reported by Otegbayo et al.18

Hepatitis C virus is now the most common bloodborne infection in the USA and is a leading cause of chronic hepatitis, cirrhosis and hepatocellular carcinoma.19 However, few blood banks in Nigeria screen routinely for HCV, and there are no national records of HCV seroprevalence, although a prevalence rate of 1.28% among blood donors has been reported.11

In West Africa, HCV seroprevalence of 1.1-6.7% has been reported,12-15 and the 6.4% reported in the present study is consistent with that reported in other tropical African countries,12-14,20 but is higher than rates reported in the Middle East,415 Asia,8,16 Europe9,17 and the USA.19

Factors responsible for the transmission of HBV also aid transmission of HCV, hence dual infection is not uncommon, especially in frequently transfused patients21 and in injected drug users.22 However, a dual infection rate of 1.6% reported in the present study is lower than rates reported among injected drug users21,23 or haemodialysis patients.21 Currently, injected drug abuse is not a problem in Nigeria and therefore is not a major factor involved in the transmission of HBV or HCV in this environment.

The HIV seroprevalence rate of 3.2% among donors is lower than the national HIV prevalence rate of 5% in the healthy adult population and of 12% among healthy blood donors reported in Nigeria in 2003.24 Hepatitis B or C have been known to co-exist with HIV, as they share similar modes of transmission. In Nigeria, Inyama et al.25 reported a seroprevalence rate of 5.7% for HCV among 590 confirmed HIV patients, while Halim et al.26 reported HBV and HIV-1 co-infections in blood donors.

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Chicken interferon-[alpha] administered perorally in drinking water acts on the ompharyngeal mucosal system as an adjuvant that causes chickens to rapidly seroconvert after natural infection by low-pathogenicity Influenza virus. These chickens, termed super sentinels, can serve as sensitive early detectors of clinically inapparent infections.

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Early detection of low-pathogenicity type A influenza virus (LPAI) circulating among chickens is important for 3 reasons: 1) these are the most prevalent strains in nature and can cause substantial losses for commercial poultry producers (1), 2) these strains can contribute genetic material to high-pathogenicity type A influenza virus (HPAI) (2), and 3) the H5 and H7 LPAI strains can mutate to HPAI with catastrophic effects in birds and with the potential for transmission to humans with lethal consequences (3). Kuiken et al. reported that an HPAI (H7N7) isolate was observed in February 2003 in the Netherlands, which most likely originated in free-living ducks and had evolved into a highly pathogenic variant after introduction into poultry farms (4). Although subsequent serologic screening of poultry showed that the H7 influenza virus had been affecting the Dutch poultry industry several months before the major epidemic, its presence had not been recognized (4). Our study addresses this problem by using a novel method that causes chickens to seroconvert under conditions in which LPAI would otherwise go undetected. This report shows that recombinant chicken interferon-[alpha] (rChIFN-[alpha]) (5) administered perorally in drinking water (6) acts as an adjuvant to produce a super-sentinel chicken that is a sensitive and early detector of clinically inapparent LPAI.

The Study

In 2003, the first clue to an aberrant condition in a commercial flock of laying hens in Connecticut was signaled by a drop in feed consumption and then in egg production. It took 6-7 weeks from the time tracheal samples were sent to a diagnostic laboratory to confirm the diagnosis of LPAI (H7N2) infection at National Veterinary Services Laboratory (NVSL) (N. Adriatico, pers. comm.). One such isolate, A/CK/CT/72/2003(H7N2), was obtained from the US Department of Agriculture, NVSL, Ames, Iowa, and used throughout this study to determine whether the peroral administration of rChIFN-[alpha] under conditions found to ameliorate Newcastle disease (6), infectious bronchitis (7), and infectious bursal disease (8), would similarly affect avian influenza. We reasoned that if the spread of LPAI could be slowed or prevented, the probability of its mutating to HPAI would be proportionately reduced, thereby lowering the chances of transmission to humans. In the course of this study, we observed a strong adjuvant effect of rChIFN-[alpha] administered in drinking water under conditions of virus transmission that mimic natural infection in chickens. This led to the concept of the super-sentinel chicken described here.

Three-week-old specific-pathogen-free (SPF) white leghorns (Charles River Specific Pathogen Free Avian Supplies [SPFAS], Inc., Storrs, CT, USA) were tagged and divided into 2 groups of 10 chickens each. Two birds in each group were overtly infected intravenously or intranasally with [10.sup.6] infectious particles, measured as plaque-forming particles in primary chicken kidney cells (Charles River SPAFAS, Inc.). This strain of LPAI (H7N2) required a high inoculum to ensure infection (data not shown), comparable to that reported for another LPAI (H7N2) strain evaluated in SPF chickens (9). The 8 remaining cage mates in each group served as sentinel birds naturally subject to infection by the respiratory tract, ingestion of fecal material, or both. One group of birds received plain drinking water; the other group received drinking water that contained 2,000 U/mL rChIFN-[alpha]. The water was provided ad libitum and changed daily. Water consumption was the same in both groups, as determined from the amount remaining after a known volume was provided each day (data not shown). With a half-life of 3-5 days in water at room temperature (6), this concentration of interferon (IFN) delivered an average dose of [approximately equal to] 3 x [10.sup.5] U rChIFN-[alpha]/bird/day. Fourteen days post overt infection (dpi), the rChIFN-[alpha]-water was replaced with plain water for the remaining 14 days of the study. This dose of rChIFN-[alpha] was sufficient to ameliorate Newcastle disease (6).

Following overt infection of 2 birds per cage, and the natural cross-infection of the 8 cage mates, serum samples were taken from each of the 10 birds at the intervals indicated in Figure 1. This figure shows data from 2 independent studies that used agar gel precipitin (AGP) tests to detect antibody against avian influenza virus nucleoprotein and M1 antigens. This qualitative test demonstrated that of the 16 naturally infected chickens given plain water, none seroconverted over the 28-day period they were exposed to the 2 infected cage mates. In marked contrast, of the 16 naturally infected chickens given water containing IFN, 14 were seropositive by 14 dpi and remained so during the 28-day test period.

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The first all-African genetically modified crop plant with resistance to the severe maize streak virus (MSV), which seriously reduces the continent’s maize yield, has been developed by scientists from the University of Cape Town and PANNAR PTY Ltd., a South African seed company. The research represents a significant advance in African agricultural biotechnology and will play an important role in alleviating Africa’s food shortages and famine.

Lead researcher Dionne Shepherd explains that, “MSV is transmitted to maize by small insects called leafhoppers. The disease is therefore a result of a complex interplay between the plant, the virus, and the insect. Factors that can influence the severity of the disease include the age at which the plant is infected, the maize variety, and environmental conditions.”

A MSV-resistant maize variety was created by genetic engineering using an approach known as pathogen-derived resistance. This means that a gene from the viral pathogen is used to protect the plant from that pathogen.

The next stage of the research involves field trials to ensure that the transformed crop is digestible, the protein is not an allergen, and that it will be ecologically friendly to other organisms within the environment. Following the results of these trials, the crop will be monitored over a number of growing seasons before it is made accessible to local farmers.

For more information, contact Lucy Mansfield, lucy.mansfield @oxon. blackwellpublishing.com.

Copyright American Society of Agricultural Engineers Oct 2007
Provided by ProQuest Information and Learning Company. All rights Reserved

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When a college researcher first coined the phrase “computer virus” in 1983, e-mail was not the dominant communications tool that it is today. Few understood the concept of a packet of malicious code that could insert itself into a machine, do damage, replicate and then spread to other machines. Fewer yet saw the future implication of economic losses as more and more business was conducted online and through e-mail.

Today, few people would think of opening an attachment to an e-mail from an unknown sender. Everyone has been taught to update their anti-virus programs, ignore spam and approach the unfamiliar with great skepticism. Nonetheless, viruses continue to thrive. A 2007 report from Computer Economics estimates that viruses, spyware and other forms of malicious code cost businesses worldwide $13.3 billion in the previous 12 months.

Viruses have made headlines in the past. In 1999, Melissa was reported as the first virus to travel through e-mail, infecting more than a million computer users and causing $80 million in damage. In 2001, Code Red infected 2,000 machines every minute at its peak, eventually infecting 360,000 computers and causing $1.2 billion in damages, according to the Cooperative Association for Internet Data Analysis. In 2004, MyDoom caused computers to send about 100 million infected e-mails in the first 36 hours.

But thanks to better protections, faster warning systems and increased vigilance, recent viruses have had far less success. In November 2005, eSecurityPlanet.com reported that the prior month had seen a record 1,685 new viruses hit the Internet but none were very widespread or dangerous.

Nonetheless, the risks and costs are still very real. The 2006 Computer Security Institute/FBI Computer Crime and Security Survey reported that although 98% of companies used a firewall and 97% had antivirus software, 65% had suffered one or more virus attacks. The companies placed the cost of these attacks at $15.7 million. Computer Economics estimates that the average business suffers five “malware” events per year, a figure that doubles for organizations with more than 5,000 desktop computers.

A company that finds its computers infected with a virus faces both direct and indirect costs. There is the expense of cleaning the viruses from the machines and restoring lost or damaged data, as well as the impact of downtime on productivity. Indirect costs can come from damaged reputation or customer frustration that may occur during the downtime. There is also the danger that a virus has allowed a hacker to obtain confidential information, such as Social Security or credit card account numbers-all of which involve another set of mandated costs for notifying customers and repairing damage.

These costs are bad enough when they are an internal matter. They become a significant liability when a business or its employees are responsible for an infection that spreads to another company, disrupting its work and causing lost income. Today’s typical insurance policies, especially the standard general liability coverage, do not cover cyber risks such as the failure to prevent the transmission of a virus, a fact that may come as an unpleasant shock to an organization that has not thought through the risks and is caught without protection.

Specialized insurance products have emerged that take cyber risks into account, however. They include coverage for the failure to prevent the transmission of a virus, failure to prevent an authorized user access to an insured’s website or private network and failure to protect private or confidential information in electronic format. Policies may even be expanded to provide funding to mount a campaign that will restore customer confidence after an incident is over and technology systems have been restored or to reimburse the insured for notification cost associated with a security breach that resulted or may have resulted in confidential information being taken.

In 2003, Ernst & Young reported that only 7% of companies had specific insurance for cyber liability. By 2006, the Computer Security Institute/FBI survey indicated that number had climbed to 29%. Businesses are realizing that they must not only protect their own computer infrastructure and information assets, but also be aware that the same technology that drives their business success exposes them to potential liability.

Craig Lapsley is the vice president of global technology at Travelers.

Copyright Risk Management Society Publishing, Inc. Oct 2007
Provided by ProQuest Information and Learning Company. All rights Reserved

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To determine resistance of highly pathogenic avian influenza (H5N1) virus to chlorination, we exposed allantoic fluid containing 2 virus strains to chlorinated buffer at pH 7 and 8, at 5[degrees]C. Free chlorine concentrations typically used in drinking water treatment are sufficient to inactivate the virus by >3 orders of magnitude

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Growing concerns about the public health threat posed by highly pathogenic avian influenza (HPAI) subtype H5N1 has prompted interest in evaluating environmental control measures for this virus. The World Health Organization has noted that more information is needed on the effectiveness of inactivation of subtype H5N1 in water (1). Since 2002, HPAI (H5N1) has been reportedly isolated from >50 different wild avian species, mainly aquatic birds in the order Anseriformes (2). Experimentally infected waterfowl shed moderate to large quantities of the virus in their feces and respiratory secretions (3,4). HPAI viruses can persist in simulated water environments, although generally for shorter periods than low pathogenic avian influenza viruses (5,6). Open bodies of water, including drinking water reservoirs, can become contaminated by birds that are actively shedding virus or by waterfowl carcasses. Surface runoff also represents a potential source of contamination for groundwater. In terms of avian health, drinking water has been implicated in the transmission of avian influenza among domestic poultry (6-8).

Chlorination represents the most common form of disinfection used in water treatment. Most published reports on virus inactivation in water have dealt with enteric viruses, and government guidelines for water treatment have focused on this group. Despite general acceptance that the outer lipid envelope associated with influenza viruses would make them susceptible to chlorination, no published reports specifically address the effect of chlorine on the H5N1 subtype of avian influenza.

The Study

Two clade 2 strains of HPAI (H5N1) virus were used in this study (9): 1 isolated from domestic poultry, A/chicken/Hong Kong/D-0947/2006 (courtesy of K. Dytring; Agriculture, Fisheries and Conservation Department, Hong Kong Special Administrative Region of China) (10), and 1 from a wild swan, A/WhooperSwan/Mongolia/244/2005 (3). The infectious virus was propagated in embryonated eggs of specific pathogen-free (SPF) leghorn chickens (11), and infective amnioallantoic fluid was harvested 96 h after inoculation.

Inactivation experiments were conducted as previously described (12). The initial chlorine level was chosen to achieve a chlorine residual that would be typical of drinking water after satisfying the initial chlorine demand of the amnioallantoic fluid. Briefly, virus-infected allantoic fluid was diluted (1:1,000) into continuously stirred, chlorinated, chlorine demand-free phosphate buffer (0.05 M, pH 7.0 and 8.0). Chlorine measurements were made immediately before the chlorine was neutralized by the addition of 0.1 mL of sodium thiosulfate (10% w/v). Separate reaction vessels were used for each exposure time. Reaction vessels containing only the virus and buffer without chlorine served as controls for determination of virus titers in the absence of chlorine and were assayed at the end of the longest exposure time period (60 s). Negative buffer controls without virus or chlorine were also included. All test and control samples were treated in the same manner. Preliminary investigations indicated that the virus can be readily inactivated at room temperature (data not shown). To slow the rate of inactivation, experiments were conducted at 5[degrees]C.

The infectivity of the samples was quantified by using microtiter endpoint titration (6), and virus titers were expressed as median 50% tissue culture infectious dose [(TCID).sub.50]/mL (13). Primary cultures of chicken embryo fibroblasts prepared from 9- to 11-day-old SPF chicken embryos were used in these assays. Virus-infected cells were incubated at 37[degrees]C under 5% C[O.sub.2] for 96 h and examined by light microscopy for cytopathic effect (CPE). Culture plates were stained with 1% (w/v) crystal violet in 10% (v/v) neutral-buffered formalin for further examination. Failure to produce CPE indicated that the virus was not capable of infecting the cells. The neutralized buffer control without virus did not cause CPE. All experiments were conducted in duplicate under Biosafety Level 3 agricultural conditions.

Inactivation levels were determined by comparing the [log.sub.10] transformed [TCID.sub.50]/mL virus titers in the control samples with the titers in the chlorine-exposed samples. The lowest detectable virus titer was 2.17 [log.sub.10] [TCID.sub.50]/mL, independent of pH or virus strain. Ct values (the chlorine concentration, C [mg/L], multiplied by the exposure time, t [min]) were used to determine the rate of inactivation for the 2 pH levels. Ct values are commonly used to make disinfection recommendations for water treatment and provide a means for comparing biocidal activity for various microorganisms (14). Ct values were plotted against [log.sub.10] virus titers to determine Ct values for a given level of inactivation (Table 1).

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Latest Version of Security Software Introduces Live Feedback from Online User Community

MOUNTAIN VIEW, Calif. — DriveSentry has launched version 3.0 of its anti-virus tool, and included the ability for real-time threat assessment augmented by feedback from its user community.

DriveSentry 3.0 is the first product of its kind to combine traditional ‘blacklist’ technology seen in many anti-virus products with advanced whitelisting thanks to its unique online database, ‘Advisor.’

The database allows the software to block unwanted scripts from accessing a user’s system. At the same time, it can automatically allow access to popular software that has been previously scanned by others, according to John Safa, chief technology officer at DriveSentry.

"DriveSentry detects files as they access your drives and checks their identity against details held in Advisor. Those programs that are known as a threat are stopped in their tracks," he said.

"Feedback and trends from our customers help to enhance Advisor by providing the correct decision of how to deal with unknown software. If the majority of other users have agreed that the program is safe, DriveSentry 3.0 will add it to the whitelist and allow it to pass through."

When the blacklist, whitelist and user community combine, the database is capable of telling the difference between the identities of many thousands of file signatures.

"Advisor combines all the knowledge of our user community into one invisible database. We hold up-to-the-minute data on threats and use this to guide people through the dangers that exist on the web," Safa said. "The Internet is a minefield of malware. DriveSentry will sweep and guide users through. Our solution equips consumers with the experience of all our users to make the web a safer place."

About DriveSentry Inc.

DriveSentry is a pioneer in software-based firewalls for hard drives that protect digital assets and personal data. The company was founded in 2005 with a mission to provide zero-day protection against new and emerging security threats. DriveSentry is privately held with offices in Mountain View, California and Nottingham, England. Further information can be found at www.drivesentry.com.

COPYRIGHT 2007 Business Wire
COPYRIGHT 2008 Gale, Cengage Learning

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