Nosocomial HIV-transmission in an outpatient clinic detected by epidemiological and phylogenetic analyses

Use of a radiopharmaceutical multidose dispenser for positron emission tomography: Risk assessment and mitigation measures for infection prevention

Positron emission tomography (PET) imaging necessitates the use of multidose vials for radiopharmaceutical delivery to patients. Conventional practices involve manual extraction of radiopharmaceuticals from a multidose vial prior to each PET procedure, which exposes the technologist to increasing levels of radiation and poses a potential infection risk to patients with frequent handling and access of the vial. New technologies for automated dosing and infusion delivery are available, however these incorporate both a multidose vial and a multi-patient infusion set. There is an absence of guidance for infection prevention (IP) units regarding the safety and acceptability of these devices. This paper describes the process of risk assessment and the mitigation measures for training, workflows, and documentation which led to the safe introduction of an automated PET infusion device in a large tertiary public healthcare facility.

Fine Needle Aspiration in the Investigation of Thyroid Nodules

BACKGROUND

Thyroid nodules are a common finding in Germany. Most are benign; thyroid cancer is very rare. The challenge for the physician is to diagnose malignant tumors early. Fine needle aspiration is an important tool for this purpose.

METHODS

This review is based on pertinent articles (1980-2014) retrieved by a selective search in PubMed and on the current recommendations of guidelines issued by the specialty societies in Germany and abroad.

RESULTS

Clinical, ultrasonographic, and scintigraphic criteria are used to identify high-risk nodules, which are then further studied by fine needle aspiration. Important ultrasonographic criteria for malignancy are low echodensity (positive predictive value [PPV]: 1.85), microcalcifications (PPV: 3.65), irregular borders (PPV: 3.76), and intense vascularization. Fine needle aspiration of the thyroid gland is an inexpensive and technically straight - forward diagnostic procedure that causes little discomfort for the patient. It helps prevent unnecessary thyroid surgery and is used to determine the proper surgical strategy if malignancy is suspected. The cytological study of fine needle aspirates enables highly precise diagnosis of many tumor entities, but follicular neoplasia can only be diagnosed histologically. In the near future, molecular genetic methods will probably extend the diagnostic range of fine needle aspiration beyond what is currently achievable with classic cytology.

CONCLUSION

Fine needle aspiration biopsy of the thyroid gland in experienced hands is an easily performed diagnostic procedure with very little associated risk. It should be performed on ultrasonographically suspect nodules for treatment stratification and before any operation for an unclear nodular change in the thyroid gland.

The Transmission and Evolution of HIV-1 Quasispecies within One Couple: a Follow-up Study based on Next-Generation Sequencing

Next-generation sequencing (NGS) has been successfully used to trace HIV-1 infection. In this study, we investigated the transmission and evolution of HIV-1 quasispecies in a couple infected through heterosexual behavior. A heterosexual couple in which both partners were infected with HIV-1 was followed up for 54 months. Blood samples including whole-blood and plasma samples, were collected at various time points. After HIV-1 subtyping, NGS (Miseq platform) was used to sequence the env region of the HIV-1 quasispecies. Genetic distances were calculated, and phylogenetic trees were generated. We found both partners were infected with HIV-1 subtype circulating recombinant form (CRF), CRF65_cpx. The quasispecies distribution was relatively tightly clustered in the phylogenetic tree during early infection. Over time, the distribution of HIV-1 quasispecies gradually became more dispersed at 12^th months, with a progressive increase in gene diversity. By 37^th months, the sequences obtained for both partners formed different clusters in the phylogenetic tree. These results suggest that the HIV-1 contact tracing results generated by the Miseq platform may be more reliable than other conventional sequencing methods, which can provide important information about the transmission and evolution of HIV-1. Our findings may help to better target preventative interventions for promoting public health.

Phylogenetic Exploration of Nosocomial Transmission Chains of 2009 Influenza A/H1N1 among Children Admitted at Red Cross War Memorial Children's Hospital, Cape Town, South Africa in 2011

Traditional modes of investigating influenza nosocomial transmission have entailed a combination of confirmatory molecular diagnostic testing and epidemiological investigation. Common hospital-acquired infections like influenza require a discerning ability to distinguish between viral isolates to accurately identify patient transmission chains. We assessed whether influenza hemagglutinin sequence phylogenies can be used to enrich epidemiological data when investigating the extent of nosocomial transmission over a four-month period within a paediatric Hospital in Cape Town South Africa. Possible transmission chains/channels were initially determined through basic patient admission data combined with Maximum likelihood and time-scaled Bayesian phylogenetic analyses. These analyses suggested that most instances of potential hospital-acquired infections resulted from multiple introductions of Influenza A into the hospital, which included instances where virus hemagglutinin sequences were identical between different patients. Furthermore, a general inability to establish epidemiological transmission linkage of patients/viral isolates implied that identified isolates could have originated from asymptomatic hospital patients, visitors or hospital staff. In contrast, a traditional epidemiological investigation that used no viral phylogenetic analyses, based on patient co-admission into specific wards during a particular time-frame, suggested that multiple hospital acquired infection instances may have stemmed from a limited number of identifiable index viral isolates/patients. This traditional epidemiological analysis by itself could incorrectly suggest linkage between unrelated cases, underestimate the number of unique infections and may overlook the possible diffuse nature of hospital transmission, which was suggested by sequencing data to be caused by multiple unique introductions of influenza A isolates into individual hospital wards. We have demonstrated a functional role for viral sequence data in nosocomial transmission investigation through its ability to enrich traditional, non-molecular observational epidemiological investigation by teasing out possible transmission pathways and working toward more accurately enumerating the number of possible transmission events.

Vaccination, consent and multidose vials

Multidose vials (MDVs) for injectable therapeutic agents, including vaccines, pose a risk of infection to injected patients as a result of contamination of the vials. The Australian Government Department of Health and Ageing (DoHA) distributed the vaccine against pandemic (H1N1) 2009 influenza in MDVs. The distribution was accompanied by consent forms. The consent forms provided an inadequate basis for a discussion with patients about the risks associated with the use of MDVs. The High Court of Australia has previously held that medical practitioners who fail to explain the material risks of medical procedures to their patients might be held liable in negligence for any adverse sequelae of the procedures, even if the risks are very low. Medical practitioners, nurses, medical indemnity insurers and the DoHA should prepare now for the probable future use of MDVs by developing a consent form that would provide a solid foundation for a discussion of material risks with patients seeking vaccination.

Hospital epidemiology and infection control in acute-care settings

Health care-associated infections (HAIs) have become more common as medical care has grown more complex and patients have become more complicated. HAIs are associated with significant morbidity, mortality, and cost. Growing rates of HAIs alongside evidence suggesting that active surveillance and infection control practices can prevent HAIs led to the development of hospital epidemiology and infection control programs. The role for infection control programs has grown and continues to grow as rates of antimicrobial resistance rise and HAIs lead to increasing risks to patients and expanding health care costs. In this review, we summarize the history of the development of hospital epidemiology and infection control, common HAIs and the pathogens causing them, and the structure and role of a hospital epidemiology and infection control program.

Multiple clusters of hepatitis virus infections associated with anesthesia for outpatient endoscopy procedures

BACKGROUND & AIMS

Hepatitis B virus (HBV) and hepatitis C virus (HCV) can be transmitted during administration of intravenous anesthesia when medication vials are used for multiple patients using incorrect technique. We investigated an outbreak of acute HBV and HCV infections among patients who received anesthesia during endoscopy procedures from the same anesthesiologist (anesthesiologist 1), in 2 different gastroenterology clinics.

METHODS

Chart reviews, patient interviews, clinic site visits and infection control assessments, and molecular sequencing of patient isolates were performed. Patients treated by anesthesiologist 1 on specific procedure days were offered testing for blood-borne pathogens. Endoscopy and anesthesia procedures were reviewed; HCV quasispecies analysis was performed.

RESULTS

Six cases of outbreak-associated HCV infection and 6 cases of outbreak-associated HBV infection were identified in clinic 1. One outbreak-associated HCV infection was identified in clinic 2. HCV quasispecies sequences from the patients were nearly identical (96.9%-100%) to those from source patients with chronic viral hepatitis. All affected patients in both clinics received propofol from anesthesiologist 1, who inappropriately used a single-patient-use vial of propofol for multiple patients. Reuse of syringes to redose patients, with resulting contamination of medication vials used for subsequent patients, likely resulted in viral transmission.

CONCLUSIONS

Twelve persons acquired HBV and HCV infections (6 hepatitis C, 5 hepatitis B, and 1 coinfection) in 2 separate offices as a result of receiving anesthesia from anesthesiologist 1. Gastroenterologists are urged to review carefully the injection, medication handling, and other infection control practices of all staff under their supervision, including providers of anesthesia services.

Infection control guidelines for prevention of health care-associated transmission of hepatitis B and C viruses

Viral hepatitis was first identified as an occupational hazard for health care workers more than 60 years ago. For the past few decades, hepatitis B has been one of the most significant occupational infectious risks for health care providers. With the increasing prevalence of hepatitis C infections around the world, occupational transmission of this flavivirus from infected patients to their providers has also become a significant concern. Several factors influence the risk for occupational blood-borne hepatitis infection among health care providers, among them: the prevalence of infection among the population served, the infection status of the patients to whom workers are exposed (ie, the source patient's circulating viral burden), the types and frequencies of parenteral and mucosal exposures to blood and blood-containing body fluids, and whether the patient or provider has been immunized with the hepatitis B vaccine. This article reviews patient-to-provider, patient-to-patient, and provider-to-patient transmission of hepatitis B and C in the health care setting. Current prevention strategies, precautions, and guidelines are discussed.

Horizontally-acquired HIV infection in Kenyan and Swazi children

Despite many reports of HIV-infected African children who have HIV-uninfected mothers, little is known about the extent and modes of horizontal HIV transmission in African children. We estimated the extent of horizontal HIV transmission in Swazi children by comparing child and mother HIV statuses in the 2006–2007 Swaziland Demographic and Health Survey (DHS). To identify correlates of horizontal HIV transmission, we conducted a case-control study of Kenyan children with horizontally acquired HIV infections and their uninfected siblings. Of 50 HIV-positive Swazi children in the DHS, 11 (weighted percent = 20, 95% confidence interval 11–33%) had HIV-negative mothers. These 11 children represented 0.6% of all Swazi children aged 2–12 who lived with their mothers. In the Kenyan study, children with horizontally acquired HIV infections had more kinds of blood exposures than their uninfected siblings. In particular, punctures related to health care for suspected malaria (phlebotomy, injection and infusion), injections while hospitalized and dental surgery (especially by informal providers) were more common in infected children. Horizontal HIV transmission appears to be common in some sub-Saharan African countries, and blood exposures seem to be the most likely routes of transmission. Rigorous surveillance and investigation of horizontally acquired HIV infection in children are urgently needed, along with universal public education about risks of specific blood exposures and ways to avoid them.

Limitations to contact tracing and phylogenetic analysis in establishing HIV type 1 transmission networks in Cuba

Sequence analysis can be used to evaluate transmission networks. We have used retrospective samples to examine two HIV-1 transmission networks established by contact tracing. Regions of the HIV-1 region representing segments of gag and env were amplified by RT-PCR from frozen plasma samples and the sequence of each PCR product was determined. Within one of the networks (composed of 38 subjects) we found only a subset of the tested sequence clusters was consistent with the reported epidemiological linkage. Of 15 presumed transmission events where sequence data were available, 9 could be rejected either by subtype mismatch or by phylogenetic tests. In the other network (composed of 89 subjects) we were able to assess sequences for 26 presumed transmission events, 18 of which were rejected based on subtype discordance. Long lags in time between the time of transmission and the time of sequence sampling (ranging from 2 to 18 years) may limit the sensitivity for the detection of sequence linkage. Also, superinfection and incomplete epidemiological information are other factors that will limit the concordance of phylogenetic reconstruction and reported epidemiological linkage.

Hospital-acquired infections related to contaminated substances

Drug-related outbreaks are frequently reported from various medical departments. A systematic review was performed to describe characteristics of these outbreaks and to determine the most frequent occasions in which contamination of substances for patient care take place. Articles were assessed by a search of the outbreak database, a search of PubMed, and hand search of reference lists from relevant articles. Articles published before 1990 were excluded. Data on affected patients, hospital-acquired infections, substances, pathogens and graded information about the location of the contamination incidence were extracted. A total of 2250 patients in 128 articles were included, mostly from intensive care units or haematological departments. Septicaemia was the most frequent hospital-acquired infection. Most often articles report contamination of blood products and heparin-sodium chloride solutions. The most frequent pathogens were hepatitis A virus, Yersinia enterocolitica, and Serratia spp. for blood products and Burkholderia cepacia and Enterobacter spp. for substances other than blood products. Mortality was highest if red blood cells or total parenteral nutrition formulas were contaminated. In 64 of the outbreaks multi-dose vials had been used against the manufacturers' recommendations. Thus, drug-related outbreaks are likely to occur particularly when basic hygiene measures are disobeyed. A large proportion of drug-related nosocomial infections could have been prevented, for example, by avoiding the use of multi-dose vials.

Proper use of multidose vials

PROBLEM

Every month when we inspect our facilities we find multidose vials (MDVs) used or stored inappropriately. It's frustrating to toss costly drugs and biologics into the trash. What can we do to heighten awareness of proper MDV handling?

SOLUTION

Staff probably know the proper procedures for safe use of MDVs, but job stress, time constraints, and poor staffing levels can underlie a medication giver's decision to skip or omit steps in the process. Hurried or careless staff may have inadequate handwashing hygiene, reuse a single-use needle or syringe, or fail to decontaminate the vial's stopper. Potential contamination is an out-of-sight, out-of-mind problem. To ensure better policy adherence, it helps to reinforce staff's understanding of the repercussion of increased infections when shortcuts are taken.

Technology of Flushing Vascular Access Devices

Maintenance of catheter lumen patency is an ongoing challenge. Catheter flushing is the primary nursing intervention used to prevent lumen occlusion from thrombotic and precipitate causes. The catheter and all devices attached to it must be regarded as a system in which each component directly affects the others. The technology of catheter flushing includes the flush solution itself, the source of these solutions, syringe design, mechanical pumps, needleless injection systems, and the design of the catheter. Effective catheter flushing is a combination of a technique and technology that requires an understanding of how both must work together.

Outbreak of hepatitis C virus infection in an outpatient clinic

BACKGROUND

From January through September 2001, seven patients were admitted to Fukaya Red Cross Hospital with typical clinical manifestations of acute hepatitis. Six were outpatients of the clinic, which is located near the hospital. An extensive survey of clinic outpatients conducted by the local health department revealed six more new acute hepatitis cases during this period.

METHODS

A case control study was carried out to identify potential risk factors for infection. In total, 1946 outpatients with clinic records were scheduled to undergo hepatitis C virus (HCV)-antibody testing. For the HCV-Ab positive patients, HCV-RNA was subtyped and quantified, and sequences of HCV hypervariable region 1 were determined.

RESULTS

Ultimately, 12 patients with acute hepatitis and two asymptomatic subjects were found to be a part of this outbreak. HCV isolates were divided into three major groups using phylogenetic tree analysis. Only a past history of visiting the clinic was significantly associated with acute hepatitis. The timing of the parenteral medical procedure at the clinic and the onset of acute hepatitis strongly suggested association of the two events.

CONCLUSIONS

Our findings suggest that nosocomial HCV infection can occur in an outpatient clinic, even in countries where post-transfusion hepatitis has been almost entirely eliminated.

Nosocomial transmission of hepatitis C virus associated with the use of multidose saline vials

OBJECTIVE

To identify the source of an outbreak of acute hepatitis C virus (HCV) infection among 3 patients occurring within 8 weeks of hospitalization in the same ward of a Florida hospital during November 1998.

DESIGN

A retrospective cohort study was conducted among 41 patients hospitalized between November 11 and 19, 1998. Patients' blood was tested for antibodies to HCV, and HCV RNA-positive samples were genotyped and sequenced.

RESULTS

Of the 41 patients, 24 (59%) participated in the study. HCV genotype lb infections were found in 5 patients. Three of 4 patients who received saline flushes from a multidose saline vial on November 16 had acute HCV infection, whereas none of the 9 patients who did not receive saline flushes had HCV infection (P = .01). No other significant exposures were identified. The HCV sequence was available for 1 case of acute HCV and differed by a single nucleotide (0.3%) from that of the indeterminate case.

CONCLUSION

This outbreak of HCV probably occurred when a multidose saline vial was contaminated with blood from an HCV-infected patient Hospitals should emphasize adherence to standard procedures to prevent blood-borne infections. In addition, the use of single-dose vials or prefilled saline syringes might further reduce the risk for nosocomial transmission of blood-borne pathogens.

Nosocomial transmission of HCV in a cardiology ward during the window phase of infection: an epidemiological and molecular investigation

Nosocomial spread of HCV and other blood-borne pathogens continues to occur in the Western world despite the screening of blood products. Using molecular and epidemiological methods we investigated an outbreak of HCV involving 3 patients following percutaneous coronary intervention at a Swedish hospital. The most likely mode of transmission was contamination of a multidose vial of saline used for the flushing of intravenous catheters. It may, therefore, be prudent to restrict the use of such vials, in addition to promoting vigorous adherence to standard hygiene procedures in order to prevent the recurrence of similar outbreaks in the future.

Outbreak of nosocomial hepatitis C virus infection resolved by genetic analysis of HCV RNA

In July 2000, symptomatic acute hepatitis C was diagnosed in five patients who had attended the emergency room of a municipal hospital on the same day, about 6 weeks before. Investigation of the remaining 65 patients visited at the emergency room on that day disclosed that 8 patients had a positive anti-hepatitis C virus (anti-HCV) test and 4 of them had biochemical evidence of acute anicteric hepatitis. HCV RNA was detected in 12 of the 13 anti-HCV-positive patients. Phylogenetic analysis of the nonstructural 5A (NS5A) and E2 regions showed that 10 patients, including all 9 with acute hepatitis, were infected with a closely related HCV strain, while the remaining 2 patients harbored unrelated strains. Flushing of intravenous catheters with heparin retrieved from a multidose heparin solution in saline was carried out for all the patients involved in the hepatitis outbreak but in only 1 of 23 (4%) matched controls recruited among HCV-noninfected patients attending the emergency room on the same day, and this was the only significant difference concerning risk factors for HCV infection between patients and controls. Thus, accidental contamination of a multidose heparin solution with blood from an unrecognized HCV carrier was identified as the source of this nosocomial outbreak of hepatitis C.

Infection control: preventing iatrogenic transmission of spongiform encephalopathy in Danish hospitals

The Danish infection control guidelines dealing with transmissible spongiform encephalopathy (TSE) recognise that preventive measures to avoid iatrogenic transmission must be taken, though the risk for patients in Danish hospitals can be characterised as minimal. A minimal risk situation cannot meanwhile be maintained unless hospitals and other healthcare institutions are prepared and have effective and well-functioning decontamination procedures in place suited for the purpose. The guidelines recommend that staff both in the operating theatre and in the Central Sterile Supply Department (CSSD) must be able to apply the procedures needed for safe handling and decontamination of used instruments. These include cleaning and effective sterilisation, as well as quarantine procedures and ways to discard and incinerate certain used instruments. The guidelines also address occupational safety, and single-use instruments are recommended where these are available and can be safely used. Effective procedures for decontamination of instruments and other medical devices are identified as the key to prevention of iatrogenic spread of TSE. Hospitals are advised to have their sterilisers and other equipment professionally checked in order to make sure that specific procedures for safe handling and decontamination of used surgical instruments and other medical equipment are available in case of suspected or confirmed TSE.

Acute HIV infection: impact on the spread of HIV and transmission of drug resistance

OBJECTIVE

To assess the impact of primary HIV infection (PHI) on the spread of HIV and the temporal trends in transmission of HIV drug resistance between 1996 and 1999 in Switzerland.

METHODS

Sequencing of the genes for reverse transcriptase (RT) and protease was performed for 197 individuals with documented PHI. Phylogenetic analyses were confronted with epidemiological data.

RESULTS

Significant clustering was demonstrated for 29% of the RT sequences. All these cases occurred closely together in place and time; contact tracing demonstrated transmission at the time of PHI in 30% of them. Genotypic drug resistance was detected in 8.6% of PHI individuals in 1996, 14.6% in 1997, 8.8% in 1998 and 5.0% in 1999. Drug-resistant variants were identified in 11.3% of individuals infected by homosexual contacts, 6.1% by heterosexual contacts, 13% of intravenous drug users and more frequently in men (10.4%) than women (2.6%). Potential factors involved in the recent decrease of transmission of drug-resistant variants include increase of HIV non-B subtypes from 23% in 1996 to 35% in 1999 (only one non-B subtype had resistance mutations) and a steady increase of patients with undetectable viraemia as documented in Swiss HIV Cohort Study (10% in 1996 vs 53% in 1999).

CONCLUSIONS

Phylogenetic and epidemiological analyses underline the impact of PHI in the spread of HIV. Moreover, this study indicates that drug resistance transmission may have decreased recently in Switzerland through the increased frequency of infection with HIV non-B subtypes and the steady increase of patients with undetectable viraemia.

Molecular investigation of transmission of human immunodeficiency virus type 1 in a criminal case

Very few criminal cases involving human immunodeficiency virus type 1 (HIV-1) transmission have been described. We report on an HIV-1 transmission case with a child being infected by an HIV-1-positive man. The objective was to determine through molecular epidemiology and phylogenetic analyses whether HIV-1 from the HIV-1-positive man could be the source of infection in the HIV-1-positive child, as claimed by the authorities. We conducted genetic analysis of three different parts of the HIV-1 genome (gag, pol, and env) by PCR, direct-sequencing, and phylogenetic analyses. We used maximum likelihood, maximum parsimony, and neighbor-joining methods for the phylogenetic analyses to investigate whether the sequences from the man and the child were related. We found that the viral sequences from the man and the child formed separate clusters in all of the phylogenetic analyses compared to the local controls. A unique amino acid deletion was identified in the C2-V3-C3 region of the env gene in the virus from the man and the child. These results were used in the criminal court to elucidate whether the virus from the man was related to the virus from the child. In summary, the results from the phylogenetic analyses, the sequence distances between the virus from the man and the virus from the child, and the identification of the unique molecular fingerprint in the env gene together indicated that the virus from the man and the virus from the child were epidemiologically linked.