Foodborne bacterial infections in individuals with the human immunodeficiency virus

The clinical characteristics of spontaneous Gram-negative bacterial meningitis in adults: A hospital-based study

The epidemiologic trend of acute bacterial meningitis can change more dramatically than any other bacterial disease, and a decrease in spontaneous adult bacterial meningitis (ABM) has been noted in serial studies of the epidemiologic trend of ABM in Taiwan. The purpose of this study was to analyze the clinical characteristics, laboratory data and therapeutic outcomes of 149 patients with spontaneous Gram-negative (G(-)) ABM collected during a study period of 31 years (1986-2016). The 149 patients included 107 men and 42 women, aged 18-86 years. The common underlying conditions were diabetes mellitus, liver cirrhosis and alcoholism, and the leading clinical presentations were fever, altered consciousness and septic shock. Compared the clinical characteristics of the patients identified in the study period of 2001-2106 to the patients identified in the study period of 1986-2000, the former group of patients had a significantly higher incidence of systemic malignance. In the recent 16 years (2001-2016), Klebsiella pneumoniae, Pseudomonas spp. and Escherichia coli were the leading three implicated bacterial pathogens of spontaneous G(-) ABM, accounting for 61.3% (38/62), 11.3% (7/62) and 11.3% (7/62%) of all cases, respectively. The overall mortality rate from spontaneous G(-) ABM was high (47.0%, 70/149) and the presence of septic shock and lower cerebrospinal fluid glucose level were significant prognostic factors. Because of the decreasing incidence of spontaneous ABM in Taiwan, close examination of this specific infectious syndrome is important in order to monitor the epidemiologic trend and improve the therapeutic strategy.

Clinical and Microbiological Features of Salmonella Meningitis in a South African Population, 2003-2013

BACKGROUND

The clinical and microbiological characteristics of nontyphoidal Salmonella (NTS) meningitis in South Africa, where human immunodeficiency virus (HIV) prevalence is high (approximately 15% in persons ≥15 years of age), were reviewed.

METHODS

From 2003 through 2013, 278 cases were identified through national laboratory-based surveillance. Clinical information (age, sex, outcome, Glasgow Coma Scale [GCS], and HIV status) was ascertained at selected sites. Isolates were serotyped; susceptibility testing and multilocus sequence typing on Salmonella enterica serovar Typhimurium isolates was performed. Multivariable logistic regression was used to determine factors associated with mortality outcome, using Stata software, version 13.

RESULTS

Where age was ascertained, 139 of 256 (54.3%) patients were <15 years. Males represented 151 of 267 (56.6%). Mortality outcome was recorded for 112 of 146 (76.7%) enhanced surveillance patients; 53 of 112 (47.3%) died. Death was associated with GCS ≤13 (adjusted odds ratio [OR], 18.7; 95% confidence interval [CI], 3.0-118.5; P = .002) on multivariable analysis. Where data were available, all 45 patients aged >15 years were HIV infected, compared with 24 of 46 (52.2%) patients aged <5 years. Neonates were less likely to be HIV infected than infants aged 2-12 months (OR, 4.8; 95% CI, 1.1-21.1; P = .039).Salmonella Typhimurium represented 106 of 238 (44.5%) serotyped isolates: 65 of 95 (68.4%) were ST313 vs ST19, respectively, and significantly associated with HIV-infected patients (P = .03) and multidrug resistance (OR, 6.6; 95% CI, 2.5-17.2; P < .001).

CONCLUSIONS

NTS meningitis in South Africa is highly associated with HIV in adults, with neonates (irrespective of HIV status), and with Salmonella Typhimurium ST313. GCS is the best predictor of mortality: early diagnosis and treatment are critical. Focused prevention requires further studies to understand the sources and transmission routes.

Reprodutibilidade de um questionário para avaliação de conhecimentos, percepções e práticas em segurança sanitária alimentar de portadores de HIV/AIDS ambulatoriais

Portadores de HIV/AIDS são vulneráveis a muitos tipos de infecções, incluindo aquelas veiculadas por água e alimentos. O alto risco às infecções gastrintestinais poderia ser minimizado através do aconselhamento dietético, no ambiente das unidades de saúde ambulatoriais, visando à adoção de práticas de segurança sanitária alimentar. A pesquisa realizada teve como objetivo, dentre outros, avaliar os conhecimentos, as percepções e práticas em segurança alimentar de portadores de HIV/AIDS ambulatoriais. Para tal, elaborou-se questionário, a partir de cinco áreas temáticas (prevenção da contaminação cruzada; higiene pessoal e ambiental; controle de temperaturas; e consumo de alimentos de risco). O que se apresenta é o estudo de reprodutibilidade desse instrumento, para o qual foi utilizado o procedimento de teste e re-teste. Os resultados deste estudo mostraram que os valores kappa oscilaram de forte para 84,6% (33), moderado para 12,8% (5), a discreto para 2,5% (1) das questões testadas. Nossos resultados sugerem que o instrumento apresenta um bom nível de reprodutibilidade sendo uma boa opção para o levantamento de informações sobre segurança alimentar de pacientes portadores de HIV/AIDS.

Application of a Five-Step Message Development Model for Food Safety Education Materials Targeting People with HIV/AIDS

Individuals with human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome have an increased risk of contracting foodborne illnesses and need to take special precautions regarding food safety. We implemented a five-step model to assess the needs of people with HIV, develop education materials targeted to their needs, and evaluate acceptance of the materials. Needs assessment focus groups (n=8) with HIV-infected people (n=65) and interviews with health care providers (n=18) were conducted to determine motivators and barriers to adopting food safety recommendations. Education materials were developed using needs assessment data, literature on foodborne illnesses, and the Health Belief Model. Acceptability of materials was evaluated by focus groups (n=4) with HIV-infected people (n=32) and a survey of health care providers (n=25). Needs assessment focus group participants expressed resistance to and confusion about many recommendations. Prototype materials were designed to address barriers and motivators. HIV-infected people who reviewed the prototype materials in evaluation focus groups expressed positive attitudes about the materials, and most indicated willingness to follow recommendations. Health care providers were interested in distributing the education materials to their clients. Carefully listening to HIV-infected people and their health care providers, as well as detailed investigation of the literature on foodborne illnesses, contributed to acceptance of the education materials.

Achieving continuous improvement in reductions in foodborne listeriosis--a risk-based approach

Listeria monocytogenes is a foodborne pathogen that can cause listeriosis, a severe disease that can lead to septicemia, meningitis, and spontaneous abortion. Ongoing efforts are needed to further reduce the incidence of listeriosis, due to its high mortality rate. The focus of this report is the use of a risk-based approach to identify strategies that will have the greatest impact on reducing foodborne listeriosis. A continuum of risk for listeriosis is observed in the human population, ranging from exquisitely sensitive groups, who are highly immunocompromised and at very high risk of listeriosis, through the normal healthy population younger than 65 years of age, who appear to have a minimal risk for listeriosis. In addition, unique subpopulations may exist; for example, pregnant Latina women appear to have a higher risk of listeriosis than pregnant women of other ethnic groups, most likely due to consumption of contaminated soft cheeses such as queso fresco and queso blanco. The International Life Sciences Institute Risk Science Institute Expert Panel concluded that certain foods pose a high risk for causing listeriosis. High-risk foods have all of the following properties: (1) have the potential for contamination with L. monocytogenes; (2) support the growth of L. monocytogenes to high numbers; (3) are ready to eat; (4) require refrigeration; and (5) are stored for an extended period of time. Control strategies are needed in the food chain from preharvest through consumption to minimize the likelihood that food will become contaminated by L. monocytogenes and to prevent the growth of the organism to high numbers. The Expert Panel identified three main strategies for ensuring continuous improvement in reducing foodborne listeriosis: (1) preventing contamination of foods with L. monocytogenes; (2) preventing growth of L. monocytogenes to high numbers in foods; and (3) science-based education messages targeted to susceptible populations and their caregivers. Of these strategies, the Expert Panel concluded that preventing growth of L. monocytogenes to high numbers would have the greatest impact in reducing cases of listeriosis. Dose-response models predict that the risk of listeriosis increases as the number of organisms in a food increases and can be used as a scientific basis for a target level below which the organism should be reduced to minimize the likelihood of listeriosis in high-risk populations. This requires implementation of effective food safety control measures and ensuring that these control strategies are consistently met. Most effective strategies to control L. monocytogenes in high-risk foods include (1) good manufacturing practices, sanitation standard operating procedures, and hazard analysis critical control point programs to minimize environmental L. monocytogenes contamination and to prevent cross-contamination in processing plants and at retail; (2) an intensive environmental sampling program in plants processing high-risk foods and an effective corrective action plan to reduce the likelihood of contamination of high-risk foods; (3) time and temperature controls throughout the entire distribution and storage period, including establishing acceptable storage times of foods that support growth of L. monocytogenes to high numbers; (4) reformulating foods to prevent or retard the growth of L. monocytogenes; and (5) using postpackaging treatments to destroy L. monocytogenes on products. Science-based education and risk communication strategies aimed at susceptible populations and focused on high-risk foods should be delivered through health care providers or other credible sources of information. Exquisitely sensitive consumers may become ill when exposed to low numbers of L. monocytogenes or other opportunistic pathogens, so reducing the risk to this population could be achieved by maintaining them on restricted low-microbe diets during those periods when they are most severely immunocompromised. High-risk individuals (i.e., the elderly, pregnant women, and most immunocompromised individuals) should be provided with guidance on healthy eating, including specific information on high-risk foods that they should avoid, and strategies to reduce their risk, such as thorough cooking, avoidance of cross-contamination, and short-term refrigerated storage of cooked perishable foods. Those at low risk for listeriosis should receive information on safe food handling practices, preferably starting at a preschool age.

Potential Virulence and Antimicrobial Susceptibility ofCampylobacter jejuniIsolates from Food and Companion Animals

Infection in humans with Campylobacter jejuni is commonly associated with exposure to food animal fecal material. In this study, we report on the recovery, potential for virulence and antimicrobial resistance levels of C. jejuni isolated from food and companion animals. Three hundred and seventy-eight fecal samples from food and companion animals and surface swabs from beef carcasses were tested for the presence of C. jejuni. C. jejuni was isolated from 13.8% (11/80) of dogs, 5% (1/20) of goats, 28.3% (17/60) of dairy cattle, 0% (0/65) of range cattle, 73.5% (36/49) of feedlot cattle, and 94.7% (18/19) of beef carcasses. Beef cattle from a single Arizona herd showed a considerable increase in fecal shedding of C. jejuni from pasture to feedlot and over time on the feedlot. Forty-two isolates were tested for susceptibility to four antimicrobial agents, each representing a class of antimicrobial drug approved for use in both humans and animals. None of the isolates were found to be resistant to erythromycin or gentamicin, whereas 2.4% of isolates were resistant to ciprofloxacin and 28.6% of isolates were resistant to tetracycline. The presence of virulence traits among the 42 isolates was assessed using in vitro macrophage survival and epithelial cell adherence and invasion assays. Of the isolates examined, 17 were able to survive within macrophages through 72 h at viable counts of >/=10(3)/well and 12 were capable of invading epithelial cells at viable counts of >/=10(3)/well. Data from these studies suggests that many of the isolates recovered from the non-poultry animal sources have the capacity to cause disease if transmitted to humans.

Factors in the emergence of food borne diseases

Food borne diseases are an important public health problem. Over the past two decades, the epidemiology of food borne diseases has changed rapidly as a consequence of changes in the social environment and the ability of pathogens to adapt to new niches. Several newly recognized pathogens have emerged and well-recognized pathogens have increased in prevalence or become associated with new food vehicles. Several factors have contributed to the changing patterns of food borne diseases, and addressing food borne diseases will require rapid surveillance and effective prevention strategies. This article examines these factors and briefly addresses prevention and control of food borne diseases.

Foodborne diseases. Emerging pathogens and trends

The epidemiology of foodborne diseases is rapidly changing. In the past 15 years, new foodborne pathogens, such as Campylobacter jejuni and Escherichia coli O157:H7, have emerged as important public health problems. Well-recognized pathogens, such as Salmonella serotype Enteritidis, have increased in prevalence or become associated with new vehicles, and pathogens such as C. jejuni and S. Typhimurium are becoming increasingly resistant to antimicrobial agents. Evolving trends in foodborne diseases are being driven by the same factors that have led to the emergence of other infectious diseases: changes in demographic characteristics of the population, human behavior, industry, and technology and the shift toward a global economy, microbial adaptation, and breakdown in the public health infrastructure. Addressing emerging foodborne disease will require more sensitive and timely surveillance, enhanced methods of laboratory identification and subtyping, and identification of effective prevention and control strategies.

Agents of diarrhea

Diarrhea is a common problem for AIDS patients, and is chronic and debilitating. A thorough evaluation will reveal a pathogen in the majority of patients, and the organisms most frequently identified in AIDS patients with chronic diarrhea are Cryptosporidium, microsporidia, and Mycobacterium avium complex. Bacterial pathogens are more common in AIDS patients than in the general population and may present in different ways from infections in immunocompetent hosts. Other pathogens, including Cryptosporidium and microsporidia, are difficult to diagnose and have no effective therapy. Moreover, enteric viruses and HIV itself may contribute to the diarrhea. In addition to microbes, other factors such as medication, immune dysregulation, automatic dysfunction, and nutritional supplementation play a substantial role in diarrhea of AIDS patients.

Emerging foodborne diseases

The epidemiology of foodborne diseases is rapidly changing. Recently described pathogens, such as Escherichia coli O157:H7 and the epidemic strain of Salmonella serotype Typhimurium Definitive Type 104 (which is resistant to at least five antimicrobial drugs), have become important public health problems. Well-recognized pathogens, such as Salmonella serotype Enteritidis, have increased in prevalence or become associated with new vehicles. Emergence in foodborne diseases is driven by the same forces as emergence in other infectious diseases: changes in demographic characteristics, human behavior, industry, and technology; the shift toward a global economy; microbial adaptation; and the breakdown in the public health infrastructure. Addressing emerging foodborne diseases will require more sensitive and rapid surveillance, enhanced methods of laboratory identification and subtyping, and effective prevention and control.

The changing epidemiology of foodborne diseases

The epidemiology of foodborne diseases in the United States have changed in recent decades as new pathogens have emerged, the food supply has changed, and the number of people with heightened susceptibility to foodborne diseases has increased. Emerging pathogens are those that have recently increased or are likely to increase within 2 decades. Emergency is often the consequence of changes in some aspect of the social environment. The global economy, for example, has facilitated the rapid transport of perishable foods, increasing the potential for exposure to foodborne pathogens from other parts of the world. Other factors altering foodborne disease patterns are the types of food that people eat, the sources of those foods, and the possible decline in public awareness of safe food preparation practices. Aging, extension of life expectancy for the chronically ill through medical technology, and the AIDS epidemic have increased the public health impact of foodborne diseases because they increase the proportion of the population susceptible to severe illness after infection with a foodborne pathogen. The evolving epidemiology of foodborne diseases must be monitored and understood to implement appropriate prevention technologies.