Erythema infectiosum. An elementary school outbreak

The nonpathogenic commensal Neisseria: friends and foes in infectious disease

PURPOSE OF REVIEW

Nonpathogenic commensal Neisseria are rarely considered in the clinical setting despite evidence that they can cause invasive opportunistic infections. In contrast, they may offer protection against pathogenic Neisseria, and such relationships are being actively explored in experimental studies.

RECENT FINDINGS

Recent case reports are presented of invasive infection caused by nonpathogenic Neisseria in patients on novel biologic therapies. On the other hand, Neisseria lactamica, a nonpathogenic commensal, has been shown in human challenge studies to inhibit colonization by Neisseria meningitidis. Experimental mouse models have also explored the inhibitory effects of nonpathogenic Neisseria on Neisseria gonnhoreae infection. Cutting-edge advances in metagenomics and microbiomics are being used to understand the mechanisms underpinning these effects.

SUMMARY

Clinicians should have increased awareness of nonpathogenic Neisseria. First, as new immunomodulating therapies become licenced, the interactions that maintain balance between commensals and their human hosts may be altered. Second, these bacteria are showing promise in their capacity to exclude pathogenic Neisseria species from their anatomical niches.

Human Parvoviruses

Parvovirus B19 (B19V) and human bocavirus 1 (HBoV1), members of the large Parvoviridae family, are human pathogens responsible for a variety of diseases. For B19V in particular, host features determine disease manifestations. These viruses are prevalent worldwide and are culturable in vitro, and serological and molecular assays are available but require careful interpretation of results. Additional human parvoviruses, including HBoV2 to -4, human parvovirus 4 (PARV4), and human bufavirus (BuV) are also reviewed. The full spectrum of parvovirus disease in humans has yet to be established. Candidate recombinant B19V vaccines have been developed but may not be commercially feasible. We review relevant features of the molecular and cellular biology of these viruses, and the human immune response that they elicit, which have allowed a deep understanding of pathophysiology.

Infection Control Measures for Human Parvovirus Bl9 in the Hospital Setting

A human parvovirus was first discovered serendipitously in blood from asymptomatic donors in 1975' and designated B19 because of the location of the original positive serum in a test panel. Subsequently, the newly discovered virus was determined to be the etiologic agent of most cases of transient aplastic crisis in the setting of chronic hemolytic anemia and of the childhood exanthem erythema infectiosum, or fifth disease. While erythema infectiosum with its classic “slapped-cheek” rash is a childhood illness, “fifth disease” in the adult should not be overlooked. At least 40% of adults lack serological evidence of past human parvovirus B19 infection and are at risk. Adults tend to have a more subtle rash, often lacking the “slapped cheeks,” and tend to have a more severe constitutional, flu-like illness with prominent joint symptoms. While the arthralgia and arthritis of adult “fifth disease” are often self-limiting, they may become chronic and lead to an arthropathy that meets American College of Kheumatology criteria for a diagnosis of rheumatoid arthritis. The arthropathy has been reported to persist up to five years, the longest follow-up now available (A. Wolf; MD, personal communication, August 27, 1987).

Dietary sodium intake in young Korean adults and its relationship with eating frequency and taste preference

Dietary sodium intake is considered one of the major causal factors for hypertension. Thus, to control the increase of blood pressure and reduce the risk of hypertension-related clinical complications, a reduction in sodium intake is recommended. The present study aimed at determining the association of dietary sodium intake with meal and snack frequency, snacking time, and taste preference in Korean young adults aged 20-26 years, using a 125-item dish-frequency questionnaire. The mean dietary sodium intakes of men and women were 270.6 mmol/day and 213.1 mmol/day, which were approximately 310% and 245% of the daily sodium intake goal for Korean men and women, respectively. Dietary sodium intake was positively correlated with systolic blood pressure in the total group, and BMI in the total and men-only groups. In the total and men-only groups, those who consumed meals more times per day consumed more dietary sodium, but the number of times they consumed snacks was negatively correlated with dietary sodium intake in the total, men-only, and women-only groups. In addition, those who consumed snacks in the evening consumed more sodium than those who did so in the morning in the men-only group. The sodium intake was also positively associated with preference for salty and sweet taste in the total and women-only groups. Such a high intake of sodium in these young subjects shows that a reduction in sodium intake is important for the prevention of hypertension and related diseases in the future.

Clinical significance of smell and taste disorders in patients with diabetes mellitus

Chemosensory dysfunction has been reported in patients with diabetes mellitus (DM). However, the clinical significance in relation to the disease stage remains unclear. The aim of this investigation was to assess olfactory and gustatory function with valid clinical tests in patients with DM types 1 and 2 with and without accompanying diseases. Seventy-six patients with DM were divided into three groups according to disease stage. Taste function was tested by means of impregnated paper strips and smell function was screened using a five-item smell identification test. The results of the patients with uncomplicated DM were compared with the results from 29 healthy subjects. The results showed no significant differences in smell and taste function between patients with uncomplicated DM and healthy subjects. However, patients with additional diseases exhibited decreased smell acuity. Moreover, patients with DM type 2 showed impaired smell function compared with patients with DM type 1.

Blood pressure relates to sodium taste sensitivity and discrimination in adolescents

To investigate salt perception and discrimination and their possible association with blood pressure (BP), 72 healthy adolescents (42 boys) aged 9-21 years (mean 16.1 years) were studied. BP was measured with a standardized technique. Anthropometric measurement and conventional renal function tests were performed. Sensitivity tests to recognize the presence of salt when given simultaneously distilled/deionized water and a low sodium concentration water solution, and discrimination tests consisting of six graded samples of different saline solutions presented in randomized order were used to assess individual gustatory sensitivity. Average systolic BP values were 113.2+/-1.6 mmHg in boys and 109.6+/-1.9 mmHg in girls. Mean threshold level for salt sensitivity was 4.55+/-0.6 mmol/l. Systolic BP and salt sensitivity showed a significant correlation ( r=-0.33, P<0.01) even when adjusting for weight. Discrimination score was correlated with salt sensitivity ( r=0.27, P<0.05). There is a significant association between gustatory perception and BP in Spain adolescents, although a real cause-effect relationship has not been established.

Confirmation of an outbreak of parvovirus B19 in a primary school using IgM ELISA and PCR on thumb prick blood samples

BACKGROUND

Although parvovirus infections are usually benign and self-limiting, it is important to confirm the diagnosis in a public health setting which might involve pregnant women and in which an outbreak could lead to medical consequences. In these situations, microbiological confirmation by thumb prick is a relatively low-invasive method that is simple to carry out.

OBJECTIVE AND STUDY DESIGN

Because relatively small blood volumes are obtained in thumb prick blood samples, we compared the results of two different techniques during an outbreak of erythema infectiosum: the usual serological detection of IgM antibodies (ELISA) versus PCR-based detection of viral DNA.

RESULTS

In a school-based outbreak, 39 cases (33 schoolchildren, three parents, three pre-schoolers) were registered over a period of 11 weeks. Sera were obtained from 23 of the school cases and two of the three parent cases. Of all thumb prick serum samples, 65% (15/23) tested positive or borderline positive for parvovirus IgM with ELISA, while 70% (16/23) tested positive or borderline positive with PCR. Although the overlap between the two tests was large (11 samples tested positive or borderline positive in both), a substantial number of samples showed contradictory results (nine samples).

CONCLUSION

The overall picture of 37 clinical cases of erythema infectiosum and two adult cases with arthritis, linked to a primary school, fits in well with positive diagnostic results by either technique for parvovirus B19, convincingly demonstrating an outbreak of fifth disease. The considerable number of discrepancies in sample results demonstrates that maximum sensitivity of parvovirus testing would require both tests to be performed.

Acid stress upregulated outer membrane proteins in clinical isolates ofNeisseria gonorrhoeae, but not most commensalNeisseria

Human immune serum recognition of outer membrane components from commensal and pathogenic Neisseria cultured under neutral and acidic conditions was investigated. Acid stress caused no detectable alterations in lipooligosaccharide migration and (or) staining, in outer membrane protein profiles, or in immune serum recognition of outer membrane components from Neisseria mucosa or Neisseria sicca. There was also no difference in the lipoologosaccharide electrophoretic pattern of acid- and neutral-grown Neisseria lactamica, but there were differences in outer membrane protein expression. The outer membrane protein alterations induced by acid stress in N. lactamica were not the same as those seen in isolates from patients with uncomplicated gonococcal infection, pelvic inflammatory disease, and disseminated gonococcal infection. Many differences were detected in the immune serum recognition of outer membrane components from acid- and neutral-cultured N. lactamica and from the clinical isolates of Neisseria gonorrhoeae, and these should be considered in vaccine design.Key words: Neisseria gonorrhoeae, commensal Neisseria, acid stress, outer membrane proteins.

Rheumatic manifestations of parvovirus B19 infection

Human parvovirus B19 is an emerging DNA virus. B19 infection is common and widespread. Major manifestations of B19 infection are transient aplastic crisis, erythema infectiosum, hydrops fetalis, acute and chronic rheumatoid-like arthropathy, and, in the immunocompromised host, chronic or recurrent bone marrow suppression. A number of less common manifestations of B19 infection include various rash illnesses, neuropathies, and acute fulminant liver failure. Of rheumatologic interest, B19 infection must be differentiated from early presentation of more classic erosive rheumatoid arthritis and, in some cases, systemic lupus erythematosus. It is unlikely that B19 plays a role in classic erosive rheumatoid arthritis, but understanding pathogenesis of B19 arthropathy may provide insights into the mechanisms by which rheumatoid arthritis develops. Evidence for persistence of B19 infection suggests that human parvovirus B19 infection may serve as a model for the study of virus-host interactions and the role of viruses in the pathogenesis of rheumatic diseases.

A school outbreak of parvovirus B19 infection investigated using salivary antibody assays

An outbreak of parvovirus B19 infection at a primary school was investigated using saliva samples. Antibody capture immunoassays for salivary B19 IgG and IgM were developed using a recombinant B19 antigen and monoclonal antibody to B19 virus. Evaluation of the salivary IgG assay using paired serum and saliva samples from 43 staff at St Thomas' Hospital showed that it had a sensitivity of 100% and a specificity of 95%. Evaluation of the salivary B19 IgM assay using 87 paired blood and saliva samples from a study of general practitioner rubella notifications showed it had a sensitivity of 60% and a specificity of 98%. Using the salivary assay the level of B19 IgG within 2 weeks of the start of the outbreak ranged from 5-33% in children and 29% in staff. By detecting salivary B19 IgM and/or B19 IgG seroconversions, attack rates of 8-50% in children in different classes and 47% in staff were observed. Household transmission was also studied and an attack rate of 45% was recorded in 11 susceptibles. After the outbreak, the level of B19 IgG in children with the highest attack rates was 60-70%, similar to that seen in adults in the UK. This study highlights the risk of B19 infection in an institutional setting and shows that saliva samples are a useful alternative to blood.

Diverse hematologic effects of parvovirus B19 infection

Human parvovirus B19 is linked with a broadening spectrum of hematologic disorders, including aplastic crises in the context of hemolytic anemias, neutropenia, thrombocytopenia, and hemophagocytic syndromes. Children with any of these cytopenias should be screened for the presence of B19 because treatment with intravenous gamma globulin may provide resolution of abnormal blood counts if other therapeutic options, such as transfusion, are not adequate or desired.

Hypertension: cognitive and behavioral considerations

This article reviews literature concerning functional changes resulting from elevated blood pressure, from reduction of blood pressure, and as a result of the medications used to treat high blood pressure. The research reviewed includes the areas of psychomotor speed, intelligence and cognitive processing, sensory and perceptual processes, and emotional and interpersonal behaviors. The conclusions reached are that the deficits noted to date in hypertensive individuals are not extreme nor are they specific. The greatest disadvantage, however, appears in the area of response speed.

The prevalence of antibody to human parvovirus B19 in Rio de Janeiro, Brazil

During 1985 and 1986 serum samples were collected from the Rio de Janeiro population and examined for the presence of IgG antibody to human parvovirus B19. No difference in prevalence was found between males and females. Antibody prevalence rose from 35% in children less than five years old to almost 80% in children aged eleven to fifteen years. The antibody prevalence in individuals over 50 years old was over 90%.

Obesity

Over the past 20 years, obesity has represented a significant focus of research conducted in Clinical Research Centers (CRCs) in the United States. This review will focus on the progress in our understanding of the disease that CRC-based research has produced; therefore, the reference list is not exhaustive and consists primarily of CRC-based research. Obesity is defined as an excess of body fat as measured by triceps skinfold thickness. The time of onset of obesity is an important factor; for example, early onset is associated with an increase in the number of fat cells. Weight loss reduces the size but not the number of fat cells. Type II diabetes mellitus is a common complication in obese adults; this condition has been related to fat cell size and, in women, to predominantly upper-body fat distribution. Pregnant obese women and their babies are at risk for a number of problems. Abnormalities commonly found in obese persons include increased plasma lipid levels, hyperinsulinism, increased cholesterol synthesis, high frequency of gallstones, and hypertension. Under a variety of experimental conditions, the only difference in the response of obese and normal weight subjects to food was that the obese subjects appeared to consume more, but other data suggest that the obese may have greater energy needs. Carbohydrate intake has been studied extensively. Metabolic rate increases with over-feeding, especially in response to carbohydrate. Basal metabolic rates are higher in obese adults and rise in response to overfeeding; they decrease after weight reduction. This decrease can be counteracted with sucrose, perhaps because sucrose maintains triiodothyronine levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Erythema infectiosum in a primary school: investigation of an outbreak in Bury

Between January and April 1987, 97 of 302 (32%) children attending a primary school in Bury, Lancashire, were affected by an exanthematous illness. The duration and extent of the episode caused considerable local interest and anxiety. Examination of 6 serum specimens obtained during the subsequent investigation demonstrated evidence of recent Human Parvovirus B19 infection in 3 children and 1 teacher. No evidence of recent rubella virus infection was found. The investigation of the episode is discussed in the context of problems which may occur in the management of similar outbreaks.

Infection control measures for human parvovirus B19 in the hospital setting

A human parvovirus was first discovered serendipitously in blood from asymptomatic donors in 1975' and designated B19 because of the location of the original positive serum in a test panel. Subsequently, the newly discovered virus was determined to be the etiologic agent of most cases of transient aplastic crisis in the setting of chronic hemolytic anemia and of the childhood exanthem erythema infectiosum, or fifth disease. While erythema infectiosum with its classic “slapped-cheek” rash is a childhood illness, “fifth disease” in the adult should not be overlooked. At least 40% of adults lack serological evidence of past human parvovirus B19 infection and are at risk. Adults tend to have a more subtle rash, often lacking the “slapped cheeks,” and tend to have a more severe constitutional, flu-like illness with prominent joint symptoms. While the arthralgia and arthritis of adult “fifth disease” are often self-limiting, they may become chronic and lead to an arthropathy that meets American College of Kheumatology criteria for a diagnosis of rheumatoid arthritis. The arthropathy has been reported to persist up to five years, the longest follow-up now available (A. Wolf; MD, personal communication, August 27, 1987).

Erythema infectiosum (fifth disease) occurrence in Iowa

Review of Iowa school nurse surveillance for erythema infectiosum, or fifth disease (FD), since 1973 demonstrated occurrence yearly except 1985 without a clear pattern of disease spread. We conclude that FD is more common than previously recognized. Failure to identify cases representing the background incidence of disease may account for underreporting.

Evaluation of a ten-minute chromogenic substrate test for identification of pathogenic Neisseria species and Branhamella catarrhalis

A ten-minute chromogenic substrate test was evaluated for its ability to rapidly identify pathogenic Neisseria spp. and Branhamella catarrhalis. Identifications obtained with this system were compared to those obtained using conventional procedures. The test correctly identified 98.9% of 90 Neisseria gonorrhoeae, 98.3% of 60 Neisseria meningitidis, 96.2% of 26 Neisseria lactamica, and 100% of 36 Branhamella catarrhalis strains. Eight Neisseria subflava strains that grew on modified Thayer-Martin agar were prolyl aminopeptidase positive and were misidentified as Neisseria gonorrhoeae. Other strains of saprophytic Neisseria spp. also reacted with the chromogenic substrates. The system was accurate and reliable for identifying the commonly encountered pathogenic species. In light of recent reports describing new species and atypical Neisseria strains, however, careful attention to the salient features of both common and atypical organisms is necessary for proper use of rapid enzymatic identification tests.

Eating patterns in childhood and adult health

This paper first reviews the evidence that the pathogenesis of many diseases which present in adult life begin in childhood, and that intervention in childhood may delay their onset. The diseases discussed include ischaemic heart disease, malignancy, cerebrovascular accidents, hypertension and obesity. The factors determining food habits are described and the possibilities of influencing food preferences and eating patterns in childhood are explored.

An outbreak of erythema infectiosum associated with human parvovirus infection

Erythema infectiosum (EI) or fifth disease is a mild, acute exanthematous disease, occurring mainly among children, for which a causative virus has long been sought. In May 1983 an outbreak of exanthematous illness was reported in a primary school in North London. Children attending the school were investigated by questionnaire and 162 (43.9%) reported an illness with the features of EI. In each of 36 cases investigated virologically the illness was associated with parvovirus infection. Moreover, pre-existing antibody to parvovirus was correlated with protection from EI in 16 of 17 close family contacts of cases. We propose therefore that EI is the common manifestation of infection with the human parvovirus.

Early nutrition: its long-term role

The widespread belief that problems such as lifelong obesity originate in infancy sometimes leads to overzealous attempts to regulate energy intake too soon and may compromise linear growth. Treatment of obesity should wait unitl after age one.

Aneurysms of the coronary arteries in infants and children. A review, and report of six cases

In recent years large numbers of the so-called "mucocutaneous lymph node syndrome" or "Kawasaki's disease" have been described by Japanese workers, but instances of this disorder are only now being reported as isolated cases by European or North American physicians. The disease has, therefore, been considered to be a new entity. One of its most striking features is the development of aneurysms of the coronary arteries in infants or children, which may lead to sudden death. Aneurysms of the coronary arteries in childhood are rare, and hence it was considered relevant to report six such cases, and to examine their possible relationship to Kawasaki's disease. The pathological changes underlying the latter disorder are not well known; they are considered to be indistinguishable from infantile polyarteritis nodosa. A diagnosis of polyarteritis nodosa was also thought to be most likely to apply in the cases presented here, particularly in view of the frequency with which aneurysms of the coronary arteries have been found in this disorder. In the absence of valid pathological distinctions between Kawasaki's disease and infantile polyarteritis nodosa, the question arises whether these entities are, in fact, different, and whether Kawasaki's disease is the new entity it is assumed to be.

Infantile periarteritis nodosa or mucocutaneous lymph node syndrome. A report on four cases and diagnostic considerations

Coronary artery aneurysm in childhood is a rare disease and has in most cases been ascribed to infantile periarteritis nodosa (IPN). In recent years a mucocutaneous lymph node syndrom (MLNS) has been found almost exclusively in Japan first described by Kawasaki 1967; this disease frequently involves the coronary arteries and myocardium. Four cases with coronary aneurysms are presented from Sweden and seem to be first described from Scandinavia. Three of these patients died a sudden death with cardiac arrest. Since MLNS and IPN have identical clinical and pathological features, we suggest that MLNS and IPN constitute a pathologic entity and that to separate them on a clinical or histological basis is nonsensical. The risk of coronary aneurysm and possible sudden death must be considered in patients with uncharacteristic symptoms including prolonged fever, conjunctivitis, exanthema, lesions in the oral mucosa, elevated sedimintation rate, and leukocytosis.