Risk factors for invasive group A streptococcal infections in children with varicella: a case-control study

Study of Complications of Varicella-Zoster Virus Infection in Hospitalized Children at a Reference Hospital for Infectious Disease Treatment

OBJECTIVES

Varicella is a disease with potentially severe complications. We aimed to investigate characteristics of hospitalized children with varicella in Brazil in the prevaccine period and to identify predictors for requiring intensive care treatment.

METHODS

A prospective cohort study was conducted from May 2011 to April 2014. Patients up to 13 years of age with varicella diagnosis were included. Information was collected through interview and review of medical records. Logistic regression analysis was performed.

RESULTS

A total of 669 patients were admitted. The median age of subjects was 2.7 years (range 0-14 years) with a predominance of boys (56.6%). The main causes of hospitalization were bacterial complications (77.7%), viral complications (11.4%), and at-risk patients (10.9%). Main bacterial complications were skin infection and pneumonia. Main viral complications were herpes zoster, cerebellitis, and encephalitis. Most at-risk patients used corticosteroids or had a diagnosis of leukemia. At-risk patients were hospitalized earlier (P < .01) and remained hospitalized for longer periods (P = .03). A total of 44 patients (6.6%) were admitted to the ICU, and 5 (0.8%) died of septic shock. Thrombocytopenia was associated with more severe illness in patients with bacterial infections (P = .001). The long-time interval between onset of infection and admission was associated with the need for intensive care in all groups (P = .007).

CONCLUSIONS

Secondary bacterial infection is the main cause of hospitalization, and thrombocytopenia in these patients leads to worse outcomes. Difficulties of access to the health system and delay in medical care are determining factors of greater severity in this population.

A clinical and safety review of paracetamol and ibuprofen in children

The antipyretic analgesics, paracetamol, and non-steroidal anti-inflammatory agents NSAIDs are one of the most widely used classes of medications in children. The aim of this review is to determine if there are any clinically relevant differences in safety between ibuprofen and paracetamol that may recommend one agent over the other in the management of fever and discomfort in children older than 3 months of age.

Incidence, Morbidity, and Costs of Human Metapneumovirus Infection in Hospitalized Children

BACKGROUND

Human metapneumovirus (HMPV) causes acute respiratory tract infections in infants and children. We sought to measure the clinical and economic burden of HMPV infection in hospitalized children.

METHODS

We conducted a retrospective cohort study from 2007 to 2013 at Primary Children's Hospital in Salt Lake City, Utah. Children <18 years of age with laboratory-confirmed HMPV infection were included. Demographic, clinical, and financial data were abstracted from the electronic medical record.

RESULTS

During the study period, 815 children were hospitalized with laboratory-confirmed HMPV infection: 16% <6 months, 50% 6-23 months, 23% 2-4 years, and 11% 5-17 years of age. A complex chronic condition was identified in 453 (56%) children hospitalized with HMPV infection; this proportion increased with increasing age (P < .001). There was marked variation in annual HMPV hospitalization rates, ranging from 9 of 100 000 person-years in 2012-2013 to 79 of 100 000 in 2009-2010. Hospitalization rates were highest among children <2 years (200 of 100 000 person-years) and lowest among children 5-17 years of age (5 of 100 000). Of hospitalized children, 18% were treated in the intensive care unit and 6% required mechanical ventilation. The median length of stay was 2.8 days (interquartile range [IQR], 1.8-4.6) and did not vary by age. The median total hospital cost per patient was $5513 (IQR, $3850-$9946) with significantly higher costs for patients with chronic medical conditions (P < .001).

CONCLUSIONS

Human metapneumovirus infection results in a large number of hospitalizations with substantial morbidity, resource utilization, and costs. The development of a safe and effective vaccine could reduce the clinical and economic burden of HMPV.

Varicella zoster virus infections in Canadian children in the prevaccine era: A hospital-based study

OBJECTIVE

To describe the clinical course of children admitted for varicella zoster virus (VZV) infections to a pediatric hospital before the release of VZV vaccine in Canada.

DESIGN

Retrospective case series.

SETTING

Tertiary pediatric hospital. Population studied was children aged 18 years or younger admitted to hospital between 1983 and 1992 who were discharged with a diagnosis of varicella or zoster. Of the 201 children who were identified, 36 were excluded, leaving 165 for analysis.

RESULTS

There was a male:female ratio of 1.5:1 and a median age of 5.3 years (range two weeks to 18 years). The group included those who were previously healthy (70, 42.4%), immunocompromised (60, 36.4%), and those with nonimmunocompromising conditions (35, 21.2%). Comparison of immunocompetent and immunocompromised children revealed that complication of VZV infection was a more common reason for admission among the former (86 of 105, 81.9%, P<0.001), whereas treatment with acyclovir to limit dissemination was the most common reason in the latter (53 of 60, 88.3%, P<0.001). Skin and soft tissue infections were the most common complications in immunocompetent children (36 of 98) and those younger than five years (26 of 53), whereas pulmonary complications predominated among immunocompromised patients (eight of 98) and neurological complications in five- to 10-year-olds (16 of 36). Only one death (0.6%) occurred in an immunocompetent patient. Group A beta-hemolytic streptococci and Staphylococcus aureus caused equal numbers of secondary infections (92% of all isolates).

CONCLUSIONS

Complications of VZV infections and secondary prophylactic antiviral treatment of immunocompromised children explain the majority of hospitalizations in this institution, and can be monitored after VZV vaccine introduction. Complications vary significantly with underlying healthy status and age.

Flesh-eating disease: A note on necrotizing fasciitis

There has been much media attention in the past few years to the condition dubbed 'flesh-eating disease', which refers, primarily, to a form of invasive group A beta hemolytic streptococcal (GABHS) infection that leads to fascia and muscle necrosis. In 1999, the Canadian Paediatric Society issued a statement on the state of knowledge and management of children, and close contacts of persons with all-invasive GABHS disease (1). The present note is intended to deal specifically with necrotizing fasciitis (NF) by providing an update on the limited current state of knowledge, diagnosis and management. Surveillance to establish actual national rates and epidemiology of NF through the Canadian Paediatric Society is proposed.

Acetaminophen and ibuprofen in the management of fever and mild to moderate pain in children

Acetaminophen has become the non-narcotic of choice for children because of concerns regarding the connection between acetylsalicylic acid exposure and Reye's syndrome. Ibuprofen, recently granted over-the-counter status for children over two years of age, offers another choice for treatment. The efficacy and safety of both drugs have been studied in numerous clinical trials. This paper reviews the published evidence about the efficacy and safety of acetaminophen and ibuprofen with regard to treating fever and mild to moderate pain in children.

Varicella-related musculoskeletal complications in children

Eight children with post-varicella musculoskeletal complications were treated between 2001 and 2009. The complications that were observed were cellulitis (three children), pyomyositis (three children), osteomyelitis (two children) and gangrene (one child). On average, 8.8 days elapsed between primary varicella infection and complication. The most common presentation was pain. Before we started treating them, all children received antibiotics during interhospital transfers (average: 2.4). Interventions included drainage (eight), fasciatomy (one), arthrotomy (one), bone drilling (one), and amputation (one). Blood cultures were negative in all children. Two children had positive pus cultures for Staphylococcus aureus, one of them had a methicillin-resistant S. aureus infection. One of the four children who developed coagulopathy ended with significant morbidity. Varicella-related methicillin-resistant S. aureus osteomyelitis suggests a widening spectrum of these infections.

Necrotising fasciitis: a sequelae of varicella zoster infection

Necrotising fasciitis (NF) can complicate varicella zoster virus in children. This is rare and has not previously been reported in the plastic surgery literature. We report a case of a female toddler who developed necrotising fasciitis secondary to chicken pox. Her presentation and progress are reported, the diagnosis of necrotising fasciitis in children and the small number of case series and case control studies are discussed.

Intravenous ibuprofen: the first injectable product for the treatment of pain and fever

This paper reviews the current data on the use of the first approved intravenous ibuprofen product for the management of post-operative pain and fever in the United States. The management of acute and post-operative pain and fever with nonsteroidal anti-inflammatory agents (NSAIDs) is well documented. A search in Medline and International Pharmaceutical Abstracts of articles until the end of November 2009 and references of all citations were conducted. Available manufacturer data on file were also analyzed for this report. Several randomized controlled studies have demonstrated the opioid-sparing and analgesic effects of 400 and 800 mg doses of intravenous ibuprofen in a series of post-operative patient populations. Two recent studies have also noted the improvement in fever curves in critically ill and burn patients. These data, along with pharmacokinetic and pharmacologic properties, are explored in this review, which addresses the clinical utility of a parenteral NSAID in a hospitalized patient for post-operative pain management and fever reduction. Further data on intravenous ibuprofen are needed to define long-term utilization, management of acute pain, and use in special populations.

A multicentre case-control study of nonsteroidal anti-inflammatory drugs as a risk factor for severe sepsis and septic shock

INTRODUCTION

We aimed to establish whether the use of nonsteroidal anti-inflammatory drugs (NSAIDs) during evolving bacterial community-acquired infection in adults is associated with severe sepsis or septic shock.

METHODS

We conducted a multicentre case-control study in eight intensive care units. Cases were all adult patients admitted for severe sepsis or septic shock due to a bacterial community-acquired infection. Control individuals were patients hospitalized with a mild community-acquired infection. Each case was matched to one control for age, presence of diabetes and site of infection.

RESULTS

The main outcome measures were the proportions of cases and controls exposed to NSAIDs or aspirin during the period of observation. In all, 152 matched pairs were analyzed. The use of NSAIDs or aspirin during the observation period did not differ between cases and controls (27% versus 28; odds ratio = 0.93, 95% confidence interval [CI] = 0.52 to 1.64). If aspirin was not considered or if a distinction was made between acute and chronic drug treatment, there remained no difference between groups. However, the median time to prescription of effective antibiotic therapy was longer for NSAID users (6 days, 95% CI = 3 to 7 days) than for nonusers (3 days, 95% CI = 2 to 3 days; P = 0.02).

CONCLUSIONS

In this study, the use of NSAIDs or aspirin during evolving bacterial infection was frequent and occurred in one-quarter of the patients with such infection. Although the use of NSAIDs by patients with severe sepsis or septic shock did not differ from their use by those with mild infection at the same infected site, we observed a longer median time to prescription of effective antibiotic therapy in NSAID users.

[Pneumonia with empyema during varicella]

Chicken pox is usually considered a benign viral affection; however, possible infectious complications are observed. Although cutaneous infections are well described, bacterial pneumonia with empyema is more exceptionally reported.

PURPOSE

To describe the clinical characteristics of bacterial pneumonia with empyema associated with chicken pox.

METHODS

This descriptive multicenter retrospective study was based on a questionnaire sent by Internet to 30 French pediatric and pediatric respiratory hospital wards.

RESULTS

We found 4 cases of children (mean age, 19 months) presenting during the chicken pox eruption concomitant bacterial pneumonia with empyema. The average time of diagnosis was 4.5 days after the beginning of the eruption. All the children were febrile and had an average pulsed oxygen saturation of 87%. The inflammatory syndrome was constant with a mean C reactive protein of 253 mg/l. Group A Streptococcus was identified in 3 cases out of 4. Admission to an intensive care unit was necessary for 3 children, 1 of them requiring mechanical ventilation. No clinical or radiological sequelae were observed during the complete year of follow-up.

CONCLUSION

Bacterial pneumoniae with empyema are not current complications of chicken pox but have to be sought when prolonged fever and/or alteration of the health status occurs during chicken pox eruption.

Varicella-related deaths in children and adolescents--Germany 2003-2004

AIM

Although varicella is acknowledged as a rare cause of death in children, there are few comprehensive data with respect to the clinical course leading to death.

METHODS

A nationwide, active surveillance was carried out in Germany for children up to age 17 years who were admitted to a paediatric hospital for varicella or associated complications, including deaths.

RESULTS

A total of 10 children with varicella-associated death were reported over period of 2 years, yielding a mortality rate of 0.4/1 000 000 children per year. Three deaths occurred in children diagnosed with acute lymphocytic leukaemia and disseminated varicella, two shortly after diagnosis of leukaemia and therefore not preventable, and one during remission with an untypical presentation. Two children died with a congenital varicella syndrome. There was no death in children with neonatal varicella. Four other cases were related to varicella pneumonia or septicaemia and one to myocarditis.

CONCLUSION

In a population with no general varicella vaccination programme, varicella accounted for a small but not negligible risk for death in immunocompetent and immunocompromised children. Together these data point to the importance of a thoroughly implemented, general varicella vaccination programme.

Growth, morbidity and mortality after chickenpox infection in young children in Guinea-Bissau

OBJECTIVE

To examine whether chickenpox in children below 2 years of age is associated with post-infection changes in growth, morbidity or mortality.

METHODS

An outbreak of chickenpox was investigated in Guinea-Bissau. An examination, interview and anthropometry were performed 6 months after the epidemic for a group of children and matched controls whose weight had been measured at the time of the chickenpox episode. All children diagnosed with chickenpox before 2 years of age were followed for survival and hospitalisations to the age of 3 years and compared with all other children in the community.

RESULTS

At the 6-month follow-up, skin infections tended to be more frequent in cases (p<0.06) and more cases had used antibiotics within the last month (p<0.03). Although there had been no difference before chickenpox infection, girls with chickenpox infection had significantly higher weight, height and larger arm-circumferences than controls (all p<0.01). After chickenpox infection, the incidence of hospitalisation and long-term mortality was the same for cases and other children in the community (respectively, incidence rate ratio=1.16 (0.77-1.74) and mortality ratio=0.74 (0.39-1.41)).

CONCLUSION

Though chickenpox may be associated with increased short-term morbidity, it does not appear to have any negative long-term effect on growth, severe morbidity and survival of young children.

Epidemiology of hospital admissions for paediatric varicella infections: a one-year prospective survey in the pre-vaccine era

To evaluate the epidemiology of hospital admissions for varicella in children, a 1-year prospective multicentre study was done in Northern France in the pre-varicella vaccine era. The 405 children aged <16 years seen at local hospitals for varicella or herpes zoster were included. Among them, 143 who had varicella and resided in the district were admitted. Admission incidence rates were 28/100000 children aged <16 years (149/100000 infants aged <1 year, 69/100000 children aged 1-4 years, and 2/100000 children aged 5-15 years). Most admissions (57%) were related to complications, usually skin infection (47%). Independent risk factors for admission were place of residence outside the district [adjusted odds ratio (aOR) 8.7], complication at admission (aOR 5.8), recurrent fever (aOR 4.5), recent varicella in a sibling (aOR 4.0), and previous physician visit for the same condition (aOR 2.0).

Acute osteomyelitis as a complication of varicella

Varicella is a common viral infection in childhood, and acute osteomyelitis is one of the rare but serious complications. We report two cases of osteomyelitis as a complication of varicella. The possibilities and limitations of the different imaging modalities are discussed, as well as imaging findings during the course of this condition.

Invasive group A streptococcal disease: should close contacts routinely receive antibiotic prophylaxis?

Group A streptococci (Streptococcus pyogenes) causes a wide range of illnesses from non-invasive disease--eg, pharyngitis--to more severe invasive infections--eg, necrotising fasciitis and toxic shock-like syndrome. There remains uncertainty about the risk of secondary cases of invasive disease occurring among close contacts of an index case and how best to manage that risk. We do not consider that currently available evidence justifies the routine administration of chemoprophylaxis to close contacts. We suggest that the appropriate response should be to routinely inform all household contacts of a patient with invasive group A streptococcal disease about the clinical manifestations of invasive disease and to seek immediate medical attention if they develop such symptoms.

Risk factors for pediatric invasive group A streptococcal disease

Invasive group A Streptococcus (GAS) infections can be fatal and can occur in healthy children. A case-control study identified factors associated with pediatric disease. Case-patients were identified when Streptococcus pyogenes was isolated from a normally sterile site, and matched controls (≥2) were identified by using sequential-digit dialing. All participants were noninstitutionalized surveillance-area residents <18 years of age. Conditional regression identified factors associated with invasive disease: other children living in the home (odds ratio [OR] = 16.85, p = 0.0002) and new use of nonsteroidal antiinflammatory drugs (OR = 10.64, p = 0.005) were associated with increased risk. More rooms in the home (OR = 0.67, p = 0.03) and household member(s) with runny nose (OR = 0.09, p = 0.002) were associated with decreased risk. Among children, household-level characteristics that influence exposure to GAS most affect development of invasive disease.

Risk factors for pediatric invasive group A streptococcal disease

Invasive group A Streptococcus (GAS) infections can be fatal and can occur in healthy children. A case-control study identified factors associated with pediatric disease. Case-patients were identified when Streptococcus pyogenes was isolated from a normally sterile site, and matched controls (>or=2) were identified by using sequential-digit dialing. All participants were noninstitutionalized surveillance-area residents <18 years of age. Conditional regression identified factors associated with invasive disease: other children living in the home (odds ratio [OR]=16.85, p=0.0002) and new use of nonsteroidal antiinflammatory drugs (OR=10.64, p=0.005) were associated with increased risk. More rooms in the home (OR=0.67, p=0.03) and household member(s) with runny nose (OR=0.09, p=0.002) were associated with decreased risk. Among children, household-level characteristics that influence exposure to GAS most affect development of invasive disease.

Invasive group A streptococcal disease in Alberta, Canada (2000 to 2002)

Invasive group A streptococcal (iGAS) disease was placed under surveillance in Alberta in August 1999. The purpose of this study was to determine the incidence rates of iGAS infections throughout Alberta over a 3-year period (2000 to 2002) and to better understand the epidemiology of iGAS in this province. There were a total of 441 cases of invasive GAS disease over the 3 years examined (average population over 3 years, 3,055,765) and 47 deaths. The incidence in Alberta was 5.0 (2000), 5.7 (2001), and 3.8 (2002) per 100,000. The two main metropolitan regions (Edmonton and Calgary) had the majority of iGAS disease cases (305 cases), producing incidence rates of 4.8 (Edmonton) and 6.9 (Calgary) in 2000, 6.9 (Edmonton) and 6.6 (Calgary) in 2001, and 4.1 (Edmonton) and 3.9 (Calgary) in 2002, as well as deaths attributable to GAS (31 deaths). The three most prevalent M types were M1 (71 cases), M3 (52 cases), and MPT2967 (44 cases). With respect to age, the highest incidence rates occurred in those less than 1 year old (11.7 per 100,000) and those 65 years or older (11.5 per 100,000). Varicella virus infection preceded iGAS disease in 25% of children 8 years of age and under. A seasonal association was observed during the 3 years studied, with the highest number of cases occurring in the winter months and the lowest occurring during the summer months. The data for years 2000 and 2001 show that the metropolitan regions of Alberta experienced some of the highest incidence rates reported in North America in the past decade.

Varicella zoster in Guinea-Bissau: intensity of exposure and severity of infection

OBJECTIVE

To describe the epidemiology of and risk factors for severe chickenpox in Guinea- Bissau.

METHODS

A prospective household study in a semiurban area of the capital. Severity was assessed by number of pox, fever response and presence of pneumonia. Severity was compared for the first case in a house, that is, the index case, and the secondary cases infected at home.

RESULT

We identified 1539 cases of chickenpox. The median age was lower for boys and secondary cases (both P < 0.03); 44.6% of children were 1-4 years of age. The likely minimum interval between index and secondary cases was 10 days; most secondary cases occurred 14-17 days after the index case. The length of the incubation period was related to the intensity of exposure (P < 0.01). The number of pox was higher for secondary cases (P < 0.01) and was related to intensity of exposure (P < 0.01). Secondary cases had higher fever and more frequently pneumonia (relative risk, 2.17; 95% confidence interval, 1.54-3.08). Children with pneumonia were younger and had more pox. Nutritional status was not related to severity.

CONCLUSIONS

Age and intensity of exposure are important determinants for severity of chickenpox infection. The length of the incubation period depends on intensity of exposure, suggesting that the dose of infection might be important.

Group A beta-hemolytic streptococcal bacteremia

OBJECTIVE

The aim of this study was to review the clinical features, laboratory findings and the risk factors associated with invasive group A streptococcal infections in children admitted to our institution over a 9-year period (January 1, 1990 through December 31, 1999).

METHODS

Medical records of children who had a positive blood culture for group A beta-hemolytic streptococci and children who had this organism isolated from any other sterile site were identified and retrospectively reviewed.

RESULTS

Forty-one children with invasive GAS were identified, of whom 15 (36%) were diagnosed between 1990 and 1994, while the balance (26 patients, 63%) were diagnosed between 1995 and 1999 (p< 0.05). The mean age was 4.3 +/- 2.5 years (age range: 2 months to 16 years). Thirteen (32%) patients were infants. Sixteen patients had only bacteremia, while 25 patients had in addition to bacteremia the following: cellulitis (n: 13), osteomyelitis (n: 6), pneumonia (n: 3), meningitis (n: 1), pharyngitis (n:3) and Toxic Shock Syndrome (n: 2). Primary varicella infection constituted the most common predisposing factor for invasive GAS infections and occurred in 11 (27%) patients. Leukocytosis (A white blood cell count > 15,000/mm3) occurred in 21 (51 %) patients, while leukopenia (A white blood cell count < 5000/mm3) occurred in 2 patients. Parenteral crystalline penicillin G followed by oral penicillin or amoxicillin were the most common antibiotics administered. The mean hospital length of stay was 8 days (range: 6 -32 days). All, but one patient survived. The one patient who died had malnutrition and died from streptococcal toxic shock syndrome.

CONCLUSION

More cases of invasive GAS were diagnosed during the second half of the study period, however, the overall rate of occurrence of bacteremia during the study period was consistent with previous reports. Primary varicella infection was the most common predisposing factor for invasive GAS infections. The low occurrence of toxic shock syndrome and fatalities among children with invasive GAS infections are consistent with other pediatric but not with adult series.

Évaluation du traitement ambulatoire de la varicelle de l’enfant

BACKGROUND

Varicella, an almost compulsory affection in children, is complicated in 2% of cases. Some treatments such as powders and non-steroidial anti-inflammatories (NSAIs) may favorise or worsen infectious complications.

OBJECTIVE

To assess out-patient prescriptions in children presenting with varicella.

METHODS

Three methods were used. Collection of the out-patient prescriptions in children (n=122) subsequently presenting with varicella in one of the hospitals in the North of France conducted from January to May 2003. A telephone survey was made among 50 general practitioners in the same area in March 2003. This collected not only the prescription of the last case reported, but also the intended prescriptions when confronted with a simulated case of the disease.

RESULTS

Powders were prescribed in 44 to 54% of cases, NSAIs in 14 to 16%, aspirin in 2 to 4%, and oral acyclovir in 4%. The three assessment methods did not reveal any differences in the prescription of antibiotics, more frequent in the children subsequently visiting the hospital (25 vs. 6%), and the prescriptions of paracetamol. Only 38% of the prescriptions during clinical cases corresponded to the guidelines.

CONCLUSION

It is crucial that practitioners be informed on the treatment of varicella and the risks of severe cutaneous surinfections enhanced by certain prescriptions.

Developing animal models for polymicrobial diseases

Although polymicrobial diseases are not a new concept for microbiologists, they are experiencing a resurgence of interest owing to the development of suitable animal models and new molecular techniques that allow these diseases to be studied effectively. This broad review provides an excellent introduction to this fascinating topic.

Examples are included of each type of polymicrobial disease and the animal models that are used to study these diseases are discussed. In many instances, schematics for the animal model are presented.

Viral co-infections including bovine viral diarrhoeal viruses, porcine reproductive and respiratory syndrome, mixed hepatitis virus infections and HIV co-infection with hepatitis virus are discussed, together with attempts to model these diseases in animals.

Viral and bacterial co-infections are reviewed with a special focus on otitis media and the rodent models that have been used to probe this important childhood illness.

Of the polybacterial diseases, periodontitis is one of the best understood and a clinically relevant rodent model is now available. This model, and the role of biofilm formation in periodontitis are examined.

Fungal infections of humans are often referred to as 'opportunistic' but in fact these infections are often fungal co-infections with viruses such as HIV and fungal mixed co-infections. The roles of these infections in disease and the rodent models used to study them are discussed.

Parasite co-infections are thought to have a role in the severity of malaria and the severity of Lyme arthritis. These diseases and attempts to model them are evaluated.

Finally, co-infections that are associated with virus-induced immunosuppression are discussed, together with their animal models.

Polymicrobial diseases involve two or more microorganisms that act synergistically, or in succession, to mediate complex disease processes. Although polymicrobial diseases in animals and humans can be caused by similar organisms, these diseases are often also caused by organisms from different kingdoms, genera, species, strains, substrains and even by phenotypic variants of a single species. Animal models are often required to understand the mechanisms of pathogenesis, and to develop therapies and prevention regimes. However, reproducing polymicrobial diseases of humans in animal hosts presents significant challenges.

Invasive group A streptococcal disease: risk factors for adults

We conducted a case-control study to identify risk factors for invasive group A streptococcal (GAS) infections, which can be fatal. Case-patients were identified when Streptococcus pyogenes was isolated from a normally sterile site and control subjects (two or more) were identified and matched to case-patients by using sequential-digit telephone dialing. All participants were noninstitutionalized surveillance area residents, >18 years of age. Conditional logistic regression identified the risk factors for invasive GAS infection: in adults 18 to 44 years of age, exposure to one or more children with sore throats (relative risk [RR]=4.93, p=0.02), HIV infection (RR=15.01, p=0.04), and history of injecting drug use (RR=14.71, p=0.003); in adults >45 years of age, number of persons in the home (RR=2.68, p=0.004), diabetes (RR=2.27, p=0.03), cardiac disease (RR=3.24, p=0.006), cancer (RR=3.54, p=0.006), and corticosteroid use (RR=5.18, p=0.03). Thus, host and environmental factors increased the risk for invasive GAS disease.

Assessing the relationship between the use of nonsteroidal antiinflammatory drugs and necrotizing fasciitis caused by group A streptococcus

Group A streptococcal (GAS) necrotizing fasciitis is a rapidly progressive soft tissue infection. Elderly and chronically ill individuals are at greatest risk, particularly when skin breakdown is present. Reports suggest that nonsteroidal antiinflammatory drugs (NSAIDs) increase the risk of developing GAS necrotizing fasciitis, impede its timely recognition and management, and accelerate the course of infection. We present a literature review conducted to examine these hypotheses and present a case of GAS necrotizing fasciitis associated with rofecoxib use. Initial symptoms of fasciitis may be nondescript, mimicking more benign conditions such as cellulitis, arthritis, or musculoskeletal pain. Case reports and retrospective studies suggest that the application of NSAIDs to relieve these nonspecific symptoms can delay diagnosis and treatment of GAS necrotizing fasciitis. However, prospective studies do not support a risk of developing GAS necrotizing fasciitis as a result of NSAID therapy, or a worsening of established streptococcal infection. To avoid the application of NSAIDs in lieu of aggressive medical and surgical management of streptococcal fasciitis, clinicians must understand the early symptoms of GAS necrotizing fasciitis that precede visible soft tissue necrosis. A rational approach to patients presenting with localized soft tissue pain will enhance detection and therapy of this rapidly progressive, life-threatening disease.

[Varicella complicated with necrotizing fasciitis caused by group A hemolytic Streptococcus]

Chickenpox has a high risk of invasive group A streptococcal disease and necroziting fasciitis.

CASE REPORT

A five-year-old girl, during chickenpox treated with ibuprofen, developed sepsis and edematous and necrotic lesions of the pelvis and the abdominal wall. The child improved with surgical treatment and adjunction of clindamycin to the antibiotic therapy.

CONCLUSION

We review the optimal medical and surgical treatment of necrotizing fasciitis and discuss the role of chickenpox and non steroidal antiinflammatory agents in this disease.

An epidemiological investigation of a sustained high rate of pediatric parapneumonic empyema: risk factors and microbiological associations

We investigated the increasing incidence of pediatric empyema during the 1990s at Primary Children's Medical Center in Salt Lake City. Of 540 children hospitalized with community-acquired bacterial pneumonia (CAP) who were discharged from 1 July 1993 through 1 July 1999, 153 (28.3%) had empyema. The annual population incidence of empyema increased during the study period from 1 to 5 cases per 100,000 population aged <19 years. Streptococcus pneumoniae was identified as the most common cause of CAP with or without empyema; serotype 1 accounted for 50% of the cases of pneumococcal empyema. Patients with empyema were more likely to be >3 years old, to have > or =7 days of fever, to have varicella, and to have received antibiotics and ibuprofen before admission to the hospital, compared with patients without empyema (P<.0001 for each factor). The increasing incidence of empyema was associated with infection due to S. pneumoniae serotype 1, outpatient treatment with certain antibiotics, ibuprofen use, and varicella.

[Severe Streptococcus pyogenes cutaneous infections]

Streptococcus pyogenes is the first bacteria encountered in severe cutaneous infections in children. They enclose erysipela (papillar derma concerned more than hypoderma, lymphatic involvement) and necrotising fasciitis NF (focus on fascia and muscles with extension to hypoderma and reticular derma; venous thrombosis; hypodermic and aponevrotic necrosis). A skin lesion is the entrance of infection: varicella lesions are a major factor of NF. In France, sporadic cases in children are observed. The annual incidence of S. pyogenes invasive diseases is 1/100,000 children under 5 years of age and 0.6/100,000 children under 15 years of age. In North America, resurgence has been notified during the past ten years with mortality and morbidity due to NF and toxic shock syndromes. Interaction between bacteria and host, natural reservoir, explains the physiopathology. During the past ten years, some serotypes have become more invasive and virulent. Any cutaneous lesion interrupt the dermal barrier. Bacterial wall, proteins M and adhesins permit colonisation. Four pyrogenic exotoxins are superantigens; some facilitate inflammation, tissular lesions and shock; other participate to bacterial extension. In young children, immune response is immature. Albeit causal link between non-steroids anti-inflammatory drugs and NF in varicella children was not clearly demonstrated, caution should be kept in mind. Diagnosis of erysipela is clinical: sudden appearance of an inflammatory zone, most often on legs, with high fever and pain; sometime peripheral surelevation, lymphangitis, adenopathia. Other aspects open discussion with NF. In NF are in favour, added to high fever, huge pain, erythema and oedema: rapid extension of lesions, cutaneous hypoesthesia appearance, gap between intense severe general status (toxic shock syndrome) and paucity of local signs. NF is a medico-surgical emergency. Early surgery with complete excision of necrotic tissues permit survival. Magnetic resonance is useful in subacute NF. Microbiological diagnosis is possible in 20 to 80% of cases, using combined methods. Blood cultures identify the bacteria in 5 to 20%, skin lesion samples in 30%. Local samples are less useful even with modern techniques. Therapeutic strategy depends on initial diagnosis. Intra-venous antibiotics are necessary: penicillin (G, A or M) is first line therapy. In erysipela, ten days allow a rapid cure without sequellae. In NF, antibiotics are associated with intensive care and surgery. A late diagnosis, a too late surgery explain 16 to 36% of deaths encountered.

[Impact of bacterial resistance on severe infections]

Since many years, the antimicrobial resistance increases as well as for community-acquired as for nosocomial infections. Antibiotic-resistant pneumococci are neither more nor less virulent susceptible strains. Except for immunocompromised patients, the outcome of penicillin-resistant pneumococcal infections have been similar to those in patients who are infected by susceptible ones. Current levels of S. pneumoniae resistance to penicillin and cephalosporin are not associated to an increase in mortality in children with meningitis if adequate doses of antibiotics are given. Because empiric therapy has changed, antibiotic resistance has not been associated with increased mortality. This statement can be extended to Meningococcus, for which 32 to 50% of the strains have a decreased susceptibility to penicillin. For nosocomial infections, S. aureus is the main studied pathogen. Several studies report that in patients with severe diseases (bacteremia or pneumonia) methicillin resistance of S. aureus had no significant impact on patient outcome after adjustment for different confounders. The main risk factor for mortality is the severe underlying diseases rather than the resistance as well for methicillin--resistant S. aureus, as for vancomycin resistant enterococci, Klebsiella with extended spectrum beta lactamase and Enterobacters. Recommendations for controlling epidemiologic surveillance, using barrier precautions and limiting the use of antibiotics as well in the hospital as in the community must be undertaken.

Invasive group A streptococcal infection and nonsteroidal antiinflammatory drug use among children with primary varicella

OBJECTIONS

To test the hypothesis that nonsteroidal antiinflammatory drug use increases the risk of necrotizing soft tissue infections and, secondarily, all invasive group A streptococcal (GAS) infections in children with primary varicella infection.

METHODS

We conducted a prospective, multicenter case-control study among children <19 years old. Cases were children hospitalized with primary varicella complicated by invasive GAS infection or necrotizing soft tissue infection identified by a network of 45 pediatric infectious disease specialists located throughout the United States. Controls were children with uncomplicated primary varicella residing in the same communities as the cases. Data on medical history, clinical features of the varicella infection, signs and symptoms of infectious complications, and medication use were collected by structured telephone interviews. Univariate and multivariate matched odds ratios were calculated using conditional logistic regression.

RESULTS

Between June 1996 and September 1998, 52 cases of invasive GAS infection, including 21 with necrotizing soft tissue infection, and 172 controls with uncomplicated primary varicella were enrolled. Risk of invasive GAS infection was increased among children who were nonwhite (multivariate odds ratio [OR] 3.8, 95% confidence interval [CI]: 1.4-11), living in low-income households (OR 5.1, 95% CI: 1.7-15), exposed to varicella at home (OR 6.4, 95% CI: 2.6-16), or had a persistent high fever (OR 9.6, 95% CI: 2.8-33). Antipyretic regimen was associated with several measures of varicella illness severity among the controls. The risk of necrotizing soft tissue infection was not associated with the use of ibuprofen before the development of signs or symptoms of this complication (OR 1.3, 95% CI: 0.33-5.3). Risk of any invasive GAS infection was increased among children who had received ibuprofen (OR 3.9, 95% CI: 1.3-12), but not acetaminophen (OR 1.2, 95% CI: 0.50-3.0). However, there was no evidence of increasing risk with increasing duration of ibuprofen use. Subgroup analyses revealed that the risk of invasive GAS infection was increased only among children who had received both acetaminophen and ibuprofen.

CONCLUSIONS

These data do not support the hypothesis that nonsteroidal antiinflammatory drugs, or ibuprofen in particular, increase the risk of necrotizing GAS infections. A statistically significant association was observed between nonnecrotizing invasive GAS infection and ibuprofen use; however, because of potential confounding, the meaning of this unexpected result is unclear. Nonetheless, these data suggest that parents use ibuprofen or ibuprofen together with acetaminophen to treat high fever and severe illness, which seems to identify children at high risk for invasive GAS infection.

The Immunization Monitoring Program Active (IMPACT) prospective five year study of Canadian children hospitalized for chickenpox or an associated complication

BACKGROUND

Varicella vaccine was approved for use in Canada in 1998. A major goal of universal varicella vaccine programs is to reduce severe infection and associated complications. Baseline data are essential against which to judge the effectiveness of routine childhood immunization.

OBJECTIVE

To describe morbidity and mortality among children hospitalized for chickenpox. Methods. From January 1, 1991, to March 31, 1996, chickenpox admissions to 11 pediatric referral centers were actively identified. Patient and illness characteristics were compared for 3 subgroups defined by prior health: healthy; unhealthy but immunocompetent; immunocompromised.

RESULTS

Of 861 cases 488 (56.7%) were healthy, 75(8.7%) were unhealthy and 298 (34.6%) were immunocompromised. The immunocompromised children differed from healthy/unhealthy cases in mean age (6.4 vs. 4.0/4.6 years, respectively, P < 0.0001); median interval from rash onset to admission (2 vs. 5/5 days, P < 0.0001); complication rate (20% vs. 90%/79%; P = 0.001); and rate of acyclovir therapy (98% vs. 24%/39%; P = 0.001). Unhealthy vs. healthy cases had a higher frequency (P < 0.01) of intensive care (13.3% vs. 4.7%), ventilation (9.3% vs. 2.0%) and death (4% vs. 0.2%).

CONCLUSION

These data provide a baseline for morbidity/mortality resulting from chickenpox before varicella vaccine use in Canada.

Invasive group A streptococcal disease in children and association with varicella-zoster virus infection. Ontario Group A Streptococcal Study Group

OBJECTIVES

To describe the incidence and clinical features of invasive group A streptococcal (GAS) disease in children in Ontario and determine the risk of invasive GAS infection following chickenpox.

METHODS

During 1992-1996, we conducted prospective, active, population-based surveillance for pediatric invasive GAS disease in Ontario, Canada (population: 11 million; 2.5 million children) and reviewed clinical and laboratory records.

RESULTS

There were 1.9 cases of invasive GAS disease per 100,000 children per year. Streptococcal toxic shock syndrome (STSS) occurred in 7% of cases and necrotizing fasciitis (NF) in 4% for incidences of.08 and.13 per 100,000 per year, respectively. Case-fatality rates were 56% for STSS, 10% for NF, and 4% overall. The presence of chronic underlying illness other than asthma was associated with death (relative risk [RR]: 11; 95% confidence interval [CI]: 2.4-45). Fifteen percent of children identified had preceding chickenpox infection, which significantly increased the risk for acquisition of invasive GAS disease (RR: 58; 95% CI: 40-85). Children with invasive GAS and recent chickenpox were more likely to have NF (RR: 6.3; 95% CI: 1.8-22.3).

CONCLUSIONS

Childhood invasive GAS disease occurs at an incidence similar to the adult population but has a lower rate of STSS and case-fatality. Chickenpox dramatically increases the risk for acquiring invasive GAS disease, and universal chickenpox vaccination could potentially prevent up to 15% of all pediatric invasive GAS disease.

Varicella vaccine

Varicella vaccine is safe, effective, and cost-effective in healthy children, adolescents, and adults. Breakthrough cases of MVLS are significantly milder than wild-type varicella infection. No severe adverse events have been reported following vaccination, and the incidence of herpes zoster is less in vaccinees than in individuals who have had natural varicella infections. To date, there is no evidence waning immunity following vaccination. "New and improved" varicella vaccines that may be more effective than the current vaccine and can be stored at refrigerator temperatures may soon become available in the United States.

A case-control study of necrotizing fasciitis during primary varicella

OBJECTIVE

An increase in the incidence of necrotizing fasciitis (NF) occurring in previously healthy children with primary varicella was noted in the Washington State area between December 1993 and June 1995. Our objective was to investigate ibuprofen use and other risk factors for NF in the setting of primary varicella.

METHODS

Case-control study. Demographic information, clinical parameters, and potential risk factors for NF were compared for cases and controls. Cases of NF were analyzed to identify potential determinants of NF complicated by renal insufficiency and/or streptococcal toxic shock syndrome. Multivariate logistic regression was used to evaluate the association between ibuprofen use and NF. A case was defined as a child with NF hospitalized within 3 weeks of primary varicella (n = 19). Controls were children hospitalized with a soft tissue infection other than NF within 3 weeks of primary varicella (n = 29). Odds ratios (ORs) of ibuprofen, as well as other potential risk factors were evaluated. In addition, demographic and clinical data as well as other potential risk factors were compared between cases and controls.

RESULTS

After controlling for gender, age, and group A streptococcus isolation, cases were more likely than controls to have used ibuprofen before hospitalization (OR, 11. 5; 95% confidence interval, 1.4 to 96.9). In most children, ibuprofen was initiated after the onset of symptoms of secondary infection. Children with NF complicated by renal insufficiency and/or streptococcal toxic shock syndrome were more likely than children with uncomplicated NF to have used ibuprofen (OR, 16.0; 95% confidence interval, 1.0 to 825.0). Children with complicated NF also had a higher mean maximum temperature (40.9 degrees C vs 39.3 degrees C), and a longer mean duration of secondary symptoms (1.7 days vs 0.6 days) before admission than children with uncomplicated NF.

CONCLUSION

Ibuprofen use was associated with NF in the setting of primary varicella. Additional studies are needed to establish whether ibuprofen use has a causal role in the development of NF and its complications during varicella.

Risk factors in the pathogenesis of invasive group A streptococcal infections: role of protective humoral immunity

An impressive change in the epidemiology and severity of invasive group A streptococcal infections occurred in the 1980s, and the incidence of streptococcal toxic shock syndrome cases continues to rise. The reason for the resurgence of severe invasive cases remains a mystery-has there been a change in the pathogen or in host protective immunity? To address these questions, we have studied 33 patients with invasive infection caused by genotypically indistinguishable M1T1 strains of Streptococcus pyogenes who had different disease outcomes. Patients were classified as having severe (n = 21) and nonsevere (n = 12) invasive infections based on the presence or absence of shock and organ failure. Levels of anti-M1 bactericidal antibodies and of anti-streptococcal superantigen neutralizing antibodies in plasma were significantly lower in both groups than in age- and geographically matched healthy controls (P < 0.01). Importantly, the levels of these protective antibodies in plasma samples from severe and nonsevere invasive cases were not different. Together the data suggest that low levels of protective antibodies may contribute to host susceptibility to invasive streptococcal infection but do not modulate disease outcome. Other immunogenetic factors that regulate superantigen responses may influence the severity of systemic manifestations associated with invasive streptococcal infection.

[Virus-bacteria co-infections]

Influenza is the best known model of bacterial-viral co-infection. Epidemics of influenza result in an increased hospital admission rate for bacterial pneumonia due to pneumococcus, Haemophilus influenzae and Staphylococcus aureus. Similarly, an increased incidence of meningococcal diseases, particularly severe forms, follows the influenza outbreaks, with a two week delay. Though the precise mechanism is not known, the depression of host's phagocytes bactericidal activity by the influenza virus seems to be involved. An increased incidence of invasive group A beta hemolytic streptococcal infections, particularly necrotizing fasciitis and toxic shock syndrome, is also observed in relation with chickenpox. The reason for this association is unclear and appears not to be limited to the disruption of the cutaneous barrier which leads to the cutaneous infections in this disease. Bacterial-viral co-infection is not a justification for a systematic antibiotic prescription in viral diseases. Severe bacterial disease will be best prevented through viral immunization, thus encouraging the development of viral vaccines and immunization campaigns.

Ibuprofen and skin and soft tissue superinfections in children with varicella

PURPOSE

To investigate the possible association between ibuprofen use and dermatologic superinfections among children with recent varicella infection.

METHODS

A retrospective cohort study of children in Harvard Pilgrim Health Care, a health maintenance organization in New England, was conducted. Outcomes and exposures of interest were identified from automated medical and pharmacy records. Exposure was defined by dispensing of ibuprofen before varicella to avoid potential confounding by indication.

RESULTS

Between July 1, 1990 and September 30, 1994, 89 superinfections developed among 7,013 cases of varicella. The 30-day risk of superinfection was 7.2/10(3) cases (95% CI = 5.8-8.8/10(3) cases). Four of 169 children dispensed ibuprofen within 180 days of varicella developed superinfection. Relative to children without prior use, children with ibuprofen dispensed in the month prior to varicella were 3.1 times more likely to be diagnosed with a superinfection (95% CI = 0.1-19.7; P-value: 0.31). Restriction of outcomes to superinfections treated with systemic antibiotics increased the odds ratio to 5.1 (95% CI = 0.1-32.5; P-value: 0.22).

CONCLUSIONS

The results of this study are consistent with a broad range of effects including no association and suggest that further study is needed.