Enteroviral infection in neonates.

Enteroviruses generally cause mild and self-limited diseases, but they have been found to affect neonates much differently, and often more severely than older children. Clinical manifestations are difficult to differentiate from those of bacterial sepsis, such as fever, poor feeding, lethargy, respiratory distress and cardiovascular collapse. Severe life threatening complications, including hepatic necrosis with coagulopathy, meningoencephalitis and myocarditis, usually present during the first week of life. Factors affecting severity and outcome include virus serotype, mode of transmission, and presence or absence of passively acquired, serotype-specific maternal antibodies. Echoviruses and coxsackievirus B viruses are most common serotypes associated with the neonatal sepsis. An awareness of the clinical syndromes, recognition of the risk factors and monitoring parameters associated with severe cases and use of rapid reverse-transcriptase polymerase chain reaction test for viral load may help physicians in diagnosing severe cases in a timely manner. Prompt aggressive treatment including early intravenous immunoglobulin treatment may help in reducing morbidity and mortality. Enterovirus infections in neonates are common and should be routinely considered in the differential diagnosis of febrile neonates, particularly during enterovirus season. This article provides an overview of what is known about non-polio enteroviruses in neonates including epidemiology, transmission, clinical presentation, diagnosis, and treatment.

Clinical and molecular features of MDR livestock-associated MRSA ST9 with staphylococcal cassette chromosome mecXII in humans.

OBJECTIVES: Clonal complex (CC) 9 is a prevalent livestock-associated (LA) MRSA clone in Asia whose pathogenicity in humans remains unknown. METHODS: In 2012, we identified a patient with CC9-MRSA infection linked to livestock. After screening 3328 clinical MRSA isolates from a national database, eight isolates (0.24%) collected between 1998 and 2012 were further confirmed to be of CC9. The detailed molecular features of the nine human CC9 strains and phylogenetic relatedness to animal CC9 strains were characterized with WGS. The antibiotic susceptibilities were determined and the clinical information was abstracted from medical records. RESULTS: WGS grouped the CC9 strains into two clades, which were respectively associated with distinct toxome profiles, resistance gene profiles and staphylococcal cassette chromosomes (SCCmecXII for 7 isolates and SCCmecVT for 2 isolates). The SCCmecXII strains were phylogenetically related to animal CC9-MRSA strains, negative for Panton-Valentine leucocidin and 100% resistant to ciprofloxacin, erythromycin, clindamycin, gentamicin and tigecycline. Four of the seven SCCmecXII isolates were associated with invasive diseases including bacteraemia leading to death (2) and osteomyelitis (2). Two SCCmecXII isolates were from patients with exposure to pigs before development of the MRSA diseases. CONCLUSIONS: The CC9-SCCmecXII MRSA prevailing in pigs in Asia is multidrug resistant and potentially pathogenic to humans. It is critical to continuously monitor the local epidemiology of MRSA and implement effective control measures to limit the spread of LA-MRSA between animals, to humans and in healthcare facilities.

Livestock-associated meticillin-resistant Staphylococcus aureus in Asia: an emerging issue?

In addition to being a human pathogen, Staphylococcus aureus causes an array of infections in economically important livestock animals, particularly pigs. In Asia, there have been few reports on livestock-associated meticillin-resistant S. aureus (LA-MRSA), mostly from developed countries, with very few data available from resource-limited countries, not because of low prevalence but probably due to a shortage of diagnostic facilities. Unlike the wide spread of sequence type 398 (ST398) LA-MRSA in European countries and North America, ST9 predominates in most Asian countries. The prevalence of LA-MRSA among pigs in Asian countries varied widely (0.9-42.5%). The prevalence may vary by geographic location, age of pigs and sampling methodologies. Among pig farmers, the prevalence of nasal MRSA colonisation varied from 5.5% in Malaysia to 15% in China and 19.2% in Taiwan. Although most LA-MRSA isolates in Asia are of the same ST, molecular characteristics are not all the same. Dominant isolates in China were characterised as spa type t899-SCCmec III and t899-SCCmec IVb or V for isolates in Hong Kong, and t899-untypeable SCCmec for Taiwan. Dominant isolates in Malaysia were spa type t4358-SCCmec V and t337-SCCmec IX for isolates in Thailand. In addition, MRSA ST221 was reported in Japan and MRSA ST398 was isolated from commercial pigs in South Korea. Attention should be paid because pigs could become an important reservoir for MRSA and spread them to humans, as observed in many countries. There is a potential risk from the livestock reservoir to community and hospitals.

Molecular epidemiology of community-associated meticillin-resistant Staphylococcus aureus in Asia.

In Asia, most reports on the epidemiology of community-associated meticillin-resistant Staphylococcus aureus (CA-MRSA) are from developed countries, with few data from resource-limited countries, not because of low actual prevalence, but probably because of scarce diagnostic facilities. The rate of MRSA in all community-associated S. aureus infections in Asian countries ranges from 2·5% to 39%. Unlike the predominance of USA300-sequence type (ST) 8 staphylococcal cassette chromosome mec (SCCmec) type IV in the USA, the molecular epidemiology of CA-MRSA in Asia is characterised by clonal heterogeneity, similar to that in Europe. The emergence of CA-MRSA is a threat in both community and hospital settings because such strains are now more prevalent than are health-care-associated MRSA (HA-MRSA) strains. Many epidemic clones are in circulation in Asia and with scarce data available, concern has arisen that CA-MRSA could have devastating results if it becomes epidemic in resource-poor regions. The epidemiology of CA-MRSA in Asia is closely linked with the health of both developing and developed countries. The present situation of CA-MRSA in Asia is important not only for local public health, but also to provide a better understanding of the successful epidemic clones of this global pathogen.

Outbreak of Shigella sonnei gastroenteritis in Northeastern Taiwan.

A gastroenteritis outbreak of Shigella sonnei involving 122 children occurred between April 2001 and January 2002 in I-lan, Taiwan. The resistant rates of the isolates to nalidixic acid, trimethoprim-sulfamethoxazole, ampicillin and ceftriaxone were 98, 97.5, 32 and 27%, respectively. None of the isolates was resistant to ciprofloxacin. Prolonged bacterial shedding in the feces can occur when an inappropriate antibiotic is used.

Toxic shock syndrome in children: epidemiology, pathogenesis, and management.

Toxic shock syndrome (TSS) is an acute, toxin-mediated illness, like endotoxic shock, and is characterized by fever, rash, hypotension, multiorgan involvement, and desquamation. TSS reflects the most severe form of the disease caused by Staphylococcus aureus and Streptococcus pyogenes. A case definition for staphylococcal TSS was well established in the early 1980s and helped in defining the epidemiology. Since the late 1980s, a resurgence of highly invasive streptococcal infections, including a toxic shock-like syndrome, was noted worldwide and a consensus case definition for streptococcal TSS was subsequently proposed in 1993. Both TSS and the toxic shock-like syndrome occur at a lower incidence in children than in adults. Changes in the manufacturing and use of tampons led to a decline in staphylococcal TSS over the past decade, while the incidence of nonmenstrual staphylococcal TSS increased. Nonmenstrual TSS and menstrual TSS are now reported with almost equal frequency. The incidence of streptococcal TSS remains constant after its resurgence, but varies with geographic location. Streptococcal TSS occurs most commonly following varicella or during the use of NSAIDs. Sites of infection in streptococcal TSS are much deeper than in staphylococcal TSS, such as infection caused by blunt trauma, and necrotizing fasciitis. Bacteremia is more common in streptococcal TSS than in staphylococcal TSS. Mortality associated with streptococcal TSS is 5-10% in children, much lower than in adults (30-80%), and is 3-5% for staphylococcal TSS in children.TSS is thought to be a superantigen-mediated disease. Toxins produced by staphylococci and streptococci act as superantigens that can activate the immune system by bypassing the usual antigen-mediated immune-response sequence. The host-pathogen interaction, virulence factors, and the absence or presence of host immunity determines the epidemiology, clinical syndrome, and outcome. Early recognition of this disease is important, because the clinical course is fulminant and the outcome depends on the prompt institution of therapy. Management of a child with TSS includes hemodynamic stabilization and appropriate antimicrobial therapy to eradicate the bacteria. Supportive therapy, aggressive fluid resuscitation, and vasopressors remain the main elements. An adjuvant therapeutic strategy may include agents that can block superantigens, such as intravenous immunoglobulin that contains superantigen neutralizing antibodies.

Multidrug-resistant non-typhoid Salmonella infections in a medical center.

Due to the high incidence of antimicrobial-resistant Salmonella in Taiwan, the emergence of multidrug-resistant Salmonella has become of particular concern. This retrospective study assessed the clinical features of patients with multidrug-resistant Salmonella treated from January 1998 through June 2000. A total of 201 children and 33 adults with multidrug-resistant Salmonella infections treated during a 2.5-year period were included. Sixty-percent of these patients had used antibiotics before multidrug-resistant Salmonella infection developed. The incidence of extra-intestinal infections was higher in adults (51.4%) than in children (4.9%). Infection with an invasive serotype of Salmonella, such as Salmonella choleraesuis, and host factors appeared to be predisposing factors for bacteremia or extra-intestinal infections. None of the patients had mortality attributable to multidrug-resistant salmonellosis. The increasing rate of resistance to third-generation cephalosporins and fluoroquinolones and the high multidrug-resistant rate of S. choleraesuis found in this study indicate the importance of judicious use of antimicrobial agents in both humans and animals to reduce the selection and spread of resistant strains.

Cefepime versus ceftazidime as empiric monotherapy for fever and neutropenia in children with cancer.

BACKGROUND: Monotherapy with cefepime or ceftazidime is an effective alternative to combination therapy for the treatment of febrile neutropenic adult cancer patients. We compared the efficacy and safety of cefepime and ceftazidime as empiric monotherapy of febrile neutropenia in children with cancer. MATERIALS AND METHODS: A prospective, open label, randomized, comparative study in pediatric cancer patients was conducted at Chang Gung Children's Hospital from January 1, 2000, to April 15, 2001. Patients with fever and neutropenia (absolute neutrophil count of < or = 500/mm3) were randomized to receive either intravenous cefepime or ceftazidime (50 mg/kg/dose as two or three doses daily). Febrile episodes were classified as microbiologically documented infection, clinically documented infection or unexplained fever. Clinical response to therapy was classified as success and failure. RESULTS: Ninety-five pediatric cancer patients with 120 febrile neutropenic episodes were randomized to receive empiric treatment with cefepime or ceftazidime. After 72 h of treatment, 82.8% (48 of 58) of the eligible patients in the cefepime group continued with unmodified therapy, compared with 87.9% (51 of 58) in the ceftazidime group. The neutrophil count was <100/mm3 at randomization for 76% of the patients in the cefepime group and 83% of those in the ceftazidime group; the median durations of neutropenia (<500/mm3) were 8.5 and 6.5 days, respectively. Of the 96 evaluable episodes the overall success rate with unmodified empiric therapy until the end of the treatment course in the cefepime group was comparable with that in the ceftazidime group (69% vs. 71%, P = 0.95). The response rate after glycopeptides were added to the regimens was 79.2% for the cefepime group and 77.1% for the ceftazidime group. The bacterial eradication rate was 33% for the cefepime group and 20% for the ceftazidime group (P = 0.85), and the rates of new infections were 10.4% vs. 4.2% (P = 0.67), respectively. Both study drugs were well-tolerated. Three (6.4%) patients in the cefepime group and 2 (4.3%) patients in the ceftazidime group died. CONCLUSION: Cefepime appeared to be as effective and safe as ceftazidime for empiric treatment of febrile episodes in neutropenic pediatric cancer patients.