6th Meeting of the World Society for Pediatric Infectious Diseases

Abstract

The 6th World Congress of the World Society for Pediatric Infectious Diseases (WSPID), which was recently held in Buenos Aires, Argentina, between 18 and 22 November 2009, attracted 2401 attendees from 90 countries representing six continents. The WSPID, founded in 1994 by Professor Saldana Gonzalez of the Mexican Pediatric Infectious Diseases Society, is a network of pediatric infectious diseases societies dedicated to the treatment and prevention of pediatric infectious diseases. All the regional societies from Europe, North America, Latin America, Asia, Australasia and Africa have participated in the WSPID.

In a stimulating lecture on methicillin-resistant Staphylococcus aureus (MRSA) infections at a plenary session, RS Daum alerted us to the increase in the frequency of infections with MRSA. Two categories of MRSA are recognized: healthcare-associated MRSA (HA-MRSA) and community-associated MRSA (CA-MRSA). CA-MRSA is now a public-health problem in many communities in the USA, and in other areas of the world [1–4]. Skin and soft tissue infections are the predominant types of CA-MRSA infections, but invasive and life-threatening infections are major concerns [5–7]. The methicillin resistance is encoded by the Staphylococcal cassette chromosome mec (SCCmec). Panton–Valentine Leukocidin (PVL), which is a virulence factor produced by S. aureus, is responsible for the severe skin and soft tissue infections, and necrotizing pneumonia and in previously healthy individuals. Although several clones of CA-MRSA have been described, one clone (USA300) is particularly common in many areas of the USA [8,9]. CA-MRSA isolates are classically clindamycin-susceptible, PVL⁺, ST8 and/or contain SCCmec type IV. Hitherto, the definition of CA-MRSA is an MRSA infection in a patient who lacks specific risk factors for healthcare exposure. However, defining CA-MRSA by the absence of risk factors for healthcare exposure greatly underestimates the burden of epidemic CA-MRSA disease. There are now high rates of antibiotic resistance mostly to clindamycin and trimethoprim–sulfamethoxazole, which are the first-line antibiotic treatments for MRSA infections.

At another plenary session, Carla M Odio from the Hospital Nacional de Niños, San Jose, Costa Rica [10] discussed the rational use of antibiotics in the neonatal intensive care unit (NICU). She opined that the excessive use of antibiotics, which is a common practice in NICUs, is a predisposing factor for the development of nosocomial infections, increased mortality and emergence of resistance. In addition excessive use of antibiotics in NICUs increases hospital costs as antibiotics are responsible for approximately 30% of the budget in tertiary care hospitals. To avoid this unfavorable trend, it is of paramount importance to characterize the overall patient population, their most prevalent underlying conditions, the microbiology of the nosocomial infections and the daily medical and paramedical staff practices. Thus, in their institution the sustained prudent and rational use of antibiotics resulted in a reduction in nosocomial infection (p < 0.001), infection-related mortality (p < 0.001), resistance of nosocomial coliform Gram-negative bacilli (p < 0.001) and costs.

Didier Pittet from the WHO, Geneva, Switzerland, in a well-attended plenary lecture, reiterated that healthcare-associated infection affects hundreds of millions of people each year and is a major global issue for patient safety [11]. ‘Clean Care is Safer Care’ was launched in October 2005; and to sustain the momentum among the healthcare providers, the ‘Save Lives: Clean Your Hands’ initiative was launched by the WHO Patient Safety on 5 May 2009, simultaneous to the publication of the finalized WHO Guidelines, to encourage healthcare workers to be part of a global movement to improve and, more importantly, to sustain hand hygiene. Since the beginning of 2009, more than 5500 healthcare facilities have registered their commitment to the initiative, demonstrating ongoing enthusiasm for acting to prevent healthcare-associated infection. Furthermore, Pittet emphasized that although hand washing with soap and water is a cornerstone of medical practice, it cannot always be performed systematically, several times a day in any healthcare facility, due to a lack of facilities and, more importantly, timetabling constraints. Appropriate use of alcohol gel is a convenient means of reducing infection to the barest minimum in the healthcare facilities of developing countries, including those with low resources and severe scarcity of water. Additional confirmation of this assertion came from the poster presentation by Prazuck et al.[12]. He and his colleagues demonstrated convincingly the reduction of gastroenteritis occurrences and their consequences in elementary schools with alcohol-based hand sanitizers.

In the European Society for Paediatric Infectious Diseases (ESPID) Society Symposium, Andrew Pollard, from the University of Oxford, Oxford, UK, discussed vaccines against meningococcal B infections [13]. Neisseria meningitidis remains one of the most feared causes of epidemic and endemic meningitis around the world. Recently, quadrivalent vaccines that should prevent disease caused by serogroup A, C, Y and W135 meningococci have become available and are now in routine use in North America. However, disease caused by serogroup B meningococcus is not prevented by these vaccines and continues to be a threat to global child health. Development of a global solution for prevention of serogroup B meningococcal disease (MenB) was held back by the poor immunogenicity of the surface polysaccharide, which presumably relates to its similarity to saccharides that decorate human neural cells. Subcapsular structures have therefore been the focus of vaccine development but progress has also been hampered here by the huge diversity in immunodominant surface proteins. Outer membrane vesicle (OMV) vaccines, developed from single strains and used for clonal epidemics of meningococcal disease, have demonstrated the possibility that disease can be controlled by vaccines constructed from surface structures. An OMV vaccine is being used today for an ongoing clonal outbreak of meningococcal disease in France and the Finlay Institute in Cuba continues production of its OMV vaccine. Unfortunately, endemic disease in most countries is not caused by a single clone but by a number of hyperinvasive serogroup B lineages, driving the search for approaches that provide broader protection. Several novel MenB vaccines have been tested in early phase clinical trials over the past decade, and several others are currently in preclinical development. Two MenB vaccines based on recombinant outer membrane proteins are now in late-stage clinical development and may hold the potential for control of this global problem.

Conclusion

Community-associated MRSA and nosocomial neonatal infections continue to exert their tolls on children and neonates, respectively. While it is prudent to use new generations of antibiotics in the control of CA-MRSA, simple prudent antibiotic stewardship would go a long way in arresting the unfavorable trend in nosocomial neonatal infections. In furtherance of the unrelenting efforts of the WHO to consolidate and sustain hand hygiene promotion in an unobtrusive manner, systematic and controlled use of alcohol-based sanitizers in healthcare facilities and elementary schools have resulted in reduction of hospital-associated infections and significant reduction in the incidence of epidemic seasonal gastroenteritis in elementary schools. After an initial setback in the development of a conjugate vaccine against serotype B meningococcal meningitis, there has been a recent breakthrough in the development of two MenB vaccines based on recombinant outer membrane proteins which are now in late-stage clinical development and may hold the potential for control of this global problem.

Financial & competing interests disclosure

The author has no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

No writing assistance was utilized in the production of this manuscript.