Pneumococcal vaccination programs and the burden of invasive pneumococcal disease in Ontario, Canada, 1995-2011.

BACKGROUND: In 1995, a publicly funded pneumococcal vaccination program for 23-valent polysaccharide vaccine (PPV23) was introduced in Ontario. Conjugate vaccines were authorized in 2001 (PCV7), 2009 (PCV10) and 2010 (PCV13). METHODS: From 1995-2011, active, population-based surveillance for invasive pneumococcal disease (IPD) was conducted in Metropolitan Toronto and Peel Region, Canada. RESULTS: 6404 IPD cases were included. After PPV23 program implementation in 1995, IPD due to PPV23 strains decreased 49% in older adults prior to PCV7 introduction. Estimated PPV23 efficacy in vaccine eligible adults was 42.2% (95% CI; 28.6-53.2%). IPD incidence due to PCV7 serotypes in children <5 years decreased significantly after PCV7 authorization and before introduction of a publicly funded PCV7 program. Seven years after PCV7 program implementation, the incidence of IPD due to PCV7 serotypes decreased to zero in children and by 88% in adults, however, overall IPD incidence remained unchanged in adults. In 2011, the incidence of IPD was 4.5 per 100,000 in adults aged 15-64 and 19.9 per 100,000 in adults aged over 65 years, with 45 serotypes causing disease. Between 1995 and 2011, the case fatality rate of IPD in adults decreased 2% per year (95% CI, -0.9% to -3.2%). In multivariable analysis, predictors of mortality included older age, chronic conditions, nursing home residence, current smoking, bacteraemia, and illness due to serotypes 3,11A, 19A, and 19F. CONCLUSIONS: While vaccination programs resulted in substantial public health benefits, herd immunity benefits of PCV7 were seen at low pediatric vaccination rates, and the case fatality rate of IPD has decreased, IPD will continue to be a cause of considerable morbidity and mortality in adults.

Rapid control of a methicillin resistant Staphylococcus aureus (MRSA) outbreak in a medical surgical intensive care unit (ICU).

BACKGROUND: Outbreaks of methicillin resistant Staphylococcus aureus in the intensive care unit setting can be prolonged and difficult to control. This report describes the rapid control of an outbreak of methicillin resistant Staphylococcus aureus in a 24-bed open-concept medical surgical intensive care unit with a baseline methicillin resistant Staphylococcus aureus acquisition rate of 1.5 cases per 1000 patient days. INTERVENTIONS/RESULTS: This institution's infection control policy mandates an outbreak investigation if two cases of hospital-acquired methicillin resistant Staphylococcus aureus colonization or infection are identified in an intensive care unit within a four-week period. In July 2007, methicillin resistant Staphylococcus aureus was identified in the sputum of two patients within a one-week period. Screening of all patients in the intensive care unit identified one additional case and a fourth case was identified from a clinical specimen before control measures were implemented. Initial control measures included healthcare worker education, enhanced surveillance, patient cohorting, and enhanced environmental cleaning. Despite these measures, three more cases occurred. All patients were then placed in contact isolation, healthcare workers were screened, and the nursing staff was cohorted. After two weeks without a case, two additional cases were identified. Decolonization of all positive patients was initiated. No further cases occurred over a five-week period and the outbreak was declared over. The outbreak resulted in nine cases of methicillin resistant Staphylococcus aureus colonization (n = 8) or infection (n = 1) over an 11-week period. Only one of 175 healthcare workers was colonized and it was not the outbreak strain. CONCLUSIONS: Early detection and the stepwise addition of infection control measures resulted in the rapid control of an outbreak of methicillin resistant Staphylococcus aureus in a medical surgical intensive care unit without unit closure. A low threshold of suspicion and the rapid initiation of unit wide surveillance were the key steps in limiting the size of the outbreak. Complete cessation of transmission occurred after the initiation of decolonization for all positive patients.

A multidisciplinary approach to reducing outbreaks and nosocomial MRSA in a university-affiliated hospital.

Endemic MRSA (methicillin-resistant Staphylococcus aureus) colonization and infection has been shown to increase morbidity, length of stay and hospital cost. Prevention of transmission demands innovative approaches. Descriptive statistics were used to determine high-incidence units. On admission, patients with a history of previous admission to a healthcare institution within the past six months were screened for MRSA. Point prevalence studies were carried out on units with more than two nosocomial (hospital-acquired) MRSA patient isolates within a four-week period. A multidisciplinary team from Infection Control and clinical units determined potential contributing factors. Recommendations included increased organism-specific education for staff, environmental cleaning and elimination of sources of transmission. Control charts to monitor nosocomial incidence rates were provided to those units that historically had a high prevalence of MRSA infections and colonization. Compliance with the infection control isolation guidelines and screening guidelines was monitored by the service. There was a 60% decrease in nosocomial MRSA between 2000 and 2001. Unit feedback was extended throughout the hospital. This decrease has been sustained since 2001 with annual rates per 1000 patient-days of 0.61 for 2000, 0.21 for 2001, 0.24 for 2002, 0.25 for 2003, 0.35 for 2004 and 0.19 for 2005.

Airway inflammation and infection in congenital bilateral absence of the vas deferens.

In cystic fibrosis (CF), airway disease begins early in life. Bacteria and elevated levels of neutrophils and inflammatory mediators have been detected in bronchoalveolar lavage (BAL) fluid from infants with CF. Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) are common in men with congenital bilateral absence of the vas deferens (CBAVD) and it has been suggested that this syndrome represents a mild form of CF. We hypothesized that men with CBAVD also have subclinical pulmonary disease. Bronchoscopy with BAL, viral and quantitative bacterial cultures, and analyses of total and differential cell count, cytokines, and free neutrophil elastase was performed in eight men with CBAVD, who had mutations in the CFTR and intermediate or elevated sweat chloride levels, and in four healthy control subjects. There was light growth of Staphylococcus aureus in one of eight men with CBAVD, and small numbers of opportunistic gram-negative bacteria in six of eight men with CBAVD and in one control subject. BAL cell counts and neutrophil elastase were within the normal range. Interleukin-8 and tumor necrosis factor-alpha levels were higher for men with CBAVD than for control subjects. These data suggest that mutations in the CFTR in men with CBAVD, in addition to causing infertility, lead to subclinical bacterial pulmonary infection and inflammation consistent with mild CF.