Nosocomial neonatal legionellosis associated with water in infant formula, Taiwan.

We report 2 cases of neonatal Legionella infection associated with aspiration of contaminated water used in hospitals to make infant formula. The molecular profiles of Legionella strains isolated from samples from the infants and from water dispensers were indistinguishable. Our report highlights the need to consider nosocomial legionellosis among neonates who have respiratory symptoms.

National surveillance of invasive pneumococcal diseases in Taiwan, 2008-2012: differential temporal emergence of serotype 19A.

INTRODUCTION: Serotype replacement after the introduction of seven-valent pneumococcal conjugate vaccine (PCV7) and the future availability of multivalent PCVs prompted the listing of invasive pneumococcal disease (IPD) as a notifiable disease in Taiwan in October 2007. Here, we report the national surveillance results. METHODS: The study population comprised the whole nation of Taiwan from 2008 to 2012. Restricting to cases with viable isolates, we calculated the incidence, case fatality ratio, prevalence of serotype 19A, and percentage of vaccine preventable IPD. RESULTS: 3659 cases of IPD were identified yielding an incidence of 3.2 per 100,000 population; the highest incidence was among children aged 2-4 years (21.1 per 100,000 population). The case fatality ratio was 9.2% and the highest ratio was among adults aged ≥75 years (19.0%). The percentage of PCV7 preventable IPD decreased for all age groups, especially sharply among children aged 2-4 years, from 65.8% in 2008 to 12.9% in 2012. The prevalence of serotype 19A increased from 5.5% in 2008 to 25.3% in 2012 among all Streptococcus pneumoniae, displaying a differential temporal emergence among different age groups. Serotype 19A became the most prevalent serotype among children aged <2 years in 2009, children aged 2-4 and 5-17 years in 2010, and adults aged 18-49 years in 2012. CONCLUSIONS: The incidence of IPD fluctuated during the study period, with ongoing decrease due to PCV7 vaccine serotypes and increase due to non-vaccine serotypes. Serotype 19A became the most prevalent serotype in 2010 among all S. pneumoniae.

Legionnaires' disease caused by Legionella longbeachae in Taiwan, 2006-2010.

The aim of the present study was to investigate the epidemiology of Legionnaires' disease (LD) caused by Legionella longbeachae in Taiwan during 2006-2010. A total of six cases were identified prospectively, accounting for 1.6% of all laboratory-confirmed LD cases and 4.4% of culture-positive LD cases. All six cases occurred between April and August. The male to female ratio was 0.5. These six LD patients had a higher median age than those with LD due to Legionella pneumophila. Four of the six patients presented with pleural effusion and five survived the infection episode. Only two patients had a potential soil contact history prior to LD onset. The patients resided in divergent geographical areas without a common exposure history. The individual genomic DNA banding patterns of the six L. longbeachae isolates analyzed by pulsed-field gel electrophoresis (PFGE) were unique, supporting the hypothesis that the L. longbeachae infections occurred sporadically.

Identification of legionella species by use of an oligonucleotide array.

The genus Legionella contains a diverse group of motile, asaccharolytic, nutritionally fastidious gram-negative rods. Legionella pneumophila is the most important human pathogen, followed by L. micdadei, L. longbeachae, L. dumoffii, and other rare species. Accurate identification of Legionella spp. other than L. pneumophila is difficult because of biochemical inertness and phenotypic identity of different species. The feasibility of using an oligonucleotide array for identification of 18 species of Legionella was evaluated in this study. The method consisted of PCR amplification of the macrophage infectivity potentiator mip gene, followed by hybridization of the digoxigenin-labeled PCR products to a panel of 30 oligonucleotide probes (16- to 24-mers) immobilized on a nylon membrane. A collection of 144 target strains (strains we aimed to identify) and 50 nontarget strains (44 species) were analyzed by the array. Both test sensitivity (144/144 strains) and specificity (50/50 strains) of the array were 100%. The whole procedure for identification of Legionella species by the array can be finished within a working day, starting from isolated colonies. It was concluded that species identification of clinically relevant Legionella spp. by the array method is very reliable and can be used as an accurate alternative to conventional or other molecular methods for identification of Legionella spp.

A legionellosis case due to contaminated spa water and confirmed by genomic identification in Taiwan.

Tracing the source of a legionellosis (LG) case revealed that the Legionella pneumophila (LP) strain isolated from patient's sputum shared the same serogroup (SG) and PFGE-type with 4 LP strains obtained from a spa center. With a high LP-contamination rate (81.2%, 13/16) in all of its 16 basins, this spa center was also found to have a multi-genotypic distribution among its 13 LP isolates, which can be categorized into 5 PFGE-types. Despite such a serious contamination in the spa center, which usually had ca. 100 visitors per day, this male patient, bearing LG-risk factors of long-term heavy smoking and alcoholism, was the only case identifiable after an active investigation. To explore the possible reason for this sporadic infection, all 5 PFGE-types of LP isolated were assayed for their presence of two important virulent genes (lvh and rtx A) and were identified as either less-virulent (lvh (+) , rtx A(+)) or non-virulent (lvh (-), rtx A (-)) types. The strong virulent type (lvh (+), rtx A (+)) usually seen in clinical strains elsewhere was not found here. Moreover, the LG-causative type in this infection was the only one to be classified as the less-virulent type, with the presence of lvh gene indicating its relatively more virulent potential than other 4 PFGE-types. Accordingly, mutual interaction between LP's virulent potential and patient's health-status was suggested to be the force directing the opportunistic infection of this sporadic case. This is the first spa-associated infection caused by SG 2 of LP.

Legionella pneumophila infection in the Taiwan area.

The aim of this study was to explore the epidemiological distribution of legionellosis among pneumonia patients in Taiwan. From January 2001 to December 2003, specimens (i.e., sputum, urine, and serum) from a total of 5097 patients with pneumonia or pneumonia-like disease registered at hospitals in the Taiwan area were analyzed for possible Legionella infection. Following the guideline issued by the Centers for Disease Control and Prevention (CDC) in the United States, a total of 237 pneumonia patients were diagnosed with legionellosis, with an incidence rate among pneumonia patients in this area of 4.7% (237/5097). The paired-serum antibody test was found to be the most effective detection method, followed by urine-antigen detection and the sputum culture method. Analysis of distribution showed that: (1) male and female occurrence rates were 70.9% (168/237) and 29.1% (69/237), respectively; (2) occurrence rates in different age groups, i.e., those aged between 61 and 80 years, those aged between 41 and 60, and those aged between 21 and 40 were 50.2% (119/237), 26.2% (62/237), and 12.2% (29/237), respectively; (3) autumn was the peak season for infection, followed by winter, summer, and spring, sequentially. This is the first study in Taiwan to have followed the three-method guideline issued by the CDC and it is the second report in Taiwan involving the investigation of a large series of pneumonia patients for legionellosis detection.