Functional characterization of the oxidative capacity of mitochondria and glycolytic assessment in benthic aquatic organisms.

The metabolism of benthic aquatic invertebrates, populating transitional water ecosystems, is influenced by both physiological and environmental factors, thus involving an adjustment of physiological processes which has a metabolic cost. In order to discover changes in metabolic pathways in response to specific factors, it's firstly necessary characterizing the principal cellular metabolic activities of the small benthic aquatic organisms. We approach here the bioenergetic state issue of two benthic organisms, i.e. Lekanesphaera monodi and Gammarus insensibilis, evidencing that no apparent and statistically significative differences between them in aerobic as well in glycolytic capacities are detected, except for COX activity.

Pandemic influenza A (H1N1) 2009 in the English- and Dutch-speaking Caribbean an epidemiological overview / Pandemia de gripe A (H1N1) de 2009 en el Caribe de habla inglesa y holandesa: panorama epidemiológico

OBJECTIVE: To describe epidemiological trends of pandemic influenza A (H1N1) in the English- and Dutch-speaking Caribbean during the pandemic period. DESIGN AND METHODS: Data on laboratory-confirmed cases and deaths associated with pandemic influenza A (H1N1) contained in two regional databases at the Caribbean Epidemiology Centre (CAREC) were analysed. The data sources were epidemiological and laboratory reports from English- and Dutch-speaking countries and the CAREC laboratory information system (LABIS). RESULTS: In the English- and Dutch-speaking Caribbean, pandemic influenza A (H1N1) was the predominant circulating influenza virus type during the pandemic period. There were three distinct phases: a first pandemic wave during mid-April to end of August 2009 (734 cases), a second pandemic wave during September-December 2009 (570 cases) and a phase of low transmission during January to mid-August 2010 (55 cases). The majority of cases (76%) were aged less than 30 years, with children of school age being most affected. Most cases (89%) presented with symptoms of the respiratory tract and smaller proportions (20-40%) presented with gastrointestinal and other symptoms. No cases tested were resistant to oseltamivir. A quarter of cases required hospitalization and the case fatality rate was 1.8%. CONCLUSIONS: The epidemiological characteristics of the pandemic in the English- and Dutch-speaking Caribbean were consistent with that in other parts of the world. It is important that post pandemic surveillance (epidemiological and virological) for respiratory illnesses continues to be enhanced in order to give a better understanding of seasonality and changing trends in respiratory illnesses and their aetiologic agents.

OBJETIVO: Describir las tendencias epidemiológicas de la pandemia de gripe A (H1N1) en el Caribe de habla inglesa y holandesa durante el periodo pandémico. DISEÑO Y MÉTODOS: Se analizaron los datos sobre casos confirmados por laboratorio y muertes asociadas con la pandemia de gripe A (H1N1), contenidos en dos bases de datos regionales del Centro Epidemiológico del Caribe (CAREC). Las fuentes de los datos fueron los reportes epidemiológicos y de laboratorio de los países de habla inglesa y holandesa, así como del Sistema de Información de Laboratorio del CAREC (LABIS). RESULTADOS: En el Caribe anglófono y de habla holandesa, la pandemia de gripe A (H1N1) fue el tipo de virus de gripe que circuló predominante durante el periodo pandémico. Hubo tres fases distintas: una primera ola pandémica desde mediados de abril a finales de agosto de 2009 (734 casos); una segunda ola pandémica en septiembre-diciembre de 2009 (570 casos); y una fase de baja transmisión de enero a mediados de agosto de 2010 (55 casos). La mayoría de los casos (76%) tenían menos de 30 años, siendo los niños de edad escolar los más afectados. La mayor parte de los casos (89%) presentaban síntomas de las vías respiratorias, y un número menor (20-40%) presentaban síntomas gastrointestinales y otros síntomas. Ninguno de los casos sometidos a prueba resultó resistente al oseltamivir. Una cuarta parte de los casos requirió hospitalización, y la tasa de letalidad fue de 1.8%. CONCLUSIONES: Las características epidemiológicas de la pandemia en el Caribe de habla inglesa y holandesa concuerdan con las encontradas en otras partes del mundo. Es importante continuar mejorando la vigilancia postpandémica (epidemiológica y virológica) de las enfermedades respiratorias, con el fin de lograr una mejor comprensión de la estacionalidad y las tendencias cambiantes de las enfermedades respiratorias y sus agentes etiológicos.

Pandemic influenza A (H1N1) 2009 in the English- and Dutch-speaking Caribbean: an epidemiological overview.

OBJECTIVE: To describe epidemiological trends of pandemic influenza A (H1N1) in the English and Dutch-speaking Caribbean during the pandemic period. DESIGN AND METHODS: Data on laboratory-confirmed cases and deaths associated with pandemic influenza A (H1N1) contained in two regional databases at the Caribbean Epidemiology Centre (CAREC) were analysed. The data sources were epidemiological and laboratory reports from English and Dutch-speaking countries and the CAREC laboratory information system (LABIS). RESULTS: In the English- and Dutch-speaking Caribbean, pandemic influenza A (H1N1) was the predominant circulating influenza virus type during the pandemic period. There were three distinct phases: a first pandemic wave during mid-April to end of August 2009 (734 cases), a second pandemic wave during September-December 2009 (570 cases) and a phase of low transmission during January to mid-August 2010 (55 cases). The majority of cases (76%) were aged less than 30 years, with children of school age being most affected. Most cases (89%) presented with symptoms of the respiratory tract and smaller proportions (20-40%) presented with gastrointestinal and other symptoms. No cases tested were resistant to oseltamivir. A quarter of cases required hospitalization and the case fatality rate was 1.8%. CONCLUSIONS: The epidemiological characteristics of the pandemic in the English- and Dutch-speaking Caribbean were consistent with that in other parts of the world. It is important that post pandemic surveillance (epidemiological and virological) for respiratory illnesses continues to be enhanced in order to give a better understanding of seasonality and changing trends in respiratory illnesses and their aetiologic agents.

Effect of tick removal on transmission of Borrelia burgdorferi and Ehrlichia phagocytophila by Ixodes scapularis nymphs.

The effect of feeding duration on pathogen transmission was studied for individual ticks infected with either laboratory or field strains of the Lyme disease spirochete Borrelia burgdorferi and field strains of Ehrlichia phagocytophila, an agent of human granulocytic ehrlichiosis. Infected nymphal Ixodes scapularis were allowed to feed individually on mice, and equal numbers were removed at 24-h intervals for < or =96 h. Mice were assayed for infection by culture, serologic testing, and polymerase chain reaction (PCR) analysis. Fed ticks were assayed by culture or PCR analysis. Transmission of B. burgdorferi did not occur during the first 24 h among 66 attempts, with maximum transmission occurring between 48 and 72 h. A model estimating the probability of infection from individual ticks removed by patients in a Lyme disease-endemic area yielded an overall probability of 4.6%. Infected I. scapularis nymphs transmitted E. phagocytophila within 24 h in 2 of 3 attempts, which indicates that daily tick removal may not be adequate to prevent human infection with this agent.

The increasing incidence of pertussis in Massachusetts adolescents and adults, 1989-1998.

From 1989 to 1998, the incidence of pertussis increased in Massachusetts adolescents and adults, reaching 71 and 5 per 100,000, respectively, by 1998, whereas the incidence in children remained stable. By 1998, 92% of cases occurred in adolescents and adults. Nationally, in contrast, adolescents and adults had incidences of only 5 and 0.8 per 100,000, respectively, and accounted for 47% of cases. The availability of a specific serologic test and active surveillance by public health personnel in Massachusetts are at least partial explanations. The rise in incidence may be real, however, because, as diagnostic efforts increased, the percentage of patients with a positive serologic test result also increased. Cases identified in adolescents and adults were quite severe: 83% and 87%, respectively, experienced paroxysmal cough, 45% and 41% experienced vomiting, and 41% and 52% experienced a cough lasting >4 weeks. Administration of acellular pertussis vaccine in these age groups could prevent this substantial morbidity.

Disparity in the natural cycles of Borrelia burgdorferi and the agent of human granulocytic ehrlichiosis.

We studied the prevalence of Borrelia burgdorferi and the agent of human granulocytic ehrlichiosis (HGE) among questing nymphal and adult Ixodes scapularis ticks of the same generation and the infectivity of wild white-footed mice for ticks feeding on them. The prevalence of B. burgdorferi infection in host-seeking ticks increased less than twofold from nymphal (31% to 33%) to adult (52% to 56%) stage, and 52% of white-footed mice were infected. Prevalence of the agent of HGE increased 4.5- to 10.6-fold from nymphal (1.5% to 1.8%) to adult stage (7.6% to 19.0%), while only 18% of mice were infectious to ticks. B. burgdorferi infection was more common in mouse-fed ticks than in ticks collected from vegetation, whereas the agent of HGE was half as common in mouse-fed ticks as in ticks collected from vegetation. The different prevalence in nature of these pathogens in ticks suggests that their maintenance cycles are also different.

Comparative vector competence of Dermacentor variabilis and Ixodes scapularis (Acari: Ixodidae) for the agent of human granulocytic ehrlichiosis.

Vector competence of Ixodes scapularis Say and Dermacentor variabilis Say for the agent of human granulocytic ehrlichiosis (HGE) was compared. Five white-footed mice, Peromyscus leucopus Rafinesque, were inoculated intra-peritoneally with blood from a mouse infected with the agent of HGE. Approximately 100 I. scapularis and D. variabilis larvae were placed on each mouse and allowed to feed to repletion. Fed larvae were collected, separated according to species and allowed to molt to nymphs. Twenty-six per cent of I. scapularis (34/131) and 11% of D. variabilis (11/96) tested positive for the agent of HGE by polymerase chain reaction (PCR) after molting to nymphs. Positive I. scapularis nymphs transmitted the agent of HGE to P. leucopus mice in 5 of 5 trials. In contrast, the positive D. variabilis nymphs did not transmit the agent of agent of HGE in any of 6 trials. In a 2nd experiment, 3 P. leucopus mice were infested with I. scapularis nymphs that were infected with the agent of HGE. All 3 mice became infected with the agent of HGE and approximately 300 D. variabilis larvae were placed on each mouse and allowed to feed to repletion. Larvae were collected and allowed to molt to nymphs as before. Approximately 8% (5/60) of the nymphs became positive for the agent of HGE as determined by PCR. Twenty-five of these nymphs were then placed on each of 9 P. leucopus mice and allowed to feed to repletion. Evidence of transmission was not observed in any of 9 mice exposed to D. variabilis nymphs. These results demonstrate that although I. scapularis is a competent vector of the agent of the HGF, D. variabilis is not.

Transmission of the agent of human granulocytic ehrlichiosis by host-seeking Ixodus scapularis (Acari:Ixodidae) in southern New York state.

Ixodes scapularis Say nymphs collected from a natural focus of human granulocytic ehrlichiosis (HGE) in Westchester County, New York, transmitted the HGE agent to uninfected mice in the laboratory. Infection was demonstrated in 3 of 8 mice by polymerase chain reaction analysis of whole blood and microscopic examination of blood smears for morulae. Two of these mice were also positive by xenodiagnosis. Positive xenodiagnostic larvae maintained infection through molting and transferred infection to 1 of 3 mice. Naturally infected I. scapularis ticks transmit the agent of human granulocytic ehrlichiosis to mice, but both acquisition and transmission of this agent by I. scapularis appear to be less efficient than would be expected for Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt & Brenner, the agent of Lyme disease.