Skip directly to search Skip directly to A to Z list Skip directly to page options Skip directly to site content

Volume 13, Number 5—May 2007

Volume 13, Number 5—May 2007   PDF Version [PDF - 4.51 MB - 139 pages]

Perspective

  • Response to Malaria Epidemics in Africa PDF Version [PDF - 68 KB - 6 pages]
    T. A. Abeku
       View Abstract

    Malaria epidemics affect nonimmune populations in many highland and semi-arid areas of Africa. Effective prevention of these epidemics is challenging, particularly in the highlands, where predictive accuracy of indicators is not sufficiently high to allow decisions involving expensive measures such as indoor residual spraying of insecticides. Advances in geographic information systems have proved useful in stratification of areas to guide selective targeting of interventions, including barrier application of insecticides in transmission foci to prevent spread of infection. Because rainfall is associated with epidemics in semi-arid areas, early warning methods based on seasonal climate predictions have been proposed. For most areas, response measures should focus on early recognition of anomalies and rapid mass drug administration. Vector control measures are useful if abnormal transmission is highly likely and if they can be selectively implemented at the early stages of an outbreak.

Research

  • Plague and the Human Flea, Tanzania PDF Version [PDF - 229 KB - 7 pages]
    A. Laudisoit et al.
       View Abstract

    Domestic fleas were collected in 12 villages in the western Usambara Mountains in Tanzania. Of these, 7 are considered villages with high plague frequency, where human plague was recorded during at least 6 of the 17 plague seasons between 1986 and 2004. In the remaining 5 villages with low plague frequency, plague was either rare or unrecorded. Pulex irritans, known as the human flea, was the predominant flea species (72.4%) in houses. The density of P. irritans, but not of other domestic fleas, was significantly higher in villages with a higher plague frequency or incidence. Moreover, the P. irritans index was strongly positively correlated with plague frequency and with the logarithmically transformed plague incidence. These observations suggest that in Lushoto District human fleas may play a role in plague epidemiology. These findings are of immediate public health relevance because they provide an indicator that can be surveyed to assess the risk for plague.

  • Trends for Influenza-related Deaths during Pandemic and Epidemic Seasons, Italy, 1969–2001 PDF Version [PDF - 377 KB - 6 pages]
    C. Rizzo et al.
       View Abstract

    Age-specific patterns of death from influenza vary, depending on whether the influenza season is epidemic or pandemic. We assessed age patterns and geographic trends in monthly influenza-related deaths in Italy from 1969 through 2001, focusing on differences between epidemic and pandemic seasons. We evaluated age-standardized excess deaths from pneumonia and influenza and from all causes, using a modified version of a cyclical Serfling model. Excess deaths were highest for elderly persons in all seasons except the influenza A (H3N2) pandemic season (1969–70), when rates were greater for younger persons, confirming a shift toward death of younger persons during pandemic seasons. When comparing northern, central, and southern Italy, we found a high level of synchrony in the amplitude of peaks of influenza-related deaths.

  • Respirator Donning in Post-Hurricane New Orleans PDF Version [PDF - 369 KB - 8 pages]
    K. J. Cummings et al.
       View Abstract

    We evaluated correctness of N95 filtering facepiece respirator donning by the public in post-hurricane New Orleans, where respirators were recommended for mold remediation. We randomly selected, interviewed, and observed 538 participants, using multiple logistic regression for analysis. Only 129 (24%) participants demonstrated proper donning. Errors included nose clip not tightened (71%) and straps incorrectly placed (52%); 22% put on the respirator upside down. Factors independently associated with proper donning were as follows: ever having used a mask or respirator (odds ratio [OR] 5.28; 95% confidence interval [CI], 1.79–22.64); ever having had a respirator fit test (OR 4.40; 95% CI, 2.52–7.81); being male (OR 2.44; 95% CI, 1.50–4.03); Caucasian race (OR 2.09; 95% CI, 1.32–3.33); having a certified respirator (OR 1.99, 95% CI 1.20–3.28); and having participated in mold clean-up (OR 1.82; 95% CI,1.00–3.41). Interventions to improve respirator donning should be considered in planning for influenza epidemics and disasters.

  • Apoptosis and Pathogenesis of Avian Influenza A (H5N1) Virus in Humans PDF Version [PDF - 299 KB - 5 pages]
    M. Uiprasertkul et al.
       View Abstract

    The pathogenesis of avian influenza A (H5N1) virus in humans has not been clearly elucidated. Apoptosis may also play an important role. We studied autopsy specimens from 2 patients who died of infection with this virus. Apoptosis was observed in alveolar epithelial cells, which is the major target cell type for the viral replication. Numerous apoptotic leukocytes were observed in the lung of a patient who died on day 6 of illness. Our data suggest that apoptosis may play a major role in the pathogenesis of influenza (H5N1) virus in humans by destroying alveolar epithelial cells. This pathogenesis causes pneumonia and destroys leukocytes, leading to leukopenia, which is a prominent clinical feature of influenza (H5N1) virus in humans. Whether observed apoptotic cells were a direct result of the viral replication or a consequence of an overactivation of the immune system requires further studies.

  • Genome Analysis Linking Recent European and African Influenza (H5N1) Viruses PDF Version [PDF - 317 KB - 6 pages]
    S. L. Salzberg et al.
       View Abstract

    To better understand the ecology and epidemiology of the highly pathogenic avian influenza virus in its transcontinental spread, we sequenced and analyzed the complete genomes of 36 recent influenza A (H5N1) viruses collected from birds in Europe, northern Africa, and southeastern Asia. These sequences, among the first complete genomes of influenza (H5N1) viruses outside Asia, clearly depict the lineages now infecting wild and domestic birds in Europe and Africa and show the relationships among these isolates and other strains affecting both birds and humans. The isolates fall into 3 distinct lineages, 1 of which contains all known non-Asian isolates. This new Euro-African lineage, which was the cause of several recent (2006) fatal human infections in Egypt and Iraq, has been introduced at least 3 times into the European-African region and has split into 3 distinct, independently evolving sublineages. One isolate provides evidence that 2 of these sublineages have recently reassorted.

  • Pet Rodents and Fatal Lymphocytic Choriomeningitis in Transplant Patients PDF Version [PDF - 180 KB - 7 pages]
    B. R. Amman et al.
       View Abstract

    In April 2005, 4 transplant recipients became ill after receiving organs infected with lymphocytic choriomeningitis virus (LCMV); 3 subsequently died. All organs came from a donor who had been exposed to a hamster infected with LCMV. The hamster was traced back through a Rhode Island pet store to a distribution center in Ohio, and more LCMV-infected hamsters were discovered in both. Rodents from the Ohio facility and its parent facility in Arkansas were tested for the same LCMV strain as the 1 involved in the transplant-associated deaths. Phylogenetic analysis of virus sequences linked the rodents from the Ohio facility to the Rhode Island pet store, the index hamster, and the transplant recipients. This report details the animal traceback and the supporting laboratory investigations.

  • International Spread of Multidrug-resistant Salmonella Schwarzengrund in Food Products PDF Version [PDF - 173 KB - 6 pages]
    F. M. Aarestrup et al.
       View Abstract

    We compared 581 Salmonella enterica serotype Schwarzengrund isolates from persons, food, and food animals in Denmark, Thailand, and the United States by antimicrobial drug susceptibility and pulsed-field gel electrophoresis (PFGE) typing. Resistance, including resistance to nalidixic acid, was frequent among isolates from persons and chickens in Thailand, persons in the United States, and food imported from Thailand to Denmark and the United States. A total of 183 PFGE patterns were observed, and 136 (23.4%) isolates had the 3 most common patterns. Seven of 14 isolates from persons in Denmark had patterns found in persons and chicken meat in Thailand; 22 of 390 human isolates from the United States had patterns found in Denmark and Thailand. This study suggests spread of multidrug-resistant S. Schwarzengrund from chickens to persons in Thailand, and from imported Thai food products to persons in Denmark and the United States.

Historical Review

  • Rudolf Virchow and the Recognition of Alveolar Echinococcosis, 1850s PDF Version [PDF - 1.30 MB - 4 pages]
    D. Tappe and M. Frosch
       View Abstract

    Alveolar echinococcosis, which is caused by the larval stage of the fox tapeworm Echinococcus multilocularis, is one of the most dangerous parasitic diseases. It is endemic in many parts of the Northern Hemisphere and an emerging health problem in the People’s Republic of China. In Europe and North America, human cases are rare, but concomitant with an increase in the population of the final host, the red fox, an increase of human infections is expected. Rudolf Virchow, the father of the concept of cellular pathology, determined in the 1850s that an Echinococcus sp. was the causative agent of this enigmatic emerging disease. In his famous publication in 1855, he described the clinical course of the disease, its macroscopic aspects, and histopathologic findings in detail. He also identified the disease formerly known as alveolar colloid of the liver to be an infection with the larval stage of an Echinococcus sp.

Dispatches

Letters

Books and Media

About the Cover

TOP