Fatal 1918 pneumonia case complicated by erythrocyte sickling

Spinal brucellosis in Hulunbuir, China, 2011-2016

Purpose: To investigate the demographic, epidemiological, clinical, and laboratory characteristics; treatment options; and outcome of human brucellosis with spine involvement at a major hospital in Hulunbuir, a brucellosis epidemic region of China. Patients and methods: A total of 842 patients with human brucellosis treated in the Department of Brucellosis, Hulunbuir People's Hospital from January 2011 to December 2016 were included and analyzed in this study. The results of 67 brucellar spondylodiscitis (BS) cases were compared with those that were negative for spine involvements. Results: The mean age of spinal brucellosis patients was 50.5±10.2 years (43 males and 24 females; age range 29-70). The risk factors for transmission are direct contact with animals, such as working in the farm, and consumption of unpasteurized milk or daily products. Back pain (92.5%), fever (85.1%), sweating (62.7%), and fatigue (52.8%) were the most common symptoms. Magnetic resonance imaging (MRI) was performed in all the patients with spondylodiscitis. The sites of involvement were lumbar (81.2%), thoracic (8.7%), cervical (4.3%), thoracolumbar (2.9%), and lumbosacral (2.9%). All isolates from blood culture were identified as Brucella melitensis, with 61% biovar 3 and 39% biovar 1 isolates. The antimicrobial therapy for BS lasted for at least 3 months. In the presence of paravertebral or epidural abscess, longer treatment was conducted to avoid possible sequelae. Conclusion: In endemic areas such as Hulunbuir, BS should be considered in patients with back pain and fever. MRI is a highly sensitive imaging modality that can be used to differentiate BS from other spinal infections. This study will be helpful to establish strategies for prevention, surveillance, and management of spinal brucellosis in China.

Autopsy series of 68 cases dying before and during the 1918 influenza pandemic peak

The 1918 to 1919 "Spanish" influenza pandemic virus killed up to 50 million people. We report here clinical, pathological, bacteriological, and virological findings in 68 fatal American influenza/pneumonia military patients dying between May and October of 1918, a period that includes ~4 mo before the 1918 pandemic was recognized, and 2 mo (September-October 1918) during which it appeared and peaked. The lung tissues of 37 of these cases were positive for influenza viral antigens or viral RNA, including four from the prepandemic period (May-August). The prepandemic and pandemic peak cases were indistinguishable clinically and pathologically. All 68 cases had histological evidence of bacterial pneumonia, and 94% showed abundant bacteria on Gram stain. Sequence analysis of the viral hemagglutinin receptor-binding domain performed on RNA from 13 cases suggested a trend from a more "avian-like" viral receptor specificity with G222 in prepandemic cases to a more "human-like" specificity associated with D222 in pandemic peak cases. Viral antigen distribution in the respiratory tree, however, was not apparently different between prepandemic and pandemic peak cases, or between infections with viruses bearing different receptor-binding polymorphisms. The 1918 pandemic virus was circulating for at least 4 mo in the United States before it was recognized epidemiologically in September 1918. The causes of the unusually high mortality in the 1918 pandemic were not explained by the pathological and virological parameters examined. These findings have important implications for understanding the origins and evolution of pandemic influenza viruses.

Population genetics of malaria resistance in humans

The high mortality and widespread impact of malaria have resulted in this disease being the strongest evolutionary selective force in recent human history, and genes that confer resistance to malaria provide some of the best-known case studies of strong positive selection in modern humans. I begin by reviewing JBS Haldane's initial contribution to the potential of malaria genetic resistance in humans. Further, I discuss the population genetics aspects of many of the variants, including globin, G6PD deficiency, Duffy, ovalocytosis, ABO and human leukocyte antigen variants. Many of the variants conferring resistance to malaria are 'loss-of-function' mutants and appear to be recent polymorphisms from the last 5000-10 000 years or less. I discuss estimation of selection coefficients from case-control data and make predictions about the change for S, C and G6PD-deficiency variants. In addition, I consider the predicted joint changes when the two β-globin alleles S and C are both variable in the same population and when there is a variation for α-thalassemia and S, two unlinked, but epistatic variants. As more becomes known about genes conferring genetic resistance to malaria in humans, population genetics approaches can contribute both to investigating past selection and predicting the consequences in future generations for these variants.