Trends and Epidemics of Influenza and Pneumonia, 1918-1951

Abstract

The virus of lhuman influenza was isolated in 1933 and 1934, followingb intranasal instillation of tlhroat washings in ferrets, by Smith, Andrewes, and Laidlaw (1, 16). In the late summer of 1934 their evidenee was first corroborated in thle United States in thle laboratories of the Rockefeller Institute (8) by the recovery of a strain of the same vir'us from an epidemic in Puerto Rico. Since that time several strains and types of influenza virus have been isolated, and from materials from patients in epidemics in 1932 an(d later years the predominant type of virus has been determined (7). Altlhough simplified methods of concentrating aii(I purifying influetiza virus lhave been developed (9), it is not practicable at present to ise virus findings on individual patients as anl aid in diagnosis, as is (lone with throat cultures in diagnosing diphtheria. However, if a considerable number of patients in an apparent influenza epidenmic are tested for influenza virus, it can l)e stated whetlher the epidemic was predominantly due to virus A, A', B, or some unknown type. Of the epidemics since 1932, the nmost common predominant etiologies have been viruses A and A', and inore frequently the latter since 1940. Another development which must have profoundly affected the trend of influenza and pneumonia mortality was the (liscovery anil 1se, of the sulfonamides, peniicillini, and otlher newer cliemotherapies in the treatment of the disease. The literature on this subject is extensive but a few studies on pneumonia aniong humnians may be cited. Some early reports on sulfanilamide therapy on human cases of pneumonia were made by Heintzelman, Hadley, anid M[ellon (11) and Price (12); on sulfanilamide an(d serum treatment bv Price and Myers (13), and oIn seruim treatment by Rogers and Goochl (1). Obviously, studies of influenza prior to 1933 and 1934, when the Virus was first isolated, were rather largely descriptive of the nature of the outbreaks, including explosiveness, extent of the epidemic in terms of deaths in excess of normal seasonal expectancy, cases reported

The impact of influenza epidemics on mortality: introducing a severity index.

“…Excess mortality during an influenza season is calculated as the difference between the number of deaths observed and the expected baseline in the absence of influenza. [2][3][4][5][6][7][8][9][10][11] The excess mortality approach is justified by numerous observations of increased mortality during influenza epidemics that is attributed to pneumonia and preexisting chronic lung, heart, and kidney conditions. 2 The primary index for assessing the severity of influenza epidemics has long been based on national levels of pneumonia-and influenza-related deaths.…”

Princípios básicos de procedimentos estatísticos aplicados na análise de dados de vigilância em saúde pública: uma revisão

“…Quanto aos métodos de regressão e de sé-ries temporais, estes têm sido utilizados mais com o objetivo de predição e estimação, no âmbito da vigilância da influenza e da pneumonia, no qual a detecção de conglomerados é feita de modo indireto: calculando o excesso de mortalidade atribuível a essas doenças (Collins & Lehmann, 1951;Eickhoff et al, 1962;Serfling, 1963;Clifford et al, 1977;Alling et al, 1981;Choi & Thacker, 1981;Tillett et al, 1983). Especificamente, no que diz respeito ao uso de sé-ries temporais, é bem conhecido o poder e a flexibilidade de tais métodos, no entanto o seu uso na área de saúde pública, de um modo geral, depende ainda de estudos e refinamentos desses instrumentos por parte dos estatísticos vinculados a essa área (Thacker, 1989).…”

Correlates of vaccine protection from influenza and its complications

“…8 Selwyn Collins summed this up succinctly in the mid-20th century using this statement, "In fact, influenza may well be thought of not as a killing disease except by the intervention of pneumonia or the presence of chronic disease in a patient." 9 Risk groups with chronic illnesses including cardiovascular disease, chronic obstructive pulmonary disease (COPD), diabetes, and cancer are priorities for influenza vaccination because of the increased risk of death, increased rates of hospitalization, and the attendant societal costs. 10 Other host factors including obesity, pregnancy, and extremes of age present similar risks.…”