Infection with Eaton's primary atypical pneumonia agent in England

The History of Mycoplasma pneumoniae Pneumonia

In the United States in the 1930s, although the pathogen was not known, atypical pneumonia was clinically distinguished from pneumococcal pneumonia by its resistance to sulfonamides. Reimann (1938) reported seven patients with an unusual form of tracheo bronchopneumonia and severe constitutional symptoms. He believed the clinical picture of this disease differed from that of the disease caused by influenza viruses or known bacteria and instead suspected "primary atypical pneumonia." For many years, the responsible infectious agent was tentatively classified as a filterable virus that could pass through a Seitz filter to remove bacteria and was reported to be a psittacosis-like or new virus. After that, Eaton et al. (1942, 1944, 1945) identified an agent that was the principal cause of primary atypical pneumonia using cotton rats, hamsters, and chick embryos. Eaton et al. (1942, 1944, 1945) did not perform an inoculation study in human volunteers. During the 1940s, there were three groups engaged in discovering the etiology of the primary atypical pneumonia. (1) Commission on Acute Respiratory Diseases Diseases directed by John Dingle, (2) Dr. Monroe Eaton's group, the Virus Research Laboratory of the California State Public Health Department, (3) The Hospital of the Rockefeller Institute for Medical Research directed by Horsfall. During 1940s, the members of the Commission on Acute Respiratory Diseases concluded that the bacteria-free filtrates obtained from the patients, presumably containing a virus, could induce primary atypical pneumonia in human volunteers via Pinehurst trials. During 1950s, serological approaches for identification of the Eaton agent developed such as Fluorescent-Stainable Antibody, and at the beginning of the1960s, the Eaton agent successfully grew in media, and finally accepted as a cause of primary atypical pneumonia. Thus, technical difficulties with visualizing the agent and failure to recognize the full significance of the Pinehurst transmission experiments resulted in a lapse of 20 years before acceptance of the Eaton agent as Mycoplasma pneumoniae. This review describes the history of M. pneumoniae pneumonia with a special focus on the recognition between the 1930 and 1960s of the Eaton agent as the infectious cause.

The first atypical pneumonia: the history of the discovery of Mycoplasma pneumoniae

The subject of atypical pneumonias is of great medical and historical interest to modern physicians. Although these diseases have no doubt affected humans throughout our history, it is not until the mid-twentieth century that physicians first began to differentiate certain atypical pulmonary infectious processes from typical pneumonia. Physicians at the time were unclear as to the precise etiology of these infections. As time progressed and study of these organisms continued, physicians were better able to identify the causative agent and devise tests with which to detect the disease. This article focuses on the description and ultimate identification of Mycoplasma pneumoniae.

VIRUSES IN ACUTE RESPIRATORY INFECTION IN A GENERAL COMMUNITY

The aetiology of acute respiratory infections between September 1962 and August 1963 was studied in two general practices in Cambridge. These practices were reasonably representative of the permanent community of Cambridge.

There were 592 spells of acute respiratory infection in the combined practices, representing an incidence of 11·4 spells per 100 persons. Children aged 0–4 had the highest rates (51·6 spells per 100 persons).

It was possible to establish a diagnosis in 62·5% of cases investigated. Influenza and parainfluenza infections featured prominently, being responsible between them for 46·6% of all respiratory infections investigated. From September 1962 to January 1963, parainfluenza viruses were prevalent, causing acute laryngo-tracheo-bronchitis in children (croup), and an influenza-like illness in adults. From February to April 1963, influenza A (Asian) was epidemic, a clinical diagnosis of influenza being frequently confirmed by laboratory studies at this time. There were nine cases of Eaton agent infection, seven of which had PAP, the other two being family contacts who later developed influenza-like illnesses.

Adenovirus (four cases), and RS virus (three cases) were not prevalent to any large extent in Cambridge during the survey.

The protean manifestations of Mycoplasma pneumoniae infection in adults

Mycoplasma pneumoniae is a well recognized respiratory pathogen in children and young adults. In addition, M. pneumoniae infections may also involve other organ systems. Reviewed here are the various clinical syndromes in adults caused by this infectious agent, with emphasis on those which have recently been seen at The New York Hospital. Two previously unreported manifestations of M. pneumoniae infection, cranial nerve mononeuropathy and hepatitis, are described, and the laboratory methods for diagnosis are discussed.

Mycoplasma pneumoniae infection in the United Kingdom--1967-73

A widespread epidemic of Mycoplasma pneumoniae infection in the United Kingdom occurred over a 30-month period in 1970-72. A small epidemic may also have occurred in 1967-68. Though the incidence of M. pneumoniae infection is known to change from year to year in small communities, a varying epidemicity in the population of a country has not previously been demonstrated.As expected, lower respiratory tract infection was the most common manifestation of infection; and the highest attack rates were in children aged 5-9 years. Elderly persons appear to be affected uncommonly.

Mycoplasma pneumoniae. One year's experience in an urban practice

During 1967, 37 patients in an urban general practice were diagnosed as having Mycoplasma pneumoniae infections giving a minimum attack rate of 1.1 per cent. Their varied clinical picture is described, along with the radiographic and haematological findings. Data relating to family infection is presented and the importance of the early school age child in relation to the spread of this infection is stressed. It is suggested that this infection is a ‘general practice illness’ with a low hospital component.

Mycoplasmas and recurrent oral ulceration

A controlled cultural and serological investigation of mycoplasmas in recurrent oral ulceration was undertaken. No evidence for an aetiological relationship between oral mycoplasmas and this condition was obtained.Mycoplasmas, principally M. orale, were frequently recovered from the oral cavities of individuals with natural teeth, but rarely from edentulous subjects.