Coe (Coxsackie A 21) virus, para-influenza virus and other respiratory virus infections in the R.A.F., 1958-60

Seroprevalence of coxsackievirus A21 neutralizing antibodies in Yamagata, Japan, between 1976 and 2019; coxsackievirus A21 has rarely affected young children

Although coxsackievirus A21 (CV-A21) has been associated with an acute respiratory infection (ARI) as well as poliomyelitis-like paralysis, reports of CV-A21 detection have been quite limited both globally and in Japan. CV-A21 strains were isolated from five sporadic pediatric cases with ARI in 2019 in Yamagata, Japan. Neutralizing antibodies (NT Abs) were then measured against CV-A21 using sera collected in 1976, 1985, 1999, 2009, and 2019 in Yamagata, to clarify the longitudinal epidemiology of CV-A21. The total Ab-positive rate in each year was 15.2% (35/233), 10.7% (30/281), 14.3% (28/196), 3.1% (7/236), and 1.3% (3/226), respectively. Ab-positive rates generally increased with age, especially between 1976 and 1999. Among the total Ab-positive cases, the Ab titers were relatively low; 50 cases belonged to the 1:8-1:16, 40 to 1:32-1:64, 12 to 1:128-1:256, and 1 to 1:1024< groups, respectively. No Ab-positive cases under the age of 10 were observed in any of the years analyzed. In conclusion, this study and previous works suggested that CV-A21 is a unique enterovirus, which is not transmitted readily among young children but causes sporadic ARI cases mainly among those ≥15 years of age in the community.

Studies of respiratory viruses in personnel at an Antarctic base

Thirteen men wintering on an Antarctic base were isolated from other human contact for 10 months. During this period Coxsackievirus A21 and later influenza A2 virus were administered to some of the men. Serum samples were collected from each of the men at monthly intervals.Coxsackievirus A21 produced symptoms and apparently spread to uninoculated men. It also appears that repeated re-infections occurred and that the virus persisted in this small community for most of the period of isolation. HI antibody responses in the absence of neutralizing antibody responses seem to be transient.The vaccine strain of influenza virus induced antibody responses but did not cause symptoms. There was no evidence of spread to uninoculated men.Antibody titres against influenza C, parainfluenzaviruses 1 and 2 and coronavirus OC43 did not fall significantly during isolation.An outbreak of respiratory illness occurred at the end of isolation and its origin was traced. No causative agent was detected.

Serological studies on infections by respiratory viruses of the inhabitants of Tristan da Cunha

Sera were obtained from about half of the Tristan da Cunha islanders on reaching Cape Town in October 1961, a few months after reaching Britain and before returning to the Island in 1963.

After vaccination against current influenza A 2 and B serotypes antibodies were evoked against earlier serotypes, in particular against influenza A1 of 1951 with which the islanders had almost certainly been infected. Those who failed to develop antibody against A 2 and B after vaccination developed it later presumably owing to natural infection.

Almost all islanders developed antibodies against parainfluenza 3 and 1 and some against parainfluenza 2 and coxsackie A 21 viruses. There were no antibody rises against reoviruses.

Experiments on the spread of colds. II. Studies in volunteers with coxsackievirus A21

The amount of virus in nasal and other secretions after infection with coxsackievirus A 21 has been measured daily in ten volunteers. Most virus was found in nasal secretion, less in throat secretion and small amounts were found intermittently in the saliva and faeces.

Virus administered as small drops or on a swab was more infectious for man if put on to the nasal mucosa than on to the throat or outside the nose. It was also infectious by the conjunctival route.

Virus was sprayed in droplets of about the same size range as those found in a natural sneeze. Virus survived better in larger (> 4 μ) than in smaller droplets. About one tissue culture infectious dose of virus in such droplets also infected volunteers.

The symptoms produced by these experimental infections have been analysed. The disease produced was largely independent of the dosage and route of infection. Those with pre-existing antibody resisted infection better than those with no antibody. Antibody rises were detected in about two-thirds of infected volunteers.

Volunteers with colds shed virus in large drops on sneezing, or into the handkerchief on blowing the nose, but virus was recovered from the air only after simulated sneezes by volunteers with high concentrations of virus in their nasal secretions. Virus died off rapidly on fabric at room temperature and humidity, and was only resuspended as airborne droplets when large doses such as 0·02 ml. of virus of high titre (107·5 TCD 50/ml.) were used.

Infection was transmitted from an infected volunteer to an uninfected partner living in the same flat in three out of twenty tests. Infection was not transmitted in experiments when volunteers mixed for a few hours with subjects with colds, or inhaled air into which a subject with a cold had just sneezed.