William McD. Hammon

Comparative Studies on Patterns of Family Infections with Polioviruses and ECHO Virus Type I on an American Military Base in the Philippines

Many excellent reports have been published on the behavior of polioviruses in family groups. These have contributed greatly to the understanding of the epidemiology of the disease. However, with rare exceptions (the outstanding one being a project of Dr. Fox,1 carried out concurrently with ours), these other studies had certain limitations common to all retrospective studies. Specimens and histories were not taken until a case of poliomyelitis had already been diagnosed in the family; thus only part of the family infection pattern might be revealed. Furthermore, little was learned of what occurred in families where only subclinical infection or undiagnosed disease occurred. The study to be reported here

Attempted Type Specific Diagnosis of Dengue Virus Infection by the Indirect Fluorescent Antibody Method Directed at Differentiating IgM and IgG Responses

The need for paired acute and convalescent phase sera for diagnostic purposes in virology has long been recognized. Along these lines, some important problems are: (a) getting an early enough acute phase serum, (b) obtaining only a convalescent phase serum perhaps none at all, (c) choice of most suitable test method (s) to use with likely small quantities of specimen(s) obtained and (d) perhaps most important of all, furnishing a diagnostically useful result to the attending physician at the time he needs it. This latter requirement is incompatable with awaiting a convalescent phase serum. Furthermore, unless the physicians early needs are met, his subsequent lack of cooperation further complicates obtaining the needed sera from the next patient. The solution in so far as serology is concerned apparently lies in the detection of early specific antibody in the IgM globulin fraction and distinguishing this from that of any preexisting antibody in the IgG globulin which may also react with the antigen used. Since fractionation procedures to separate IgG or selectively inactivate IgM are time consuming or impractical in large scale routine diagnostic work, the indirect fluorescent antibody technique employing highly specific conjugates against human IgM and human IgG appears to be most desirable. Diagnostic use of such a procedure in virology was introduced by Brown and his associates in 1968 (1, 2) for mumps, but to our knowledge this has not been applied in diagnostic arbovirology prior to the studies reported here. The major interest in this laboratory is in the area of the arboviruses and currently in the dengue (DEN) subgroup of group B most specifically, therefore these viruses were employed. Another reason for selecting group B and the DEN subgroup relates to the lack of type specificity, using current serological tests, of sera of persons having a second or subsequent infection with a group B virus.

Failure of trypan red to protect against certain neurotropic viruses; M. M. and Russian spring-summer encephalitis.

Conclusions Trypan red failed to produce a significant protection against Russian Spring-summer encephalitis virus and “M.M.” virus when the dye was injected subcutaneously and the virus was inoculated by the intraperitoneal route. These experiments fail to confirm the results of others who injected both dye and virus intraperitoneally. We interpret the apparent protective effect obtained by Wood and Rusoff 3 as being due to a well recognized and non-specific peritoneal protection afforded by certain inert substances when injected previous to the inoculation of infectious agents by the same route. Our results suggest that these two neurotropic viruses do not enter the central nervous system directly by way of the vascular channels as is the case with such an agent as cocaine, the passage of which into the central nervous system tissue may be altered by trypan red.