Patients with type I strain (which express the virulence factors cytotoxin-associated gene product (CagA) and Vacuolating cytotoxin A (VacA)) have lower circulating ghrelin levels than those with the less virulent type II strain which does not express the virulence factors.
Global health experts had barely finished making their predictions last year when one of the strains they chose, a virulent type of H3N2 influenza, began to morph.
A strain of West Nile that first appeared in Russia, Romania and elsewhere in the early 1990's is a more virulent type that is now being spread here and in Canada.
The main reason for the increased severity this season is that a more virulent type of virus, called A(H3N2), has predominated, said Dr. Dan Jernigan, deputy director of the influenza division at the disease centers.
The scientists said the anthrax used in the attacks is similar to a highly virulent type known as the Ames strain, which was discovered in Iowa in 1980 (not in the 1950's as is sometimes reported).
But within a few days, she fell ill and died of a virulent type of meningitis known as W135; she had been vaccinated for two other strains, but not that one.
The reports led to speculation that the Florida germ might be a highly virulent type of anthrax known as the Ames strain, which was discovered in Iowa and studied as a possible germ weapon by the American military before President Richard M. Nixon renounced germ weapons in 1969.
Federal scientists examining the anthrax used in the Florida and New York attacks have tentatively concluded that the type is a domestic strain similar to a highly virulent type known as the Ames strain, which was discovered in Iowa in 1980.
When Borlaug was in his 90s, a new and highly virulent type of the fungus emerged from Uganda.
Analysis of mortality rates in infected mice indicated that Type BrI is highly virulent, Type BrII is intermediately virulent and Type BrIII is non-virulent, which is in agreement with previous report.
Vaccination with the live vaccine strain (LVS), developed from a Type B strain, confers partial protection against aerosal exposure to the more virulent Type A strains and provides proof of principle that a live attenuated vaccine strain may be efficacious.
