within the chain of infection the disease producing agent is referred to as salmonella.
within the chain of infection the disease producing agent is referred to as salmonella.
within the chain of infection the disease producing agent is referred to as?
salmonella
"blastocystis" is one of the most common human parasites in the world and has a global distribution. it is the most common parasitic infection in the united states, where it infected approximately 23% of the total population during year 2000. in less developed areas, infection rates as high as 100% have been observed. high rates of infection are found in individuals in developed countries who work with animals. although the role of "blastocystis hominis" in human disease is often referred to as controversial, a systematic survey of research studies conducted by 11 infectious disease specialists from nine countries, found that over 95% of papers published in the 10 years prior identified it as causing illness in immunocompetent individuals. the paper attributed confusion over pathogenicity to the existence of asymptomatic carriers, a phenomenon the study noted is common to all gastrointestinal protozoa. however, "blastocystis" has never fulfilled koch's postulate that infection of a healthy individual with "blastocystis" leads to disease. the fact that "blastocystis"' infection route is oral-anal indicates that carriers have been in contact with faecal contaminated matter which might have included other intestinal pathogens that explain the observed symptoms. a more likely explanation is the presence of virulent and non-virulent strains as there exists and enormous genetic variation between different strains (or genotypes). see the genotype paper by rune stensvold and the recent "blastocystis" genome paper expanding on this diversity. an alternative theory that "blastocystis" is not a pathogen at all has recently been strengthened based on its biochemistry.
blastocystis
inactivated vaccine









































an inactivated vaccine (or killed vaccine) is a vaccine consisting of virus particles, bacteria, or other pathogens that have been grown in culture and then lose disease producing capacity. in contrast, live vaccines use pathogens that are still alive (but are almost always attenuated, that is, weakened). pathogens for inactivated vaccines are grown under controlled conditions and are killed as a means to reduce infectivity (virulence) and thus prevent infection from the vaccine. the virus is killed using a method such as heat or formaldehyde.
inactivated vaccine