Latent infection period

HSV causes both encephalitis and meningitis in adults encephalitis is usually caused by infection with HSV type 1, and meningitis is most commonly caused by HSV type 2. HSV encephalitis is a severe infection with a high morbidity and mortality treatment with acyclovir reduces the mortality from approximately 70% in untreated infections to 19% to 28%. Neurological impairment, however, is common (about 50%) in those who survive.HSV encephalitis may reflect primary infection or reactivation of latent infection. HSV meningitis is usually a self-limited disease, which resolves during the course of several days without therapy. In some patients the disease may recur as a lymphocytic meningitis over a period of years. ... 

Many systemic fungicides can be applied after the initial infection period, before symptoms appear (the latent period) these treatments are called curative. When disease symptoms are visible then an eradicant fungicide is required these chemicals have the ability to eradicate a disease that is already present and then protect the plant for a certain time after applicatioa Persistency, curative and eradicative activity varies between chemicals. 

Bacteriophage T7 Bacteriophage T7 and its close relative T3 are relatively small DNA viruses that infect Escherichia coli. (Some strains of Shigella and Pasteurella are also hosts for phage T7.) The virus particle has an icosahedral head and a very small tail. The virus particle is fairly complex, with S different proteins in the head and 3-6 different proteins in the tail. One tail protein, the tail fiber protein, is the means by which the virus particle attaches to the bacterial cell surface. Only female cells of Escherichia coli can be infected with T7 male cells can be infected but the multiplication process is terminated during the latent period. 

Peripheral pathogenesis involves the lymphoreticular system. Although the pathological consequences of prion infection occur in the central nervous system, and experimental transmission of these diseases is most efficiently accomplished by intracerebral inoculation, most natural infections do not occur by these means. Indeed, administration to sites other than the central nervous system is known to be associated with much longer incubation periods, which may extend to 20 years or more [5,12]. Experimental evidence suggests that this latent period is associated with clinically silent prion replication in... 

In individuals infected with either P. vivax or P ovale, the exoerythrocytic tissue (e.g., liver) forms can persist after a latent period and give rise to relapses. In P. falciparum and P. malariae malaria, however, there do not appear to be any persistent secondary liver forms. Thus, in both of these forms of malaria, the physician must contend only with the asexual erythrocytic forms and the gametes, not with the latent liver forms found in P. vivax and P. ovale. 

Detailed laboratory studies showed that the total length of the lytic growth cycles of the Phaeocystis viruses infecting exponentially growing host cells ranged between 25 and 50 h (Jacobsen et al. 1996 Baudoux and Brussaard 2005). For PpV the latent period, the time period from infection until the first increase in the abundance of extracellular free viruses, was around 12-18 h (Jacobsen et al. 1996). The study by Baudoux and Brussaard (2005) showed three different latent periods for the various PgV isolates in culture, i.e., 10,12 and 16 h (Fig. 3). These periods match the range of latent periods for all characterized phytoplankton viruses so far, and are somewhat... 

Spatial and Temporal relationships. A common characteristic of biotic sensitization of plants is a latent or lag period between initiation of the inducer infection and manifestation of disease resistance. In the cucumber/TNV or C lagenarium system, enhanced resistance against pathogens is first manifest about 48-72 hr after initial infection and maximal resistance is achieved by 120-144 hr... 

In Japan, red mold disease or Akakabi-byo of wheat due to F. graminearum infection was reported to cause gastroenteritis in humans (Saito and Ohtsubo, 1974). In China, 60% of people who ate rice contaminated with T-2 toxin were reported to have nausea, dizziness, vomiting, chills, abdominal distension, abdominal pain, thoracic stuffiness, and diarrhea with a latent period of 10 to 30 min (Wang et al, 1993). 

The minuta and magna forms excreted in the faeces in intestinal amoebiasis are usually not infectious, as they perish rapidly in the stools once they have been excreted. Today, differentiation can be made between the two forms using molecular biology techniques. Only the cysts are responsible for transmission, but they are not present in the stool in the acute phase infection from the cysts is transmitted by the faecal-oral route and hence only in the symptom-free, chronic stage of the disease. An exact incubation period has not been defined. The latent period may last for several years. 

Herpes labialis (cold sore or fever blister) is a painful and highly contagious infection caused by the herpes simplex type 1 virus (HSVl). The herpesviruses are a large group of double-stranded DNA viruses that cause a variety of diseases in humans and animals. One of the interesting features of some herpesviruses is their ability to remain latent ( lying dormant ) in the body for long periods of time after the primary infec-... 

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