It seems obvious that the number of pathogens should be important in the pathogenesis of an infectious disease [1,2]. The relationship between the pathogen load and severity is one of the most fundamental questions, and yet, strangely, one of the most difficult to answer [3]. One reason for this is that it is often rather difficult to determine the total pathogen load in an infected host, parti...

BACKGROUND Visceral leishmaniasis (VL) is distinguished by a complex interplay of immune response and parasite multiplication inside host cells. However, the direct association between different immunological correlates and parasite numbers remains largely unknown. METHODOLOGY/PRINCIPAL FINDINGS We examined the plasma levels of different disease promoting/protective as well as Th17 cytokines ...

The protection of mouse erythrocytes (RBC) parasitized with Plasmodium vinckei vinckei against activated oxygen species was examined in relation to the intraerythrocytic parasite load. RBC from highly infected animals were separated by density gradient centrifugation into six bands with increasing parasite content and with parasitemias ranging from 17% to 100%. Increase in parasite load was acc...

An antileishmanial compound, 14-deoxy-11-oxo-andrographolide, a derivative of andrographlide, isolated from the Indian medicinal plant Andrographis paniculata was evaluated for efficacy in free form and in different vesicular delivery modes on hamster model of Leishmaniasis. The subcutaneous injection of free drug reduced the spleen parasite load by 39%, whereas for drug incorporated in liposom...

Introduction: The term Leishmaniasis applies to a group of parasitic diseases caused by the genus Leishmania. Route of infection is one of the variables that have been reported to influence the immune responses as well as the disease outcome in experimental models of leishmaniasis. This research aims to study the effect of route of infection on the pathogenicity of Leishmania major in BALB/c mi...

BACKGROUND Congenital transmission is a major source of new Trypanosoma cruzi infections, and as vector and blood bank control continue to improve, the proportion due to congenital infection will grow. A major unanswered question is why reported transmission rates from T. cruzi-infected mothers vary so widely among study populations. Women with high parasite loads during pregnancy are more like...

The reduction in host fitness caused by parasite infections (virulence) depends on infection intensity and the degree of damage per parasite. Environmental conditions can shape both virulence components, but contrast to intensity, environmental impacts per-parasite are poorly understood. Here, we studied effect ambient temperature damage, which is jointly determined ability parasites induce har...

Earlier migration in males than in females is the commonest pattern in migrating passerines and is positively related to size dimorphism and dichromatism. The early arrival of males is a costly trait that may confer reproductive advantages in terms of better territories and/or mates. Given the physiological cost of migration, early migrants are those in best condition and accordingly the preval...