ABSTRACT
Dengue has become a major public health problem in the last few decades in India contributing significantly to the overall disease burden. Most of the cases of dengue from India are reported during the monsoon season. The vector population of dengue is affected by seasonal rainfall, temperature, and humidity fluctuations. Rajasthan is a northwestern state of India, which has shown several dengue outbreaks in the past. In this paper, we have tried to analyze the effects of annual cumulative rainfall on dengue incidence in one of the largest and severely affected states of India. Retrospective data for dengue incidence and rainfall for the state of Rajasthan was collected and Pearson’s coefficient correlation was calculated as a measure of association between the variables. Our results indicate that annual cumulative rainfall shows a strong positive correlation with dengue incidence in the state of Rajasthan. Such analyses have the potential to inform public health official about the control and preparedness for vector control during monsoon season. This is the first study from the Indian state of Rajasthan to assess the impact of annual rainfall on dengue incidence, which has seen several dengue outbreaks in the past.
ABSTRACT
Age associated decline of the immune system continues to be a major health concern. All components of innate and adaptive immunity are adversely affected to lesser or greater extent by ageing resulting in an overall decline of immunocompetence. As a result in the aged population, there is increased susceptibility to infection, poor responses to vaccination, and increased incidence of autoreactivity. There is an increasing focus on the role of T cells during ageing because of their impact on the overall immune responses. A steady decline in the production of fresh naïve T cells, more restricted T cell receptor (TCR) repertoire and weak activation of T cells are some of the effects of ageing. In this review we summarize our present understanding of the effects of ageing on naïve CD4 T cells and potential approaches for therapeutic interventions to restore protective immunity in the aged population.
ABSTRACT
The highly complex nature of interactions of Mycobacterium tuberculosis with cells of the immune system has puzzled researchers the world-over in understanding the pathogenesis and immunology associated with tuberculosis (TB). This has contributed to the delay in development of effective vaccine(s) for TB. Several excellent studies have provided only a glimpse of the kind and degree of immune responses elicited following infection by mycobacteria. Preferred entry via respiratory route results in the capture of mycobacteria by alveolar macrophages that eventually become their long-term hosts. Since the pathogen is rarely cleared this has resulted in the human population serving as a large reservoir for mycobacteria. Owing to their unique ability to prime naïve and memory T cells, dendritic cells (DCs) play important and indispensable roles in the initiation and maintenance of protective immune responses following infection. The kind of immune response initiated by DCs with respect to mycobacteria determines the character of immune responses mounted by the host against the pathogen. The profile of cytokines and chemokines secreted as a result of infection of DCs by mycobacteria further plays an important role in defining the course of infection. This minireview attempts to highlight key interactions of mycobacteria with dendritic cells. We discus the uptake of mycobacteria by DCs followed by DC activation and the spectrum of immune responses initiated by infected/activated DCs, followed by numerous ways the pathogen has devised to subvert protective responses.