Respiratory virosis and invasive bacterial superinfections - The case for influenza and meningococcal diseases
The pathophysiology of bacterial superinfections of influenza, including meningococcal diseases, remains obscure. Mice, normally resistant to the meningococcus, become susceptible after previous influenza A virus infection. This immunosuppressive effect is transitory and is associated with the peak of the inflammatory anti-virus reaction. These results underline the importance of preventing bacterial superinfections of influenza by the surveillance of any relapse of fever after improvement of the influenza syndrome. At the community level, influenza vaccine, beside its specific effects, might also prevent many cases of invasive superinfections, including meningococcal diseases.
- [Show abstract] [Hide abstract] ABSTRACT: Vaccines are essential to prevent, control (as for poliomyelitis) or eradicate (as for smallpox) infectious diseases. In some cases, when a curative treatment is not available or efficient, they are the only way to fight the spread of the disease, by prevention. The national recommended childhood immunization schedule may vary each year and in each country (changes in infections characters, outbreaks, new vaccines availability...). In this review, new patterns in childhood vaccination in France are discussed.0Comments 2Citations
- [Show abstract] [Hide abstract] ABSTRACT: In 2002, the National Reference Center for Meningococci received 609 strains of Neisseria meningitidis isolated from invasive infections. Strains of serogroup B remain predominant. The proportion of strains of serogroups C and W135, that increased regularly since 1995, reached 38,2 % and 9,3 % respectively in 2002. The majority of cases occurred in age-classes under 20 years. Fatal invasive infections mostly occurred among children under 5 years and adults above 70 years. Susceptibility to β-lactamins is under close surveillance and the percentage of strains with reduced susceptibility to penicillin G seems to increase. Anti-meningococcal vaccination is recommended for prophylaxis of contacts when strains of A, C, Y or W135 are incriminated.0Comments 1Citation
- [Show abstract] [Hide abstract] ABSTRACT: Despite the use of antimicrobial prophylaxis, cytomegalovirus (CMV) and Pneumocystis carinii (PC) pneumonia (PCP) are both leading causes of morbidity and mortality in immunocompromised patients. It has previously been reported that CMV infection modulates host immune responses with a variety of mechanisms which include the suppression of helper T cell functions and antigen presenting cell (APC) functions, both of which are critical for PCP resolution. However, the mechanisms of these interactions and other possible immune regulatory effects are not clearly understood. In this study, we investigated the impact of murine CMV (MCMV) induced immunomodulation on the progression of PCP in a co-infection model. Initial results show that dually infected mice had evidence of more severe PC disease, which include a greater loss of body weight, an excess lung PC burden and delayed clearance of PC from lungs, compared to mice with PC infection alone. At day 7 post-infection, dually infected mice had reduced numbers of MHC-II expressing cells in the lung interstitium and lymph nodes and reduced migration of CD11c+ cells to both the tracheobronchial lymph nodes and alveolar spaces. Dual infected mice showed elevated numbers of specific CD8 responses concomitant with a decrease in activated CD4+ T cells in both the lymph nodes and in alveolar spaces when compared to mice infected with MCMV alone. These data suggest that MCMV infection inhibits the immune responses generated against PC which contribute to the delayed clearance of the organism.0Comments 18Citations