A live-attenuated pneumococcal vaccine elicits CD4+ T-cell dependent class switching and provides serotype independent protection against acute otitis media

Acute otitis media (AOM) caused by Streptococcus pneumoniae remains one of the most common infectious diseases worldwide despite widespread vaccination. A major limitation of the currently licensed pneumococcal vaccines is the lack of efficacy against mucosal disease manifestations such as AOM, acute bacterial sinusitis and pneumonia. We sought to generate a novel class of live vaccines that (1) retain all major antigenic virulence proteins yet are fully attenuated and (2) protect against otitis media. A live vaccine candidate based on deletion of the signal recognition pathway component ftsY induced potent, serotype-independent protection against otitis media, sinusitis, pneumonia and invasive pneumococcal disease. Protection was maintained in animals coinfected with influenza virus, but was lost if mice were depleted of CD4(+) T cells at the time of vaccination. The live vaccine induced a strong serum IgG2a and IgG2b response that correlated with CD4(+) T-cell mediated class switching. Deletion of genes required for microbial adaptation to the host environment is a novel live attenuated vaccine strategy yielding the first experimental vaccine effective against pneumococcal otitis media.

Burden of disease caused by otitis media: systematic review and global estimates

BACKGROUND

Otitis media (OM) is a leading cause of health care visits and drugs prescription. Its complications and sequelae are important causes of preventable hearing loss, particularly in developing countries. Within the Global Burden of Diseases, Injuries, and Risk Factors Study, for the year 2005 we estimated the incidence of acute OM, chronic suppurative OM, and related hearing loss and mortality for all ages and the 21 WHO regional areas.

METHODS

We identified risk factors, complications and sequelae of OM. We carried out an extensive literature review (Medline, Embase, Lilacs and Wholis) which lead to the selection of 114 papers comprising relevant data. Data were available from 15 of the 21 WHO regions. To estimate incidence and prevalence for all countries we adopted a two stage approach based on risk factors formulas and regression modelling.

RESULTS

Acute OM incidence rate is 10.85% i.e. 709 million cases each year with 51% of these occurring in under-fives. Chronic suppurative OM incidence rate is 4.76 ‰ i.e. 31 million cases, with 22.6% of cases occurring annually in under-fives. OM-related hearing impairment has a prevalence of 30.82 per ten-thousand. Each year 21 thousand people die due to complications of OM.

CONCLUSIONS

Our study is the first attempt to systematically review the available information and provide global estimates for OM and related conditions. The overall burden deriving from AOM, CSOM and their sequelae is considerable, particularly in the first five years of life and in the poorest countries. The findings call for incorporating OM-focused action within preventive and case management strategies, with emphasis on the more affected.

[Mortality rate among patients with oto- and rhinogenic intracranial complications]

The authors present selected results of the analysis of medical histories of the subjects who died from complications of inflammatory aural diseases and paranasal sinus pathology in multifield city hospitals of Moscow for the period from 1993 till 2003. The character and the frequency of each intracranial complication are reported.

Serotype-specific mortality from invasive Streptococcus pneumoniae disease revisited

Background

Invasive infection with Streptococcus pneumoniae (pneumococci) causes significant morbidity and mortality. Case series and experimental data have shown that the capsular serotype is involved in the pathogenesis and a determinant of disease outcome.

Methods

Retrospective review of 464 cases of invasive disease among adults diagnosed between 1990 and 2001. Multivariate Cox proportional hazard analysis.

Results

After adjustment for other markers of disease severity, we found that infection with serotype 3 was associated with an increased relative risk (RR) of death of 2.54 (95% confidence interval (CI): 1.22–5.27), whereas infection with serotype 1 was associated with a decreased risk of death (RR 0.23 (95% CI, 0.06–0.97)). Additionally, older age, relative leucopenia and relative hypothermia were independent predictors of mortality.

Conclusion

Our study shows that capsular serotypes independently influenced the outcome from invasive pneumococcal disease. The limitations of the current polysaccharide pneumococcal vaccine warrant the development of alternative vaccines. We suggest that the virulence of pneumococcal serotypes should be considered in the design of novel vaccines.

Acute bacterial meningitis as a complication of otitis media and related mortality factors

The aim of this study was to evaluate the characteristics of patients with acute bacterial meningitis (ABM) developed secondary to acute and chronic otitis media (OM). Between 1991 and 2001, among 269 adult patients with ABM, 56 who were secondary to OM were included in the study. We reviewed the charts of patients who were diagnosed as ABM following acute or chronic OM. Risk factors associated with mortality were determined by using a logistic regression model. The mean age of the patients, 38 male and 18 female, was 25.8 +/- 10.8 years (range 14 - 65). Forty-four of these cases (79%) have had chronic OM, of whom 19 (43% of the 44) have also had chronic mastoiditis and 12 (27% of the 44) acute OM. Twenty-three patients (41%) died, during either hospitalization or the follow-up period. Univariate analysis revealed comatose mental status on admission, inappropriate antibiotic treatment before admission, and elevated erythrocyte sedimentation rate (ESR) as significant risk factors for mortality. In multifactorial analysis, comatose mental status (OR=42.5, CI=6.4-280.1, p=0.001) and elevated ESR (OR=1.0, CI=1.01-1.07; p=0.005) remained as significant predictors for mortality. In conclusion, the primary sources of infection leading to the development of ABM should be investigated carefully to reduce the morbidity and mortality rates. It is hoped that this study will raise awareness among general practitioners and otolaryngologists concerning the role of ABM as one of the most important complications of OM.

The differential roles of LFA-1 and Mac-1 in host defense against systemic infection with Streptococcus pneumoniae

Mice deficient in CD18, which lack all four CD11 integrins, have leukocytosis and increased susceptibility to bacterial infection. To determine the effect of deficiencies in LFA-1 (CD11a/CD18) or Mac-1 (CD11b/CD18) on host defense against systemic bacterial infection, knockout mice were inoculated i.p. with Streptococcus pneumoniae. Increased mortality occurred in both LFA-1(-/-) (15 of 17 vs 13 of 35 in wild type (WT), p < 0.01) and Mac-1(-/-) (17 of 34 vs 6 of 25, p < 0.01) mice. All deaths in LFA-1(-/-) mice occurred after 72 h, whereas most deaths in Mac-1(-/-) mice occurred within 24-48 h. At 24 h, 21 of 27 Mac-1(-/-) mice were bacteremic, vs 15 of 25 WT (p = 0.05); no difference was observed between LFA-1(-/-) and WT. Increased bacteria were recovered from Mac-1(-/-) spleens at 2 h (p = 0.03) and 6 h (p = 0.002) and from livers (p = 0.001) by 6 h. No difference was observed at 2 h in LFA-1(-/-) mice, but by 6 h increased bacteria were recovered from spleens (p = 0.008) and livers (p = 0.04). Baseline and peak leukocyte counts were similar between Mac-1(-/-) and WT, but elevated in LFA-1(-/-). At 8 h, peritoneal neutrophils were increased in Mac-1(-/-), but not significantly different in LFA-1(-/-). Histopathologically, at 24 h Mac-1(-/-) animals had bacteremia and lymphoid depletion, consistent with sepsis. LFA-1(-/-) mice had increased incidence of otitis media and meningitis/encephalitis vs WT at 72 and 96 h. Both Mac-1 and LFA-1 play important but distinct roles in host defense to S. pneumoniae.

A mortality follow-up study of WW II submariners who received nasopharyngeal radium irradiation treatment

BACKGROUND

During World War II, large numbers of submarine trainees received nasopharyngeal radium irradiation therapy to treat aerotitis media or middle ear barotrauma.

METHODS

Using a life table and the Cox proportional hazards model, mortality risk of 1, 214 submariners believed to have received treatment for aerotitis media was compared to 3,176 "untreated" submariners.

RESULTS

"Treated" submariners had a significant increased mortality risk for all causes (odds ratio (OR) = 1.32; 95% confidence interval (CI) = 1. 14-1.53) and circulatory diseases (OR = 1.51; 95% CI = 1.20-1.90), and a non-significant increased mortality risk of head and neck cancer (OR = 1.40; 95% CI = 0.54-3.58).

CONCLUSIONS

While the excess risk was not statistically significant by conventional standards, the finding does suggest that those who received NP radium irradiation therapy may be at increased risk of death due to head and neck cancers. Due to the lack of data the role of risk factors other than radium exposure cannot be assessed.

Otologic surgery in patients with HIV-1 and AIDS

Otologic disease in patients infected with HIV occurs frequently and usually represents rhinologic disease and associated eustachian tube dysfunction rather than manifestations of HIV infection. As in all patients, the decision to operate on an HIV-infected individual who would benefit from major otologic surgery is a balance between the risks of the procedure and the possible benefits to the patient. Many concerns regarding wound infection and healing have been raised. The objective of this study is to evaluate the outcome of otologic procedures in this population. The charts of 9 men and 4 women were reviewed. Seven patients (54%) met the Centers for Disease Control and Prevention criteria for AIDS. Patients with chronic otitis media (46%) underwent tympanomastoidectomies, and the cases of acute mastoiditis (31%) were managed with simple mastoidectomies. Other procedures included repair of cerebrospinal fluid leak (15%) and stapedectomy (8%). Two patients had early complications and died during their hospitalizations. Three patients had prolonged hospital courses requiring long-term antibiotics. These 5 patients underwent urgent procedures and were severely immunocompromised. Of the remaining 8 patients only 2 had AIDS, and all had an uncomplicated postoperative course. Six of these patients were followed up for more than 1 year, and only 2 developed subsequent otologic disease.

Otogenic intracranial infections in adults

OBJECTIVE

To assess the type and bacteriology of otologic diseases associated with bacterial meningitis in adults.

METHOD

Retrospective review of 79 patients over an 18-year period.

RESULTS

Acute otitis media was diagnosed in 32 patients, chronic otitis in 29 (16 with cholesteatoma), and cerebrospinal fluid leak in 18. Streptococcus pneumoniae was a common cause of meningitis-complicating acute otitis media (69%) or cerebrospinal fluid leak (50%), whereas other bacteria or negative cultures were found in the cerebrospinal fluid of patients with chronic otitis. Surgery was performed promptly in 26 patients; four patients died.

CONCLUSIONS

Early diagnosis of otogenic bacterial meningitis is essential to allow appropriate antimicrobial treatment. Antimicrobials active on gram negative bacilli and anaerobes should be used in patients with chronic otitis. An emergency surgical procedure is required in patients whose neurologic or infectious status fails to improve under antimicrobial treatment.

The mortality in an age cohort followed from birth to age 70

The Study of Men Born in 1913 is a prospective population study of cardiovascular diseases in Gothenburg, Sweden, that started in 1963. To describe survival curves and mortality pattern, all boy-children born alive in 1913 in the city of Gothenburg, were identified. This birth cohort was followed from birth to age 70 for residence, vital status and cause of death. At the age of 50 years, 25% of the birth cohort were dead and at age 70, 43% had died. The high infant mortality and the great impact of infectious diseases in the beginning of this century is illustrated. The death rate for the cohort was almost identical to national figures for men in the same age group. Men who migrated from Gothenburg had a death rate very similar to those who stayed. It can therefore be concluded that the men in the Study of Men Born in 1913 is a representative sample not only of men in Gothenburg but also of men in Sweden as far as mortality is concerned. Special attention was paid to death from otitis media complications, congestive heart failure, and diabetes. Few persons died from these diseases before age 50 when the prospective study started and therefore did not influence the study of the natural history for these conditions to any great extent. Otitis media infections might be studied retrospectively from this age.

Otogenic tetanus in Zaire

Sixty-seven patients with tetanus of otogenic origin were hospitalized at the Mama Yemo hospital, Kinshasa, Zaire over the two-year period from 1975 through 1976. The care of these patients was the same as that for all 620 tetanus cases admitted during this period. No otologic surgical procedures were performed on this group; nor were any special ear procedures utilized. The survival rate in the otogenic tetanus group was 83%. The survival rate in the 620 tetanus admissions was 79%. All 67 patients had evidence of chronic otitis media. None of these patients had evidence of otologic complications before, during or for one month after developing tetanus, other than uncomplicated otorrhea. Tetanus antitoxin of 10,000 or 50,000 IU did not appear to affect survival rates. Mortality rates were not increased in the 18% of patients who did not receive tetanus antitoxin. Sedation sufficient to eliminate muscle spasms and maintain the patient sleeping seems to be important in increasing survival rates in tetanus. The need for tracheotomies appeared to be reduced with the increased sedation. Mortality rates increased among the patients who had tracheotomies. Otologic surgical procedures do not appear to be indicated in the management of patients with otogenic tetanus.

Modification of otitis media following vaccination with the capsular polysaccharide of Streptococcus pneumoniae in chinchillas

An animal model was used to determine whether vaccination with the capsular polysaccharide of Streptococcus pneumoniae could alter the development of experimental otitis media induced by the same type of S. pneumoniae as the vaccine. Following vaccination with the capsular polysaccharide of S. pneumoniae type 7, 36(63%) of 57 chinchillas seroconverted with at least a 100% increase in concentration of antibody in serum which remained elevated for at least six weeks. The middle ears of 23 chinchillas that were vaccinated and seroconverted, 13 that were vaccinated and did not seroconvert, and 47 that were not vaccinated were inoculated with S. pneumoniae type 7. Vaccinated animals that seroconverted developed otitis media as readily as nonseroconverting and unvaccinated animals but had fewer pneumococci in their middle ears, a lower incidence of bacteremia, and lower mortality rates during the first week after inoculation of bacteria. Animals that did not seroconvert showed no evidence of modification of their middle ear infections. These results indicate that type 7 pneumococcal capsular polysaccharide vaccine is antigenic for the chinchilla and modifies experimental otitis media due to type 7 S. pneumoniae.

Sudden death in infancy: a microbiological and epidemiological study

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