Association of meningococcal serotypes with the course of disease: serotypes 2a and 2b in the Netherlands, 1959-1981

Case histories of 692 patients with meningococcal disease due to serogroup B, C, or W (W-135) were reviewed to study the association of the serotypes 2a and 2b with the course of disease. The case-fatality rate in group B disease was significantly associated with serotype 2b (B:2b) strains (P = 0.03). Age and year of admission did not account for this association. Septicemia was also found more frequently with B:2b than with other B serotypes, but neurological complications and sequelae were not. Neither C:2a nor W:2a was associated with a higher case-fatality rate, with more cases of septicemia, or with more sequelae than were other C or W serotypes. We concluded that the 2b antigen, although not likely a causal factor, is a virulence marker among group B strains and that the protective effect of a vaccine containing this protein (among others) needs to be studied.

Association of meningococcal serogroups with the course of disease in the Netherlands, 1959-83

To study the association of meningococcal serogroups with the course of disease, we reviewed the case histories of 1221 patients. The meningococci from these patients constituted a sample from isolates collected and serogrouped systematically in the Netherlands since 1959. Of these 1221 isolates, 64% were serogroup B. The overall case fatality rate was 5.1%, and the rate was lowest for patients with serogroup A infections (2.3%) and highest for serogroup W135 (18%) (P < 0.01). The occurrence of septicaemia without meningitis (case fatality rate 15.3%) was similarly distributed among the serogroups (A, 4.0%; W135, 30%). Sequelae occurred in 7.9% of patients (loss of hearing, 3.2%) and were remarkably prevalent after disease due to minor serogroups (X and Y: 4 out of 12). In a log-linear analysis, both age and serogroup were significantly associated with case fatality rate and with the occurrence of septicaemia and sequelae. It is argued that these data are representative, despite the problems inherent in a retrospective investigation. The course and outcome of meningococcal disease appear to be related to the Neisseria meningitidis serogroup and to host factors.

Increased incidence of childhood bacterial meningitis. A 25-year study in a defined population in Sweden

In a retrospective study in Orebro, Sweden 1956-1980, 201 cases of bacterial meningitis in children over the age of 1 month were analysed. The aetiology was Haemophilus influenzae in 123 cases, Neisseria meningitidis in 55 cases and Streptococcus pneumoniae in 19 cases. We registered a significant increase in incidence of H. influenzae meningitis from 5.6 (1956-1965) to 13.0 (1971-1980) per 100,000 children and year (p less than 0.01). The mortality decreased from 19% to 4% during the period studied. This decrease was primarily due to a reduced mortality in hospital later than 12 h after admission. Hearing impairment was the most frequent sequel (10%) and no change in frequency was observed during the 25 years studied. Hearing impairment was registered significantly more often in cases with a late admission to hospital (greater than 48 h) as compared to cases with an earlier admission (p less than 0.001).

Antimicrobial therapy and case fatality in meningococcal disease

The effect of different initial antimicrobial treatments on the case fatality rate (CFR) was evaluated in 112 consecutive patients with meningococcal disease. The overall CFR was 9.8%. 85 patients received initial therapy with chloramphenicol in addition to benzylpenicillin or other antimicrobials, and 27 patients benzylpenicillin or other antimicrobials without chloramphenicol. Patients treated with chloramphenicol had a lower CFR than those not given chloramphenicol (5% vs. 26%; p = 0.004). However, severely ill patients were treated more often with penicillins, and adjustment for the severity of disease on admission to hospital demonstrated that this difference in favour of chloramphenicol was slight and nonsignificant (p = 0.58). High doses of benzylpenicillin and no chloramphenicol were also associated with a higher CFR than low doses. However, the difference was not significant (p = 0.22). More extensive studies should be carried out to evaluate the effect of benzylpenicillin doses and chloramphenicol on the outcome of meningococcal disease.

Invasive haemophilus influenzae and meningococcal infections in Finland. A climatic, epidemiologic and clinical approach

A nationwide epidemiological survey on invasive (blood and/or CSF culture positive) Haemophilus influenzae (HI) and meningococcal infections was performed in Finland in 1976-1980. The mean annual incidence of HI infection was 3.4/100,000 inhabitants (813 cases) vs. 2.0/100,000 (469 cases) of meningococcal infection. HI infections showed no geographical predilection, but meningococcal disease, mainly of group B, was more common in northern than in southern Finland (p less than 0.005). Meningitis accounted for 61% of the HI and 91% of the meningococcal infections. The overall fatality rates were 3.1% and 7.9%, respectively. Children accounted for 94% of the HI and 59% of the meningococcal cases. The overall annual incidence of bacterial meningitis in children (less than 15 years) was 19/100,000; in children less than 5 years it was 52/100,000. HI was the most common (62%) causative agent, followed by meningococci (18%) and pneumococci (5%). The fatality rate was 4%. Major neurological sequelae were found in 5%, minor ones in 16%. It was calculated that 42% of the cases of meningitis could have been prevented by vaccines now available on the market. Vaccines now under field investigation may increase the preventability to about 65%.

Case fatality of meningococcal disease in western Norway

In the period 1976-84, 211 patients hospitalized with meningococcal disease were examined for possible relation between various epidemiological parameters and fatality. The peak incidences were in the age groups 0-4 and 13-18 years, with teenage girls peaking 2 years ahead of the boys. The overall case fatality rate was 8.5%. In septicemic patients (without meningitis) hypotension and/or ecchymoses on admission correlated strongly with a poor prognosis. Most deaths occurred during the months of March and November, and none during the summer months. There was a significant clustering of deaths among patients admitted during the morning hours, probably due to delayed diagnosis and treatment during the night. Since almost all patients who died had skin bleedings on admission, frequent examination of the skin in cases with acute unexplained fever might have saved lives.

Bacterial meningitis in Arizona American Indian children

Bacterial meningitis is a major cause of morbidity and mortality in Arizona infants and children. A retrospective review of 102 cases of meningitis occurring in the American Indian population documents the prevalence of the Haemophilus influenzae organism with a peak incidence in the first year of life. The rate of H influenzae resistance to ampicillin was 16%. Overall morbidity and mortality rates are comparable with reviews of diverse populations, but there is an exceptional mortality and prolonged hospitalization in patients less than 1 year of age. The development of an efficacious vaccine against H influenzae may substantially reduce and prevent this cause of meningitis.

Promptness of antibiotic therapy in acute bacterial meningitis

We reviewed 135 cases of acute community-acquired bacterial meningitis at a municipal teaching hospital during a six-year period, with special emphasis on promptness of initial antimicrobial therapy. Overall mortality was 5% for the 121 childhood cases, compared to 43% for the 14 adult cases (P less than .001). The mean duration between arrival in the emergency department and the administration of appropriate antibiotics was 2.1 hours for the pediatric cases, compared to 4.9 hours for the adult cases (P less than .02). Factors that may contribute to delays in institution of appropriate antimicrobial therapy for adult patients with meningitis include the relative infrequency of this condition, the presence of concomitant disease processes, and the frequent practice of obtaining a computed tomography scan prior to performing lumbar puncture. Prompt institution of antimicrobial therapy for acute meningitis, especially for adult pneumococcal meningitis, remains a major challenge for emergency physicians.

[Epidemiological characteristics of meningococcal infection in Cuba]

The results of the epidemiological analysis of the morbidity rate in meningococcal infection for 1976-1984 are presented. The maximum rise of morbidity rate, equal to 14.4 per 100000 of population, was observed in 1983. Primarily, the rise of morbidity rate in 1979 was induced by meningococci of two serogroups: C (44.6%) and B (36.4%). The vaccinal prophylaxis of the population, carried out in 1979 with the use of polysaccharide vaccine A + C, did not affect morbidity caused by group B meningococci. The isolation rate of these organisms reached 98.7% from patients and 81.0% from carriers. The characteristic feature of the epidemic process of meningococcal infection in Cuba was a considerable increase in the number of patients under 1 year of age and the absence of seasonal fluctuations in morbidity rate.

Control of epidemic meningococcal meningitis by mass vaccination. I. Further epidemiological evaluation of groups A and C vaccines in northern Nigeria

Mass vaccination campaigns were mounted by several state governments in the northern Nigerian sector of the African meningitis belt. Bivalent groups A and C polysaccharide vaccines were used. The results of these campaigns in four of the states which are adjacent to each other are presented and assessed. A total of 7535350 persons in the four States, Bauchi, Borno, Gongola and Plateau, were given the vaccine over a period of 4 years (1978-1981). There was a decline in the overall number of cases reported as well as in the number of deaths in the area, where, since 1978, there has not been an epidemic of meningococcal meningitis. Variations were observed among the states which vaccinated over 50% of their populations and had many fewer cases than those which did not. These results show that mass vaccination is an effective means of preventing outbreaks of meningococcal meningitis and may lead to eradication of the disease.

Validity of the recording of meningococcal disease according to various sources of information

A study was made in Belgium in order to assess the completeness and specificity of the recording of meningococcal disease by routine sources of information. Ninety-three cases identified in a hospital survey were linked with those recorded in mortality statistics, in the notification of communicable diseases, and by the National Reference Laboratory for meningococci. Statistics based on mortality data appeared to be of low validity. The overall completeness of recording was 44% for the notification of communicable disease, and 40% for the reference laboratory. When these two sources were used for surveillance, the completeness of case-finding increased to 56%. When the analysis was restricted to bacteriologically-confirmed cases, the completeness of recording was 62% for the notification system, 70% for the laboratory, and 84% for both sources. The surveillance of communicable diseases should rely on various sources of information. Laboratory data should be systematically used in order to improve both the completeness of recording and the specificity of case-ascertainment.

Mortality in meningococcal disease in Belgium

A survey of children admitted with meningococcal disease to 53 paediatric units in Belgium between 1975 and 1979 was made in order to assess the case mortality rate (CMR) and to identify risk factors associated with death. A total of 309 cases (226 bacteriologically confirmed and 83 unconfirmed) was recorded. The overall CMR was 6.1 per cent. It was 4.4 for bacteriologically confirmed cases and 10.8 for unconfirmed cases. The CMR was higher for septicaemia without meningitis (22.2 per cent) than for meningitis with or without signs of septicaemia (3.4 per cent). The risk of death was not related to the sex or nationality of the patients. Age was a major determinant of the CMR, independently of the clinical picture. The highest risk of death was in children under one year of age. Poor socio-economic conditions were a significant risk factor. Failure to recognise the severity of the disease by some poorly educated mothers, and the admission of the patient to a hospital lacking adequate facilities for managing severely affected children, were the two significant causes of delay of adequate treatment.

[Mortality of rare purulent meningitis, (Staphylococcus, Listeria Pseudomonas, Proteus, Klebsiella, E. coli, Salmonella). An epidemiologic study using the literature from the last 30 years]

3056 cases of purulent meningitis caused by seven rare microorganisms (Staphylococci, Listeria, Pseudomonas, Proteus, Klebsiella, E. coli, Salmonella) were collected from the West European and North American literature of the last 30 years. The average lethality has been calculated for the periods ranging from 1948 to 1962 and from 1963 to 1979 in order to compare the results due to the use of penicillin and older antibiotics with those accomplished with ampicillin and the aminoglycosides. After 1963 the death-rate of each type of meningitis decreased considerably (except for Salmonella meningitis): the lethality of the whole group fell from 48% to 33%, in the subgroup of gram-negative meningitis from 55% to 38%, and in the group of neonatal gram-negative meningitis from 67% to 52%. The best results were seen in Proteus meningitis where lethality decreased from 55% to 15%. In E. coli meningitis there was a reduction from 60% to 43% only. Using the chi-square test all these differences were highly significant (p less than 0.001).

Bacterial meningitis in Nottingham

Records of 171 cases of bacterial meningitis admitted to Nottingham hospitals from January 1974 to June 1980 were reviewed. The distribution of organisms producing meningitis and the factors influencing mortality in different age groups were assessed. Neisseria meningitidis, Haemophilus influenzae and Streptococcus pneumoniae accounted for 69% of all proven cases. The overall mortality was 26% being lowest in patients with meningococcal meningitis (0%) and highest in those with pneumococcal meningitis (53%). The following factors were associated with a poor prognosis: age more than 40 years, or less than 2 months; state of consciousness on admission; high CSF protein concentration; and a positive blood culture. There was no evidence that antibiotic therapy prior to admission affected prognosis. Although many laboratory findings were altered by prior treatment with antibiotics, this did not prevent the establishment of a diagnosis in the individual patient.

Epidemic of meningococcal meningitis in Bamako, Mali: epidemiological features and analysis of vaccine efficacy

Many studies have demonstrated the efficacy of meningococcal vaccine in nonepidemic meningococcal meningitis, but few have examined its efficacy in epidemic conditions. The effects of the vaccine on the course of a meningococcal meningitis epidemic in Bamako, Mali, between January and April, 1981, were studied. The vaccine was effective in limiting further spread of the epidemic. The attack rate among those who received vaccine was lower than that in the unvaccinated (0.7/10 000 vs 4.7/10 000), and the case-fatality rate among vaccinees in whom meningitis developed was lower than that of the unvaccinated. Routine vaccination against meningococcal meningitis in Africa may be impracticable owing to the cost, the relatively short duration of effectiveness, and the irregular occurrence of epidemics. Vaccination early in the course of an epidemic, however, appears to be a useful and practicable method of limiting the spread of disease.

[Epidemiology of meningococcal meningitis in Austria]

In Austria the report of epidemic meningitis is obligatory. Similar to other countries most of the observed strains of meningococci belong to the serogroups A, B and C. The morbidity is decreasing at present, the last peak occurred in the years 1966 to 1971. While several epidemics occurred in other parts of the world during the last years, only 1.2 cases in 100,000 persons were registered in Austria at that time, indicating an epidemiologic wave trough. During the observation period of 20 years the case fatality rate remained relatively constant at 8.6%. In comparison with other infectious diseases the percentage of deaths due to meningococcal infections has increased considerably during the last years. At present about half the deaths in children by infectious diseases are due to meningococci. Mortality and case fatality are very high in childhood and in persons over 50 years. Inversely the mean bactericidal antibody titer against group A and C meningococci is low in these age groups. Indications for meningococcal vaccination in the present situation are discussed.

Bacterial meningitis in Washington state

During 1977 the state of Washington maintained a surveillance system for reporting cases of bacterial meningitis. Hemophilus influenzae meningitis was the most common etiologic agent causing bacterial meningitis. A high incidence rate for H. influenzae meningitis was found among American Indians less than five years ago. A focus of ampicillin-resistant H. influenzae meningitis was found in Pierce County among military dependents or persons who had family members or relatives working or attending school with Fort Lewis Army Base personnel. Although relationships between the individual cases were not detected, the surveillance system continues to seek some association.