Henk A. Bijlmer

World-wide epidemiology of Haemophilus influenzae meningitis; industrialized versus non-industrialized countries

The epidemiology of Haemophilus influenzae meningitis in non-industrialized areas shows considerable differences from that in the industrialized world. The incidence rates among Alaskan Eskimos, Navaho and White Mountain Indians, Australian Aboriginals and among populations in Africa such as Gambians and Senegalese are three- to fourfold higher than those in the USA and up to ten times higher than those in Europe. The peak age in populations with a high incidence is around 5 to 6 months of age compared to 9 months of age in other countries. The case fatality rate (CFR) is not related to the state of industrialization but seems to be more dependent on the accessibility of health care facilities. Africa the CFR is about ten times higher than that seen elsewhere. Apart from other dissimilarities such as the pattern of serotypes causing disease and the transmission rate, the epidemiology of Hib disease is sufficiently different from industrialized areas that it demands a thorough testing of a conjugated Hib vaccine before it can be introduced on a large scale in populations in non-industralized areas.

Clinical Manifestations and Course of Meningococcal Disease in 562 Patients

To describe the clinical manifestations and course of meningococcal disease (MD) data were collected on patients with culture-proven MD, reported in the Netherlands between April 1, 1989 and April 30, 1990 by means of a questionnaire completed by the specialist in attendance. During the study period, 562 patients (295 males, 267 females) were reported. The age of the patients ranged from 2 weeks to 88 years. Of the patients, 57.8% were classified as meningitic, 20.3% as bacteraemic and 21.9% as both meningitic and bacteraemic. In 4.6% of the patients a predisposing factor was present, and in 1.4% a previous episode of meningitis had occurred. A positive family history of meningitis was reported in 12.9% of the patients. On admission, 65.2% of the patients had haemorrhagic skin lesions, 7.9% coma and 4.2% seizures. During admission, 17.8% of the patients developed serious complications. The fatality rate was 7.7%. In 73.2% of the deceased, death occurred within 2 days after admission. Of the survivors, 8.5% recovered with serious sequelae. In conclusion, 16% of the patients with meningococcal disease either died or became severely disabled. Prevention of this putative life-threatening disease seems to be the only means of circumventing the problems caused by this serious condition.

Patient and strain characteristics in relation to the outcome of meningococcal disease: a multivariate analysis.

To investigate the joint association of patient and strain characteristics with the outcome of meningococcal disease (MD), data were collected on 563 consecutive cases of MD reported between 1989 and 1990 in The Netherlands. The meningococcal isolates were characterized with regard to their surface characteristics. Sequelae occurred in 8.5% of the patients, and were only associated with the presence of bacteraemia. The case-fatality rate was 7.7%. Infants aged < or = 5 months and patients in the age-groups of 10-19 years and > or = 50 years had an increased risk for a fatal outcome compared with children from 6 months to 9 years old (Odds Ratios [ORs]: 5.1, 3.4 and 9.8, respectively). The OR for females versus males was 2.3. The ORs for patients with bacteraemia, or a combination of bacteraemia and meningitis, compared with meningitic patients, were 2.3 and 3.1. Meningococcal strain characteristics did not influence the case-fatality rate substantially. In conclusion, host factors were found to be determinants for a fatal outcome of MD in The Netherlands from 1989 to 1990.

Carriage of Haemophilus influenzae in healthy Gambian children

1240 throat samples were processed during different seasons in 11 different communities of The Gambia (West Africa). The carriage rate for Haemophilus influenzae type b ranged from 0 to 33%, but often attained 10% or more, higher than that reported from other open communities. The duration of carriage was short (less than 3 months) and H. influenzae b was found in only 10% of the carriers isolated during the previous or the following survey. Children less than 5 years old carried H. influenzae b in their throat significantly more often than children older than 14 years (P less than 0.05). A high carriage rate did not correlate with the wet or dry season. The carriage rate of children in rural areas was similar to that of children in urban areas. Children in day-care centres or nurseries had a surprisingly low carriage rate (2%). The carriage rate of H. influenzae b was compared to the presence of H. influenzae subspecies in a random sample, which revealed that H. influenzae subspecies was found in 90% of the children under 5 years old. Encapsulated strains of H. influenzae were found in 25% of the same sample, two-thirds of which were not type b. All capsule types were represented. No meningitis cases occurred in the survey populations. We conclude that the prevalence of H. influenzae b in open Gambian communities is similar to that in closed communities elsewhere, but that the kinetics are different from those in closed communities, as persistence of infection in Gambian children is short-lived.

Prognostic indicators of the outcome of meningococcal disease: a study of 562 patients

To assess prognostic indicators of a fatal outcome in patients with meningococcal disease, data from 562 patients with culture-proven meningococcal disease, reported in the Netherlands between 1 April 1989 and 30 April 1990, were collected prospectively by means of a questionnaire completed by the specialist in attendance. Analysis was done by the chi2 test and multiple logistic regression. During the study period 43 patients (7.7%) died. The risk of a fatal outcome was increased in patients aged 0-5 months, 10-19 years, and > or = 50 years, in female patients and in patients presenting with coma, temperature < or = 38.0 degrees C, mean arterial pressure < or = 70 mmHg, white blood cell count < or = 10 x 10(9)/L and platelet count < or = 100 x 10(9)/L. Predisposing factors and duration of disease before admission were significantly associated with outcome, but these associations disappeared in the multivariate analysis. Race, the administration of antibiotics prior to admission, seizures and haemorrhagic skin lesions were not associated with outcome. In conclusion age, gender, coma, temperature, mean arterial pressure, white blood cell count and platelet count were independent prognostic indicators of the outcome of meningococcal disease. The assessment of these characteristics may be helpful for the identification of high risk patients, whose prognosis might be improved by prompt transfer to an intensive care unit.