The 2017 Annual Report on Purulent Meningitis

The 2017 Annual Report on Purulent Meningitis

In 2017, a total of 128 cases of purulent meningitis were observed of which 119 were notified, whereas nine cases were identified through searches in the Danish Microbiology Database, MiBa. Figure 1 presents the development in the number of cases of purulent meningitis by aetiology in the period 1992-2017. Table 1 shows the distribution by aetiology and age. 

Meningococcal meningitis (11 cases) in 2017 is described in EPI-NEWS 49/18  and in the 2017 Annual Report on Meningococcal Disease.

Information about underlying diseases and sequelae are categorised into groups based on diagnosis codes collected from the National Patient Registry. Infections were included as from one month prior to the current meningitis case, but no time restrictions were applied for the remaining underlying diseases/predispositions. Only diagnosis codes given more than five days after disease onset or after the patient’s admission for meningitis were categorised as sequelae.




2017 saw a total of 72 notified cases of meningitis with Streptococcus pneumoniae, of which 63 were notified. A total of 50 cases were detected by culture of cerebrospinal fluid (CSF). Another 16 cases were detected by PCR in CSF. Eight of these cases also had a positive blood culture. One case had a positive culture after autopsy. Five cases were notified with the combination of pneumococci established by blood culture and clinical meningitis.

The figures provided in the present report diverge from the figures in EPI-NEWS 40-41/18 on pneumococcal disease and coverage of pneumococcal vaccination in the childhood vaccination programme 2017, as the case definition is broader in the current report, among others because it includes meningitis notified exclusively on the basis of clinical suspicion.  

Eleven persons under 18 years of age had meningitis with pneumococci, of whom only two had a type comprised by the Prevenar13 vaccine (serotype 3). Both were unvaccinated. 

Another ten cases among persons >18 years of age included serotypes contained in the Prevenar13 vaccine; seven serotype 3 cases, one serotype 6B case and two serotype 19F cases. Two of the 11 patients were vaccinated; one patient with serotype 3 had been vaccinated with Prevenar13 17 days prior to symptom onset, and one of the two serotype 19F patients had been vaccinated with Prevenar13 and Pneumovax. 

In all, 29 of the 72 cases had serotypes contained in the Pneumovax vaccine (23 valent); ten with serotype 8, six with serotype 22F, four with serotype 12F, three with serotype 15B, three with serotype 9N, and one with serotype 10A, 11A and 33F, respectively. Only two of these 29 persons had been vaccinated. One of these two, a serotype 8 case, had been vaccinated with Pneumovax, and the other, a serotype 15B case, had been vaccinated a year before symptom onset, but it was not stated if this patient had received Pneumovax or Prevenar. 

Among the 63 notified cases, information about underlying disease was provided for 44 persons, and information about infection ahead of symptom onset was provided for 21 persons. A total of 16 persons were recorded as having both underlying disease and infection prior to symptom onset. Among the 21 who had infection before symptom onset, nine had an inner-ear infection, three had pneumonia and nine persons were registered as having had other infections. 

In 21 cases, sequelae caused by the illness had been recorded. The most frequently observed sequela was hearing impairment. 

A total of 14 persons died due to their illness; a 13-day-old infant, two persons in their thirties, and 11 persons aged 44-90 years. Six of these persons had underlying disease, and four also had infection prior to symptom onset. Two were only registered with infection prior to falling ill, whereas the remaining six had not been registered with either underlying disease of infection prior to their illness.

Other streptococci

Meningitis due to other streptococci than pneumococci was detected in eight cases. 

A total of seven cases were caused by beta haemolytic streptococci: four with group A streptococci (GAS) and three with group B streptococci (GBS). Additionally, one case of non-haemolytic streptococci, Streptococcus mitis, was notified.

One of the three GBS cases occurred in a 1-day-old neonate, who had presumably become infected during birth. The neonate had no special risk factors, but suffered pareses following the condition. One case occurred in a 23-day-old infant who presumably became infected from its surroundings. The child was premature and no sequelae to the condition were recorded. The third GBS patient was an elderly woman with alcohol misuse and cirrhosis of the liver. 

Two of the four GAS cases were children aged 3-10 years. One of these children had underlying disease registered, the other child experienced sequelae following the condition. One of the two adults who had GAS meningitis had received surgery to the uterus prior to her meningitis, whereas the other had influenza-like disease and was found dead at home. The patient with meningitis caused by S. mitis was a woman in her late thirties with underlying disease. In all eight cases, the streptococci were detected by CSF culture. 

Haemophilus influenzae

A total of 14 cases with H. influenzae were detected, three of type b in persons aged 6 months, 9 years and 27 years, respectively. The two younger persons had been vaccinated in accordance with the Danish childhood vaccination programme, receiving two and three vaccinations, respectively. The vaccination status of the 27-year-old was not stated, but the patient was probably unvaccinated, as H. influenzae vaccination was not introduced into the childhood vaccination programme until 1993. Among the other 11 cases, one person was 14 years old and ten persons were aged 41-84 years; seven were caused by non-capsular strains (one with biotype I, three with biotype II and three with biotype III), three were of unknown type due to lacking isolates, and one case was of type f. 

Two of the patients with type b and five of the other cases had underlying disease. Seven experienced sequelae. 

Listeria monocytogenes

A total of five cases of meningitis caused by Listeria monocytogenes were notified in patients aged 60-85 years; all cases had become infected in Denmark. Underlying disease and/or pre-dispositions were recorded for four patients. No patients died due to the condition. 

In three of the patients, the diagnosis was made by positive culture of cerebrospinal fluid, in one patient by detection of listeria in cerebrospinal fluid by PCR and in one patient by the clinical picture and a positive blood culture.

Other aetiology

One elderly patient had meningitis caused by Escherichia coli. This patient had underlying disease in the form of cardio-pulmonary disease and had previously had cancer.  

Three persons were notified with meningitis caused by Staphylococcus aureus, including a German tourist who had experienced a brain abscess following brain surgery. The two other persons were approx. 50 and 70 years old and both had septic cerebral embolisation due to endocarditis. 

Two persons had meningitis caused by Capnocytophaga canimorsus (previously DF-2), one woman and a man aged 50-70 years of age. Both had several underlying conditions. 

Two persons aged 60+ years had meningitis with Enterococcus faecium and Elizabethkingia meningoseptica, respectively. The first of these two persons had received neurosurgery prior to falling ill; the latter had no underlying disease/risk factors. 

None of the patients mentioned above with meningitis of “other aetiology” died due to their condition.

Unknown aetiology

In a total of 10 cases, patients were notified on the basis of clinical tests and/or cell counts and microscopy of cerebrospinal fluid consistent with purulent meningitis, but without detection of bacteria by culture or PCR. Three of these cases had initiated treatment before a lumbar puncture had been performed. In eight cases, the person had underlying disease/risk factors. One patient died due to the condition.