Dynamics of childhood invasive meningococcal disease in Israel during a 22-year period (1989-2010)

Invasive Disease Due to Neisseria meningitidis: Surveillance and Trends in Israel Prior to and during the COVID-19 Pandemic

Invasive meningococcal disease (IMD) is a devastating disease with significant mortality and long-term morbidity. The COVID-19 pandemic and containment measures have affected the epidemiology of infectious pathogens. This study's aim was to assess IMD trends in Israel prior to and during the COVID-19 pandemic. The Neisseria meningitidis invasive infection is a notifiable disease in Israel. Laboratory analysis includes serogrouping and molecular characterization. The overall national IMD incidence rate (1998-2022) was 0.8/100,000 population. The IMD incidence rates declined during the pandemic years (0.3/100,000 in 2020-2022 vs. 0.9/100,000 in 1998-2019). The number of notified IMD cases declined by 65% in 2020-2022. The case fatality rate among laboratory-confirmed IMD cases was 9% (47/521, 2007-2022). Mortality risk markers included cases' age (older) and socio-economic status (lower). Overall, most Neisseria meningitidis isolates were of serogroup B (62.6%), and the most prevalent clonal complex (CC) was CC32 (24.2%). Serogroup B prevailed in cases aged 0-9 years (74.5%) and less in cases aged 10 years and above (39%). Neisseria meningitidis serogroups and CC distribution altered recently with a decline in serogroup B fraction, an increase in serogroup Y, and a decline in CC32. Ongoing IMD surveillance is necessary to assess trends in circulating strains and support decision-making on meningococcal vaccination programs.

Genetic workup as a complementary tool for the diagnosis of primary complement component deficiencies: a multicenter experience

Diagnosis of primary complement deficiencies requires a high index of suspicion. Thus, susceptible patients are often underdiagnosed and untreated. Here, we present a multicenter experience with two novel inborn errors of the classical complement system. This is a retrospective multicenter analysis of computerized medical records of children (<18 years) admitted in the period between 2012 and 2018 at Shaare Zedek Medical Center in Jerusalem and Edmond and Lily Safra Children's Hospital, Tel-Hashomer Medical Center, in Ramat Gan, Israel. Patients were genetically diagnosed by a complementary immune workup. We identified 5 patients (3 males) from four different families harboring two novel mutations in the complement components C6-C8. Genetic mutations were identified by whole-exome sequencing or by sequencing of the coding exons of a single gene based on the findings in the immune workup. Clinical manifestations consisted of meningitis with or without meningococcemia. The immune workup demonstrated nearly absent levels of CH50, compatible with a complement pathway defect. Diagnosis delay ranged between 0 and 30 years.

CONCLUSION

Awareness of risk factors for primary complement deficiencies, even at the first infectious episode, should facilitate prompt immune and genetic workup, commencing diagnosis and proper treatment for the patient and family.

WHAT IS KNOWN

• Deficiencies in the classical terminal complement components increase susceptibility to invasive meningococcal infections. • Recurrent meningococcal infections mandate a diagnostic workup of the complement system.

WHAT IS NEW

• Genetic workup can be utilized for prompt diagnosis of complement deficiencies. • High rates of consanguinity, even in the presence of a single meningococcal infection, should promote immune and genetic workups.

Purpuric rash and fever among hospitalized children aged 0-18 years: Comparison between clinical, laboratory, therapeutic and outcome features of patients with bacterial versus viral etiology

BACKGROUND

The evaluation of children with purpuric rash and fever (PRF) is controversial. Although many of them have viral infections, on occasion such patients may be infected with Neisseria meningitidis. We described all children aged 0-18 years with PRF in southern Israel during the period 2005 ̶ 2016 and compared their microbiologic, laboratory, clinical and outcome characteristics in relation to various etiologies of this syndrome.

METHODS

Data were summarized from electronic patient and microbiology files. Viral diagnoses were made by serology and/or PCR.

RESULTS

Sixty-nine children with PRF were admitted; 30 (43.48%), 9 (13.04%) and 30 (43.48%) had a syndrome of bacterial, viral or non-established etiology, respectively. N. meningitidis infection was diagnosed in 16/69 (23.19%) patients and in 16/30 (53.33%) patients with bacterial etiology; 14/30 (46.67%) patients suffered from a non-invasive bacterial disease (9 with Rickettsial disease). Adenovirus and Influenza B (3 and 2 cases, respectively) represented the most frequent etiologic agents among patients with viral etiology. More patients with PRF of bacterial etiology were older, of Bedouin ethnicity, looked ill on admission, had higher rates of meningitis and were treated more frequently with antibiotics compared with patients with non-bacterial PRF. Fatality rates among patients with bacterial, viral and non-established etiology were 5/30 (16.7%), 0% and 2/39 (5.1%).

CONCLUSIONS

Although PFR was uncommon, high rates of meningococcal infections were recorded in children with PRF, which was associated with high fatality rates. Rickettsial infections were frequent, emphasizing the need for a high index of suspicion for this disease in endemic geographic areas.

Surveillance of invasive meningococcal disease in the Tel Aviv District, Israel, 2007-2017

Invasive meningococcal disease (IMD) is one of the leading causes of bacterial meningitis and septicemia in Israel. The purpose of the study was to describe the IMD in the Tel Aviv District and to identify specific populations who could benefit from vaccine introduction. In the Tel Aviv District, the incidence rates ranged from 0.4 to 1.4 cases per 100,000 population per year during 2007-2017. During the study period, seventy-nine patients (65%) occurred among children younger than four years of age. Eight deaths occurred (7%), most of them among children under the age of 1 year (5 deaths; 15%). A serogroup was identified in 82 isolates. Most of the isolates (69 cases - 84%) belonged to serogroup B (NmB). IMD clustered geographically in the city of Bnei Brak, with a predominantly Ultra-Orthodox Jewish population. It is the youngest and most densely populated city in the district. The overall incidence rates of IMD among children in Bnei Brak were more than seven times higher in children up to nine years, compared to the rest of the district. Specifically for NmB, disease rates were 9.08 times higher in children up to the age of four, and 7.74 times higher in children from five to nine years old in Bnei Brak, compared to the rest of the district. Our findings describe the burden of a vaccine-preventable disease and reinforce the need for routine 4CmenB introduction, especially in groups where the disease clusters.

Invasive meningococcal disease epidemiology and characterization of Neisseria meningitidis serogroups, sequence types, and clones; implication for use of meningococcal vaccines

BACKGROUND AND AIMS

Neisseria meningitidis (N. meningitidis) is a Gram-negative bacterium that can cause life-threatening invasive infections referred to as invasive meningococcal disease (IMD). In the last decade the incidence of IMD in Israel is about 1/100,000 population annually. We aimed to describe the epidemiology of IMD in Israel combining epidemiological data and characterization of N. meningitidis isolates.

METHODS

Invasive infection caused by N. meningitidis is a notifiable disease in Israel. Data were collected by epidemiological investigations and control measures were employed. Laboratory work-up included serogrouping, N. meningitides molecular characterization and whole-genome sequencing.

RESULTS

During 1998-2017, 1349 cases of IMD were notified in Israel (mean annual incidence rate 0.94/100,000). The peak incidence rates were observed in infants under 1 year of age (10.9/100,000). Case fatality rate was 9.7%. The majority of the N. meningitidis isolates were of serogroup B (67.9%). During 2007-2017, three clonal complexes (CC) 32, 41/44 and 23 (hyper-invasive clonal complexes) were the leading CC (61%). CC32 was the leading CC causing meningococcemia and mortality. In 2017, 35 isolates were tested for 4CMenB antigens variants; of the serogroup B isolates tested 46.7% showed a match to one or more antigens (fHbp or PorA:VR1), most were ST32 (CC32).

CONCLUSIONS

Preliminary analysis based on limited number of samples suggests that the 4CMenB coverage would be about half the strains; further research is necessary. Integration of clinical, epidemiological and laboratory data is essential to support decision-making on the introduction of the novel MENB vaccines in Israel.

Cost-utility analysis of a nationwide vaccination programme against serogroup B meningococcal disease in Israel

OBJECTIVES

Using cost-utility analysis, to evaluate whether or not to adopt a Neisseria meningitidis serogroup B vaccination programme for Israeli children.

METHODS

Epidemiological, demographic, health service utilisation and economic data were integrated into a spreadsheet model to calculate the cost per averted disability-adjusted life year (DALY) of the intervention.

RESULTS

Assuming 78 % vaccine efficacy with no herd immunity, vaccination will prevent 223 cases and 22 deaths over a 100-year period. Based on vaccine price of $60 per dose, total intervention costs ($315,400,000) are partially offset by a $22,700,000 reduction in treatment and sequelae costs as a result of decreased morbidity. The intervention was not cost-effective since the net cost ($292,700,000) per averted DALY gained (1249 mostly due to decreased mortality) was $234,394. Additional two dose catch-up programmes vaccinating children in cohorts aged 1-2 to 1-13 were also not cost-effective.

CONCLUSIONS

The vaccination will become cost-effective if vaccine costs fall below $19.44 per dose. However, in identified high risk areas, the vaccine would be cost-effective and could be recommended for use both with and without catch-up campaigns.

Global incidence of serogroup B invasive meningococcal disease: a systematic review

Use of recently licensed vaccines against Neisseria meningitidis serogroup B (NmB) will depend partly on disease burden estimates. We systematically reviewed NmB incidence and mortality worldwide between January, 2000, and March, 2015, incorporating data from 37 articles and 12 websites. Most countries had a yearly invasive NmB incidence of less than 2 per 100,000 people. Within these relatively low incidence rates (compared with common causes of invasive bacterial diseases), substantial variation was detected between countries, with a notably higher incidence in Australia, Europe, North America, and South America. China and India had reports only of sporadic cases, and except for South Africa, sub-Saharan Africa showed a near absence of disease. In countries with consistently collected data, NmB incidence has tended to decrease, even as the proportion of invasive meningococcal disease cases caused by serogroup B has increased. With few exceptions, case-fatality ratios were fairly consistent, ranging between 3% and 10%. In high-income countries, incidence rates of NmB were relatively low compared with other vaccine-preventable diseases and might be decreasing. High case-fatality ratios, substantial disease-related morbidity, and the threat of outbreaks could nevertheless make NmB an attractive target for preventive and reactive immunisation programmes. The low availability of data from low-income and middle-income countries suggests the need for improved surveillance before vaccination strategies are designed.

A cluster of invasive meningococcal disease revealed by the characterization of a novel serogroup B meningococcal clone

The incidence of invasive infections due to Neisseria meningitidis in Israel is about 1/100 000 population annually. Three cases of meningococcal meningitis were reported in employees at a single plant; the first case appeared in March 2013 and the second and third cases appeared in December, almost 9 months later. N. meningitidis serogroup B was isolated from cerebrospinal fluid samples. Multilocus sequence typing assigned the three meningococcal isolates to ST10418, a new sequence type and a member of the ST32 clonal complex. The clonality was confirmed by performance of pulsed-field gel electrophoresis. Post-exposure antibiotic prophylaxis was administered to close contacts of the first case. Upon the diagnosis of the additional two cases, post-exposure prophylaxis was administered to all the plant employees. This report demonstrates the importance of combining public health measures and advanced laboratory studies to confirm clonality and to prevent further disease spread in a closed setting.

Pediatric invasive Haemophilus influenzae infections in Israel in the era of Haemophilus influenzae type b vaccine: a nationwide prospective study

BACKGROUND

The conjugated Haemophilus influenzae (Hi) type b vaccine caused a marked decrease in invasive Hi disease rates. Nonencapsulated Hi infection now constitutes most invasive Hi morbidity and mortality. This study examines invasive Hi infection incidence in Israel in the postvaccine era years, 2003-2012, and characterizes the epidemiology, clinical diagnosis and case fatality rates of invasive Hi disease in children <15 years of age.

METHODS

An ongoing, nationwide prospective surveillance program for invasive Hi infections in Israel. Epidemiologic and clinical data were collected. Diagnoses were classified as meningitis, pneumonia, bacteremia/sepsis and other clinical foci.

RESULTS

Overall, 389 cases of invasive Hi infections were identified; 242 (62%) nontypable Hi (NTHi), 103 (26%) Hi type b (Hib) and 41 (11%) encapsulated non-b Hi (enbHi). Children <1 year of age accounted for 51% of the overall disease. Invasive Hi disease incidence in children <15 years of age was stable with a mean annual incidence (per 100,000) of 2.0 ± 0.4. The highest incidence of invasive Hi infections was among infants <1 year with rates of 6.2, 4.9, 1.6 and 12.7 for NTHi, Hib, enbHi and total Hi, respectively. The clinical diagnoses of NTHi and enbHi were similar, but differed from Hib with the former presenting mostly as isolated sepsis/bacteremia and the latter primarily as meningitis. Among children with invasive Hib infection, 40% were classified as vaccine failure.

CONCLUSIONS

In the post-Hib vaccination era, invasive Hi morbidity and mortality are largely attributed to NTHi sepsis. Still, with the changing epidemiology of invasive Hi, continued surveillance of all Hi strains is justified.

Secular trends in invasive meningococcal disease, Massachusetts, 1988–2011: what happened to invasive disease?

Invasive meningococcal disease (IMD) reported to the Massachusetts Department of Public Health from 1988 to 2011 was reviewed. The average annual incidence of IMD/100 000 decreased from 1·57 [95% confidence interval (CI) 1·42–1·73] for 1988–1991 to 0·22 (95% CI 0·17–0·29) for 2008–2011. The pattern of decreasing incidence over time differed by age group. There was a decrease in IMD/100 000 in the 0–4 years age group after 1991 from 10·92 (95% CI 8·08–14·70) in 1991 to 5·76 (95% CI 3·78–8·72) in 1992. Incidence in the 0–4 years age group remained below 5/100 000 per year on average thereafter. A substantial reduction in incidence in all age groups was observed between 2000 and 2009, which began before the introduction of conjugate meningococcal vaccine in 2005. Marked reductions in incidence of IMD in Massachusetts, and elsewhere, deserve further investigation with respect to potential factors that go beyond the introduction and deployment of improved meningococcal vaccines.