Bacterial meningitis in adults after splenectomy and hyposplenic states

Immunization coverage among asplenic patients and strategies to increase vaccination compliance: a systematic review and meta-analysis

BACKGROUND

Asplenic or splenectomized patients have a higher risk (ranging from 10 to 50-fold) than the general population of developing an overwhelming post-splenectomy infection (OPSI). Thus, they should receive specific vaccinations to prevent bacterial infections and influenza. The aim of this meta-analysis was to estimate vaccination coverage (VC) with the recommended vaccines among splenectomized patients; strategies recommended in those studies to improve VC worldwide are considered as well.

RESEARCH DESIGN AND METHODS

Scopus, MEDLINE/PubMed, Google Scholar and ISI Web of Knowledge databases were searched. Research papers, short reports, reviews, and meta-analyses published between January 1, 2010 and July 18, 2020 were included; no geographic restrictions were included. Twenty-four studies were included in the meta-analysis.

RESULTS

For anti-pneumococcal vaccination, coverage was 55.1% (95%CI = 41.0-69.2%), for anti-Hib 48.3% (95%CI = 34.3-52.3%), for anti-meningococcal C/ACYW135 33.7% (95%CI = 23.6-43.9%), for anti-meningococcal B 13.3% (95%CI = 7.0-19.5%) and for anti-influenza 53.2% (95%CI = 22.0-84.4%). Most studies determined a lack of adherence to international guidelines by healthcare workers and suggested the need to better educate health professionals in the management of post-splenectomy patients.

CONCLUSIONS

The meta-analysis showed the suboptimal immunization coverage for the vaccines recommended for asplenic patients. Greater efforts must be made by public health professionals to increase VC in this group of patients at risk. Introducing specific prophylaxis protocols in the clinical routine seems to guarantee better immunization compliance in those patients.

Hyposplenism, Hashimoto's Autoimmune Thyroiditis and Overlap Syndrome (Celiac Disease and Autoimmune Hepatitis Type 1)

Hyposplenism is associated with autoimmune diseases, inflammatory bowel disease, severe celiac disease, autoimmune thyroiditis, untreated HIV infection and chronic graft-versus-host disease. The aim of this study was to review the existing data on hyposplenism associated with celiac disease and Hashimoto's autoimmune thyroiditis. Our research was based on a clinical case concerning a 41-year-old female who presented with asthenia, fatigue, dyspepsia and chronic diarrhea. The medical history revealed autoimmune Hashimoto's thyroiditis, type 2 diabetes, fatty liver disease, chronic gastritis and thrombocytosis. Multiple investigations showed hyposplenism and complex autoimmune dysfunction with positive serum markers for celiac disease and type 1 autoimmune hepatitis along with minor symptomatology. The intestinal symptomatology of celiac disease is often hid by hypothyroidism-associated autoimmune thyroiditis. Asymptomatic or minimally symptomatic celiac disease associated with Hashimoto's autoimmune thyroiditis is diagnosed by biomarkers. Hyposplenism in celiac disease can occur regardless of the disease stage, latent or symptomatic.

Complications in the adult asplenic patient: A review for the emergency clinician

BACKGROUND

The spleen performs several important physiologic functions. However, patients can have functional asplenia or have their spleen removed for a number of reasons, which can put them at risk for several dangerous complications.

OBJECTIVE

This narrative review provides a focused evaluation of adult asplenic patients and complications in the emergency departing setting.

DISCUSSION

The spleen plays integral roles in the immune and reticuloendothelial systems and also modulates the inflammatory and coagulation cascades. Asplenia refers to the anatomic or physiologic loss of splenic function, which may be due to trauma, immunological, hematological, or oncological etiologies. Asplenic patients are at risk for several complications including infection, arterial and venous thrombosis, and pulmonary hypertension. Fever in an asplenic patient and overwhelming post-splenectomy infection (OPSI) are medical emergencies with a high mortality and require rapid evaluation and management with broad-spectrum antibiotics. Asplenic patients are at increased risk of arterial thrombosis, such as coronary artery disease, and venous thrombosis including deep venous thrombosis, pulmonary embolism, and splenic and portal vein thrombosis. Management of venous thrombosis includes anticoagulation. Pulmonary hypertension with associated right ventricular dysfunction may also occur in asplenia. These patients require hemodynamic stabilization with an emphasis on inciting causes and treatment of the pulmonary hypertension.

CONCLUSIONS

The spleen is an integral organ involved in several physiologic functions. Asplenia, or absence of spleen function, is associated with severe complications. Knowledge of these complications can improve the care of these patients.

Bacterial Meningitis in Patients using Immunosuppressive Medication: a Population-based Prospective Nationwide Study

We studied occurrence, presentation, disease course, effect of adjunctive dexamethasone, and prognosis of bacterial meningitis in patients using immunosuppressive medication. Patients were selected from our nationwide, prospective cohort on community-acquired bacterial meningitis performed from March 1, 2006 through October 31, 2014. Eighty-seven of 1447 episodes (6 %) of bacterial meningitis occurred in patients using immunosuppressive medication, and consisted of corticosteroids in 82 %. Patients with bacterial meningitis using immunosuppressive medication were less likely to present with headache (P = 0.02) or neck stiffness (P = 0.005), as compared those not on immunosuppressive medication. In 46 % of episodes CSF leukocyte count was below 1000/mm3. CSF cultures revealed S. pneumoniae in 41 % and L. monocytogenes in 40 % of episodes. Outcome was unfavorable in 39 of 87 episodes (45 %) and death occurred in 22 of 87 episodes (25 %). Adjunctive dexamethasone was administered in 52 of 87 (60 %) episodes, and mortality tended to be lower in those on adjunctive dexamethasone therapy as compared to those without dexamethasone therapy (10 of 52 [19 %] vs 12 of 35 [34 %], P = 0.14). We conclude that bacterial meningitis in patients using immunosuppressive medication is likely to present with atypical clinical and laboratory features, and is often caused by atypical bacteria, mainly L. monocytogenes. Adjunctive dexamethasone is widely prescribed in these patients and was not associated with harm in this study.

Risk factors for community-acquired bacterial meningitis

BACKGROUND

Bacterial meningitis is a significant burden of disease and mortality in all age groups worldwide despite the development of effective conjugated vaccines. The pathogenesis of bacterial meningitis is based on complex and incompletely understood host-pathogen interactions. Some of these are pathogen-specific, while some are shared between different bacteria.

METHODS

We searched the database PubMed to identify host risk factors for bacterial meningitis caused by the pathogens Streptococcus pneumoniae, Neisseria meningitidis and Haemophilus influenzae type b, because they are three most common causative bacteria beyond the neonatal period.

RESULTS

We describe a number of risk factors; including socioeconomic factors, age, genetic variation of the host and underlying medical conditions associated with increased susceptibility to invasive bacterial infections in both children and adults.

CONCLUSIONS

As conjugated vaccines are available for these infections, it is of utmost importance to identify high risk patients to be able to prevent invasive disease.

Vaccinations in asplenic adults

PURPOSE

The recommended immunizations for adult asplenic patients are reviewed.

SUMMARY

Patients without a spleen are at risk of developing overwhelming postsplenectomy infections due to encapsulated organisms, mainly pneumococcal, meningococcal, and Haemophilus influenzae type b (Hib). Due to the high mortality rates associated with these infections, vaccinations are recommended as a preventive measure. It is challenging to ensure optimal immunizations in these high-risk patients due to the number of recommended vaccines, the availability of multiple formulations, and the inability to administer specific formulations at the same time, as well as differences in subsequent vaccine administration schedules. Pharmacists play a key role in recommending specific vaccines and timing for these patients in order to achieve the most robust immune response. This article reviews the specific recommendations for pneumococcal, meningococcal, Hib, and influenza vaccinations in asplenic patients.

CONCLUSION

In order to prevent potentially life-threatening infections, asplenic individuals should be vaccinated against S. pneumoniae, N. meningitidis, Hib, and influenza. The optimal timing of vaccination in relation to splenectomy depends on the nature of the splenectomy.

Community-acquired bacterial meningitis

Meningitis is an inflammation of the meninges and subarachnoid space that can also involve the brain cortex and parenchyma. It can be acquired spontaneously in the community - community-acquired bacterial meningitis - or in the hospital as a complication of invasive procedures or head trauma (nosocomial bacterial meningitis). Despite advances in treatment and vaccinations, community-acquired bacterial meningitis remains one of the most important infectious diseases worldwide. Streptococcus pneumoniae and Neisseria meningitidis are the most common causative bacteria and are associated with high mortality and morbidity; vaccines targeting these organisms, which have designs similar to the successful vaccine that targets Haemophilus influenzae type b meningitis, are now being used in many routine vaccination programmes. Experimental and genetic association studies have increased our knowledge about the pathogenesis of bacterial meningitis. Early antibiotic treatment improves the outcome, but the growing emergence of drug resistance as well as shifts in the distribution of serotypes and groups are fuelling further development of new vaccines and treatment strategies. Corticosteroids were found to be beneficial in high-income countries depending on the bacterial species. Further improvements in the outcome are likely to come from dampening the host inflammatory response and implementing preventive measures, especially the development of new vaccines.

Exome Array Analysis of Susceptibility to Pneumococcal Meningitis

Host genetic variability may contribute to susceptibility of bacterial meningitis, but which genes contribute to the susceptibility to this complex disease remains undefined. We performed a genetic association study in 469 community-acquired pneumococcal meningitis cases and 2072 population-based controls from the Utrecht Health Project in order to find genetic variants associated with pneumococcal meningitis susceptibility. A HumanExome BeadChip was used to genotype 102,097 SNPs in the collected DNA samples. Associations were tested with the Fisher exact test. None of the genetic variants tested reached Bonferroni corrected significance (p-value <5 × 10(-7)). Our strongest signals associated with susceptibility to pneumococcal meningitis were rs139064549 on chromosome 1 in the COL11A1 gene (p = 1.51 × 10(-6); G allele OR 3.21 [95% CI 2.05-5.02]) and rs9309464 in the EXOC6B gene on chromosome 2 (p = 6.01 × 10(-5); G allele OR 0.66 [95% CI 0.54-0.81]). The sequence kernel association test (SKAT) tests for associations between multiple variants in a gene region and pneumococcal meningitis susceptibility yielded one significant associated gene namely COL11A1 (p = 1.03 × 10(-7)). Replication studies are needed to validate these results. If replicated, the functionality of these genetic variations should be further studied to identify by which means they influence the pathophysiology of pneumococcal meningitis.

Bacterial meningitis in patients with HIV: A population-based prospective study

OBJECTIVE

We studied occurrence, disease course, and prognosis of community-acquired bacterial meningitis in HIV-infected adults in the Netherlands.

METHODS

We performed a nationwide, prospective cohort study. Patients over 16 years old with bacterial meningitis were included. Data on patient history, symptoms and signs on admission, laboratory findings, radiologic examination, treatment, and outcome were collected prospectively. For HIV-positive patients additional information was collected retrospectively.

RESULTS

From March 2006 to December 2013, 1354 episodes of community-acquired meningitis were included in the cohort. Thirteen patients were HIV-infected (1.0%). The annual incidence of bacterial meningitis was 8.3-fold higher (95%CI 4.6-15.1, P < 0.001) among HIV-infected patients as compared to the general population (10.79 [95%CI 5.97-19.48] vs 1.29 [95%CI 1.22-1.37] per 100.000 patients per year). Predisposing factors (other than HIV), clinical symptoms and signs, ancillary investigations, causative organisms and outcome were comparable between HIV-infected and patients without HIV infection.

CONCLUSIONS

HIV-infected patients in the Netherlands have a 8.3-fold higher risk for bacterial meningitis as compared to the general population despite cART therapy. Clinical presentation and outcome of patients with acute bacterial meningitis with and without HIV are similar.

Capnocytophaga canimorsus Meningitis: Three Cases and a Review of the Literature

Bacterial meningitis is a disease with a high morbidity and mortality. It may be caused by the zoonotic pathogen Capnocytophaga canimorsus, which is part of the commensal oral flora in dogs and cats. We report three cases of C. canimorsus meningitis in a nationwide cohort study of bacterial meningitis patients and performed a review of the literature. Three episodes of C. canimorsus meningitis were identified in three patients included in a nationwide cohort study from 2006 through 2014. The calculated annual incidence was 0.03 per million adults. When combined with the literature, 33 patients were identified of which 28 were male (85%). The median age was 63 years, and 13 (42%) were immunocompromised, which consisted of alcoholism in 7 (21%). Animal contact could be established in 29 of 30 patients (93%) and consisted of dog bites in 22 of 29 (76%). One patient died (3%) and 8 had neurological sequelae upon discharge (25%), most often hearing loss (n = 6, 19%). Capnocytophaga canimorsus meningitis is associated with dog bites. Although mortality is relatively low, survivors often have neurological sequelae.

Community-acquired bacterial meningitis in adults in the Netherlands, 2006-14: a prospective cohort study

BACKGROUND

We studied causative pathogens, clinical characteristics, and outcome of adult community-acquired bacterial meningitis after the introduction of adjunctive dexamethasone treatment and nationwide implementation of paediatric conjugate vaccines.

METHODS

In this cohort study, we prospectively assessed adults (age >16 years) with community-acquired bacterial meningitis in the Netherlands, identified through the National Reference Laboratory for Bacterial Meningitis or individual physicians between Jan 1, 2006, and July 1, 2014. We identified independent predictors of an unfavourable outcome (Glasgow Outcome Scale score 1-4) by logistic regression.

FINDINGS

We assessed 1412 episodes of community-acquired bacterial meningitis. Incidence declined from 1·72 cases per 100,000 adults per year in 2007-08, to 0·94 per 100,000 per year in 2013-14. Streptococcus pneumoniae caused 1017 (72%) of 1412 episodes. Rates of adult bacterial meningitis decreased most sharply among pneumococcal serotypes included in paediatric conjugate vaccine, and in meningococcal meningitis. We found no evidence of serotype or serogroup replacement. The overall case fatality rate was 244 (17%) of 1412 episodes and unfavourable outcome occurred in 531 (38%) of 1412 episodes. Predictors of unfavourable outcome were advanced age, absence of otitis or sinusitis, alcoholism, tachycardia, lower score on the Glasgow Coma Scale, cranial nerve palsy, a cerebrospinal fluid white-cell count lower than 1000 cells per μL, a positive blood culture, and a high serum C-reactive protein concentration. Adjunctive dexamethasone was administered for 1234 (89%) of 1384 assessed episodes. The multivariable adjusted odds ratio of dexamethasone treatment for unfavourable outcome was 0·54 (95% CI 0·39-0·73).

INTERPRETATION

The incidence of adult bacterial meningitis has decreased substantially, which is partly explained by herd protection by paediatric conjugate vaccines. Adjunctive dexamethasone treatment was associated with substantially improved outcome.

FUNDING

European Research Council, National Institute of Public Health and the Environment, European Union, Academic Medical Center, and Netherlands Organization for Health Research and Development.

The detail of the en bloc technique and prognosis of spleen-preserving laparoscopic distal pancreatectomy for pancreatic cancer

BACKGROUND

Although laparoscopic spleen-preserving distal pancreatectomy surgery is more and more popular, the reports about the en bloc technique used for pancreatic cancer were still rare. The aim of our study was to illustrate the detail of the spleen-preserving en bloc technique as well as the short-term and long-term outcomes.

METHODS

The detail of the en bloc technique with pictures was described. The prognosis of the successive 23 cases that underwent the laparoscopic distal pancreatectomy (LDP) surgery was evaluated.

RESULTS

There were 17 cases that underwent spleen-preserving LDP while six cases underwent spleen-resecting LDP. The average surgery time was 203 ± 54 min, and the average blood loss volume was 208 ± 264 ml; one case transferred to open surgery because of severe adhesion. The complication rate was 47 % (n = 8) shortly after surgery. Pancreatic fistula rate was 41 % (n = 7). No lethal case occurred. The average diameter of the tumor was 32 ± 12 mm. The average number of the lymph nodes obtained was 19.8 ± 9.3. All the cutting edges were negative. Survival rates of the patient after 1, 3, and 5 years are 64.7, 52.9, and 41.2 %, respectively. These records showed no statistical significance compared with spleen-resecting LDP and open distal pancreatectomy (ODP) surgeries.

CONCLUSIONS

The en bloc spleen-preserving LDP can be performed by experienced surgeons. This surgery has good short-term and long-term outcomes.

Methods of rapid diagnosis for the etiology of meningitis in adults

Infectious meningitis may be due to bacterial, mycobacterial, fungal or viral agents. Diagnosis of meningitis must take into account numerous items of patient history and symptomatology along with regional epidemiology and basic cerebrospinal fluid testing (protein, etc.) to allow the clinician to stratify the likelihood of etiology possibilities and rationally select additional diagnostic tests. Culture is the mainstay for diagnosis in many cases, but technology is evolving to provide more rapid, reliable diagnosis. The cryptococcal antigen lateral flow assay (Immuno-Mycologics) has revolutionized diagnosis of cryptococcosis and automated nucleic acid amplification assays hold promise for improving diagnosis of bacterial and mycobacterial meningitis. This review will focus on a holistic approach to diagnosis of meningitis as well as recent technological advances.

Practical review of immunizations in adult patients with cancer

Compared with the general population, patients with cancer in general are more susceptible to vaccine-preventable infections, either by an increased risk due to the malignancy itself or immunosuppressive treatment. The goal of immunizations in these patients is therefore to provide protection against these infections, and to decrease the number of vulnerable patients who can disseminate these organisms. The proper timing of immunization with cancer treatment is key to achieving better vaccine protection. As the oncology field continues to advance, leading to better quality of life and longer survival, immunization and other aspects of preventive medicine ought to move to the frontline in the care of these patients. Herein, we review the vaccines most clinically relevant to patients with cancer, as well as special cases including vaccines after splenectomy, travel immunization and recommendations for family members.