Single visit rabies pre-exposure prophylaxis: A literature review.

BACKGROUND: The current WHO-recommended rabies pre-exposure prophylaxis (PrEP) are two-visit vaccination schedules, but there are studies suggesting that single visit schedules might be sufficient to prime the immunity. METHODS: A literature review was conducted to retrieve and summarize published data on single visit rabies PrEP. PubMed database was screened for articles published between January 1st, 2003 and December 31st, 2022. The bibliographies of the articles chosen to undergo full text review and of the current major WHO publications on rabies were searched to find additional references, regardless of publication date. The primary outcome was the percentage of subjects having received rabies PrEP on single visit schedules who achieved antibody levels ≥0.5 IU/mL one week after post-exposure prophylaxis (PEP), regardless of the PEP regimen. RESULTS: 11 studies were selected for inclusion, totalling 935 subjects, of which 696 received a simulated PEP schedule. Of these 696, a serological test result on day 7 was available for 408 of them, and 406 subjects (99.51%) seroconverted after PEP without any difference regarding time delay between PrEP and PEP or the vaccination schedule used for PEP. CONCLUSION: Single visit PrEP schedules seem to confer sufficient protection in most healthy individuals without immunocompromised status if a booster PEP is administered after a suspected rabies exposure. Further studies in real-life settings and in different age categories are needed to confirm this finding, which may increase the availability of vaccines and thus the accessibility of PrEP for vulnerable populations.

Imported diseases in travellers presenting to the emergency department after a stay in a malaria-endemic country: a retrospective observational study.

BACKGROUND: We aimed to investigate the aetiology and outcomes of illnesses in patients presenting to an emergency department after travelling to a malaria-endemic country, in order to raise awareness of both tropical and cosmopolitan diseases. METHODS: A retrospective chart review was performed for all patients who underwent blood smear testing for malaria at the Emergency Department of the University Hospitals Leuven from 2017 to 2020. Patient characteristics, results of laboratory and radiological examinations, diagnoses, disease course and outcome were collected and analysed. RESULTS: A total of 253 patients were included in the study. The majority of ill travellers returned from Sub-Saharan Africa (68.4%) and Southeast Asia (19.4%). Their diagnoses fell into three major syndrome categories: systemic febrile illness (30.8%), inflammatory syndrome of unknown origin (23.3%) and acute diarrhoea (18.2%). Malaria (15.8%) was the most common specific diagnosis in patients with systemic febrile illness, followed by influenza (5.1%), rickettsiosis (3.2%), dengue (1.6%), enteric fever (0.8%), chikungunya (0.8%) and leptospirosis (0.8%). The presence of hyperbilirubinemia and thrombocytopenia increased the probability of malaria, with a likelihood ratio of 4.01 and 6.03, respectively. Seven patients (2.8%) were treated in the intensive care unit, and none died. CONCLUSION: Systemic febrile illness, inflammatory syndrome of unknown origin and acute diarrhoea were the three major syndromic categories in returning travellers presenting to our emergency department after a stay in a malaria-endemic country. Malaria was the most common specific diagnosis in patients with systemic febrile illness. None of the patients died.

Screening the asymptomatic soldiers after a stay in sub-Saharan Africa. A retrospective observational study.

BACKGROUND: Many tropical clinics offer post-travel screening for parasitic infections in asymptomatic travellers. However, literature on attack rates and incidence rates of parasitic infections is scarce. METHOD: All military personnel returning from a tropical region during the year 2018 were tested for the presence of antibodies against Strongyloides stercoralis, Schistosoma and Entamoeba histolytica. Test results were compared with previous results if available to distinguish recent and old infection. RESULTS: In total, 949 soldiers were included in the study. The median age was years 31 (IQR: 26-41), 96.3% were male. The median duration of stay in the tropics was 35 days (IQR: 14-90). The destination was predominantly central Africa. Serological tests were positive for S. stercoralis in 10 patients (1.1%), Schistosoma in 3 (0.3%), and E. histolytica in 16 (1.7%). The attack rates were 0.84, 0.32 and 1.69 respectively. The incidence rates were 3.99, 1.49 and 7.97 respectively. CONCLUSIONS: The risk for parasitic infection in the asymptomatic returning soldiers is low. However, the potentially serious complications of unrecognised parasitic infection can legitimise systematic screening.

Factors influencing the immune response after a single-dose 3-visit pre-exposure rabies intradermal vaccination schedule: A retrospective multivariate analysis.

BACKGROUND: The World Health Organization (WHO) recommends intradermal (ID) rabies vaccination as a safe and immunogenic alternative to intramuscular administration. The aim of this study is to determine which factors influence the levels of rabies virus neutralizing antibodies (RVNA) after a 3-visit ID rabies vaccination. METHODS: This is a retrospective secondary data analysis study based on electronic health record vaccination data of Belgian military subjects who received ID rabies Pre-exposure prophylaxis (PrEP) with a single-dose 3-visit regimen during the period 2014-2017. Logistic regression was performed to identify predictive factors of RVNA level ≥3.0 IU/mL and >10 IU/mL. RESULTS: The second analysis performed on the 2025 subjects (100% seroconverted with a RVNA ≥ 0.5 IU/mL) shows a significantly better immune response in subjects younger than 30 years compared to all other age-groups, a gender-difference to predict RVNA ≥ 3.0 IU/mL (OR 2.30 [1.26-4.22] comparing "female" to "male") and the influence of the vaccination schedule (OR 2.28 [1.15-4.53] comparing "late - very variable" to "correct" schedule) to predict > 10 IU/ml. Multivariate analysis also demonstrates that a postponed serology control significantly influences the Rapid Fluorescent Focus Inhibition Test (RFFIT). CONCLUSION: Gender and age significantly influence the response to ID rabies vaccine. Timing of RVNA determination is important to correctly assess the response to vaccination. A single-dose 3-visit ID rabies PrEP schedule is a dose-sparing effective alternative to the double-dose 2-visit ID schedule. When the minimum time interval between doses is respected, RVNA determination is not necessary.

Factors influencing the immune response after a double-dose 2-visit pre-exposure rabies intradermal vaccination schedule: A retrospective study.

BACKGROUND: Double-dose 2-visit intradermal rabies schedules (22ID) have recently been accepted by the World Health Organization (WHO) as Pre-Exposure Prophylaxis (PrEP). The aim of this study is to determine which factors influence the levels of rabies virus neutralizing antibodies (RVNA) after a 22ID rabies vaccination schedule. METHODS: This is a retrospective study based on electronic health record vaccination data of subjects from the Belgian Armed Forces who received the 22ID rabies PrEP. An antibody titer ≥0.5 IU/mL, measured by rapid fluorescent focus inhibition test, is defined by the WHO as an adequate immune response after PrEP. Logistic regression was performed in order to identify predictive factors of RVNA level ≥3.0 IU/ml and >10 IU/ml. RESULTS: 301 subjects were included. 297 (98,6%) seroconverted with a RVNA ≥ 0.5 IU/ml. Multivariate analysis shows a significant better immune response in the subjects where the second dose was administered later on than on day 7 (RVNA >10 IU/ml (OR: 3.01 [1.36-6.67])). Postponing the timing of the serology control also influenced significantly the rapid fluorescent focus inhibition test (RVNA ≥ 3.0 IU/ml (OR: 0.12 [0.06-0.24]) and RVNA > 10 IU/ml (OR: 0.14 [0.06-0.29])). CONCLUSION: A 22ID rabies PrEP vaccination schedule is highly effective and provides an adequate immune response in most subjects in a real live setting. Timing of the second vaccine dose significantly influences the response to ID rabies vaccine. Timing of RVNA determination is important in order to correctly assess the response to vaccination.

Timing of Intradermal Rabies Pre-exposure Prophylaxis Injections: Immunological Effect on Vaccination Response.

INTRODUCTION: Rabies remains a global threat, with annually over 59,000 deaths. Intradermal (ID) pre-exposure prophylaxis (PrEP) is very efficient and reduces the need for rabies immunoglobulins. Not much is known about factors that influence the immune response to ID administered rabies vaccine. The aim of this study is to determine if variations in timing of vaccine administration and serology determination, age and gender have an influence on the levels of rabies virus neutralizing antibody (RVNA) after ID rabies vaccination. MATERIALS AND METHODS: This is a retrospective study based on electronic health record vaccination data of Belgian military personnel who received ID rabies PrEP with a three injections regimen during the period 2014-2017. Serology was determined by using the RFFIT method. Fischer's exacts tests were used to evaluate the effect of each independent variable on RVNA levels. RESULTS: In this study, 2,112 subjects were included. All but one seroconverted with a RVNA level ≥0.5 IU/mL. About 48% of subjects developed an antibody titer of >10 IU/mL, 36% had antibody levels 3-10 IU/mL and 16% had an antibody level 0.5-2.99 IU/mL. Statistically significant (p = 0.0018) higher RVNA levels are observed in the groups that received vaccination doses later as planned. Timing of serology determination also influenced RVNA levels significantly (p = 0.000). Antibody levels were significantly higher in females than in males (p = 0.000). Age did influence RVNA levels significantly (p = 0.022). CONCLUSIONS: Timing of vaccine dose administration, timing of serology testing, sex and age do significantly influence the humoral B-cell response to ID administered rabies vaccine.

Processing Phage Therapy Requests in a Brussels Military Hospital: Lessons Identified.

There is a growing interest in phage therapy as a complementary tool against antimicrobial resistant infections. Since 2007, phages have been used sporadically to treat bacterial infections in well-defined cases in the Queen Astrid military hospital (QAMH) in Brussels, Belgium. In the last two years, external requests for phage therapy have increased significantly. From April 2013 to April 2018, 260 phage therapy requests were addressed to the QAMH. Of these 260 requests, only 15 patients received phage therapy. In this paper, we analyze the phage therapy requests and outcomes in order to improve upon the overall capacity for phage therapy at the QAMH.