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The article discusses the methodology behind joint malaria prevention recommendations from Switzerland, Germany, Belgium, and The Netherlands. These countries have collaborated to align their recommendations based on epidemiological data quality and refined methodology. The process involves defining malaria risk categories, compiling data on malaria incidence, creating raw risk maps, adjusting maps based on expert discussions, and publishing final recommendations. The aim is to provide transparent and evidence-based recommendations for travel medicine advisors and travelers. [Extracted from the article]

Background Despite being the leading cause of mortality from bloodstream infections worldwide, little is known about regional variation in treatment practices for Staphylococcus aureus bacteremia (SAB). The aim of this study was to identify global variation in management, diagnostics, and definitions of SAB. Methods During a 20-day period in 2022, physicians throughout the world were surveyed on SAB treatment practices. The survey was distributed through listservs, e-mails, and social media. Results In total, 2031 physicians from 71 different countries on 6 continents (North America [701, 35%], Europe [573, 28%], Asia [409, 20%], Oceania [182, 9%], South America [124, 6%], and Africa [42, 2%]) completed the survey. Management-based responses differed significantly by continent for preferred treatment of methicillin-susceptible S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA) bacteremia, use of adjunctive rifampin for prosthetic material infection, and use of oral antibiotics (P <.01 for all comparisons). The 18F-FDG PET/CT scans were most commonly used in Europe (94%) and least frequently used in Africa (13%) and North America (51%; P <.01). Although most respondents defined persistent SAB as 3 – 4 days of positive blood cultures, responses ranged from 2 days in 31% of European respondents to 7 days in 38% of Asian respondents (P <.01). Conclusions Large practice variations for SAB exist throughout the world, reflecting the paucity of high-quality data and the absence of an international standard of care for the management of SAB. [ABSTRACT FROM AUTHOR]

Defining urinary tract infection (UTI) is complex, as numerous clinical and diagnostic parameters are involved. In this systematic review, we aimed to gain insight into how UTI is defined across current studies. We included 47 studies, published between January 2019 and May 2022, investigating therapeutic or prophylactic interventions in adult patients with UTI. Signs and symptoms, pyuria, and a positive urine culture were required in 85%, 28%, and 55% of study definitions, respectively. Five studies (11%) required all 3 categories for the diagnosis of UTI. Thresholds for significant bacteriuria varied from 103 to 105 colony-forming units/mL. None of the 12 studies including acute cystitis and 2 of 12 (17%) defining acute pyelonephritis used identical definitions. Complicated UTI was defined by both host factors and systemic involvement in 9 of 14 (64%) studies. In conclusion, UTI definitions are heterogeneous across recent studies, highlighting the need for a consensus-based, research reference standard for UTI. [ABSTRACT FROM AUTHOR]

Background Pre-existing lower urinary tract symptoms (LUTS), cognitive impairment, and the high prevalence of asymptomatic bacteriuria (ASB) complicate the diagnosis of urinary tract infection (UTI) in older women. The presence of pyuria remains the cornerstone of UTI diagnosis. However, >90% of ASB patients have pyuria, prompting unnecessary treatment. We quantified pyuria by automated microscopy and flowcytometry to determine the diagnostic accuracy for UTI and to derive pyuria thresholds for UTI in older women. Methods Women ≥65 years with ≥2 new-onset LUTS and 1 uropathogen ≥104 colony-forming units (CFU)/mL were included in the UTI group. Controls were asymptomatic and classified as ASB (1 uropathogen ≥105 CFU/mL), negative culture, or mixed flora. Patients with an indwelling catheter or antimicrobial pretreatment were excluded. Leukocyte medians were compared and sensitivity–specificity pairs were derived from a receiver operating characteristic curve. Results We included 164 participants. UTI patients had higher median urinary leukocytes compared with control patients (microscopy: 900 vs 26 leukocytes/µL; flowcytometry: 1575 vs 23 leukocytes/µL; P <.001). Area under the curve was 0.93 for both methods. At a cutoff of 264 leukocytes/µL, sensitivity and specificity of microscopy were 88% (positive and negative likelihood ratio: 7.2 and 0.1, respectively). The commonly used cutoff of 10 leukocytes/µL had a poor specificity (36%) and a sensitivity of 100%. Conclusions The degree of pyuria can help to distinguish UTI in older women from ASB and asymptomatic controls with pyuria. Current pyuria cutoffs are too low and promote inappropriate UTI diagnosis in older women. Clinical Trials Registration. International Clinical Trials Registry Platform: NL9477 (https://trialsearch.who.int/Trial2.aspx?TrialID=NL9477) [ABSTRACT FROM AUTHOR]

The emergence of SARS-CoV-2 variants raised questions regarding the durability of immune responses after homologous or heterologous boosters after Ad26.COV2.S-priming. We found that SARS-CoV-2–specific binding antibodies, neutralizing antibodies, and T cells are detectable 5 months after boosting, although waning of antibodies and limited cross-reactivity with Omicron BA.1 was observed. [ABSTRACT FROM AUTHOR]

Background Treatment of staphylococcal prosthetic joint infection (PJI) usually consists of surgical debridement and prolonged rifampicin combination therapy. Tailored antimicrobial treatment alternatives are needed due to frequent side effects and drug-drug interactions with rifampicin combination therapy. We aimed to assess the effectiveness of several alternative antibiotic strategies in patients with staphylococcal PJI. Methods In this prospective, multicenter registry-based study, all consecutive patients with a staphylococcal PJI, treated with debridement, antibiotics and implant retention (DAIR) or 1-stage revision surgery between January 1, 2015 and November 3, 2020, were included. Patients were treated with a long-term rifampicin combination strategy (in 2 centers) or a short-term rifampicin combination strategy (in 3 centers). Antimicrobial treatment strategies in these centers were defined before the start of the registry. Patients were stratified in different groups, depending on the used antimicrobial strategy. Cox proportional hazards models were used to compare outcome between the groups. Results Two hundred patients were included and stratified in 1 long-term rifampicin group (traditional rifampicin combination therapy) or 1 of 3 short-term rifampicin groups (clindamycin or flucloxacillin or vancomycin monotherapy, including rifampicin for only 5 postoperative days). Adjusted hazard ratios (aHRs) for failure in patients treated with short-term rifampicin and either flucloxacillin or clindamycin were almost equal to patients treated with long-term rifampicin combination therapy (aHR = 1.21; 95% confidence interval,.34–4.40). Conclusions A short-term rifampicin strategy with either clindamycin or flucloxacillin and only 5 days of rifampicin was found to be as effective as traditional long-term rifampicin combination therapy. A randomized controlled trial is needed to further address efficacy and safety of alternative treatment strategies for staphylococcal PJI. [ABSTRACT FROM AUTHOR]

Background: In 2013, the World Health Organization (WHO) revised their position on yellow fever vaccination, in which revaccination every 10 years was no longer required, and that a single-dose provided life-long protection. However, research data on the immunogenicity of YF vaccine in people aged 60 years and over are scarce. Indeed, immunosenescence may result in lower virus neutralizing antibody titers after primary vaccination and a more rapid waning immunity. Therefore, we tested the hypothesis that older travelers, vaccinated at 60 years or older are more likely to become seronegative in comparison to young adults 10 years after primary YF vaccination.Methods: This is a 10-year follow-up study of an earlier prospective controlled cohort study. In the original trial, the neutralizing antibody response was measured in older travelers (aged 60-81 years, N = 28) and young adults (aged 18-28 years, N = 30) up to 28 days after a primary yellow fever vaccination. Ten years later, we collected serum samples of 22/28 (78%) elderly (71-85 years) and 14/30 (47%) controls (29-40 years), and determined their neutralizing antibody titers by plaque reduction neutralization test (PRNT80). Seropositivity was defined as plaque formation reduction of 80% at a serum dilution of 10 or more (PRNT80 ≥ 10).Results: All participants (36/36) were still seropositive 10 years after primary vaccination. The geometric mean concentrations were not statistically different between the older and younger participants (6.7 IU/mL vs. 8.6 IU/mL, P = 0.5).Conclusions: All older travelers were seropositive, 10 years after a primary YF vaccination at the age of ≥60 years. These data suggest that in older travelers a single vaccination is sufficient to convey long-lasting immunity for at least 10 years, and is in support the position of the WHO on a single-dose yellow fever vaccination. [ABSTRACT FROM AUTHOR]

A 28-year old otherwise healthy Dutch male presented at the emergency department with fatigue, joint complaints and migratory subcutaneous swellings on back, and legs. These infestations include fascioliasis, gnathostomiasis, loaiasis, dirofilariasis, mansolelliasis, paragonimiasis and toxocariasis. However, fascioliasis, paragonimiasis and mansolelliasis are characterized by nodular subcutaneous swelling; loaiasis is only seen at the African continent and I G. spinigerum i larvae cannot mature in humans larger than 3 mm. [Extracted from the article]

Background: Controlled human hookworm infections could significantly contribute to the development of a hookworm vaccine. However, current models are hampered by low and unstable egg output, reducing generalizability and increasing sample sizes. This study aims to investigate the safety, tolerability, and egg output of repeated exposure to hookworm larvae.Methods: Twenty-four healthy volunteers were randomized, double-blindly, to 1, 2, or 3 doses of 50 Necator americanus L3 larvae at 2-week intervals. Volunteers were monitored weekly and were treated with albendazole at week 20.Results: There was no association between larval dose and number or severity of adverse events. Geometric mean egg loads stabilized at 697, 1668, and 1914 eggs per gram feces for the 1 × 50L3, 2 × 50L3, and 3 × 50L3 group, respectively. Bayesian statistical modeling showed that egg count variability relative to the mean was reduced with a second infectious dose; however, the third dose did not increase egg load or decrease variability. We therefore suggest 2 × 50L3 as an improved challenge dose. Model-based simulations indicates increased frequency of stool sampling optimizes the power of hypothetical vaccine trials.Conclusions: Repeated infection with hookworm larvae increased egg counts to levels comparable to the field and reduced relative variability in egg output without aggravating adverse events.Clinical Trials Registration: NCT03257072. [ABSTRACT FROM AUTHOR]

Four healthy volunteers were infected with 50 Necator americanus infective larvae (L3) in a controlled human hookworm infection trial and followed for 52 weeks. The kinetics of fecal egg counts in volunteers was assessed with Bayesian multilevel analysis, which revealed an increase between weeks 7 and 13, followed by an egg density plateau of about 1000 eggs/g of feces. Variation in egg counts was minimal between same-day measurements but varied considerably between days, particularly during the plateau phase. These analyses pave the way for the controlled human hookworm model to accelerate drug and vaccine efficacy studies. [ABSTRACT FROM AUTHOR]

To accelerate the development of novel vaccines for schistosomiasis, we set out to develop a human model for Schistosoma mansoni infection in healthy volunteers. During natural infections, female schistosomes produce eggs that give rise to morbidity. Therefore, we produced single-sex, male Schistosoma mansoni cercariae for human infection without egg production and associated pathology. Cercariae were produced in their intermediate snail hosts in accordance with the principles of good manufacturing practice (GMP). The application of GMP principles to an unconventional production process is a showcase for the controlled production of complex live challenge material in the European Union or under Food and Drug Administration guidance. [ABSTRACT FROM AUTHOR]

Combined fecal microbiota transfer and antibiotic treatment prevented recurrences of urinary tract infections with multidrug-resistant (MDR) Pseudomonas aeruginosa, but it failed to eradicate intestinal colonization with MDR Escherichia coli. Based on microbiota analysis, failure was not associated with distinct diminished microbiota diversity. [ABSTRACT FROM AUTHOR]

An editorial is presented which discusses rabies booster injections, whether administered via the intradermal (ID) or intramuscular (IM) route following ID or IM preexposure prophylaxis (PrEP), elicited neutralizing antibodies. It mentions that World Health Organization (WHO) has updated its recommendation for preexposure prophylaxis (PrEP).

Background Immunization of healthy volunteers during receipt of chemoprophylaxis with Plasmodium falciparum sporozoites (CPS-immunization) induces sterile protection from malaria. Antibody responses have long been known to contribute to naturally acquired immunity against malaria, but their association with sterile protection after whole sporozoite immunization is not well established. We therefore studied the induction and kinetics of malaria parasite antigen-specific antibodies and memory B-cells (MBCs) during CPS-immunization and their correlation with protection from challenge infection. Methods We assessed humoral reactivity to 9 antigens representing different stages of the life cycle of P. falciparum by performing standardized MBC enzyme-linked immunospot and enzyme-linked immunosorbent assays on peripheral blood mononuclear cells and plasma samples from 38 Dutch volunteers enrolled in 2 randomized controlled clinical trials. Results MBCs and antibodies recognizing pre-erythrocytic and cross-stage antigens were gradually acquired during CPS-immunization. The magnitude of these humoral responses did not correlate with protection but directly reflected parasite exposure in CPS-immunization and challenge. Conclusions Humoral responses to the malarial antigens circumsporozoite protein, liver-stage antigen-1, apical membrane antigen-1, and merozoite surface protein-1 do not to predict protection from challenge infection but can be used as sensitive marker of recent parasite exposure. Clinical Trials Registration NCT01236612 and NCT01218893. [ABSTRACT FROM AUTHOR]

Background. Immunization of healthy volunteers by bites from Plasmodium falciparum–infected mosquitoes during chloroquine chemoprophylaxis (hereafter, chemoprophylaxis and sporozoites [CPS] immunization) induces sterile protection against malaria. CPS-induced protection is mediated by immunity against pre-erythrocytic stages, presumably at least partially by cytotoxic cellular responses. We therefore aimed to investigate the association of CPS-induced cytotoxic T-cell markers with protection.Methods. In a double-blind randomized controlled trial, we performed dose titration of CPS immunization followed by homologous challenge infection in 29 subjects. Immune responses were assessed by in vitro restimulation of peripheral blood mononuclear cells and flow cytometry.Results. Dose-dependent complete protection was obtained in 4 of 5 volunteers after immunization with bites from 45 P. falciparum–infected mosquitoes, in 8 of 9 volunteers with bites from 30, and in 5 of 10 volunteers with bites from 15 (odds ratio [OR], 5.0; 95% confidence interval [CI], 1.5–17). Completely protected subjects had significantly higher proportions of CD4 T cells expressing the degranulation marker CD107a (OR, 8.4; 95% CI, 1.5–123; P = .011) and CD8 cells producing granzyme B (OR, 11; 95% CI, 1.9–212; P = .004) after P. falciparum restimulation.Conclusions. These data underline the efficiency of CPS immunization to induce sterile protection and support a possible role for cytotoxic CD4 and CD8 T-cell responses in pre-erythrocytic immunity.Clinical Trials Registration. NCT01218893. [ABSTRACT FROM AUTHOR]

A large outbreak of acute muscular sarcocystosis (AMS) among international tourists who visited Tioman Island, Malaysia, is described. Clinicians evaluating travelers returning ill from Malaysia with myalgia, with or without fever, should consider AMS in their differential diagnosis.Background. Through 2 international traveler-focused surveillance networks (GeoSentinel and TropNet), we identified and investigated a large outbreak of acute muscular sarcocystosis (AMS), a rarely reported zoonosis caused by a protozoan parasite of the genus Sarcocystis, associated with travel to Tioman Island, Malaysia, during 2011–2012.Methods. Clinicians reporting patients with suspected AMS to GeoSentinel submitted demographic, clinical, itinerary, and exposure data. We defined a probable case as travel to Tioman Island after 1 March 2011, eosinophilia (>5%), clinical or laboratory-supported myositis, and negative trichinellosis serology. Case confirmation required histologic observation of sarcocysts or isolation of Sarcocystis species DNA from muscle biopsy.Results. Sixty-eight patients met the case definition (62 probable and 6 confirmed). All but 2 resided in Europe; all were tourists and traveled mostly during the summer months. The most frequent symptoms reported were myalgia (100%), fatigue (91%), fever (82%), headache (59%), and arthralgia (29%); onset clustered during 2 distinct periods: “early” during the second and “late” during the sixth week after departure from the island. Blood eosinophilia and elevated serum creatinine phosphokinase (CPK) levels were observed beginning during the fifth week after departure. Sarcocystis nesbitti DNA was recovered from 1 muscle biopsy.Conclusions. Clinicians evaluating travelers returning ill from Malaysia with myalgia, with or without fever, should consider AMS, noting the apparent biphasic aspect of the disease, the later onset of elevated CPK and eosinophilia, and the possibility for relapses. The exact source of infection among travelers to Tioman Island remains unclear but needs to be determined to prevent future illnesses. [ABSTRACT FROM PUBLISHER]

We established a new field clone of Plasmodium falciparum for use in controlled human malaria infections and vaccine studies to complement the current small portfolio of P. falciparum strains, primarily based on NF54. The Cambodian clone NF135.C10 consistently produced gametocytes and generated substantial numbers of sporozoites in Anopheles mosquitoes and diverged from NF54 parasites by genetic markers. In a controlled human malaria infection trial, 3 of 5 volunteers challenged by mosquitoes infected with NF135.C10 and 4 of 5 challenged with NF54 developed parasitemia as detected with microscopy. The 2 strains induced similar clinical signs and symptoms as well as cellular immunological responses.Clinical Trials Registration NCT01002833. [ABSTRACT FROM AUTHOR]

Background Many studies have explored the risk perception of frequent business travelers ( FBT) toward malaria. However, less is known about their knowledge of other infectious diseases. This study aimed to identify knowledge gaps by determining the risk perception of FBT toward 11 infectious diseases. Methods Our retrospective web-based survey assessed the accuracy of risk perception among a defined cohort of FBT for 11 infectious diseases. We used logistic regression and the chi-square test to determine the association of risk perception with source of travel advice, demographic variables, and features of trip preparation. Results Surveys were returned by 63% of the 608 self-registered FBT in Rijswijk, and only the 328 completed questionnaires that adhered to our inclusion criteria were used for analysis. The majority (71%) sought pre-travel health advice and used a company health source (83%). Participants seeking company travel health advice instead of external had significantly more accurate risk knowledge ( p = 0.03), but more frequently overestimated typhoid risk (odds ratio = 2.03; 95% confidence interval = 1.23-3.34). While underestimation of disease risk was on average 23% more common than overestimation, HIV risk was overestimated by 75% of FBT. Conclusions More accurate knowledge among FBT seeking company health advice demonstrates that access to in-company travel clinics can improve risk perception. However, there is an obvious need for risk knowledge improvement, given the overall underestimation of risk. The substantial overestimation of HIV risk is probably due to both public and in-company awareness efforts. Conversely, typhoid risk overestimation was statistically associated with seeking company health advice, and therefore specifically reflects the high focus on typhoid fever within Shell's travel clinic. This study serves as a reminder that a knowledge gap toward infectious diseases besides malaria still exists. Our article will explore the future requirements for more targeted education and research among FBT in companies worldwide. [ABSTRACT FROM AUTHOR]

Background. Despite significant morbidity and mortality among business travelers due to malaria, very little has been published on knowledge, attitudes, and practices (KAP) toward malaria risk. The aim of this study was to assess KAP among frequent international business travelers (FBT) and to identify recommendations for improving malaria prevention that could be applied to the wider FBT community in occupational health. Methods. A retrospective web-based survey was conducted in 2005 among self-registered FBT of an oil and gas company based in the Netherlands. Results. The survey was completed by 328 of the 608 self-registered FBT (54%). Fifty-four percent of respondents had visited a high-risk area for malaria. Most respondents (96%) were experienced travelers; the majority (71%) sought health advice before their trip and made use of a company health resource. Fever was recognized as a malaria symptom by all FBT; travel to high-risk malaria areas was correctly identified by 96%, and 99% of these travelers adhered to use of adequate personal protective measures. The proportion of travelers carrying appropriate anti-malaria drug regimen was positively associated with receiving company advice among FBT traveling to high-risk destinations (RR = 2.10, 95% CI: 1.21-3.67), but not for those traveling to low- or no-risk destinations. Only 8% (14) of those going to a high-risk area were not carrying malaria prophylaxis. One in five of FBT traveling to no-risk areas were unnecessarily carrying malaria prophylaxis. Conclusions. The majority of KAP results were excellent. We postulate that a company culture with a strong focus on health, safety, security, and environment can positively contribute to high KAP scores. Notwithstanding the excellent findings, this study also provides a cautionary tale for company health functions against overprescribing of malaria prophylaxis. It demonstrates the need for constant review and audit of adherence to quality criteria. [ABSTRACT FROM AUTHOR]

Background. KABISA TRAVEL is a clinical decision support system developed by the Institute of Tropical Medicine of Antwerp, Belgium, for the diagnosis of febrile illnesses after a stay in the tropics. This study aimed to compare the diagnostic accuracy of KABISA TRAVEL with that of expert travel physicians. Methods. From December 2007 to April 2009, travelers with fever after a stay in the tropics were included in a multicenter trial conducted in travel referral centers in the Netherlands, Italy, Spain, and Belgium. Physicians were asked (1) to rank their first assessment diagnoses, (2) to enter in KABISA TRAVEL clinical and laboratory data available within 36 hours, and (3) to interact with the tutor until its final diagnostic ranking. Both physicians and KABISA TRAVEL rankings were then compared with the final diagnosis confirmed by reference methods. The clinical utility was also surveyed. Results. A total of 205 cases with confirmed diagnosis were evaluated (male/female ratio: 1.85; mean age: 35 y). Most patients were western travelers or expatriates (60%) and were returning from sub-Saharan Africa (58%). Travel physicians and KABISA TRAVEL ranked the correct diagnosis in the first place for 70 and 72% of the cases, respectively, and within the top five both for 88% of them. Travel physicians reported having been suggested useful further investigations in 16% of the cases, and having been helped for obtaining the diagnosis in 24%. This was reported more frequently when they had initially missed the diagnosis (suggestion: 48% in missed vs 12% in found diagnoses, p < 0.001; helpful: 48% in missed vs 21% in found diagnoses, p = 0.005). Conclusions. KABISA TRAVEL performed as well as expert travel physicians in diagnosing febrile illnesses occurring after a tropical stay. Clinicians perceived the system as more helpful when they had not immediately considered the correct diagnosis. [ABSTRACT FROM AUTHOR]

Summary: In Jakarta, Indonesia, over 80% of patients with typhoid fever or paratyphoid fever are treated in outpatient settings. In a community-based prospective passive surveillance study, we identified 59 typhoid, 23 paratyphoid fever and 259 non-enteric fever outpatients, all blood culture-confirmed. We compared their symptoms with the aim of developing a clinical prediction rule that may help direct empirical antibiotic treatment to cases with suspected (para)typhoid fever, rather than all febrile patients, or refer patients for additional diagnostic tests. Paratyphoid fever (Salmonella paratyphi A) could not be distinguished clinically from typhoid fever. Decisions on empirical antibiotic treatment and advice on hygiene measures in patients with suspected (para)typhoid fever should take into account chills and absence of cough in the first week of fever and delirium in the second week of illness. This prediction rule increases the likelihood of (para)typhoid fever from 1:10 in the first week to, at most, 2:3 in the second week of a febrile illness. However, we were not able to propose a robust clinical prediction rule that could be used as absolute screening method for decisions on additional diagnostic tests, because of the low sensitivity of presenting symptoms in (para)typhoid fever. [Copyright &y& Elsevier]

Yellow fever outbreaks have continued to occur and caused infection and deaths in travelers from non-endemic regions. Yellow fever vaccine has proven effective, but vaccination decisions require balancing benefits with risks. Of concern is the continued vaccine shortage worldwide, including of the YF-VAX® stockout in North America, which has presented many challenges. [ABSTRACT FROM AUTHOR]

Nontyphoid Salmonella (NTS) bacteremia has a very high mortality and recurrence rate among human immunodeficiency virus (HIV)--infected Malawian adults. Concurrent schistosomal infection might cause persistence of NTS infection and poor response to antibiotic therapy. Therefore, we tested serum samples for Schistosoma-specific circulating anodic antigen to diagnose coinfection with schistosomiasis among consecutive HIV-positive adults with NTS bacteremia. The results suggest that active schistosomiasis is not associated with adverse outcome of NTS bacteremia in this population, in contrast to other groups. [ABSTRACT FROM AUTHOR]

Rationale for review: The global yellow fever vaccine supply is insufficient to provide full-dose vaccination to millions threatened by outbreaks. Given the excess of live-attenuated 17D yellow fever virus in the current single dose vials, dose sparing would increase available vaccine doses manifold. Fractional-dose yellow fever vaccination is now accepted as an emergency solution, as short-term protection has been confirmed in an outbreak situation in the Democratic Republic of Congo, but broader application of this dose-sparing strategy is still not recommended. In this review, important knowledge gaps that hamper this application such as long-term protection after fractional-dose vaccination, safety, comparability across different genetic backgrounds and different World Health Organization-licensed yellow fever vaccines and immunogenicity in infants are addressed.Main findings: Recently, published results on long-term protection after fractional-dose vaccination in healthy young volunteers indicate that if a person mounts a protective response shortly after vaccination, the protective response will persist for 10 years and possibly longer. It also appears that fractional-dose vaccination does not elicit more serious adverse events than standard dose vaccination. Short-term immunogenicity studies are currently underway in specific populations (infants, human immunodeficiency virus (HIV)-infected persons and healthy adults living in Uganda and Kenya), of which the results will become available in 2021-22.Conclusions: Available results on long-lasting immunogenicity of fractional-dose yellow fever vaccination are encouraging, although confirmation is required in larger populations including young children living in yellow fever endemic areas. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article which discusses the impact of Ivermectin therapy on the treatment of Strongyloides hyperinfection syndrome.

A letter to the editor in response to the article "Special infectious disease risks of expatriate and long-term travelers in tropical countries, Part I: Malaria," by S. Toovey, F. Moerman and A. van Gompel in the 2007 issue is presented.