Travel Medicine and Infectious Disease最新文献

We describe the evolution of the outbreak of Highly Pathogenic Avian Influenza (HPAI) A(H5N1) in sea lions (Otaria flavescens) of South America. At least 24,000 sea lions died in Peru, Chile, Argentina, Uruguay, and Brazil between January–October 2023. The most plausible route of infection is cohabiting with or foraging on infected birds. However, we urge a detailed evaluation of the sea lions actual source of infection given that the concomitant massive wild bird mortalities registered in the Pacific Ocean did not occur in the Atlantic Ocean.

Introduction

Approximately 10–40 million travelers get Traveler's Diarrhea (TD) yearly. A significant decrease in TD incidence has not been achieved by depending solely on antibiotic prophylaxis and educational initiatives. Using prebiotics to prevent TD has also not been examined in previous evaluations of probiotics for TD, which failed to consider the strain-specificity of probiotic efficacy. This review investigates the overall effects of probiotics on preventing TD, including the impact of dosage, duration, and age.

Methods

Standard literature databases were searched without restriction on publication year or language. The following criteria are included: randomized controlled trials (RCTs) in English or non-English unrestricted to publication year, excluding animal and observational studies. This systematic review applied the Preferred Reporting Items for Systematic Reviews and Meta-Analyses.

Results

Of the 166 screened papers, 10 RCTs were included. Lactobacillus acidophilus showed no efficacy in preventing TD except when mixed with other strains. Other genera of lactobacilli showed a protection rate of up to 39% against TD. Similarly, Saccharomyces cerevisiae and Saccharomyces boulardii have been effective in preventing TD.

Conclusion

Studies investigating probiotics as a preventive measure for TD remain limited. Only a few probiotics that reduce TD risk exist. Based on this systematic review and meta-analysis, specific probiotic strains, including L. acidophilus, L. rhamnosus, L. fermentum, S. cerevisiae, and S. boulardii, may prevent TD. The effect of additional probiotic strains on TD prevention must be further investigated.

Dengue virus (DENV) is one of the most significant vector-borne pathogens worldwide. In this report, we describe clinical features and laboratory detection of dengue in a 45-year-old traveler to Nicaragua on return home to the United States in 2019. Clinical presentation was mild, with rash, headache, and fatigue, with only low-grade transient fever. Infection dynamics were documented by serology and PCR of serially collected body fluids. DENV serotype 2 was detected in whole blood 1 day after symptoms emerged, with viral RNA isolated to the red cell fraction, and remained detectable through day 89. DENV-2 RNA was detected in serum only on day 4, and IgM was undetectable on day 4 but evident by day 13. Viral RNA was also detected in urine. This report of DENV-2 RNA persistence in blood cells but only transient appearance in serum, supports the potential diagnostic value of whole blood over serum for PCR and opportunity of an expanded testing window. Informed testing approaches can improve diagnostic accuracy and inform strategies that preserve individual and public health.

Background

The 2022–2023 period marked the largest global Mpox outbreak, with Latin America's situation notably underexplored. This study aims to estimate Mpox's instantaneous reproduction number (R(t)), analyze epidemiological trends, and map vaccination efforts in six Latin American countries.

Methods

Utilizing Pan American Health Organization Mpox surveillance data, we examined demographic characteristics, cumulative incidence rates, and epidemic curves, calculated R(t) with weekly sliding windows for each country, alongside a review of vaccination initiatives.

Results

From 2022 to 2023, 25,503 Mpox cases and 71 deaths were reported across Argentina, Brazil, Chile, Colombia, Mexico and Peru, with a significant majority (91.8%–98.5%) affecting men, with a mean age of 32–35 years. Maximum R(t) values varied across countries: Argentina (2.63; 0.85 to 5.39), Brazil (3.13; 2.61 to 3.69), Chile (2.91; 1.55 to 4.70), Colombia (3.15; 2.07 to 4.44), Mexico (2.28; 1.18 to 3.75), and Peru (2.84; 2.33 to 3.40). The epidemic's peak occurred between August and September 2022 with R(t) values subsequently dropping below 1. From November 2022, and as of February 2024, only Chile, Peru, and Brazil had initiated Mpox vaccination campaigns, with Colombia launching a Clinical Trial.

Conclusion

The peak of the Mpox epidemic in the studied countries occurred before the commencement of vaccination programs. This trend may be then partly attributed to a combination of behavioral modifications in key affected communities and contact tracing local programs. Therefore, the proportion of the at-risk population that remains susceptible is still uncertain, highlighting the need for continued surveillance and evaluation of vaccination strategies.

Background

Rabies remains a deadly zoonotic disease, primarily prevalent in Eastern European countries, with a significant global burden in Asia and Africa. Post-exposure prophylaxis (PEP) is critical to prevent clinical rabies. Serbia, a country with a relatively low animal rabies incidence, has been implementing a 4-dose Essen PEP regimen for 13 years. This real-world study aimed to assess the effectiveness of the 4-dose Essen regimen, considering demographic and clinical factors, after WHO Category III exposure.

Method

The study included 601 patients who received the 4-dose Essen PEP and 79 who received an additional 5th dose.

Results

Age emerged as a critical factor influencing seroconversion rates after the 4-dose regimen, with older individuals exhibiting lower RVNA titers. Logistic regression indicated a 3.18% decrease in seroconversion odds for each added year of age. The Cox proportional hazards mixed model highlighted age-related risks, with age groups 45–60 and 75–92 at the highest risk of non-seroconversion. Human Rabies Immune Globulin (HRIG) administration was associated with lower RVNA values after the 4-dose regimen, suggesting interference with vaccine immunogenicity among people who received larger doses of HRIG.

Conclusions

This study provides valuable real-world evidence for rabies PEP in a non-homogeneous population with potential comorbidities. The results underscore the importance of optimizing PEP strategies, particularly in older individuals, and reconsidering HRIG dosing to improve seroconversion rates.

Subject

Rickettsia is a zoonotic bacterial pathogen transmitted by vectors and has extensive reservoirs in animal and human populations. Rickettsiosis is a public health problem all over the world. However, comprehensive information on the geographical distribution of different Rickettsia species, infection status of reservoirs, vectors, and human cases is lacking in most parts of the world. Therefore, this study aimed to investigate the geographical distribution of different Rickettsia species and their vectors in countries of the WHO-EMRO region.

Methods

In this review study, a search was conducted for reports and published studies on Rickettsia species from WHO-EMRO region countries in various databases from 1995 to 2022. Finally, the reported status of human cases, reservoirs, and vectors associated with each species in different countries was documented.

Results

Reports of infections related to the detection of Rickettsia species were only available for 15 out of 22 WHO-EMRO member countries. A total of twenty-four Rickettsia species, including R. sibrica, R. lusitaniae, R. africae, R. prowazekii, R. felis, R. typhi, R. rickettsii, R. aeschlimannii, R. conorii, R. massiliae, R. helvetica, R. monacensis, R. rhipicephali, R. bellii, R. asembonensis, R. hoogstraalii, R. andeanae, R. raoultii, R. asiatica, R. slovaca, R. australis, R. barbariae, Candidatus R. amblyommii, and Candidatus R. goldwasserii, were reported from WHO-EMRO member countries. Furthermore, human cases infected with six different Rickettsia species, including R. sibrica, R. prowazekii, R. felis, R. typhi, R. rickettsii, R. aeschlimannii, R. conorii, R. massiliae, and R. helvetica, were reported from these countries.

Conclusion

The vast diversity of Rickettsia vectors has contributed to the ongoing discovery of new Rickettsia species. Therefore, further research on the reservoir hosts of Rickettsia infections in the understudied WHO-EMRO region is crucial. This research sheds light on Rickettsia disease's epidemiology and transmission dynamics in this region.

Background

Tick-borne diseases (TBD) are considered neglected diseases in Thailand with disease burden likely underestimated. To assess risk for emerging TBD in Thailand, the seasonality of questing tick and pathogen prevalence were studied in Khao Yai National Park, a top tourist destination.

Methods

During 2019, questing ticks around tourist attractions were systematically collected bimonthly and analyzed for Rickettsia and Anaplasmataceae bacterial species by polymerase chain reaction and DNA sequencing.

Results

Larvae and nymphs of questing ticks peaked in Khao Yai National Park during the late rainy-winter season, though no specific trends were observed in adult ticks. Winter (November to February) was the highest risk for human tick-bites due to higher numbers of both ticks and visitors. Of the total 5916 ticks analyzed (651 pools), Anaplasma phagocytophilum, Neoehrlichia mikurensis, Ehrlichia ewingii, and Ehrlichia chaffeensis were detected at low rates (≤0.05%). There was a higher prevalence of human rickettsioses (0.2–7%) in ticks surveyed with Rickettsia tamurae, Rickettsia raoultii, and Rickettsia montana the major species. Amblyomma ticks had the highest prevalence of Rickettsia (85%, 35/44 Amblyomma adults), in which only R. tamurae and R. raoultii were found in Amblyomma with mixed species infections common. We report the first detection of R. africae-like and N. mikurensis in Ixodes granulatus adults in Thailand, suggesting I. granulatus as a potential vector for these pathogens.

Conclusion

This study demonstrated the risk of emerging TBD in Thailand and underscores the need for tick-bite prevention among tourists in Thailand.

Background

COVID-19 pandemic challenged the UNAIDS 90-90-90 targets. How the COVID-19 pandemic affected HIV retention in care and whether it has disproportionally affected migrant people with HIV (PWH) remained to be investigated.

Methods

PWH in ICONA Cohort in follow-up in each of the study periods were included: 01/09/2019-29/02/2020 (pandemic period) and 01/03/2018-31/08/2018 (historical period, as a control). Risk of temporary loss to follow-up (LTFU, defined as no data recorded for a person for one year) was analyzed by logistic regression, with migrant status as the main exposure variable. Difference in difference (DID) analysis was applied to evaluate the effect of COVID-19 pandemic in the different risk of LTFU between natives and migrants.

Results

8864 (17.1% migrants) and 8071 (16.8% migrants) PWH constituted the pandemic and the historical period population, respectively.

Proportion of PWH defined as LTFU in the pandemic period was 10.5% in native and 19.6% in migrant PWH.

After controlling for age, sex and geographical location of enrolling site, risk of temporary LTFU was higher for migrants than native PWH [adjusted odds ratio 1.85 (95%CI 1.54–2.22)] in pandemic period. In PWH contributing to both periods, LTFU was 9.0% (95% CI 8.3–9.8) in natives vs 17.0% (95% CI 14.7–19.4) in migrants during the pandemic. Instead, LTFU was 1.2% (95%CI 0.9, 1.5) in natives vs 2.2% (95% CI 1.3–3.1) in migrants during the historical period, with a resulting DID of 7.0% (95% CI 4.4–9.6).

Conclusions

A greater proportion of LTFU in migrant PWH was observed in both periods, which remained unaltered over time. Interventions to reduce LTFU of migrants are necessary.