Louseborne Relapsing Fever among East African Refugees, Italy, 2015

Head lice as vectors of pathogenic microorganisms

Body lice and head lice are the most common ectoparasites of humans. Head lice (Pediculus humanus capitis) occur worldwide in children and their caretakers, irrespective of their social status. In contrast, body lice (Pediculus humanus corporis) are confined to marginalized population groups in countries of the Global South, homeless people, and refugees. Body lice are known to transmit an array of bacterial pathogens, such as R. prowazekii, R. rickettsii, C. burneti, B. quintana, B. recurrentis, and Y. pestis. The vector capacity of head lice is still a matter of debate. The objective of the review was to scrutinize the existing evidence on the vector capacity of head lice for the transmission of bacterial pathogens. The PUBMED database was searched using a combination of the terms "pediculus humanus" OR "body lice" OR "head lice" AND "pathogen" OR "Rickettsia prowazekii" OR "Bartonella quintana" OR "Borrelia recurrentis" OR "Coxiella burneti" without a time limit. Data from epidemiological studies as well as historical observations demonstrate that body lice and head lice can carry the same array of pathogens. Since the presence of a bacterial pathogen in an arthropod is not sufficient to state that it can be transmitted to humans, and since experimental models are lacking, as yet one cannot conclude with certainty that head lice serve as vectors, although this review presents circumstantial evidence that they do. Adequately designed experimental and epidemiological studies are needed to ascertain the exact transmission potential of head lice.

Emerging bacterial infectious diseases/pathogens vectored by human lice

Human lice have always been a major public health concern due to their vector capacity for louse-borne infectious diseases, like trench fever, louse-borne relapsing fever, and epidemic fever, which are caused by Bartonella quintana, Borrelia recurrentis, and Rickettsia prowazekii, respectively. Those diseases are currently re-emerging in the regions of poor hygiene, social poverty, or wars with life-threatening consequences. These louse-borne diseases have also caused outbreaks among populations in jails and refugee camps. In addition, antibodies and DNAs to those pathogens have been steadily detected in homeless populations. Importantly, more bacterial pathogens have been detected in human lice, and some have been transmitted by human lice in laboratories. Here, we provide a comprehensive review and update on louse-borne infectious diseases/bacterial pathogens.

Louse-borne relapsing fever-A systematic review and analysis of the literature: Part 2-Mortality, Jarisch-Herxheimer reaction, impact on pregnancy

Louse-borne relapsing fever (LBRF) is a classical epidemic disease, which in the past was associated with war, famine, poverty, forced migration, and crowding under poor hygienic conditions around the world. The disease's causative pathogen, the spirochete bacterium Borrelia recurrentis, is confined to humans and transmitted by a single vector, the human body louse Pediculus humanus corporis. Since the disease was at its peak before the days of modern medicine, many of its aspects have never been formally studied and to date remain incompletely understood. In order to shed light on some of these aspects, we have systematically reviewed the accessible literature on LBRF since the recognition of its mode of transmission in 1907, and summarized the existing data on mortality, Jarisch-Herxheimer reaction (JHR), and impact on pregnancy. Publications were identified by using a predefined search strategy of electronic databases and a subsequent review of the reference lists of the obtained publications. All publications reporting patients with a confirmed diagnosis of LBRF published in English, French, German, and Spanish since 1907 were included. Data extraction followed a predefined protocol and included a grading system to judge the certainty of the diagnosis of reported cases. The high mortality rates often found in literature are confined to extreme scenarios. The case fatality rate (CFR) of untreated cases is on average significantly lower than frequently assumed. In recent years, a rise in the overall CFRs is documented, for which reasons remain unknown. Lacking standardized criteria, a clear diagnostic threshold defining antibiotic treatment-induced JHR does not exist. This explains the wide range of occurrence rates found in literature. Pre-antibiotic era data suggest the existence of a JHR-like reaction also in cases treated with arsenicals and even in untreated cases. LBRF-related adverse outcomes are observed in 3 out of 4 pregnancies.

Louse-borne relapsing fever-A systematic review and analysis of the literature: Part 1-Epidemiology and diagnostic aspects

Louse-borne relapsing fever (LBRF) is a classical epidemic disease, which in the past was associated with war, famine, poverty, forced migration, and crowding under poor hygienic conditions around the world. The disease's causative pathogen, the spirochete bacterium Borrelia recurrentis, is confined to humans and transmitted by a single vector, the human body louse Pediculus humanus. Since the disease has had its heyday before the days of modern medicine, many of its aspects have never been formally studied and to date, remain incompletely understood. In order to shed light on some of these aspects, we have systematically reviewed the accessible literature on LBRF, since the recognition of its mode of transmission in 1907, and summarized the existing data on epidemiology and diagnostic aspects of the disease. Publications were identified by using a predefined search strategy on electronic databases and a subsequent review of the reference lists of the obtained publications. All publications reporting patients with a confirmed diagnosis of LBRF published in English, French, German, and Spanish since 1907 were included. Data extraction followed a predefined protocol and included a grading system to judge the certainty of the diagnosis of reported cases. Historically, Ethiopia is considered a stronghold of LBRF. The recognition of LBRF among East African migrants (originating from Somalia, Eritrea, and Ethiopia) arriving to Europe in the course of the recent migration flow from this region suggests that this epidemiological focus ostensibly persists. Currently, there is neither evidence to support or refute active transmission foci of LBRF elsewhere on the African continent, in Latin America, or in Asia. Microscopy remains the most commonly used method to diagnose LBRF. Data are lacking on sensitivity and specificity of most diagnostic methods.

Infectious and dermatological diseases among arriving migrants on the Italian coasts

Background

Since 2008 Italy has been the destination of the 'central Mediterranean route', used by migrants to reach Europe. The aim of this study is to describe demographic characteristics and health problems of migrants at the time of arrival on the Italian coasts, focussing on dermatological and infectious diseases.

Methods

Cross-sectional study of data routinely collected (n = 6, 188) by the National Institute for Health Migration and Poverty (INMP) in the centres for migrants of Lampedusa and Trapani-Milo (2015-16). Logistic models were performed to identify factors associated with scabies, varicella and the occurrence of two or more not related diagnosis.

Results

The average age was 21.6 years; 83.5% of the patients were males. The most frequent countries of origin were Eritrea, Nigeria, and Somalia. The most frequent diagnosis was scabies (58% of patients), skin infections, pediculosis and dermatitis; respiratory infections and varicella were the most represented infectious diseases. The diagnosis of scabies was more probable among Somalis (OR: 11.60) and Eritreans (OR: 10.05); the diagnosis of varicella was more probable among Ghanaians (OR: 13.58) and Nigerians (OR: 9.79). Somalis (OR: 4.10) and Eritreans (OR: 3.32) were the patients more likely to receive two or more diagnosis.

Conclusions

The majority of the diseases affecting migrants is in most cases, related to the migration experience and is likely not to represent a major threat for public health. Up-to-date information regarding the burden of diseases is needed in order to identify the health needs of incoming migrants and to arrange the appropriate response in terms of health services provision.

Case Report and Genetic Sequence Analysis of Candidatus Borrelia kalaharica, Southern Africa

Tickborne relapsing fever caused by Borrelia species is rarely reported in travelers returning from Africa. We report a case of a 71-year-old woman who sought treatment at University Medical Center in Freiburg, Germany, in 2015 with recurrent fever after traveling to southern Africa. We detected spirochetes in Giemsa-stained blood smears. Treatment with doxycycline for suspected tickborne relapsing fever was successful. Sequence analyses of several loci (16S rRNA, flagellin, uvrA) showed high similarity to the recently described Candidatus Borrelia kalaharica, which was found in a traveler returning from the same region earlier that year. We provide additional information regarding the genetic relationship of Candidatus B. kalaharica. Sequence information for an additional 6 housekeeping genes enables improved comparability to other borrelial species that cause relapsing fever. Our report underlines the importance and possible emergence of the only recently delineated pathogen in southern Africa.

Killing Clothes Lice by Holding Infested Clothes Away from Hosts for 10 Days to Control Louseborne Relapsing Fever, Bahir Dah, Ethiopia

Louseborne relapsing fever (LBRF) was once a cosmopolitan disease, but it now occurs only in the Horn of Africa. Recent cases in refugees to Europe made LBRF topical again. Crowded boarding houses and church dwellings in Ethiopia are analogous to the crowded air-raid shelters of World War II. Thus, we might learn from experiments the London School of Tropical Hygiene and Medicine conducted during World War II. When the vector of Borrelia recurrentis (Pediculus humanus lice) was held away from the host for 10 days, 100% of nymphal and adult lice starved to death and 100% of eggs did not hatch. We hypothesize that holding infested clothes away from hosts in plastic shopping bags will kill enough lice to control LBRF in Ethiopia. Owning 2 sets of clothes might be useful; 1 set might be held in a plastic shopping bag for 10 days to kill lice and their eggs.

[A Somali refugee with fever and abnormal blood smear]

The increasing migration into Europe may confront clinicians with diseases barely known any more in this part of the world. We present a case of louse-borne relapsing fever in a Somali refugee. Blood smears led to the diagnosis of relapsing fever and DNA sequencing was positive for Borrelia recurrentis. This disease should be considered in all patients with unclear fever and a compatible travel or migration history. Blood smears are employed as the primary diagnostic method. Therapy harbors the danger of a Jarisch-Herxheimer reaction, a complication that may require intensive medical care.

Diagnosis of Louse-Borne Relapsing Fever despite Negative Microscopy in Two Asylum Seekers from Eastern Africa

We report two cases of louse-borne relapsing fever observed at our Institution in June 2016. Both patients were young asylum seekers from Africa who had recently arrived in Milan, Italy. Notably, direct microscopic examination of peripheral blood smears was repeatedly negative for the presence of spirochetes and the diagnosis, supported by clinical and epidemiologic evidence, required molecular confirmation by polymerase chain reaction amplification of DNA extracted from blood and sequencing of the amplified products.

First insights in the variability of Borrelia recurrentis genomes

Background

Borrelia recurrentis is the causative agent of louse-borne relapsing fever, endemic to the Horn of Africa. New attention was raised in Europe, with the highest number of cases (n = 45) reported among migrants in 2015 in Germany and sporadically from other European countries. So far only one genome was sequenced, hindering the development of specific molecular diagnostic and typing tools. Here we report on modified culture conditions for B. recurrentis and the intraspecies genome variability of six isolates isolated and cultured in different years in order to explore the possibility to identify new targets for typing and examine the molecular epidemiology of the pathogen.

Methodology/Principal findings

Two historical isolates from Ethiopia and four isolates from migrants from Somalia (n = 3) and Ethiopia (n = 1) obtained in 2015 were cultured in MPK-medium supplemented with 50% foetal calf serum. Whole DNA was sequenced using Illumina MiSeq technology and analysed using the CLC Genomics Workbench and SPAdes de novo assembler. Compared to the reference B. recurrentis A1 29–38 SNPs were identified in the genome distributed on the chromosome and plasmids. In addition to that, plasmids of differing length, compared to the available reference genome were identified.

Conclusions/Significance

The observed low genetic variability of B. recurrentis isolates is possibly due to the adaptation to a very conserved vector-host (louse-human) cycle, or influenced by the fastidious nature of the pathogen and their resistance to in vitro growth. Nevertheless, isolates obtained in 2015 were bearing the same chromosomal SNPs and could be distinguished from the historical isolates by means of whole genome sequencing, but not hitherto used typing methods. This is the first study examining the molecular epidemiology of B. recurrentis and provides the necessary background for the development of better diagnostic tools.

Louse-borne relapsing fever, as the name suggests, is the only relapsing fever transmitted by lice, and caused by the spirochaete Borrelia recurrentis. Today it is endemic to the Horn of Africa, but due to the cosmopolitan nature of the vector, the pathogen still bears epidemic potential to spread globally among vulnerable populations. The most recent account of that has been observed among migrants arriving to Europe in 2015. Up to date, only one strain was sequenced, thus hampering the development of species-specific typing tools. We employed state-of-the-art high-throughput sequencing to six B. recurrentis isolates obtained at different time-points and currently available in culture. Our aim was to address the question of genome variability of this pathogen at the highest resolution and provide information necessary for the development of specific typing tools. B. recurrentis has highly conserved genomes, differing in 29–38 SNPs compared to the reference genome B. recurrentis A1, all identified outside the loci currently developed and used for relapsing fever Borrelia typing. Therefore, applying these typing methods would render them indistinguishable, while at the SNP level we found a distinction between isolates obtained in 2015 from migrants and the two historical isolates. Our data provide first insights in the genome variability and baseline information necessary for further studies of the molecular epidemiology of the pathogen and for the development of improved diagnostic tools.

Louse-borne relapsing fever in a refugee from Mali

INTRODUCTION

Due to the increasing number of refugees from East Africa, louse-borne relapsing fever (LBRF) has become an emergent disease in Europe. No single case of LBRF has been reported in Europe in refugees from other parts of Africa.

CASE REPORT

We report a case of LBRF in a refugee from Mali, likely acquired in Libya, where several migration routes into Europe meet. The disease must be considered in any febrile refugee regardless the country of origin.

Louse-borne relapsing fever in Finland in two asylum seekers from Somalia

We report two cases of louse-borne relapsing fever (LBRF) in young Somali asylum seekers having recently arrived to Finland. They had sought medical attention for a febrile illness. Blood smears were examined for suspected malaria, but instead, spirochete shaped bacteria were observed. The bacteria were confirmed as Borrelia recurrentis by PCR and sequencing. The patients survived, but their treatment was complicated by Jarisch-Herxheimer reaction. We conclude that LBRF must be considered as a diagnostic option in febrile refugees also in the northernmost parts of Europe.

Relapsing fever in asylum seekers from Somalia arriving in Belgium in August 2015

Current population displacements favor the re-emerging of diseases, nowadays very rare in Europe. We report two cases of 'imported' relapsing fever in two Somali asylum seekers occurring shortly after their arrival in Belgium. A diagnosis of relapsing fever should be considered in all migrants coming from endemic regions or having traveled in low hygiene and crowded conditions, presenting with recurrent fever, especially if no malaria parasites are found.

Fourth case of louse-borne relapsing fever in Young Migrant, Sicily, Italy, December 2015. Mini Review Article

OBJECTIVES

Currently louse-borne relapsing fever (LBRF) is primarily found in limited endemic foci in Ethiopia, Somalia and Sudan; no case of imported LBRF has been reported in Europe in the 9 years prior to 2015. The aim of our paper is to describe a new case of imported LBRF detected in Sicily, Italy, and to review all cases reported in migrants arrived in Europe in the last 10 years.

STUDY DESIGN

Mini review of all published cases of louse-borne relapsing fever in Europe in the last 10 years.

METHODS

A computerized search without language restriction was conducted using PubMed combining the terms '(louse-borne relapsing fever or LBRF or recurrentis) and (refugee or Europe or migrant)' without limits. Furthermore, the 'Ahead-of-Print Articles' of the top 10 journals (ranked by Impact factor - Web of Science) of Infectious diseases and of Epidemiology were checked.

RESULTS

Our search identified 26 cases of LBRF between July and October 2015 in migrants recently arrived in Europe: 8 had been described in Italy; 1 in Switzerland; 2 in the Netherlands; 15 in Germany. We describe data regarding the clinical characteristics, diagnostic methods, therapy and outcome of these patients and of the new case.

CONCLUSIONS

LBRF by Borrelia recurrentis should be considered among the clinical hypotheses in migrants presenting with fever, headache, chills, sweating, arthralgia, myalgia, dizziness, nausea and vomiting.

Louse-borne relapsing fever - report of four cases in Switzerland, June-December 2015

Background

Louse-borne relapsing fever (LBRF) is a neglected disease that has been restricted to East Africa for many decades. Several cases in refugees from the Horn of Africa have been recently diagnosed in four European countries.

Case presentation

We report four additional cases of LBRF in asylum seekers from Somalia and Eritrea who presented with fever shortly after arriving in Switzerland during a seven-month period. Multiple spirochetes were visualized on stained blood films which were identified as Borrelia recurrentis by 16S rRNA gene sequencing. All patients recovered after antibiotic treatment with ceftriaxone and/or doxycycline. Concurrent infections (malaria and tuberculosis) were diagnosed in half of our patients. Possible modes of transmission and preventive measures are discussed.

Conclusions

These reported cases highlight the ongoing transmission of LBRF in migrants from East Africa. Diagnosis of LBRF cases and prevention of autochthonous transmission in asylum seeker camps are important steps for the near future.

Measles outbreak in a refugee settlement in Calais, France: January to February 2016

We report a measles outbreak in a refugee settlement in Calais, France, between 5 January and 11 February 2016. In total, 13 confirmed measles cases were identified among migrants, healthcare workers in hospital and volunteers working on site. A large scale vaccination campaign was carried out in the settlement within two weeks of outbreak notification. In total, 60% of the estimated target population of 3,500 refugees was vaccinated during the week-long campaign.

Louse-Borne Relapsing Fever with Meningeal Involvement in an Immigrant from Somalia to Italy, October 2015

INTRODUCTION

Borrelia recurrentis, transmitted by Pediculus humanus humanus, is the etiological agent of louse-borne relapsing fever (LBRF). Currently the main focus of endemicity of LBRF is localized in East African countries. From July 2015 to October 2015, 36 cases of LBRF have been diagnosed in Europe in immigrants from the Horn of Africa. Here we report a case of LBRF with meningitis diagnosed in Florence, Italy, in an immigrant arrived from Somalia.

CASE STUDY

In October 2015, a 19-year-old Somali male presented to the emergency department of the Azienda Ospedaliero Universitaria Careggi, Florence, Italy, with a 3-day history of high fever. The patient had disembarked in Sicily 10 days before admission after a long migration trip from his country of origin. On clinical examination, neck stiffness was found. Main laboratory findings were thrombocytopenia, increased procalcitonin, and increased polymorphonucleates in the cerebrospinal fluid. Suspecting a possible meningitis, the patient was treated with ceftriaxone, pending results of laboratory testing for malaria, and developed severe hypotension that was treated with fluid resuscitation and hydrocortisone. Hemoscopic testing revealed the presence of spirochetes and no malaria parasites. The patient rapidly improved with doxycycline for 7 days and ceftriaxone for 11 days, then was lost to follow-up. Total DNA from blood was extracted, and amplification and sequencing with universal 16S rDNA primers D88 and E94 revealed a 100% identity with B. recurrentis A1.

CONCLUSIONS

LBRF is a rare but emerging infectious disease among vulnerable displaced immigrants from the Horn of Africa. Since immigrants from endemic areas can carry the vector with them, the infection should be suspected even in subjects with compatible clinical features living in the same place where new arrival immigrants are hosted. Healthcare providers should be aware of this condition to implement adequate diagnostic, therapeutic, and public health measures.

Louse-borne relapsing fever among East African refugees in Europe

Louse-borne relapsing fever a neglected and forgotten disease by western physicians has recently re-emerged among East African migrants seeking asylum in Europe. We review here the cases observed so far together with a critical reappraisal of several issues regarding clinical presentation, diagnosis and treatment.