Short report: Detection of borrelia (relapsing fever) in rural Ethiopia by means of the quantitative buffy coat technique

Epistaxis and thrombocytopenia as major presentations of louse borne relapsing fever: Hospital-based study

BACKGROUND

Louse-borne relapsing fever (LBRF) remains a cause of sporadic illness and occasional outbreaks in Ethiopia and other east African countries in overcrowded and unhygienic settings. In this article, we present clinical profiles and treatment outcome of patients treated as confirmed or probable cases of LBRF at Jimma Medical Center (JMC) in southwest Ethiopia.

METHODS

Patients treated as confirmed or probable cases of LBRF at JMC during a period of May-July 2022 were prospectively followed during their course of hospital stay. All patients were evaluated with blood film for hemoparasites, complete blood count, and liver enzymes on hospital presentation. They were followed with daily clinical evaluation during their hospital stay.

RESULT

Thirty-six patients were treated as cases of LBRF. All patients except one were from Jimma Main Prison in Jimma Town, Ethiopia. All the patients were male with mean age of 28.7 years (SD = 12.7). The diagnosis of LBRF was confirmed by detection of B. recurrentis in blood film of 14 (38.9%) of the patients; the rest were treated as presumptive case of LBRF. Fever, reported by all patients, and an acute onset epistaxis, 30 (83.3%), were the major reasons for healthcare visits. Twenty-two (61.1%) patients were having thrombocytopenia with a platelet count < 150,000/μL; nine (25%) of which had severe forms (<50,000/μL). All patients were treated with oral doxycycline and discharged with improvement after a mean length of hospital stay of 4.25 days (SD = 0.77), range 2-6 days. Public health emergency was activated within two days of the first cases and helped in delousing all the cases and their contacts.

CONCLUSION

LBRF remains a public health problem in Ethiopia in settings with poor personal hygiene. Patients with LBRF may present with severe thrombocytopenia and life-threatening bleeding. Early detection and treatment initiation prevents outbreak propagation and improves treatment outcome.

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.

Relapsing Fever: Diagnosis Thanks to a Vigilant Hematology Laboratory

Three cases of relapsing fever from southern Israel were diagnosed promptly thanks to vigilance of the hematology laboratory technicians. In this region of Israel, patients presenting with prolonged fever and leukopenia without localizing symptoms are generally suspected of having brucellosis or a rickettsial disease. Pediatric patients with prolonged fever, cytopenias, and negative aforementioned serologies are often hospitalized for further work-up. Because of the policy of performing a manual blood smear when results of the automated blood count demonstrate severe anemia and abnormal platelet and/or white blood cell counts, a diagnosis of tick-borne relapsing fever was confirmed and promptly relayed to the physician. This routine prevented unnecessary examinations and hospitalization days and provided important information to regional epidemiology and public health authorities.

Relapsing fever borreliae in Africa

The study of relapsing fever borreliae in Africa has long suffered from the use of non-specific laboratory tools for the direct detection of these spirochetes in clinical and vector specimens. Accordingly, Borrelia hispanica, Borrelia crocidurae, Borrelia duttonii, and Borrelia recurrentis have traditionally been distinguished on the basis of geography and vector and the unproven hypothesis that each species was exclusive to one vector. The recent sequencing of three relapsing fever Borrelia genomes in our laboratory prompted the development of more specific tools and a reappraisal of the epidemiology in Africa. Five additional potential species still need to be cultured from clinical and vector sources in East Africa to further assess their uniqueness. Here, we review the molecular evidence of relapsing fever borreliae in hosts and ectoparasites in Africa and explore the diversity, geographical distribution, and vector association of these pathogens for Africans and travelers to Africa.

Multiplex 5' nuclease-quantitative PCR for diagnosis of relapsing fever in a large Tanzanian cohort

Relapsing fever (RF) is caused by tick- and louse-borne Borrelia spp., is characterized by recurrent fever, and is often misdiagnosed as malaria. Because of submicroscopic bacteremia, microscopy can be insensitive between febrile bouts. We designed a multiplex quantitative PCR (qPCR) assay to distinguish RF Borrelia from Plasmodium falciparum and P. vivax. The assay specifically (100%) amplified pathogenic RF Borrelia (1 copy/reaction). We then tested blood from participants within a Tanzanian cohort assessed at scheduled intervals and with fever. Among 8,617 blood samples from 2,057 participants surveyed routinely, 7 (0.08%) samples and 7 (0.3%) participants had RF DNA (median, 4.4 × 10(3) copies/ml). Of 382 samples from 310 febrile persons, 15 (3.9%) samples from 13 (4.2%) participants had RF DNA (median, 7.9 × 10(2) copies/ml). Five (1.3%) samples from 4 (1.3%) participants were found to harbor Borrelia by microscopy. We conclude that multiplex qPCR holds promise for improved clinical diagnosis and epidemiologic assessment of RF.

Current issues in relapsing fever

PURPOSE OF REVIEW

Relapsing fever has the highest incidence of any bacterial disease in Africa and a massive epidemic potential due to current political turmoil in the Horn of Africa. This review focuses on recent advances in diagnostics, molecular biology and host-pathogen interactions.

RECENT FINDINGS

Complete relapsing fever genomes have recently been published, and the first site-specific genetic knockout complementation has been performed. Relapsing fever has gone from being a neglected disease to garnering interest in aspects such as tissue invasion, membrane biochemistry and complement evasion. Relapsing fever symptoms are variable, and the disease is commonly misdiagnosed as, for example, malaria. Although relapsing fever is considered a transient disease, it persists as a residual infection in the brain, which can be reactivated on immunosuppression. Therefore, single-dose antibiotic treatment should be avoided. Instead, treatment should cover a longer period, similar to the recommended regime for Lyme disease. Relapsing fever is a common cause of pregnancy complications such as intrauterine growth retardation and placental damage with spirochaetes crossing the maternal-foetal barrier, resulting in congenital infection.

SUMMARY

Although relapsing fever remains a big problem, recently described host-pathogen interactions, diagnostics and molecular biology advances such as completed genome sequences and the dawn of genetic tools have brought relapsing fever research into the 21st century.

A novel and simple method for laboratory diagnosis of relapsing Fever borreliosis

Relapsing fever caused by Borrelia bacteria is often obscured by malaria and incorrectly treated. Here a novel method for diagnosis is presented. The method is cheap, simple and requires minimal laboratory material. Despite its simplicity, the method shows surprisingly high sensitivity, detecting concentrations less than 10 bacteria/ml blood.

Borreliosis: a rare and alternative diagnosis in travellers' febrile illness

We report a case of borreliosis mimicking uncomplicated malaria in a patient returning from Mali. Identification of spirochetes through examination of a thick blood smear completed by an acridine-orange quantitative buffy coat allowed the diagnosis of borreliosis. All symptoms rapidly resolved following tetracycline therapy. Epidemiological and clinical features of borreliosis, diagnostic tools and management are discussed.

Detection of relapsing fever in human blood samples from Israel using PCR targeting the glycerophosphodiester phosphodiesterase (GlpQ) gene

Relapsing fever caused by Borrelia persica is an acute tick-borne disease infecting people in the Middle East. A PCR test targeting the glycerophosphodiester phosphodiesterase (GlpQ) gene was used to detect infection in the blood of suspected relapsing fever patients. The assay detected infection in all 19 patients from Israel who were spirochetemic by blood smear examination and in two additional patients with clinical relapsing fever who were negative by smear examination. Patients were positive by PCR of blood only at the febrile stage and not during the incubation period prior to the appearance of clinical symptoms. Of 52 tick-bitten subjects who were tested and followed-up after being bitten by ticks, 10 developed symptoms of relapsing fever and all became positive by PCR following an earlier negative test. Partial sequencing of the 16S rRNA gene supported by phylogenetic analysis indicated that infection was caused by B. persica or a closely related species. A phylogenetic analysis of the GlpQ sequence showed that it was different yet closely related to other relapsing fever Borrelia spp. present in the Old World. The GlpQ PCR was positive also with the relapsing fever spirochetes B. recurrentis and B. crocidure but not with the Lyme disease agent B. burgdorferi DNA. A second modified GlpQ PCR was able to discriminate between probable B. persica and B. recurrentis and B. crocidurae infection. This study describes the first molecular assay for the diagnosis of relapsing fever caused by B. persica.