Rickettsial illnesses, a leading cause of acute febrile illness

Etiologies of Zoonotic Tropical Febrile Illnesses That Are Not Part of the Notifiable Diseases in Colombia

In Colombia, tropical febrile illnesses represent one of the most important causes of clinical attention. Febrile illnesses in the tropics are mainly zoonotic and have a broad etiology. The Colombian surveillance system monitors some notifiable diseases. However, several etiologies are not monitored by this system. In the present review, we describe eleven different etiologies of zoonotic tropical febrile illnesses that are not monitored by the Colombian surveillance system but have scientific, historical, and contemporary data that confirm or suggest their presence in different regions of the country: Anaplasma, Arenavirus, Bartonella, relapsing fever group Borrelia, Coxiella burnetii, Ehrlichia, Hantavirus, Mayaro virus, Orientia, Oropouche virus, and Rickettsia. These could generate a risk for the local population, travelers, and immigrants, due to which they should be included in the mandatory notification system, considering their importance for Colombian public health.

Detection of Rickettsia amblyommatis and Rickettsia bellii in ticks collected from pet dogs in peri-urban and rural areas in Yucatan, Mexico

Rickettsia species are bacteria that may cause multiple diseases in animals and humans, via transmission through multiple arthropod vectors. Routine surveillance of Rickettsia spp. within vectors is critical to determine their presence and risk to mammalian hosts within human populations. Therefore, to better characterize the circulating Rickettsia species in an understudied region we targeted pet dogs to survey. Ticks were collected from pet dogs in three populations of the Yucatan where we tested for the presence of Rickettsia spp. by PCR in metagenomic DNA. In these ticks removed from pet dogs we detected Rickettsia amblyommatis and Rickettsia bellii in Amblyomma auriculatum, Amblyomma ovale and Amblyomma mixtum ticks obtained in a rural community in the Mexican state of Yucatan. This is the first report detecting both species for this state in Mexico, underpinning the importance of more routine surveillance.

INDIAN TICK TYPHUS PRESENTING AS GANGRENE: A CASE REPORT

Rickettsial infections are an important cause of acute febrile illness in developing countries. They can rarely present with cutaneous manifestations such as gangrene. Here we report a 12-year-old boy who presented with acute undifferentiated fever, multiorgan dysfunction, and gangrene of bilateral toes and ear lobes. The diagnosis was made by serologic testing of paired sera and clinical recovery occurred with doxycycline.

The diagnosis and treatment of scrub typhus should be emphasized in non-endemic areas: A retrospective case series study

The morbidity of tsutsugamushi is increasing and is no longer limited to endemic areas. Delayed diagnosis and inappropriate treatment can cause severe complications and increase mortality rates. We conducted a retrospective case series of patients with scrub typhus at our institution to report our experience and discuss the diagnostic modalities. We encountered 21 cases of scrub typhus at our institution between 2014 and 2022. The average age of the patients was 52 years (range: 22-63 years), 11 (52%) were farmers, and 11 (52%) had clear outdoor activities. Twenty (95%) patients had an ineffective history of general antibiotic treatment. The classic presentation was repeated fever in 95% of patients. Seventeen patients (81%) had eschar mainly on the groin (35%) and armpit (35%). Common laboratory findings included eosinophilia (95%), elevated alanine aminotransferase (95%), elevated aspartate aminotransferase (86%), thrombocytopenia (76%), lower hemoglobin (71%), and neutrophilia (38%). Six (29%) patients received the treatment of tigecycline, 4 (19%) patients received the treatment of doxycycline, and 11 (52%) patients received the treatment of minocycline. After 3 days of specific treatment, the eosinophilic levels showed a recovery trend. Twenty (95%) patients fully recovered, and 1 (5%) died. Careful physical examination and medical history are important for the early diagnosis of scrub typhus; clinicians in non-endemic areas need to strengthen their understanding of scrub typhus.

Emerging tick-borne spotted fever group rickettsioses in the Balkans

The impact of tick-borne pathogens (TBPs) on human health has increased in the last decades, since the incidence of emerging and re-emerging infectious and zoonotic tick-borne diseases has increased worldwide. Tick-borne rickettsiae of the Spotted Fever group (SFGR) are considered as emerging pathogens that can infect humans and cause a variety of non-specific clinical symptoms. Here, we report nine cases of atypical tick-borne diseases (9/460; 1.95%) that occurred over a period of four months (from 15 April 2021 to 16 August 2021) in Serbia, from which five cases were classified as confirmed SFGR infection, two cases as probable SFGR infection and two cases as suspected SFGR infection. Within cases of confirmed SFGR infection, R. helvetica was detected as the causative agent in two cases. The most common clinical finding was non-expanding persistent circular redness, followed by eschar and enlargement of regional lymph nodes, and pain at lesion site. Rickettsia outer membrane protein B (ompB) and citrate synthase (gltA) gene fragments were amplified from clinical samples and ticks attached to patients and IgG reacting with Rickettsia conorii antigen were detected in sera samples of patients, which are highly suggestive of exposure to SFGR. Surveillance and monitoring of rickettsial diseases in Serbia should continue and extended to new areas due to the increasing trend of clinical infections caused by SFGR in the country.