Study on rickettsial diseases evidenced by Weil-Felix test among febrile patients visiting a tertiary care hospital in Mymensingh

Background: Rickettsial diseases are neglected, re-emerging vector borne zoonosis & increasingly considered as one of the most important causes of pyrexia of unknown origin (PUO). They are grossly underdiagnosed due to wide range of non-specific symptoms, low index of clinical suspicion, lack of widely available specific diagnostic tools, leading to significant morbidity & mortality. Appropriate diagnosis in early stages is therefore necessary to prevent fatal complications associated with this disease. Objective: Present study was attempted to assess the burden of rickettsial illness by Weil-Felix agglutination test, among the suspected febrile patients, visiting a tertiary care hospital as well as to analyze the demographic profile & clinical manifestations of the seropositive cases. Methods: This was a cross-sectional study, conducted at department of microbiology, Mymensingh Medical College from March 2018 to February 2019. A total of 453 febrile patients of suspected rickettsial illness, irrespective of age and sex, were enrolled in this study. Serum sample from all the enrolled cases were then analyzed for rickettsial antibodies by Weil-Felix slide agglutination test. Results: Out of 453 cases, a total of 260 (57.39%) showed significant agglutination by Weil-Felix test, of which 101 (38.84%) were reactive to OX2 (spotted fever group rickettsiae), 65 (25%) were reactive to OXK (Scrub typhus) & 13 (5%) showed significant titers to OX19 (typhus fever). Remaining 81 (31.15%) sera were reactive to more than one antigens (mixed reactivity). Seropositivity was higher among female subjects (142; 54.61%) & age group >15-30 accounted for highest number of cases (95; 36.53%). Positive cases showed diverse clinical manifestations like headache (55.76%), myalgia (50.76%), skin rash (10.38%), eschar (9.23%), oliguria (7.3%), jaundice (10.76%), splenomegaly (6.81%), hepatomegaly (7.30%) etc. Conclusion: Rickettsial diseases should be considered as an important etiology of PUO & early diagnosis should be done to initiate proper treatment to prevent fatal complications. Though it lacks sensitivity & specificity, in a resource constraint area like Bangladesh, Weil-Felix test still serves as the cheapest initial diagnostic tool for rickettsial illness to guide the physician for further approaches. Mediscope 2021;8(2): 112-121

Patient characteristics, treatment patterns, and outcomes of Rickettsial diseases among a commercially insured population in the United States, 2005–2017

Rickettsial diseases (RDs) are transmitted to humans by ectoparasites, including ticks and fleas. Symptoms range from mild febrile illness, to severe disease or death. Doxycycline is the treatment of choice for patients of all ages; early treatment based on clinical diagnosis is critical to prevent severe outcomes. We conducted a descriptive analysis using insurance claims data captured by IBM MarketScan® research databases to describe demographics, treatment patterns, and outcomes of patients diagnosed with RDs in the United States during 2005–2017. Overall, 14,830 patients had a RD diagnosis during 2005–2017; 7,517 (50.7%) spotted fever rickettsiosis (SFR), 4,571 ( 30.8%) ehrlichiosis, 1,362 (9.2%) typhus group rickettsiosis (TGR), and 1,193 (8.0%) other rickettsial diseases. Among all patients diagnosed, 53.1% received doxycycline. Prescription rates varied by diagnosis and age; 24.1% of TGR and 61.1% of SFR patients received doxycycline; 23.9% of persons < 8 years received doxycycline, compared with 47.7% for 8–17 years, and 55.4% for ≥ 18 years. RDs are frequently diagnosed in the outpatient population; however, providers prescribed the recommended treatment to about half of patients. Continued education of treatment recommendations is critical to prevent severe outcomes.

О находках Rhipicephalus (Boophilus) annulatus (Say, 1821) (Acari, Ixodidae) на западе Атырауской области

Blood-sucking ticks are vectors of protozoal, bacterial, viral and rickettsial diseases. The study of ixodes ticks: fauna, ecology, biology is of great importance not only for epidemiology but is also of scientific interest. Changes in natural and climatic conditions, hydrological regime, rapid development of human economic activities lead to the changes in the fauna of invertebrates including ixodid ticks. As they invade new territories ticks may expand their habitats for these dangerous for animals and humans infections. That is why the study of tick fauna, changes in species diversity of ticks and monitoring of their abundance is so important for monitoring of natural foci. The emergence of a new species of ixodid tick Rhipicephalus annulatus, in western Kazakhstan, which began to be registered from 2019 in Kurmangazy district of Atyrau region, bordering the Astrakhan region of the Russian Federation and its re-finding in 2020 is a very important fact to assess the epidemiological danger for humans and animals in this territory.

Meat Borne Diseases

Red and white meat is a perfect, high-quality protein that comprises all of the nine essential amino acids (EAAs) that cannot be synthesized endogenously. Meat is the normal source of this vitamin, as well as other types of vitamins. Meat affords a range of significant vitamins and minerals that the human body needs, many of which are more bioavailable and easily absorbed than the nutrients found in plant sources. The nutrients in meat support the immune system, participate in the formation of muscle tissue, red blood cells (RBCs), and hormones, and warranty accurate functioning of the nervous system. These nutrients also affect the human senses of smell and taste, benefit our thyroids, and support antioxidant production. The main sources of pathogens in meat and meat products are; the animal itself; human handlers; equipment’s in contact, environmental sources, and water used in the preparation. Meat Borne Diseases, since ancient times, played a central role in public health. This chapter is divided into nine parts, part one to part eight deals with the most important pathogens that have been associated with meat borne diseases (MBDs), these include, Meat Borne Prionic Diseases; Viral Diseases; Bacterial Diseases; Protozoal Diseases; Parasitic Diseases; Fungal Diseases; Mycotoxins; Rickettsial Diseases; while the nine-part deal with the methods of meat preservation and storage.

Leptospirosis and Rickettsial Diseases Sero-Conversion Surveillance Among U.S. Military Personnel in Honduras

ABSTRACT Introduction Leptospirosis and rickettsial diseases are global zoonotic diseases. In severe infection cases, mortality can range from 10% to 30%. Currently most epidemiological data available are based on outbreak investigations and hospital-based studies from endemic countries. The U.S. soldiers at military bases in these countries are highly vulnerable due to the fact that most of them are immunologically naïve to these pathogens. No risk assessment of leptospirosis and rickettsial diseases among U.S. military personnel in Honduras is currently available. This study was aimed at determining the prevalence of leptospirosis and rickettsial diseases in U.S. military personnel deployed to Honduras using serological assays. Materials and Methods A cohort of pre- and post-deployment sera from the most recent 1,000 military personnel stationed in Honduras for at least 6 months between 2000 and 2016 was identified for this study. Serum specimens from these eligible subjects were retrieved. All post-deployment serum specimens were screened at a dilution of 1:100 for the presence of IgG antibodies to Leptospira and Rickettsia pathogens. The pre-deployment sera from those individuals with post-deployment IgG antibodies above cutoff (i.e., seropositive) were tested to determine seroconversion. Seroconversion was defined as conversion of an optical density value from below the cutoff (i.e., negative) in a pre-deployed specimen to above the cutoff (i.e., positive) in a post-deployed specimen at a titer of 100. Results The seropositive post-deployment specimens for antibodies against Leptospira (causing leptospirosis), Rickettsia typhi (causing murine typhus [MT]), spotted fever group rickettsioses (SFGR, causing SFG Rickettsia), Orientia tsutsugamushi (causing scrub typhus [ST]), and Coxiella burnetii (causing Q fever [QF]) were 11.6%, 11.3%, 6%, 5.6%, and 8.0%, respectively. The seroconverted rate in those assigned to Honduras from 2000 to 2016 was 7.3%, 1.9%, 3.9%, 4.3%, and 2.7% for leptospirosis, MT, SFGR, ST, and QF, respectively. Among the seroconverted specimens, 27 showed seroconversion of at least two antibodies. These seroconverted individuals accounted for 8.8% (3 out of 34) of the personnel who looked for medical attention during their deployment. Conclusions Our results suggest a leptospirosis seroconversion rate of 7.3%, which is higher than the 0.9% and 3.9% seroconversion in Korea and Japan, respectively. The higher rate of seroconversion indicates potential risk of Leptospira exposure. Additional testing of water samples in the pools and pits around the training sites to locate the infected areas is important to eliminate or reduce future exposure to Leptospira during trainings. The rates of seroconversion for ST, MT, spotted fever Rickettsia, and QF were 4.3%, 1.9%, 3.9%, and 2.7%, respectively, indicating the potential exposure to a variety of rickettsial-related pathogens. Testing of vectors for rickettsial pathogens in the areas could inform effective vector control countermeasures to prevent exposure. Proper precaution and protective measures are needed to better protect military personnel deployed to Honduras.

Vector-borne haemoparasitic and rickettsial diseases of dogs in South west, Nigeria: An eleven years retrospective study

Adequate knowledge of the occurrence and seasonal variation in the distribution of parasitic and rickettsial diseases affecting dogs is required for formulation of effective disease control measures. Hence, this study assessed the prevalence of vector borne haemoparasites and rickettsial of dogs between 2009 and 2019. Clinical records of dogs presented for clinical examination and confirmed by microscopic screening of their blood were assessed and analysed statistically. Overall, 1483 dogs were presented to the Veterinary Teaching Hospital (VTH). This included 641 (43.2%) male, 842 (56.8%) female, 967 (65.2%) young and 516 (34.8%) adult dogs. 33 (2.2%) and 1450 (97.8%) were mongrel and exotic breeds, respectively. 511 (34.5%) were infected with either haemoparasites or rickettsial. This comprised 34.0% (218/641) and 34.8% (293/842) male and female, 317 (32.8%) and 194 (37.6%) young and adult dogs, respectively. There was no significant (p =0.05) difference in the prevalence among sexes and age groups. Seasonal prevalence was 35.88% (315/878) and 32.40% (196/605) in wet and dry seasons, respectively. Six haemoparasites/rickettsials were reported from 511 dogs, these included single infections of Babesia species 477 (93.5%), Ehrlichia species 8 (1.6%), Hepatozoon canis 2(0.39%), Mycoplasma haemocanis 7 (1.4%), Trypanosoma species 16 (3.1%) and mixed infection of Babesia and Hepatozoon canis 1 (0.2%). The mean PCV values were significantly (t = 2.45; P = 0.014) different between infected and non-infected dogs. This study suggests that Babesia spp. isthe most prevalentin the dogs presented to the VTH in the study area and the detection of Trypanosoma spp. in some dogssuggeststhat dogs could be reservoir of trypanosomesfor both animals and human. Keywords: Dogs, haemoparasites, prevalence, retrospective-study

International Rickettsia Disease Surveillance: An Example of Cooperative Research to Increase Laboratory Capability and Capacity for Risk Assessment of Rickettsial Outbreaks Worldwide

Cooperative research that addresses infectious disease surveillance and outbreak investigations relies heavily on availability and effective use of appropriate diagnostic tools, including serological and molecular assays, as exemplified by the current COVID-19 pandemic. In this paper, we stress the importance of using these assays to support collaborative epidemiological studies to assess risk of rickettsial disease outbreaks among international partner countries. Workforce development, mentorship, and training are important components in building laboratory capability and capacity to assess risk of and mitigate emerging disease outbreaks. International partnerships that fund cooperative research through mentoring and on-the-job training are successful examples for enhancing infectious disease surveillance. Cooperative research studies between the Naval Medical Research Center's Rickettsial Diseases Research Program (RDRP) and 17 institutes from nine countries among five continents were conducted to address the presence of and the risk for endemic rickettsial diseases. To establish serological and molecular assays in the collaborative institutes, initial training and continued material, and technical support were provided by RDRP. The laboratory methods used in the research studies to detect and identify the rickettsial infections included (1) group-specific IgM and IgG serological assays and (2) molecular assays. Twenty-six cooperative research projects performed between 2008 and 2020 enhanced the capability and capacity of 17 research institutes to estimate risk of rickettsial diseases. These international collaborative studies have led to the recognition and/or confirmation of rickettsial diseases within each of the partner countries. In addition, with the identification of specific pathogen and non-pathogen Rickettsia species, a more accurate risk assessment could be made in surveillance studies using environmental samples. The discoveries from these projects reinforced international cooperation benefiting not only the partner countries but also the scientific community at large through presentations (n = 40) at international scientific meetings and peer-reviewed publications (n = 18). The cooperative research studies conducted in multiple international institutes led to the incorporation of new SOPs and trainings for laboratory procedures; biosafety, biosurety, and biosecurity methods; performance of rickettsia-specific assays; and the identification of known and unknown rickettsial agents through the introduction of new serologic and molecular assays that complemented traditional microbiology methods.

Comparison of Immunofluorescence Assays Results for Diagnosis of Rickettsial Diseases Using Direct Serum and Filter Paper Serum Spots

Background: Rickettsial diseases are difficult to diagnose in Bangladesh due to low index of suspicion and lack of diagnostic facilities in most laboratories especially in rural areas. Immunofluorescence assay (IFA) is the gold standard serological test for diagnosis of Rickettsial diseases. For serological diagnosis of rickettsial diseases, use of filter paper is an inexpensive and convenient method for collecting, storing, and transporting of blood samples with little space without refrigeration. Current study shows that the rickettsial diseases were present in febrile patients in Bangladesh. The study also compared the results of direct serum by IFA and filter paper serum spot followed by IFA as an alternative way of testing frozen samples. Materials and Methods: This observational study for evaluation of rickettsial diseases from direct serum by IFA and sera dried on blotting paper followed by IFA at the department of Virology, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh. A total of 152 patients’ sera were selected by systemic random sampling of every 3rd sera of 556 febrile patients who were tested negative for dengue and or Chikungunya virus infection. Forty cases were confirmed by IFA from direct sera. In addition, 60 samples were selected from 152 sera by systemic random sampling of every 3rd sera for blotting on filter paper for further IFA test. Out of 60 sera, 35 were confirmed by IFA from direct sera and of the 35 confirmed positive cases, 31(88.6%) were positive by IFA after blotting paper assay. Taking the IFA of direct sera as gold standard test, the sensitivity, specificity, positive predictive value and negative predictive value of IFA from blotting paper eluted sera were 88%, 100%, 100% and 86% respectively. Conclusion: The study showed the use of filter paper is an inexpensive and convenient method for storing and transporting samples for serological tests like IFA in diagnosis of rickettsial diseases. J Dhaka Medical College, Vol. 28, No.2, October, 2019, Page 153-158