Laboratory Diagnosis and Genotype Identification of Scrub Typhus from Pinggu District, Beijing, 2008 and 2010

Abstract

Abstract. This study was conducted to determine the diagnosis and genotype of Orientia tsutsugamushi in Pinggu district, Beijing. Indirect immunofluorescence assay (IFA) was performed to detect O. tsutsugamushi-specific immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies. Nested polymerase chain reaction (PCR) and DNA sequencing analysis targeting the O. tsutsugamushi-specific groEL gene and 56 kDa protein gene were performed on whole-blood samples from scrub typhus patients. We confirmed that 47 patients were infected with scrub typhus in Pinggu district, Beijing. Representative sequences amplified by primers according to the groEL gene (BJ-PG-2008; GenBank accession No. JQ894502) and the 56 kDa protein gene (PG-56kDa; GenBank accession No. JX843795) both clustered with Kawasaki. PG-56kDa had sequence homology of 100% with TADY12-0308, shandong-XDM2, Neimeng-90, and sdu-1 and sequence homology of 96% with Kawasaki, Taguchi, Oishi, and Kanda. We confirmed the genotype of O. tsutsugamushi in Pinggu district, Beijing, as Kawasaki, and the patient in 2008 confirmed in this study was the first patient with confirmed scrub typhus in Beijing. INTRODUCTIONScrub typhus, also known as tsutsugamushi disease, is an acute, febrile illness that is caused by Orientia tsutsugamushi, which is an obligate intracellular bacterium that belongs to the family Rickettsiaceae in the order Rickettsiales. It is a zoonosis transmitted by infected larval trombiculid mites, and it is widespread in the Asia-Pacific region, including Afghanistan, China, Korea, the islands of the southwestern Pacific, and northern Australia.1 The clinical manifestations of this disease range from mild disease with symptoms of fever, rash, eschar, and lymphadenopathy to fatal disease.2 The disease can be treated effectively with doxycycline, azithromycin, or chloramphenicol.

A review of the global epidemiology of scrub typhus

“…An eschar is not observed in every confirmed patient, and cutaneous lesions from other diseases, e.g., spider bites, leishmaniasis, spotted fever rickettsiosis and anthrax, may make the presence of an eschar less than a definitive diagnostic sign. Scrub typhus can be misdiagnosed as many acute febrile illnesses, including malaria, dengue, leptospirosis, other rickettsioses, meningococcal disease, typhoid fever, infectious mononucleosis and HIV [ 6 , 198 , 199 ].…”

Uptake of Modern Contraceptive Methods among Burundian Women and Associated Factors: Analysis of Demographic and Health Survey Data, Burundi 2016–2017

“… 16 However, recent studies have shown that DM prevalence among TB cases is variable and it ranges from 29.3% in Southern Mexico to 11.4% in Georgia USA 17 , 18 Studies conducted in Africa reported low prevalence of DM among TB patients; 8.5% in Uganda, 8.3% in Ethiopia, 2.8% in Guinea-Bissau and 1.9% in Benin. 13 , 19 – 21 Some studies have shown high prevalence of DM among TB patients; 29.5% in Taiwan, and 25.3% in India 22 , 23 …”

Spatiotemporal Dynamics of Scrub Typhus Transmission in Mainland China, 2006-2014

“…Until the 1980s, scrub typhus cases primarily occurred in the regions south of Yangtze River with established natural foci including Zhejiang in the east and Yunnan in the west part of China [ 13 , 14 ]. However, with rapid societal development, changing environment, climate change, population movement, better recognition by health care professionals and ever-improving detection techniques, both sporadic cases and disease outbreaks began to be identified in the northern provinces of Shandong, Jiangsu, Tianjin and Beijing, as well as the emergence of new natural foci in the past three decades [ 13 , 15 – 17 ]. Currently, the disease is widespread in most of the provinces in mainland China, where the incidence has increased rapidly in recent years.…”