The Epidemiology and Characteristics of Q fever and Co‐infections with Scrub Typhus, Murine Typhus or Leptospirosis in Taiwan: A Nationwide Database Study

Abstract

Q fever (QF) is a worldwide zoonosis associated with outbreaks. Only a few nationwide studies regarding the surveillance and epidemiology of human QF have been reported. Although QF is endemic in Taiwan, a nationwide database investigation of the epidemiology and characteristics of QF and its associations with scrub typhus (ST), murine typhus (MT) and leptospirosis (LS) has never been reported. We analysed nationwide databases of suspected QF, ST, MT and LS cases from October 2007 to December 2014 obtained from the Centers for Disease Control, Taiwan. A total of 468 (4.2%) QF cases were identified among 11 109 suspected QF cases. QF cases were mainly distributed in the southern and Kaohsiung-Pingtung regions but rarely in the eastern region. Compared to non-QF cases, QF cases had significantly higher percentages of males (88.7 versus 66.2%) and high-risk occupations (farming, animal husbandry or veterinary medicine) (16.2 versus 10.5%). But the percentages of specific animal contact, including cattle (0.6 versus 0.8%) and goats (0.9 versus 1.0%), were low in both. The majority of suspected QF cases (89.4%) were simultaneously suspected with ST, MT or LS, and the combinations of suspected diseases differed between regions. The number of suspected QF cases from the eastern region decreased since 2009, which was not observed in other regions. A total of 1420 (12.8%) cases had confirmed diseases, including QF (453, 4.1%), QF+ST (7, 0.06%), QF+MT (4, 0.04%), QF+LS (4, 0.04%), MT (186, 1.7%), ST (545, 4.9%), ST+LS (11, 0.1%) and LS (210, 1.9%). Compared to cases of unknown disease, QF cases had larger percentages of high-risk occupations (16.2 versus 9.6%) but similar histories of animal contact (29.8 versus 25.1%). QF is an endemic disease in southern Taiwan. It is difficult to differentiate QF from ST, MT or LS only by high-risk occupations and history of animal contact, and co-infection of QF with these diseases should be considered.

The Re-Emergence and Emergence of Vector-Borne Rickettsioses in Taiwan

“…Both cases determined to be acutely infected with SFGR had unknown etiology after being screened at Taiwan CDC, representing 2 of 255 cases of unknown etiology for acute undifferentiated fever included in this study [ 17 ]. Despite the limited number of cases with unknown etiology screened for SFGR in this study, Lai et al [ 79 ] identified that a staggering 87% of cases screened for clinically suspected acute Q fever, scrub typhus, murine typhus, and leptospirosis reported to the CDC from 2007 to 2014, were negative, representing 9,689 cases of unknown etiology. Based on the findings of Lai et al [ 17 ], it is not unreasonable to postulate that SFGR caused some of these acute undifferentiated febrile illnesses.…”

“…Although rare, co-infection of VBR with these bacterial zoonoses has been observed in Taiwan. Lai et al [ 79 ] analyzed Taiwan CDC data from 2007 to 2014 and identified co-infection of acute Q fever with scrub typhus (7 cases), murine typhus (4 cases), and leptospirosis (4 cases), also identifying co-infection of scrub typhus with leptospirosis (11 cases). Strikingly, of 11,109 cases suspected of acute Q fever or co-infection with scrub typhus, murine typhus, or leptospirosis (or mixed infection) reported to the Taiwan CDC, only 13% of cases were confirmed (1420) [ 79 ].…”

The epidemiology, characteristics and outbreaks of human leptospirosis and the association with animals in Taiwan, 2007–2014: A nationwide database study

“…This suggests that clinicians might be more confident in the diagnosis of LS than individual rickettsial diseases in Taiwan. There are several reports about coinfection of LS with ST in previous studies, mainly in Taiwan (Lai et al, ; Lee & Liu, ; Wei, Chiu, Lai, Lai, & Lin, ) and Thailand (Suputtamongkol et al, ; Watt, Jongsakul, & Suttinont, ). In northern Thailand, LS coinfection with ST (mainly), MT and spotted fever group rickettsiae has been identified (Suputtamongkol et al, ).…”

“…LS, ST, QF and MT are common zoonoses in Taiwan (Lai et al, , ; Tsai & Yeh, ). In contrast to our previous study where the QF cases are usually reported with ST and MT (45.6%) cases (Lai et al, ), single LS cases are most commonly reported (45.7%, 4991/10927), and this accounts for 342 of 665 (51.4%) confirmed LS cases in the current study (Table ). This suggests that clinicians might be more confident in the diagnosis of LS than individual rickettsial diseases in Taiwan.…”

“…In addition to LS, Q fever (QF; infection by Coxiella burnetii) (Lai et al, ), scrub typhus (ST) (infection by Orientia tsutsugamush ) (Tsai & Yeh, ) and murine typhus (MT) (infection by Rickettsia typhi ) (Chang et al, ) are other endemic zoonoses and notifiable diseases in Taiwan. Clinical differentiation between these diseases is difficult because the symptoms, clinical manifestation and history of environmental or animal exposure are similar (Lai et al, ), and coinfection among these diseases occurs on occasion (Lai et al, ; Lee & Liu, ).…”