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Fulltext Serological findings of Coxiella burnetii infection among patients with fevers in a health centre in Sarawak, Malaysia

Tay ST, Ho TM, Rohani MY

Southeast Asian J Trop Med Public Health, 1998 Mar;29(1):94-5.
PMID: 9740277
Matched MeSH terms: Q Fever/microbiology*; Q Fever/epidemiology
Seroprevalence of Q Fever Among the Indigenous People (Orang Asli) of Peninsular Malaysia

Khor CS, Mohd-Rahim NF, Hassan H, Chandren JR, Nore SS, Johari J, et al.

Vector Borne Zoonotic Dis, 2018 03;18(3):131-137.
PMID: 29336685 DOI: 10.1089/vbz.2017.2153

Q fever is a disease caused by Coxiella burnetii. It is a disease of public health concern in many parts of the world. In this study, we described the seroprevalence of Q fever among selected populations of Orang Asli (OA), indigenous people, many of whom live within the forest fringe areas of Peninsular Malaysia. Serum samples were obtained from 887 OA participants from selected villages. Samples were analyzed for the presence of IgG antibodies reactive against C. burnetii by enzyme-linked immunosorbent assay. Statistical methods were used to identify possible associations between seropositivity for C. burnetii and a number of demographic variables obtained from the questionnaires. In total, 9.6% (n = 85/887) of the serum samples were reactive to C. burnetii. Statistical results suggest that elderly male OA residing in OA village, Bukit Payung, were most likely to be tested seropositive for C. burnetii. This study suggests that OA are at a significant risk of contracting C. burnetii infection, and both demographic and geographic factors are important contributors to this risk. Further prospective studies are needed to establish the true burden of C. burnetii infection within the indigenous population as well as within Peninsular Malaysia as a whole.

Matched MeSH terms: Q Fever/blood; Q Fever/epidemiology*
Fulltext Coxiella-like bacteria in fowl ticks from Thailand

Trinachartvanit W, Maneewong S, Kaenkan W, Usananan P, Baimai V, Ahantarig A

Parasit Vectors, 2018 Dec 27;11(1):670.
PMID: 30587229 DOI: 10.1186/s13071-018-3259-9

BACKGROUND: Coxiella bacteria were identified from various tick species across the world. Q fever is a zoonotic disease caused by the bacteria Coxiella burnetii that most commonly infects a variety of mammals. Non-mammalian hosts, such as birds, have also been reported to be infected with the pathogenic form of "Candidatus Coxiella avium". This research increases the list of tick species that have been found with Coxiella-like bacteria in Thailand.
METHODS: A total of 69 ticks were collected from 27 domestic fowl (Gallus gallus domesticus), 2 jungle fowl (Gallus gallus) and 3 Siamese firebacks (Lophura diardi) at 10 locations (provinces) in Thailand. Ticks were identified and PCR was used to amplify Coxiella bacteria 16S rRNA, groEL and rpoB genes from the extracted tick DNA. MEGA6 was used to construct phylogenetic trees via a Maximum Likelihood method.
RESULTS: The phylogenetic analysis based on the 16S rRNA gene showed that the Coxiella sequences detected in this study grouped in the same clade with Coxiella sequences from the same tick genus (or species) reported previously. In contrast, rpoB gene of the Coxiella bacteria detected in this study did not cluster together with the same tick genus reported previously. Instead, they clustered by geographical distribution (Thai cluster and Malaysian cluster). In addition, phylogenetic analysis of the groEL gene (the chaperonin family) showed that all Coxiella bacteria found in this study were grouped in the same clade (three sister groups).
CONCLUSIONS: To our knowledge, we found for the first time rpoB genes of Coxiella-like bacteria in Haemaphysalis wellingtoni ticks forming two distinct clades by phylogenetic analysis. This may be indicative of a horizontal gene transfer event.

Matched MeSH terms: Q Fever/microbiology; Q Fever/transmission; Q Fever/veterinary*
First record of Megaselia scalaris (LOEW) (DIPTERA: PHORIDAE) infesting a spinose ear tick, Otobius megnini, colony in Sri Lanka

Diyes GCP, Karunaratne WAIP, Tomberlin JK, Rajakaruna RS

Trop Biomed, 2015 Dec 01;32(4):791-795.
PMID: 33557472

Megaselia scalaris (Loew) is a cosmopolitan polyphagous small fly with the ability of exploiting variety of ecological niches. Different life history stages act as detritivore, parasite, and parasitoid of wider spectrum of plant and animal matter under natural and laboratory conditions. Here, for the first time we present the opportunistic parasitism of M. scalaris on Otobius megnini, which act as a vector of Q fever and is capable of causing paralysis, toxic conditions, otoacariasis and otitis in humans and other animals. Tick samples from the ear canals of 14 thoroughbred horses were brought to the laboratory and several days later, larvae of M. scalaris were found feeding on immature stages of O. megnini. When the development was completed pupae were found attached to adult ticks and all nymphs were found dead. This context reveals the capability of M. scalaris surviving on O. megnini and the risk of their invading ear canals of horses.

Matched MeSH terms: Q Fever