Bartonella and Rickettsia in arthropods from the Lao PDR and from Borneo, Malaysia

Abstract

Rickettsioses and bartonelloses are arthropod-borne diseases of mammals with widespread geographical distributions. Yet their occurrence in specific regions, their association with different vectors and hosts and the infection rate of arthropod-vectors with these agents remain poorly studied in South-east Asia. We conducted entomological field surveys in the Lao PDR (Laos) and Borneo, Malaysia by surveying fleas, ticks, and lice from domestic dogs and collected additional samples from domestic cows and pigs in Laos. Rickettsia felis was detected by real-time PCR with similar overall flea infection rate in Laos (76.6%, 69/90) and Borneo (74.4%, 268/360). Both of the encountered flea vectors Ctenocephalides orientis and Ctenocephalides felis felis were infected with R. felis. The degrees of similarity of partial gltA and ompA genes with recognized species indicate the rickettsia detected in two Boophilus spp. ticks collected from a cow in Laos may be a new species. Isolation and further characterization will be necessary to specify it as a new species. Bartonella clarridgeiae was detected in 3/90 (3.3%) and 2/360 (0.6%) of examined fleas from Laos and Borneo, respectively. Two fleas collected in Laos and one flea collected in Borneo were co-infected with both R. felis and B. clarridgeiae. Further investigations are needed in order to isolate these agents and to determine their epidemiology and aetiological role in unknown fever in patients from these areas.

Identification of Different Bartonella Species in the Cattle Tail Louse (Haematopinus quadripertusus) and in Cattle Blood

“…In addition, cattle and feline associated Bartonella DNA were detected in the blood of dairy cattle from seven Israeli dairy farms. Previous studies that screened Bartonella DNA on Haematopinus species lice collected from pigs and cattle reported negative results (33,34). Therefore, to the best of our knowledge, this is the first report of Bartonella detection in this louse genus.…”

Rickettsial Infections in Southeast Asia: Implications for Local Populace and Febrile Returned Travelers

“…35,37 Ectoparasite field surveys of villages in Laos and Malaysian Borneo of domestic animals also showed significantly high overall R. felis DNA detection rates of 76.6% and 74.4%, respectively. 36 However, in contrast, another study in peninsula Malaysia showed a lower rate (2.9%) of R. felis DNA detection. 38 In addition, previously unrecognized vectors or rickettsial species have also been reported in these studies.…”

“…[26][27][28][29] Socioeconomically, agricultural, plantation, or forest workers in Thailand, Malaysia, and Indonesia were frequently affected by scrub typhus and SFGR infections. 21 [32][33][34][35][36][37][38] Rodents were found to be important reservoirs for SFGR and murine typhus; high seropositive rates (up to 39.1% for SFGR) were observed in some parts of rural Indonesia. 32,33 Infection of rat flea Xenopsylla cheopis with R. felis has also been found in Indonesia, which increases the possibility of human infections with R. felis in the region, although no clinical case has been reported to date.…”

<strong>First survey of the hard tick (Acari: Ixodidae) fauna of Nakai District, Khammouane Province, Laos, and an updated checklist of the ticks of Laos</strong>

“…Tick species that occur in Laos have been discussed by (i) Toumanoff in 1944(Toumanoff, 1944, (ii) Hoogstraal et al and Wilson between the 1960s and 1980s (Hoogstraal et al, 1965, Wilson, 1970, Hoogstraal et al, 1971, Hoogstraal et al, 1973b, Hoogstraal et al, 1985b, (iii) Petney and Keirans in the mid-1990s (Petney et al, 1994, Petney et al, 1995, Petney et al, 1996a, Petney et al, 1996b, (iv) Robbins et al in 1996(Robbins et al, 1996, and (v) Kernif et al in 2012(Kernif et al, 2012, the most recent work.…”

“…Historically, about 104 species of ticks, representing 12 genera, have been known to occur in Southeast Asia (Petney et al, 2007), with the recent addition of two new species of Dermacentor (Apanaskevich et al, 2015a, Apanaskevich et al, 2015b. The relationship between ticks and tickborne pathogens in the region is largely unknown, even though the presence of these pathogens has been recognized for many years and the number of new pathogens discovered in ticks has increased markedly (Yu et al, 2011, Kernif et al, 2012, Kho et al, 2015.…”