Armigeres subalbatus incriminated as a vector of zoonotic Brugia pahangi filariasis in suburban Kuala Lumpur, Peninsular Malaysia

Abstract

BackgroundIn 2011, we reported occurrence of natural human infections with Brugia pahangi, a filarial worm of dogs and cats, in a surburb of Kuala Lumpur, the capital city of Malaysia. Our preliminary entomological survey at that time suggested the mosquito species Armigeres subalbatus as the vector of the zoonotic infections. In this present report, we provide biological evidence to confirm our preliminary finding.FindingsA total of 1798 adult female Ar. subalbatus mosquitoes was caught in the vicinity of the suburb, and 1599 were dissected for the presence of filarial larvae. Sixty-two mosquitoes were positive, and 27 of these were infected with L3 larvae. The L3 were inoculated into male gerbils. Microfilariae could be detected in the gerbils 92 days post-infection. Post-mortem on the gerbils recovered adult worms in the peritoneal cavity, heart, lungs, tail and testis. Male adult worms were confirmed to be B. pahangi by the ratio length of their spicules (left spicule: right spicule). Female adult worms were confirmed by the absence of minute cuticular bosses in the tail region. The worms were further confirmed to be B. pahangi by PCR.ConclusionsOur results showed that Ar. subalbatus was the vector for the zoonotic Brugia pahangi infections. This mosquito species should now be categorised as a medically important mosquito species in Malaysia. Its role in the transmission of zoonotic B. pahangi must therefore be considered in future studies on filarial infections.

Molecular Detection of Rickettsia felis and Rickettsia bellii in Mosquitoes

“…subalbatus, a species found widely in China, Japan, and Southeast Asia (Chaves et al 2015). The females feed primarily on people and are the natural vectors of filarial worms (Muslim et al 2013). Our findings that R. felis occurs widely in China in an increasing number of mosquito species that are known to feed on people should alert health workers to the possibility of mosquito-transmitted infections in their patients.…”

The Potential Sources of Transmission and Distribution of Lymphatic Filariasis in Semarang City, Central Java, Indonesia

“…This is similar to a study conducted in Nigeria, which showed the infection rate of 10.1% and C. quinquefasciatus as the major vector (56.0%) (Manyi et al, 2014). In another study in Malaysia found 62 mosquitoes were positive and 27 mosquitoes infected with L3 out of 1,599 mosquitoes dissected for the presence of filarial larvae (Muslim et al, 2013).…”

Imported Asymptomatic Bancroftian Filariasis Discovered from aPlasmodium vivaxInfected Patient: A Case Report from Singapore

“…It is mainly transmitted by the mosquito of the genera Mansonia and Anopheles , for example, Mansonia uniformis and Anopheles barbirostris , which are present in Singapore [ 54 , 55 ]. Regarding the felid parasite B. pahangi , it has recently been reported as a zoonotic pathogen inducing LF with domestic cats as reservoir [ 13 , 58 ] in several transmission events in the suburb of the capital city of Malaysia, Kuala Lumpur [ 13 , 58 ], and in a semirural town of Selangor [ 12 , 59 ]. The incriminated vector was Armigeres subalbatus [ 12 , 59 ], a mosquito species also present in Singapore [ 55 , 60 ].…”