Natural transovarial and transstadial transmission of Leishmania infantum by naïve Rhipicephalus sanguineus ticks blood feeding on an endemically infected dog in Shiraz, south of Iran

Dabaghmanesh, Tahereh
Asgari, Qasem
Moemenbellah-Fard, Mohammad Djaefar
Soltani, Aboozar
Azizi, Kourosh

^aDepartment of Medical Entomology and Vector Control, School of Health, Shiraz University of Medical Sciences, Shiraz, Iran
^bDepartment of Parasitology and Mycology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
^cResearch Centre for Health Sciences, Department of Medical Entomology and Vector Control, School of Health, Shiraz University of Medical Sciences, Shiraz, Iran

Corresponding author: Tel: +98 713 7251001-08 ext 346; Fax: +98 713 7260225; E-mail: [email protected], [email protected]

Received January 26, 2016

Received in revised form June 05, 2016

Accepted June 06, 2016

Transactions of the Royal Society of Tropical Medicine and Hygiene 110(7):p 408-413, July 2016. | DOI: 10.1093/trstmh/trw041

Background

The visceral leishmaniasis parasite, Leishmania infantum, is naturally transmitted through the bites of phlebotomine sand flies. Alternative routes of transmission are questioned. The main aim is to verify the passage of L. infantum kDNA in ticks, Rhipicephalus sanguineus, blood feeding on a parasitemic dog in Shiraz, south of Iran.

Methods

A total of 180 Leishmania-free ticks collected from fields and bred on lab rodents, were divided into eight groups and allowed to feed on a dog (Canis familiaris) for fixed periods of time. These and all third generation stages of ticks were checked for L. infantum kDNA using conventional PCR protocol.

Results

The infection rate was significantly higher in female than male ticks (p=0.043). The rates were higher among nymphs (25/60; 42%) than adult ticks (37/120; 30.8%). The kDNA of L. infantum was not detected in ticks 24 h post-feeding. It was, however, positive among the second to fourth groups of nymphs (4/10; 40%, 10/20; 50% and 11/20; 55%) and adult (12/30; 40%, 14/30; 46.6% and 11/30; 36.6%) ticks. Eggs and unfed larvae recovered from the third and fourth adult groups (2 weeks, 4 weeks) were 100% PCR-positive. The data revealed the passage of L. infantum kDNA in nymphs and adults of brown dog tick following fixed time intervals post blood feeding on an infected dog.

Conclusions

The natural transovarial and transstadial passage of kDNA through ticks was shown by PCR.