scholarly journals Physiological Age Structure andLeishmaniaspp. Detection inPhlebotomus (Larroussius) orientalis(Parrot, 1936) (Diptera: Psychodidae) at an Endemic Focus of Visceral Leishmaniasis in Northern Ethiopia

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Araya Gebresilassie ◽  
Ibrahim Abbasi ◽  
Oscar David Kirstein ◽  
Essayas Aklilu ◽  
Solomon Yared ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
Age Structure ◽  
Leishmania Donovani ◽  
Age Determination ◽  
Blood Feeding ◽  
Physiological Age ◽  
Agricultural Fields ◽  
Northern Ethiopia ◽  
Sand Flies ◽  
Endemic Focus

Visceral leishmaniasis (VL) caused byLeishmania donovaniis endemic in northern Ethiopia, whereP. orientalisis the most important presumed vector. This study was designed to determine the physiological age structure and the occurrence ofLeishmaniainfection in the vector of VL in Tahtay Adiyabo district, northern Ethiopia. Sand flies were collected using CDC light traps from peridomestic and agricultural fields between May 2011 and April 2012 andP. orientalisfemales were dissected for age determination and detection ofLeishmaniapromastigotes. Sand flies were also analyzed forL. donovanidetection using molecular methods. Of 1,282P. orientalisexamined for abdominal stages and age characterization, 66.2%, 28.2%, 4.1%, and 1.6% were unfed, freshly fed, half-gravid, and gravid. Parous rate in unfed females was 34.1% and 35.4% in peridomestic and agricultural fields, respectively. Out of 921P. orientalisfemales dissected, one specimen (0.1%) was found naturally infected with promastigotes. Five pools (25 females) of unfedP. orientaliswere also found with DNA ofLeishmaniaspp. In particular, a singleP. orientaliswas positive forL. donovani(0.5%). Based on this and other evidences (abundance, human blood feeding, and xenodiagnostic studies),P. orientalisis the principal vector of VL in this endemic focus.

scholarly journals Odour of domestic dogs infected with Leishmania infantum is attractive to female but not male sand flies: evidence for parasite manipulation

2020 ◽  
Author(s):  
Monica E. Staniek ◽  
James G.C. Hamilton
Keyword(s):  
Visceral Leishmaniasis ◽  
Leishmania Infantum ◽  
Feeding Activity ◽  
Blood Feeding ◽  
Human Infection ◽  
T Test ◽  
Domestic Dogs ◽  
Lutzomyia Longipalpis ◽  
Sand Flies ◽  
Paired T Test

AbstractGlobally visceral leishmaniasis (VL) causes thousands of human deaths every year. In South America, the etiologic agent, Leishmania infantum, is transmitted from an infected canine reservoir to human hosts by the blood-feeding activity of the sand fly vector, predominantly, Lutzomyia longipalpis. Previous evidence from model rodent systems have suggested that the odour of infected hosts is altered by the parasite making them more attractive to the vector leading to an increased biting rate and improved transmission prospects for the pathogen. However, the effect of Le. infantum infection on the attractiveness of naturally infected dogs which are integral to human infection, has not been assessed.Hair collected from infected and uninfected dogs residing in a VL endemic city in Brazil. was entrained to collect the volatile chemical odours present in the headspace. Female and male Lu. longipalpis sand flies were offered a choice of infected or uninfected odour in a series of behavioural experiments. Control experiments established that female and male Lu. longipalpis were equally attracted to uninfected dog odour, female Lu. longipalpis were significantly more attracted to infected dog odour than uninfected dog odour in all 15 experimental replicates (average 45.7±0.87 females attracted to infected odour; 23.9±0.82 to uninfected odour; paired T-test, P=0.000). Male Lu. longipalpis did not significantly prefer either infected or uninfected odour (average 36.1±0.4 males to infected odour; 35.7±0.6 to uninfected odour; paired T-test, P=0.722). A significantly greater proportion of females chose the infected dog odour compared to the males (paired T-test, P=0.000).The results show that dogs infected with Le. infantum are significantly more attractive to blood-feeding female than male sand flies. This is strong evidence for parasite manipulation of the host odour in a natural transmission system and indicates that infected dogs may have a disproportionate significance in maintaining infection in canine and human infection.Author SummaryVisceral leishmaniasis (VL) is a disease caused by the Protist parasite Leishmania infantum. In Brazil and other South and Central American countries, the parasite is transmitted by the blood-feeding activity of infected female Lutzomyia longipalpis sand flies. The disease leads to thousands of human cases and deaths every year. Domestic dogs are the reservoir of infection for humans therefore understanding the effect of infection on dogs is important in developing an understanding of the epidemiology of the disease. Although previous studies on rodent models of Le. infantum infection have shown that infected Golden Hamsters are more attractive to Lu. longipalpis the attractiveness of naturally infected dogs to the insect vector has not been previously been investigated. In this study we showed that the odour of infected dogs is significantly more attractive to female sand flies which can transmit the pathogen than to male sand flies which do not. This clear-cut difference in attraction of female and males suggests that the females are preferentially attracted by parasite infected hosts and may lead to enhanced infection and transmission opportunities for the parasite.

scholarly journals INVESTIGATION OF LEISHMANIASIS VECTORS IN EL-KADOBA VILLAGE, WHITE NILE STATE, SUDAN

2017 ◽  
Vol 5 (1) ◽  
pp. 430-441
Author(s):  
Belal Abdallah A. Adam ◽  
Moawia Mukhtar Hassan ◽  
Osman Mohammed Abd Elnour ◽  
Ahmed Hamid Awadallah
Keyword(s):  
Visceral Leishmaniasis ◽  
Leishmania Donovani ◽  
Morphological Characters ◽  
Sand Fly ◽  
Leishmania Infection ◽  
Sand Flies ◽  
Kala Azar ◽  
Ecological Aspects ◽  
Binocular Microscope ◽  
White Nile

Visceral leishmaniasis (VL; kala-azar) is one of the most important parasitic tropical diseases in Sudan   and the Sudan is considered to be one of the most important foci in the world. The visceral leishmaniasis has been described in Sudan since the beginning of the twentieth century. In Sudan, VL is caused by Leishmania donovani complex: MON 18, MON 30 and MON 82 zymodemes and  The proven vector is Phlebotomus (Larroussius) orientalis, in this study a survey was carried out to identify the principal vector of VL based on Leishmania infection, morphological characters and to determine some ecological aspects of the sand flies prevalent in the area . Ten species of sand flies were recorded, three Phlebotomus species and seven Sergentomyia species of these sandflies, P. rodhaini was collected only from Acacia seyal/Balanities aegyptiaca at the Island whereas S. hunti was collected from the Acacia nilotica forest only of the total collections, P. orientalis representing 3.80% (248 specimens) of the total collection and P. papatasi were 3.11% of the collection. Sand flies identification was done under a binocular microscope at 40x (magnification). The main features used for sand flies identification were the sperm theca of the female, the termination of the male and the pharyngeal and the ciboria toothed structures of both sexes. According to results of this study we recommended the following:  more studies are needed in the future to determine the transmission season, and infection rates of Leishmania parasites in human and the animal host in this area. Annually Entomological surveys must be done to determine density of Sand fly Vectors and Encourage the use of personal protection tools (ITNs), repellents, and improving of houses to avoid bite of sand fly.

scholarly journals Host-feeding preference of Phlebotomus orientalis (Diptera: Psychodidae) in an endemic focus of visceral leishmaniasis in northern Ethiopia

2015 ◽  
Vol 8 (1) ◽  
Author(s):  
Araya Gebresilassie ◽  
Ibrahim Abbasi ◽  
Essayas Aklilu ◽  
Solomon Yared ◽  
Oscar David Kirstein ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
Feeding Preference ◽  
Northern Ethiopia ◽  
Host Feeding ◽  
Endemic Focus ◽  
Phlebotomus Orientalis

scholarly journals PCR-Based Detection of Leishmania donovani DNA in a Stray Dog from a Visceral Leishmaniasis Endemic Focus in Bangladesh

2013 ◽  
Vol 75 (1) ◽  
pp. 75-78 ◽  
Author(s):  
Mohammad Zahangir ALAM ◽  
Md. Golam YASIN ◽  
Hirotomo KATO ◽  
Tatsuya SAKURAI ◽  
Ken KATAKURA
Keyword(s):  
Visceral Leishmaniasis ◽  
Leishmania Donovani ◽  
Endemic Focus ◽  
Stray Dog

scholarly journals Response to thermal and infection stresses in an American vector of visceral leishmaniasis

2020 ◽  
Author(s):  
Kelsilandia A. Martins ◽  
Caroline S. Morais ◽  
Susan J. Broughton ◽  
Claudio R. Lazzari ◽  
Paul A. Bates ◽  
...  
Keyword(s):  
Heat Shock ◽  
Body Temperature ◽  
Visceral Leishmaniasis ◽  
Heat Shock Proteins ◽  
Blood Meal ◽  
Blood Feeding ◽  
The Body ◽  
Sand Fly ◽  
Sand Flies ◽  
Shock Proteins

AbstractThe phlebotomine sand fly Lutzomyia longipalpis is the primary insect vector of visceral leishmaniasis in the Americas. For ectothermic organisms such as sand flies, the ambient temperature is a critical factor influencing all aspects of their life. However, the impact of temperature has been ignored in previous investigations of stress-induced responses by the vector, such as taking a blood meal or during Leishmania infection. Therefore, this study explored the interaction of Lu. longipalpis with temperature by evaluating sand fly behaviour across a thermal gradient after sugar or blood-feeding, and infection with Leishmania mexicana. Thermographic recordings of sand fly females fed on mice were analysed, and the gene expression of heat shock proteins HSP70 and HSP90(83) was evaluated when insects were exposed to extreme temperatures or infected. The results showed that 72h after blood ingestion females of Lu. longipalpis became less active and preferred relatively low temperatures. However, at later stages of blood digestion females increased their activity and remained at higher temperatures prior to taking a second blood meal; this behaviour seems to be correlated with the evolution of their oocysts and voracity for a second blood meal. No changes in the temperature preferences of female sand flies were recorded in the presence of a gut infection by Le. mexicana, indicating that this parasite has not triggered behavioural immunity in Lu. longipalpis. Real-time imaging showed that the body temperature of female flies feeding on mice increased to the same temperature as the host within a few seconds after landing. The body temperature of females remained around 35 ± 0.5 °C until the end of blood-feeding, revealing a lack of thermoregulatory behaviour. Analysis of expression of heat shock proteins revealed insects increased expression of HSP90(83) when exposed to higher temperatures, such as during blood feeding. Our findings suggest that Lu. longipalpis interacts with the environmental temperature by using its behaviour to avoid temperature-related physiological damage during the gonotrophic cycle. However, the expression of certain heat shock proteins might be triggered to mitigate against thermal stress in situations where a behavioural response is not the best option.

The biology of Anopheles claviger (Mg.) (Dipt., Culicidae) in southern England

1973 ◽  
Vol 63 (2) ◽  
pp. 347-359 ◽  
Author(s):  
M. W. Service
Keyword(s):  
Larval Development ◽  
Age Structure ◽  
First Generation ◽  
Natural Populations ◽  
Blood Feeding ◽  
Physiological Age ◽  
Immature Stages ◽  
Blood Digestion ◽  
Southern England ◽  
Suction Traps

AbstractThe biology of Anopheles claviger (Mg.) was studied for a varying number of years in three localities in southern England. The fluctuations in the proportions of the larval instars and pupae were studied by weekly sampling throughout the year. The population overwintered from October to April as pre-adults, and in mid-winter larval development was arrested, but was resumed in March. The construction of a simple life-table showed the existence of a large mortality of immature stages during the overwintering period. Females were sampled at two localities by human bait catches, and at one also by insect suction traps. There was an interval of 1–2 weeks between adult emergences in April and blood-feeding, during which time females apparently fed on sugar solutions. Maximum biting densities of nullipars in May and September showed that A. claviger was bivoltine. The physiological age structure of the population showed that most parous adults at bait had oviposited only once or twice, but a few females had laid four batches. Live Hygrobatid-type mites proved reliable in indicating nulliparity. Mature larvae developed in the eggs 5–7 days after oviposition and while most eggs hatched within the next three days, a few remained unhatched until the 30th day. Females of the second generation (September) laid fewer eggs than those of the first generation (May). About six days were required for blood digestion, and females supplied with sugar were able to live 46 days. The marked delays between successive gonotrophic cycles in natural populations would make parous rates unreliable for the estimation of daily mortalities.

scholarly journals Diversity and Within-Host Evolution of Leishmania donovani from Visceral Leishmaniasis Patients with and without HIV Coinfection in Northern Ethiopia

mBio ◽  
2021 ◽  
Author(s):  
Susanne U. Franssen ◽  
Yegnasew Takele ◽  
Emebet Adem ◽  
Mandy J. Sanders ◽  
Ingrid Müller ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
East Africa ◽  
Migrant Workers ◽  
Leishmania Donovani ◽  
Northern Ethiopia ◽  
Agricultural Work ◽  
Hiv Coinfection ◽  
Cause Of Deaths ◽  
Parasite Infections ◽  
Host Evolution

Visceral leishmaniasis (VL) is the second largest cause of deaths due to parasite infections and a growing problem in East Africa. In Ethiopia, it is particularly associated with migrant workers moving from regions of nonendemicity for seasonal agricultural work and is frequently found as a coinfection with HIV, which leads to frequent VL relapse following treatment.

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