A possible role of bats as a blood source for the Leishmania vector Lutzomyia longipalpis (Diptera: Psychodidae).

Abstract

Some evidence suggests that bats may provide an alternative blood source for Lutzomyia longipalpis, the main vector of American visceral leishmaniasis. Feeding trials were conducted to determine whether L. longipalpis feeds on captive bats. The high feeding success indicated that L. longipalpis is capable of feeding on at least four species of bats. Implications for the epidemiology of leishmaniases are discussed.

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Am. J. Trop. Med. Hyg., 62(6), 2000, pp. 718–719
Copyright ? 2000 by The American Society of Tropical Medicine and Hygiene
A POSSIBLE ROLE OF BATS AS A BLOOD SOURCE FOR THE LEISHMANIA VECTOR
LUTZOMYIA LONGIPALPIS (DIPTERA: PSYCHODIDAE)
MARGARITA LAMPO, M. DORA FELICIANGELI, LUIS M. MA´RQUEZ, CAROLINA BASTIDAS, AND PABLO LAU
Centro de Ecologı ´a, Instituto Venezolano de Investigaciones Cientı ´ficas, Caracas, Venezuela; Facultad de Ciencias de la Salud,
Departamento de Biomedicina, Universidad de Carabobo, Maracay, Venezuela.
Abstract.
the main vector of American visceral leishmaniasis. Feeding trials were conducted to determine whether L. longipalpis
feeds on captive bats. The high feeding success indicated that L. longipalpis is capable of feeding on at least four
species of bats. Implications for the epidemiology of leishmaniases are discussed.
Some evidence suggests that bats may provide an alternative blood source for Lutzomyia longipalpis,
Lutzomyia longipalpis is the most widely distributed vec-
tor of American visceral leishmaniasis in the New World.1
Its frequent presence in caves and crevices commonly in-
habited by bats suggests that they may provide a blood
source for these sand flies.2Other sand fly species from the
Old World have also been recorded in caves.3,4This raises
the question of the role of bats as a natural blood source for
L. longipalpis, and the possibility that bats could host Leish-
mania parasites.
A few bat species from the Old World have been screened
for Leishmania parasites,4–6but results are not conclusive.
Leishmania donovani sensu lato (L.D. bodies) were found
in 3 out of 104 bats collected at caves in Kenya, but blood
meal analyses from Phlebotomus pedifer adults trapped in
the vicinity of these caves revealed no evidence to indicate
that this sand fly species fed on bats.4Also, histopathological
changes in liver, spleen, and kidney were observed in ves-
pertilionid bats, though the significance of such results re-
mains questionable.5However, the detection of seropositive
titers (1:128 and more) in 7 bats from Egypt,6suggests that
further studies must be carried out before we can assess the
role of bats in the transmission of leishmaniases. In the New
World, bats have not been reported as hosts of Leishmania.
However, we do not know of any studies in which bats have
been specifically screened for these parasites. Moreover,
whether L. longipalpis feeds naturally on bats is unknown,
as blood meals from this species have only been tested
against antisera of domestic animals, birds, opossums, and
reptiles.7,8As a first step towards the evaluation of bats as a
natural blood source for L. longipalpis in the New World,
feeding trials were conducted on captive bats.
Bats and sand flies were collected at two sites in Vene-
zuela: La Rinconada, Lara State (9?52?N; 69?55?W; 627 m)
and Los Morros de Macaira, Gua ´rico State (9?55?N;
66?17?W; ?600 m). The first site consists of a xerophytic
shrub forest with abundant boulders with crevices that serve
as refuges for bats, whereas the second is a cave located at
the base of a montane humid forest. Although at La Rin-
conada only adult bats were observed, the presence of young
bats within the cave at Los Morros de Macaira suggests that
they are breeding there. Bats were captured between 1800
and 2200 hours using mist nets. Sand flies were trapped be-
tween 1800 and 600 hours on the previous night using Cen-
ter for Disease Control and Prevention (CDC) miniature light
traps (Model 512; John W. Hock Company, Gainesville, FL).
To allow for habituation to cages, each bat was placed
individually inside a cage for half an hour before the feeding
trial commenced. Feeding trials were conducted during the
day in the dark, as bats are normally inactive at this time.
Bats were only used in a single trial. Maintenance and care
of bats complied with the guidelines of the Bioethics Code
of the Consejo Nacional de Investigaciones Cientı ´ficas y
Tecnolo ´gicas (Venezuela). Unfed female sandflies were
placed in each cage for 1 hour, the time usually required for
them to feed on laboratory rats. At the end of each trial,
engorged and unfed alive and dead sand flies were separated
and counted. Engorged sand flies were kept alive in cages
with 30% sucrose for a minimum of 4 days, after which they
were washed in detergent and stored in DMSO at ?70? for
later dissection and detection of flagellates. All specimens
were identified morphologically as L. longipalpis.1
The results of the feeding trials are summarized in Table
1. Lutzomyia longipalpis is capable of feeding on at least 4
species of bats from 3 different families: Pteronotus parnellii
(Mormoopidae), Glossophaga longirostris (Phyllostomidae),
Carollia perspicillata (Phyllostomidae), and Myotis oxyotus
(Vespertilionidae). The percentage of insect females that fed
varied among individual bats. For example, feeding success
varied from 0 to 26.19% in Pteronotus parnellii, from 1.15
to 15.94% in Carollia perspicillata, and from 0 to 13.64%
in Myotis spp. The highest feeding success, 41.24%, was
recorded in Glossophaga longirostris. The high mortality of
the sand flies recorded in some of the trials may be attributed
to the fact that not all of the bats remained immobile
throughout the trials. None of the dead female flies showed
blood meals.
Screening of the foregut and thoracic midgut of 43 fed
females revealed no evidence of flagellates that may have
been previously harbored by them or acquired from the of-
fered bats. However, this is not surprising given the small
sample size and the low incidence of leishmaniasis at both
sites.
The status of bats as a natural blood source for L. longi-
palpis has important implications in the control of leishman-
iases. The high dispersal capabilities and longevity of bats
could have important effects on the persistence and dispersal
of Leishmania parasites if they are reservoirs of these par-
asites. Although adult bats normally abandon the caves at
night when sand flies are feeding, some bats (i.e., young-
sters) stay inside throughout the night. Analyses of blood
meals from L. longipalpis must be carried out in habitats
where bats and L. longipalpis coexist to determine whether
these sand flies feed on bats under natural conditions. Also,

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BATS AS BLOOD SOURCES FOR L. LONGIPALPIS
TABLE 1
Feeding success of Lutzomyia longipalpis in four species of bats
Location Bat species
Lutzomyia longipalpis (no.)
Initial
En-
gorged Unfed Dead
Feeding
success
(%)*
LR
LR
LR
LR
LR
LR
MM
MM
MM
Pteronotus parnellii
P. parnellii
P. parnellii
Carollia perspicillata
C. perspicillata
Glossophaga longirostris
Myotis oxyotus
M. oxyotus
Myotis spp.
100
100
100
100
100
100
25
25
25
22
4
0
1
11
40
62
78
69
86
58
57
21
23
19
16
18
31
13
31
26.19
4.88
0
1.15
15.94
41.24
4.55
0
13.64
1
0
3
3
3
2
3
* no. engorged/(no. engorged ? no. unfed).
LR ? La Rinconada Lara State, Venezuela; MM ? Morro de Macaira, Guarico State,
Venezuela.
naturally infected bats must be sought in areas where the
incidence of leishmaniasis is high.
Acknowledgments: We are grateful to Belkis Rivas from La Salle
Museum for assisting with the species diagnosis of bats and to Ron-
ald Egea and Arturo Bravo for their field and technical assistance.
Financial support: This study was supported by the World Health
Organization-World Bank grant 021-007.
Authors’ addresses: Margarita Lampo, Centro de Ecologı ´a, Instituto
Venezolano de Investigaciones Cientı ´ficas, Apartado 21827, Caracas
1020-A, Venezuela. Marı ´a Dora Feliciangeli, Centro Nacional de
Referencia de Flebo ´tomos, Departamento de Biomedicina, Univer-
sidad de Carabobo, Nu ´cleo Aragua, Maracay, Venezuela. Luis Mi-
guel Ma ´rquez, Department of Biochemistry and Molecular Biology,
James Cook University, Townsville, Qld. Australia 4811. Carolina
Bastidas, Australian Institute of Marine Science, PMB No. 3 Towns-
ville MC, Qld 4810, Australia. Pablo Lau, Centro de Agroecologı ´a
Tropical. Universidad Simon Rodrı ´guez, Caracas, Venezuela.
Reprint requests: M. Lampo, Centro de Ecologı ´a, Instituto Venezo-
lano de Investigaciones Cientı ´ficas, Apartado 21827, Caracas 1020-
A, Venezuela.
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