WO2006121222A1

WO2006121222A1 - Vector and rodent holding devices during parasite transmission experiments in the laboratory

Info

Publication number: WO2006121222A1
Application number: PCT/KE2006/000014
Authority: WO
Inventors: Ndungu Kariuki
Original assignee: Kari- Trypanosomiasis Research Centre
Priority date: 2005-05-11
Filing date: 2006-05-11
Publication date: 2006-11-16

Abstract

A device for holding rodent and vector during vector infection and transmission process (Fig: 7 & 8) comprising of a rodent holding compartment (Fig 1 & 2 - 1, 2, 3, 4, 5 & 6) and a vector cage (Fig 4); said rodent holding compartment having means for resting it on the bench (1 & 2 - 14, 15), and further fitted with means for engaging the vector cage (Fig 1; 12, 13) and fitted with a rodent release sliding door (Fig 1; 18) and a ladder (Fig 1 & 2 -A); said ladder leading the rodent to a resting cage (Fig 6) through entrance (75) that is closed with door (74) and the said rodent holding compartment accompanied by a special rodent cage (Fig 3)for introducing the rodent into the rodent holding compartment; said special rodent cage comprises of component A joined together and a door B to form an enclosure and a rodent escape route C.

Description

Background

Laboratory controlled vector infection and infection-transmitting studies are important m that they represent natural disease transmission as occurs in the field These studies are however limited by lack of an ideal system that would hold both the rodent and the vector and allow them close contact that will enable transmission to take place naturally without interference Harry E.Knuppel, in US patent No.6, 202,339Bl disclosed a system for trapping and monitoring wild mice and insect enabling the investigator to study the type of insects trapped through a glass top and is not amenable for use duπng transmission expeπments Toshio Watanabe, Kanagawa (JP), in US patent No. 2003/0051668 Al disclosed a milking apparatus for laboratory animals such as rats by a single experimenter It is designed to only hold the rodent and has no provision for the vector making it therefore not amenable for use duπng transmission expeπments Patrick R.Hughes, Ithaca, in US patent No. 5,351,643 disclosed an insect rearing device not amenable for use during transmission experiments since it is designed to only hold insects when rearing CharlesW. Carr, Edgewater and Douglas M. Kolodny- Hirsch, Fells point, in US patent No. 5,178,084 discloses an apparatus for mass rearing of Entomoparasites and production of insect related Entomopathogens and therefore not amenable in vector transmission studies Thomas N. Mather, in US patent US 4,622,104 discloses an apparatus for destroying ectoparasites of rodents and its application is not amenable for use duπng transmission expeπments Louis Haege, in US patent no. 1,379,685 discloses a trap for wild rodents and insect for the purpose of killing them once trapped

Of the disclosed systems, none is appropriately designed to hold both the vector and the rodent and allow hands off handling during controlled infection transmitting process.

Prior to the development of the disclosed vector and rodent holding devices, vector infection and transmission of the infection were carried out manually by holding the rodent in one hand and vector cage in the other hand Some vectors feed fast and others require a longer time in contact with rodent necessitating holding the rodent for a longer time to get the vector to feed This result m the rodent being stressed and some die before the experiment is completed Apart from stressing the rodent, the investigator runs the πsk of that if the experiment requires large number of rodents and vectors, more people will be required and consequently a larger space

The term transmission used in this application refers to picking of the infection from an infected host by the vector and transferring it to an uninfected host The term vector refers to any insect capable of picking and transferring the infection e g mosquito, tsetse fly, sandfly and other biting flies

The advantages of the disclosed devices are i) Vector infection and transmission can take place with minimal handling by the investigator ii) The chances of investigator being bitten by either the vector or rodent are minimized iii) In order to avoid isolation-related stress during the experiments, the units can be assembled in a manner that allow the rodents to see each other iv) These devices are portable and can easily fit in an incubator and therefore it is possible to do transmission studies in the field as well as under controlled environment i e at optimum temperature, light and humidity v) Vectors can be left to feed at their own pace while the investigator carries out other work in the laboratory vi) The devices can be modified to handle rodents of various sizes for various transmission expeπments vii) The devices can be used while infecting rodents intravenously (IV) and bleeding rodents from the tail in the laboratory viii) The device may be modified to enable mating and hatching of vectors in a controlled environment (incubator) xiv) Reduction in personnel involved when carrying out transmission experiments

Transmission process comprises infecting the vector en mass on an infected rodent followed by each infected vector singly transmitting the infection to un infected rodent

Mass vector infection method comprise the following steps:

(i) Inserting the vector cage with the un infected vector in vector cage holder mounted on the rodent holding compartment,

(ii) Placing the infected rodent m the special rodent introducing cage directing it to the rodent holding compartment through the rodent entrance in the front, compartment by locking it using a door with notch that allows hanging of the tail outside the cage;

(iv) Allowing the infected vector adequate time to feed on the uninfected rodent; (v) Releasing the rodent at the end of the experiment through the escape door at the rear end and the ladder in the front.

Single vector infection transmission method comprise the following steps:

(i)Inserting the vector cage with the infected vector in vector cage holder mounted on the rodent holding compartment;

(ii) Placing the uninfected rodent in the special rodent introducing cage and gently direct it to the rodent holding compartment through the rodent entrance in the front;

(iii) Preventing the uninfected rodent from getting out of the rodent holding compartment by locking it using a door with notch that allows hanging of the tail outside the cage;

(iv) Restraining the movement of the vector within the vector cage by use of the vector cage piston

(v) Allowing the infected vector adequate time to feed on the uninfected rodent.

(vi) Releasing the rodent at the end of the experiment through the escape door and the ladder in the front.

DESCRIPTION OF FIGURES

Rodent and vector holder (Fig 1) during the process of single vector transmitting infection to the rodent This is made up of the following parts: - a) Rodent holding compartment (1,2,3,4,5,6) b) Single vector cage (Fig 5) c) Vector cage holder (12 &13) d) Netting material (Fig 5: 71) (v) Special cages for introducing the rodent into rodent holding compartment

(Fig 3) (39,40,41,43,44,45,46,47,48,49,50,51,52,53,54, 55 &56) made of any appropriate material, (vi) Special cage stand (53)

(vii) The ladder (Fig 1 &2) (20,21,22,23,24,25,26,27,28 &8) (viii) Rodent release door to the ladder (18) with a handle (19)

(ix) Rodent resting cage Figure (6) with an entrance (75) and a door (74). a) The rodent cage joined to (5 &6) by gas welding or other appropriate substance. This skeleton is then wrapped with expanded wire (8) leaving three open spaces one on the upper side of the cage (11), the other in front of the rodent holding compartment (16) and the other at the rear end of the rodent holding compartment (17). The rodent is placed in the special cage (Fig 3) and directed into the rodent holding compartment through (16) and prevented from escaping by a door (9) with a notch (10) that enables hanging of the tail outside the cage. The perforation (17) at the rear end of the rodent holding compartment allows light in that attracts the rodents. The infected vector contacts the uninfected rodent through (11) and transmits infection. To prevent the rodent from escaping through this opening the single vector cage (Fig: 5) is slotted first before introducing the rodent so as to seal this opening. Rodent resting base (7) made of metal plate or other suitable material is fixed on the lower side of rodent holding compartment. Vector tube receptacle (13) attached to the rodent holding compartment by (12) holds the vector tube upright while fixed on (74). The stand (14) with a resting base (IS) is fixed onto the lower side of the rodent holding compartment to provide means for resting it on the bench. At the end of the experiment, the rodent is released through door (18) with a handle (19) and walk through the ladder (A) to the rodent-resting cage (Fig. 6). Fig: 5 - Single vector cage

This is a modified 10ml plastic syringe or any appropriate design whose one end has been smoothly cut and covered with a netting material (71). The netting material is held on to the tube by adhesive tape (72) or any other appropriate means of attaching. The piston (73) serves as a stopper and is used to restrain the movement of the vector within the tube by reducing the area available for its free movement.

Rodent and vector holding devices (Fig 2) when infecting the vector en mass

This is made up of the following parts: -

(i) Rodent holding compartment (1,2,3,4,5,6) (ii) Mass vector cage (Fig 4)

(iii) Vector cage holder (receptacle) (29,30,31,32,33,34,35,36,37,38)

(iv) Stand (14 &15)

(vii) The ladder (20,21,22,23,24,25,26,27 &8)

(viii) Rodent release door to the ladder (19) with a handle (19) (v) Special cage for introducing the rodent into rodent holding compartment (Fig 3)

(39,40,41,43,44,45,46^47,48,49,5051,52,53, 54 &55) made of any appropriate material. (vi) Special cage stand (53) a) The rodent cage

This is a skeleton made of piano wire or any appropriate material disclosed by (1,2,3&4) joined together by gas welding to (5 &6). This skeleton is wrapped with an expanded wire or any other appropriate material (8) leaving three open spaces one on the upper side (11) of the cage that allows the vector inside the vector cage (Fig: 4) direct contact with the rodent. To prevent escape of the rodent through the opening (11) the vector cage is slotted before the rodent is introduced into the cage. The rodent (mouse) is placed in the special rodent introducing cage (Fig 3) and directed into the rodent holding compartment through (16) as in Fig 1 and prevented from escaping by a door (9) with a notch (10) that enables hanging of the tail outside the cage. The perforation (17) on the rodent release door allows light in that attracts the entering rodent. At the end of the experiment, the rodent is released through door (18) with a handle (19) and walk through the ladder (A) to the resting cage (Fig. 6). b) Rodent feet resting base (7).

This is on the lower side of the rodent cage, and is made of a flat sheet of iron sheet or other suitable material.

c)Vector cage holder This is made of piano wire or other suitable material as disclosed

(29,30,31,32,33,34,35,36,37,38) joined together into a rectangular shape fixed in flush onto the rodent holding compartment to enable the vector contact the rodent easily. d) The stand (14 )

This is made of piano wire or other suitable material and has a resting base (15) fixed on the lower side of the rodent holding compartment. e) The door (9)

This prevents the rodent from coming out once in the cage. A notch on the door (10) provides hanging of the tail outside the cage. f) Rodent release door (18) This is opened at the end of experiments and allows the rodent access to the ladder (A) through which it walks to its resting cage (Figure 6). It can be made of piano wire or any appropriate material (g) Ladder (A)

This is made of piano wire enclosed with a mesh wire (8) or any appropriate material and fixed onto the rear end of the rodent holding compartment in a slating position to enable the rodent comfortable walk to the resting cage. The enclosing mesh wire (8) prevents the rodent from jumping off the ladder on its way to the resting cage. Figure 4: Mass Vector cage

This is a skeleton made of piano wire or any appropriate material disclosed by (57,58,59,60,61,62,63,64,66,67, 69,70) and wrapped with a mosquito net (65). The top is covered with a metallic or wooden plate (56) or other appropriate material and protects the vector from leaving the cage by means of a door (68). Figure 3: Special rodent introducing cage

This is a special cage designed to hold the rodent when introducing it to the rodent holding compartment. It is made of plastic material or any other appropriate material and has a door (42) with means of spring. The rodent escapes through tube (54) and opening (55). This opening is attached to (16) of the rodent holding compartment while the rodent release door (18) is closed. On entry into this compartment, the special cage is withdrawn and the rodent prevented from getting out using door (9). Stands (53) enables the special cage to stand on its own if necessary.

Figure 6: Rodent resting cage

This is the normal rodent cage but improved to receive the rodent from the rodent holding compartment at the end of the experiment. The ladder (A) through which the rodent walks is attached to this cage through opening (75). Once in this cage, the ladder is withdrawn and the rodent prevented from getting out by door (74) with means of spring. Several such openings can be put for insertion of several ladders. When in this cage, the rodent rests on sawdust (bedding material) not visible in this figure where food (76) and water (77) are provided. The rodent is prevented from jumping of this cage by a cage cover (78) made of stainless steal wire or any other appropriate material. Figure: 7

Discloses single unit assemblage of both vector and rodent holding device used when infecting the vector en mass with vector cage inserted in place. Several such units can be joined together in any configuration to allow handling of multiple vectors and rodents. Figure 8:

Discloses single unit assemblage of both vector and rodent holding device used when individual vector transmits infection to a single rodent with single vector cage inserted in place. Several such units can be joined together in any configuration to allow handling of multiple vectors and rodents.

Claims

1. A device for holding rodent and vector during vector infection and transmission process comprising of a rodent holding compartment and a vector cage; said rodent holding compartment having means for resting it on the bench, and further fitted with means for engaging the vector cage as well a ladder and a rodent release sliding door; said rodent holding compartment accompanied by a special rodent cage for introducing the rodent into the rodent holding compartment.

2. A device as in claim I₅ wherein the rodent holding compartment comprises side, bottom and a top walls joined together to form an enclosure covered with an expanded wire as well as three openings with one at the top and the others the front and rear ends respectively.

3. A device as in claim I₅ wherein the rodent holding compartment is mounted with the means for engaging the vector cage.

4. A device as in claim 3, wherein the front door has a notch that allows hanging of the tail outside the rodent compartment and the rear has a handle and a means of holding when sliding up and down.

5. A device as in claim 3, wherein the rear door has means of allowing light from the rear end to penetrate into the rodent holding compartment

6.A device as in claim 1 wherein the said ladder comprises of side, bottom and top walls joined together and covered with an expanded wire to form an enclosure.

7. A device as in claim I₅ wherein the rodent holding compartment has doors at the front and rear ends

8. A device as in claim I₅ wherein the said special rodent cage comprises of side and bottom walls joined together and a door with means of a spring door fixed to form an enclosure; said special cage fixed with a rodent escape route.

9. A device as in claim I₅ wherein the single vector cage has openings at both ends, one opening being covered with a netting material and the other side fitted with a means for restricting the vector movement.

10. A device as in claims 1 wherein vector cage is rectangular or cylindrical.

11. An assemblage as in claims 1 to 10 wherein the devices are combined in multiples and in a linear, circular, rectangular or triangular configuration to form a larger unit with a capacity of holding larger number of rodents and vectors simultaneously.