The Status of Rabies in the Lao P.D.R

(日本語)

　

ＴＨＥ　ＳＴＡＴＵＳ　ＯＦ　ＲＡＢＩＥＳ

ＩＮ　ＴＨＥ　ＬＡＯ　Ｐ．Ｄ．Ｒ．

　

January,1995

　

Hitoshi Inagaki

Veterinarian,

Livestock and Veterinary Section in Savannakhet Province

(Member of JOCV)

　

　

ＳＵＭＭＡＲＹ

Rabies is endemic in the Lao P.D.R. and there are presently very few facilities or resources for combating this disease. The stastical data available in Lao shows that rabies is widely distributed throughout the country and measures to counter the further spread of this disease are urgently required. This reports proposes that the local production of low-cost vaccines is a suitable way to control rabies in this country.

　

　

Introduction

Rabies is a disease transmitted through biting. In infected animals, the ausative organism, a rabdovirus, multiplies in the salivary glands and is actually spread in the saliva of animals. In the muscle of a wound, the virus multiplies and travels to the peripheral nerve from where it then affects the whole central nervous system.

　

The incubation period for the disease is variable. For small animals, it ranges from two weeks to several months. For most humans, the incubation period is between one and three months but occasionally it may be over three years.１

The Rabdovirus can infect all mammals and once animals become ill,100% die. Muscle spasms and convolutions are characteristic symptoms of the disease together with the more well-known hydrophobia (fear of water). The first symptoms of the disease are a change in behavior (shy animals will often become tame ). In later stages the animals will fall into a coma and finally die as their central nervous system is invaded by the virus.

Rabies is terrible disease and vaccination is the only way of preventing animals from becoming ill.

Most countries in the world have rabies but there are some who are rabies-free such as Australia, Japan, Singapore, and the United Kingdom.

For most of the developing countries, rabies is a serious problem for humans, Livestock and pets. In the Philippines for example, 25,000 dogs die of rabies each year while in India, 20,000 people die each year. In Thailand, there are over 1,000,000 dogs and each year 140,000 people undergo treatment for rabies of which 200-300 people die.１

In Lao, there are few statistic but a recent investigation of the problem by the author of this proposal, sheds some light on the seriousness of the disease in this country. The summary statistics from the investigation are presented below.

　

　

Methodology

The data presented below are taken from the Livestock and Veterinary Section in Vientiane (1988). All of the dogs reported, bit humans. The dogs were killed by stick or rope and then brought to the Veterinary Section for inspection of rabies. The method of inspection is;(1)Confirm Negli body presence by dying with Gerlach Solution. Examination by microscope (Negli body appear in Cornu Ammonis in brain of the dogs that have rabies virus),(2)The mashed brain of dogs inject to mouse and observe two weeks.Cost of inspection is: (1)=1,000 kip,(1)+(2)=3,500 kip. Therefore many people request only (1),but this data don't give positive sure proof.

　

VIENTIANE

1. Investigation of the Livestock and Veterinary Section in Vientiane　

Inspections by Government officials and the incidence of rabies

Year	No. of inspection	No. of infected dogs
1988 1989 1990 1991 1992 1993 1994 1995 1996	90 96 107 112 144 163 199 241 273	83 (92.2 %) 89 (92.7 %) 97 (90.1 %) 102 (91.1 %) 136 (94.4 %) 112 (68.7 %) 117 (58.8 %) 127 (52.7 %) 143 (52.4 %)

　

No. of animals vaccinated for rabies in Vientiane-DOGS

Year	No. of dogs vaccinated
1988 1989 1990 1991 1992 1993 1994 1995 1996	2,800 3,200 3,600 4,520 7,230 11,004 12,179 14,100 18,400

This data comes from the National Institute of Vaccine Production.

　

2．Investigation of the NATIONAL INSTITUTE OF HYGIENE AND EPIDEMIOLOGY

1)Number of cases recorded of dogs biting people.

1992	1993	1994	1995	1996
820	886	1,067	1,540	1,499

　

2)Number of dogs caught which have rabies.

1992	1993	1994	1995	1996
242	118	130	187	-

　

3)Number of people who were vaccinated 3-5 times after being bitten.

1992	1993	1994	1995	1996
280(34.1%)	294(33.2%)	432(40.5%)	712(46.2%)	801(53.4%)

　

4)Number of people who were vaccinated 1-2 times after being bitten.

1992	1993	1994	1995	1996
502(61.2%)	575(64.9%)	635(59.5%)	828(53.8%)	698(46.6%)

　

5)Number of people who not vaccinated after reported as being bitten

1992	1993	1994	1995	1996
46( 5.6%)	22( 2.5%)	0( 0.0%)	0( 0.0%)	0( 0.0%)

　

6)Number of cases that people are bitten by dogs each months.

Year	1	2	3	4	5	6	7	8	9	10	11	12	Total
1992 1993 1994 1995	79 74 93 117	64 76 76 96	65 91 85 129	64 64 83 124	67 64 85 146	49 69 81 132	72 56 77 155	57 71 102 138	81 63 89 121	67 92 104 143	65 82 82 113	90 80 108 126	820 886 1,067 1,540

　

3．Investigation of the Ministry of Public Health

Year	No.cases recorded dogs biting people	No.dogs infected	No.people vaccinated	No.people died from rabies
1989 1990 1991 1992	274 (22.8/month) 208 (17.3/month) 503 (42.0/month) 490 (22.8/month)	69 (25.2%) 96 (46.1%) 358 (71.2%) 224 (45.7%)	273 (99.6%) 184 (88.4%) 503 (100.0%) 486 (98.0%)	- 2 3 -

　

4．Investigation at the animal clinic in Vientiane

1)Number of dogs that were vaccinated.

1992…280　　　 1993…526　　　　1994…378

2)Number of dogs that were diagnosed as having rabies.

1992… 44　　　 1993… 92　　　　1994… 32

3)Number of cases recorded at the clinic of dogs biting people.

1992…8〜9　　　1993… 0 　　　　1994… 0

As the diagnosis of rabies is undertaken on the appearance only, it is not known how many of the dogs actually had rabies (examination of nervous tissue is required for difficult diagnosis).

　

5．Cost of vaccination

For dogs：

Live viral vaccine made in Lao　… 1shot 700〜 1,000 kip (1-1.4$)

Inactivated vaccine made in foreign countries… 1shot 3,000〜 5,000 kip (4.2-7$)

For people：

Inactivated vaccine made in foreign countries… 1shot8,000〜10,000 kip (11-14$)

　

6．Investigation in the hospitals of Vientiane (January,1994)

Presently, people who are bitten by dogs suspected of having rabies go to the National Institute of Hygiene and Epidermiology and only very occasionally go to hospital. Most people who are bitten are treated at home. The number of people who die from rabies each year is therefore unknown.

　

SAVANNAKHET

1．Investigation of the Department of Agriculture and Forestry in Savannakhet

Year	1991	1992	1993	1994	1995	1996
No.of dogs vaccinated	100	150	1,900	465	1,420	1,335

・The dog population (1992) …1、591

・Cost of vaccination … 1、500 Kip(2$)

・Vaccination was doing only in capital city of Savannakhet P.(kantably)

　

2．Investigation of the Department of Public Health in Savannakhet

Month/ 92'	No.cases recorded dogs biting people	No.dogs infected	No.people vaccinated	No.people died from rabies
2 6 8 10 11 12	6 3 5 10 31 14	1 - 1 - 1 -	0 1 3 8 5 14	- - - - - -
Total	69	3(4.3%)	31(44.9%)	0

　

Month/ 93'	No.cases recorded dogs biting people	No.dogs infected	No.people vaccinated	No.people died from rabies
1 2 3 4 5 6 7 8 9 10 11 12	11 16 4 10 12 12 20 9 13 11 13 17	- 1 - - - - 1 - - - -(3) -(2)	11 10 4 10 10 12 16 8 10 11 13 17	- 1 2 - - - 1 3 - - - -
Total	148	2(1.4%)(5)	132(89.2%)	7(4.7 %)

　

Month/ 94'	No.cases recorded dogs biting people	No.dogs infected	No.people vaccinated	No.people died from rabies
1 2 3 4 5 6 7 8 9 10	13 17 27 11 14 10 22 17 11 9	- 　 -(2) 　 1(1) -(2) -(1) - -(1) - - -	13 17 27 11 14 10 22 17 11 9	- - - - - - - - - -
Total	151	1(0.7%)(7)	151(100%)	0

Include the dates of the number dogs infected,( ) are number of dogs that died in 3-4 days after bited people. these have many doubt of rabies.

　

CHAMPASAK

・Number of dogs vaccinated

1993 … 430 　　　1994 … 250

・Number of cases recorded of dogs biting people

1993 … 263 　　　1994 … 261

・Number of dogs inspected rabies

1993 … 51　　　　1994 … 52

・Number of infected dogs

1993 … 15　　　　1994 … 10

・Number of people who went to hospital after being bitten

1993 …　51　　　 1994 … 78

・Number of people who died in hospital

1993 … 　0 　　　1994 … 0

・Number of people who died from rabies of a year

1993 …　 5 　　　1994 … 0

・Cost of vaccination for dogs 　…　700 kip (1$)

・Cost of vaccination for people … 5 shot 1,500〜2,500 barts (60-100$)

　

LUANGPHABANG （1993）

Name of district	dog population	No.dogs vaccinated
Muang Park Uhu Muang Changpet Muang Luangphabang	- 11,430 9,070	- - 11 (0.1%)

　

XIENGKHUANG

・In 1990,woman who was almost 30 years old died in hospital. After that nobody came hospital for rabies. May be all dogs are not vaccinated in Xiengkhuang.

　

・Number of rabies vaccines send to each province from National Institute Vaccine Production Nongteng.（1.1.1993 〜 31.10.1993）

Name of province	Number of rabies vaccines
Vientiane (prefecture) Vientiane (province) Savannakhet Champasak Salavan Khammuan Sainyabuli Bolikhamsai Udomxai Attapeu Luangphabang Hua Phan Xieng Khuang Sekong Luangnamtha Bokeo Phongsali	8.422 40 1.300 1.500 100 150 170 30 - - 400 - - - - 50 -
Total	12,212

　

The investigations reported above were undertaken in Vientiane, the capital city of the Lao PDR and countryside. There are few statistics and the collection of similar data from the countryside is very problematic.

Although I collected much data, the data are fragmentary and so I could not make a comparison between provinces. Always statistics of this country are not exact. Data which is collected one year, may not be collected the following year. Method of statistics have many problem here. For example, Number of dog population in Savannakhet (1993) is very unreliable and doubtful. And number of people who died from rabies is unreliable too.

Many people of this country don't have habit of going to hospital. Therefore, if some one die from rabies in his home, this case don't appear on statistics. In these datas, number of infected dogs are very few, but these are very rare cases. So, if we want inspect rabies, we must catch the dog that bited human and send this to Vientiane. Actually, even dog population is not accurate. However, the opinion of officials in the Department of Livestock and Veterinary is that less than 10% of the dogs in Lao are vaccinated against rabies.　

If it assumed that the statistics collected in Vientiane are representative of the rest of the country (population apporx.4,000,000),it could be estimated that as many as 7,000 dogs in Lao have rabies and that over 800 people each year may die from the disease.(1992)

This figure has been estimated from Vientiane statistics in the following way:

― Population of Lao PDR is ten times of Vientiane.

― 10% dogs are vaccinated.

― Number of the owners of dogs per population is same.

― There are 723,000 dogs in Lao.(1992)

― 8,200 incidents in 1992 of dogs biting humans.

― 94.4% of dogs have rabies = 7,741 dogs

― Treatment is not total effective,16% of people who are bitten die from rabies.

― 548 people were not effectively vaccinated in Vientiane.(1992)

　

Year	dogs population	No.cases recorded dogs biting people	No.dogs infected	No.people died from rabies
1992	723,000	8,200	7,741	827
1993	1,100,400	8,860	6,086	656
1994	1,227,900	10,670	6,274	597

　

One of the established ways of reducing the incidence of rabies in a country is to vaccinate the dog population. This has proved a very effective measure in neighboring Thailand were until recently the disease was also reaching epidemic proportions

The best way to root out rabies are 1)root out stray dogs,2)raise dogs must be chained,3)quarantine animals from foreign country,4)all dogs must be vaccinated. But now in this country, there are no 1),2) and few 3).4).

These data show that number of people who were vaccinated after being bitten are increasing. But it is said about only Vientiane and other few cities. People in the countryside don't yet know about the danger of rabies and the necessity for vaccination.

From 1993 to 1994 in Savannakhet and Chmpasak the number of people being vaccinated after being bitten has increased. However, during the same period the number of dogs vaccinated has decreased. In Vientiane and part of Savannakhet, Champasak, Luangphabang, some dogs are vaccinated. But in Xiengkhuang, Udomxai, Attapeu, Huaphan, Sekong, Luangnamtha, and Phongsali may be every dogs are not vaccinated.

Unfortunately however the only production facility in the Lao PDR for an animal vaccine is at the National Institute of Vaccine Production at Nongteng. This factory is a public enterprise. Therefore, this institute sale the animal vaccine to each province cheaper than the cost price. The United Nations Development Program(UNDP) assisted this institute. However the support has now been withdrawn in 1993. Now this institute is in financial difficulties. If this institute will become insolvent the price of animal vaccine in Lao will be 3,000-5,000 kip, too expensive for most people to purchase. (GNP of one person in a year is almost 300$)

Other life treating disease such as AIDS and hepatitis-B are preventable with some moderate from of protection. Protection against rabies however is more problematic and vaccination of dogs is an effective and relatively inexpensive cure.

Rabies is a very terrible disease but people do not fear the disease like AIDS. The cause of the disease is clear and a good supply of vaccine therefore essential. The prevention of rabies in this country is still a large problem.

　

Acknowledgment

The author wishes to express their sincere respects and deep appreciation to : Dr.N.Innestaylor (AIT).Dr.T.Chosa (JICA) and National Institute of Hygiene and Epidemiology,Dr.Khamdeng and Vientiane Veterinary Clinic,Dr.Douanchith and Livestock and Veterinary Section in Svannakeht,Dr.P.Singkham,Dr.B.Silivong and Department of Livestock and Veterynary in Vientiane,Dr.B.Nounouannavong and National Institute Vaccine Production Nongteng,Ministry of Agriculture,Ministry of Public Health and Government of Lao People's Democratic Republic.

　

References

1.Sakamoto,K. Rabies in India and Thailand,juuichikusanshinpou Vol.46,No.5 1993; 388-391.

2.Nicolson,K.G. Mordan Vaccines Rabies,The Lancet 1990; 1201-1205.

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