EPIDEMIOLOGI Veteriner

Calvin Schwabe, widely known as the "father of modern epidemiology". His insightful words, "The critical needs of man include the combating of diseases, ensuring enough food, adequate environmental quality, and a society in which humane values prevail," are even more compelling today.

Sabtu, 03 April 2010

Current situation with highly pathogenic avian influenza (HPAI) in Indonesia, with special emphasis on control at village level

This article below can be read on-line at: http://www.aciar.gov.au/publication/PR131

Village chickens, poverty alleviation and the sustainable control of Newcastle disease
Publication Code: PR131
ISBN: 978 1 921531 75 0 (print) 978 1 921531 76 7 (online)
Author(s): Alders R.G., Spradbrow P.B. and Young M.P. (eds)

Presented at the International Conference - AusAID Southern Africa Newcastle Disease Control Project, Dar es Salaam, Tanzania, 5 – 7 October 2005.

Tri Satya Putri Naipospos*

Abstract

Indonesia has both a modern, commercial poultry industry and very large numbers of village poultry. The first outbreak of highly pathogenic avian influenza (subtype H5NI) in 2003 was initially misdiagnosed as Newcastle disease. The disease spread widely, with the first human death being recognised in June 2005. Strategic control processes were introduced in January 2004. These included improved biosecurity, vaccination in infected and high-risk areas and selective culling. There is an emphasis on control at village level.

The poultry sector in Indonesia

The poultry industry in Indonesia consists of a large population of commercial chickens. The capacity of breeders is around 1.8–2 million day-old chicks per week for layers and 18–20 million per week for broilers. The layer population is 80–85 million, while broilers number 1.2 billion per annum. The population of backyard/village poultry is estimated to be 295 million local chickens and 45 million ducks, spread throughout Indonesia.

The main market for poultry is the rapidly urbanising population of Indonesia, mainly in Java, which is hence also a centre for production. Although Indonesia is not a poultry-exporting country, it has small and limited regional trade in day-old chicks and broilers with Singapore, Malaysia, Vietnam, Myanmar and Japan. This has been banned by importing countries following the emergence of highly pathogenic avian influenza (HPAI).

There are about 2,300 poultry companies across the country, and poultry workers number around 25,000. Figure 1 shows the structure of the poultry industry in Indonesia, where 58% of the poultry population is located in Java, 24% in Sumatra, mainly in North Sumatra and Lampung provinces, 6% in Kalimantan and 10% in South Sulawesi province. Only a very small percentage (2%)of the poultry population is in the eastern part of Indonesia.

The commercial integrators (sector 1) and other commercial farms (sectors 2 and 3) produce 80% of domestic poultry, whereas smallholders (sector 4) raise the remaining 20%, which is mainly indigenous poultry. The off-take from the considerable backyard/village poultry production system is not well documented but considered to be significant. Characteristics of each sector or poultry production system in Indonesia are described in Table 1. Around 30 million households raise local chickens and ducks. Newcastle disease is the main poultry disease prevalent in the country.

The history of the current HPAI outbreak in Indonesia

High mortality of chickens in layer farms was reported for the first time in Legok subdistrict, Tangerang district, Banten province, in August 2003. The cause of the outbreak was initially diagnosed as very virulent Newcastle disease, until it was confirmed to be caused by the HPAI virus. The outbreak then spread very rapidly to 11 provinces in Indonesia between August 2003 and January 2004: six in Java, one in Sumatra, three in Kalimantan and one in the province of Bali.

The Director General of Livestock Services of the Government of Indonesia announced officially on 25 January 2004 that an HPAI outbreak existed in Indonesia, with nearly 20 million chicken deaths. The occurrence of the HPAI outbreak was also reported to the World Organisation for Animal Health.

The Director of Animal Health then announced on 3 February 2004 that the subtype of HPAI virus was H5N1. The disease continued to spread within the poultry population within many provinces, districts and subdistricts, but until 2004 did not infect humans. Figure 2 plots the number of poultry deaths due to HPAI between August 2003 and September 2005.

On 19 May 2005, the Minister of Agriculture informed that the H5N1 virus had been found in pigs in Tangerang district, but with no evident symptoms. On 28 June 2005, the Minister of Health announced that the first case of ‘bird flu’ in a human had occurred in Indonesia. Up to July 2006, HPAI resulted in 42 human deaths from 54 confirmed cases.

Current short-term strategies for controlling HPAI

Considering the wide distribution of the disease, the high number of cases and complexity of the disease’s ecology, it was deemed economically too expensive and socially unwise to cull all the birds in the infected areas. Based on these considerations, the Indonesian Government adopted a series of measures known as the nine strategies:
1. improvement of biosecurity
2. vaccination in infected and high-risk areas
3. depopulation (selective culling)
4. compensation
5. control of movement of live poultry, poultry products and farm waste
6. surveillance and tracing back
7. restocking, stamping out in newly infected areas
8. public awareness
9. monitoring and evaluation.

Figure 1. Distribution of commercial poultry numbers across Indonesia. Source: Information derived from Food and Agriculture Organization of the United Nations and Directorate General of Livestock Services (Indonesia) statistics.

These were introduced in January 2004. Mass vaccination linked to post-vaccination monitoring is the core national control strategy, but is only one tool that has to be carried out in conjunction with the other strategies. All breeder and layer farms (sectors 1 and 2; see Table 1) in the infected and high-risk areas are adopting vaccination routinely, using their own technical and financial capacity. Only 30% of broiler farms are adopting vaccination. Some breeders are adopting a ‘differentiating infected and vaccinated animals’ strategy and a few others are using a sentinel system.

The mass-vaccination campaign was launched by the government in July 2004, targeting poultry sectors 3 and 4. Vaccine is given free of charge. The government has provided nearly 300 million doses of vaccines, which are locally produced. The mass-vaccination program is supported by post-vaccination monitoring. The vaccinations have met with variable success, but with good success in especially the commercial sector. Seven regional disease-investigation centres and some provincial laboratories have to handle large-scale diagnostic loads with post-vaccination monitoring. Tables 2 and 3 give the results of post-vaccination monitoring in different species of poultry.

The supporting equipment for the mass-vaccination campaign and surveillance — such as refrigerators, ice boxes, automatic and disposable syringes and cellmatics — is distributed to every infected province/district/municipality, the numbers of items provided being based on the poultry population in the area. In addition, personal protective equipment is distributed to infected provinces/districts/municipalities and regional laboratories.

Public awareness is a critical component of the HPAI disease-control program. The government has provided different types of public awareness materials on HPAI, such as roll-up banners, posters, flyers, booklets and video presentations. In order to support the mass-vaccination campaign, a radio-commercial program has been developed and broadcast for a certain period over several local radio stations throughout the infected areas.

Table 1. Characteristics of each category of Indonesian poultry production system


Figure 2. Numbers of poultry deaths due to highly pathogenic avian influenza in Indonesia between August 2003 and September 2005. Source: Information provided by Provincial Livestock Services, Indonesia.

Table 2. Results of highly pathogenic avian influenza post-vaccination monitoring in Indonesia, by poultry species and types

Source: Information provided by Disease Investigation Center, Region VI, Denpasar, in 2005

Table 3. Results of highly pathogenic avian influenza post-vaccination monitoring by type of vaccine used

Source: Information provided by Disease Investigation Center, Region VI, Denpasar, in 2005

Medium- and long-term strategies for control, eradication and prevention, with an emphasis on control at the village level

Constraining factors in Indonesia had to be taken into account when considering control strategies in the medium and long term. These include the large and diverse poultry population, the large smallholder segment, weak veterinary infrastructure at the lower levels, and suboptimal awareness programs. On the other hand, that there were no human cases or fatalities at the beginning and during the 2004 epidemic masked the emergence of HPAI as a potentially serious disease. Recognition of the importance of HPAI increased due to the human deaths documented.

The weakness of the veterinary system has to be clearly recognised by the government. There is no strategic field surveillance and no improved epidemiological inputs that can assist the authorities to deal quickly with the disease and halt the spread of HPAI across the country. The implementation of the strategic control plan is seriously hampered by the lack of clearly defined legal and regulatory frameworks under which disease control programs can be enforced in the field.

The impact of a government decentralisation system has had a significant influence on the government’s ability to combat HPAI. This is evident from the difficulties in establishing the national policy base and managing the public sector budget being experienced at the district and subdistrict levels. Districts and subdistricts are independent from the central government and manage their own public funds, which has fragmented the flow of disease information and control programs from the national to the provincial level. This institutional constraint also hampers rapid and effective alert and response.

The implementation of medium- and long-term strategies (10–12 years) includes the following policy and legislation framework to support control of HPAI:
• veterinary capacity building
• program management training
• socioeconomic impact assessment
• risk-based surveillance programs
• eradication at source of infection
• epidemiology-driven disease-control activities
• policy/protocol/standard operating procedures when sero-positive results occur
• private sector involvement
• poultry sector restructuring.

The focus of the strategies, with special emphasis on control at village level from 2005 onwards, will be on pilot activities to support the current nine strategies as follows:
• enhancing farmer awareness
• implementing grassroots early warning
• establishing village-based field surveillance systems
• upgrading veterinary support
• establishing emergency preparedness.

The key factor in fostering farmer awareness is to empower the communities themselves. Therefore, the farmers’ role in helping in control and prevention in their villages is of great importance in gaining grassroots cooperation.

Grassroots early warning and surveillance are two most important strategic components in early detection, early reporting and early response. The early warning and surveillance network will be formed around the members of village poultry farmers groups. These groups will form the village community’s basic social core from which basic surveillance must originate. Village team leaders will be selected from leading village poultry farmers and trained to head up village surveillance teams. Farmers groups and animal health workers will be trained in simple disease recognition, sample collection and biosecurity.

Veterinary support at district level has to be given a high priority by the government at all levels. District veterinary laboratories will be upgraded with equipment, consumables and technician training, and dedicated to improved and increased HPAI diagnosis and serological survey. Emphasis will be placed on getting owners of sector 3 poultry farms to practise compulsory HPAI vaccination and undergo biosecurity training.

Emergency preparedness has to be ready at all times and fully adopted by field personnel and laboratory staff. Each district will be stocked with emergency gear and disinfectants to support stamping-out operations. Village groups and animal health workers will be trained in protocols for emergency stamping-out campaigns.

Conclusion and lessons learnt

Success in controlling HPAI in Indonesia needs a strong political commitment at the national and provincial levels to invest more resources in all aspects of disease control. Early diagnosis, reporting and rapid response have to exist at the grassroots level. District veterinary personnel have to understand the national policy and be adequately equipped to carry out comprehensive, active surveillance and mobilisation for vaccination programs.

They must also be more effective and prompt in implementing biosecurity and other control measures. Eradication of the virus source from backyard poultry will be a difficult and long-term task. It is essential to explore disease-control options in carrier domestic ducks, including restructuring of domestic ducks and terrestrial poultry flocks, strategic culling of domestic ducks, and progressively enhancing flock immunity through vaccination, to reduce virus shedding.

*) Directorate of Animal Health, Directorate General of Livestock Services, Department of Agriculture, Indonesia

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