Avian Influenza Risk Perceptions, Laos

To the Editor: After the 2004 outbreak of highly pathogenic avian influenza (HPAI) in poultry in Lao People’s Democratic Republic (PDR), the Ministry of Health implemented extensive virologic surveillance (1,2). Surveillance began in July 2005, and by early 2006, only sporadic cases were found. In July 2006, an outbreak of HPAI was confirmed on 2 chicken farms in Vientiane, the capital city of Lao PDR (1,3). Most of Laos’ ≈20 million chickens are kept on family-owned backyard farms; 3.2 million are on commercial farms (4). This production meets 80% of Lao poultry (chicken, duck, goose, quail) needs; imports from neighboring countries, either through legal trade or cross-border smuggling, account for the rest (3). Common poultry diseases occur frequently during the cold season, and lack of reporting of poultry deaths is of concern (4). 
 
Until February 2007, no human cases of influenza A (H5N1) had been reported in Lao PDR. To learn more about Laotians’ knowledge of HPAI and perceptions of their risk, we conducted a cross-sectional survey. 
 
In March–April 2006, participants in 3 settings (Vientiane, urban; Oudomxay, semiurban; Attapeu Province and Hinheub District, both rural) were interviewed in the Lao language by means of a standardized 33-question survey. We recorded information about behavior, poultry handling and keeping practices, and poultry deaths. We used multivariate analysis (Stata, version 8; Stata Corporation, College Station, TX, USA) to analyze the factors associated with behavior changes. 
 
Using a random sampling list of visitors and vendors, we interviewed 461 respondents in 4 Vientiane city markets (Vientiane has 114,793 households and 3,700 registered poultry farms) (5). Semiurban respondents were recruited in Oudomxay (40,987 households, 715 poultry farms), an active trading zone near the Chinese border. Rural respondents were recruited from Hinheup District and in Attapeu (19,050 households, 360 poultry farms), near the Vietnam border. Twenty villages were randomly selected, and 10 participants per village were randomly selected for interview. Approval for the investigation was obtained from the health and market authorities. Oral consent for interview was obtained from participants. 
 
A total of 842 participants were interviewed (Table). Differences in occupation and literacy were associated with different study areas. Differences in participant sex and age were also noted because, in the rural areas, interviews took place in the home. A total of 583 (69.3%) participants were female: 302 (65.5%), 139 (68.2%), and 150 (79.3%), in urban, semiurban, and rural areas, respectively; p = 0.002, 95% confidence interval 66–72. Mean ages for participants in these areas were 41 (range 40–43), 34 (range 32–36), and 38 (range 37–41) years, respectively; p<0.001. Animal breeding was conducted by 50% of families. Daily close exposure to poultry was common (39.6%). Few families owned a henhouse, and no special handling of poultry was reported. Rates of poultry vaccination against common poultry diseases were higher in urban and semiurban areas; veterinary surveillance was low (10.2%). 
 
 
 
Table 
 
Avian influenza knowledge, risk perception, and poultry-keeping behavior, Lao People’s Democratic Republic* 
 
 
 
Overall, 96.9% of respondents had already heard of HPAI, mainly through television. Urban residents ranked it as the most well-known poultry disease, but rural residents ranked it fifth. Less than half of the respondents had some knowledge of the disease signs and symptoms for humans and poultry; 28.4% could describe 1 symptom. Half of the respondents believed that they were not at risk for human avian influenza or that their poultry were not at risk for it. Respondents in urban and semiurban areas knew more about avian influenza than those in rural areas. 
 
During the cold season, poultry deaths were higher in the north (colder) and south than in Vientiane. The poultry mortality rate during the cold season was similar to that of Cambodia (6). Behavior regarding poultry deaths differed between areas. Despite a high rate of poultry deaths, none of the interviewees had notified authorities. Since hearing about HPAI, 67.1% respondents, mainly in Vientiane, claimed that they had changed behavior regarding poultry. Multivariate analysis showed the following factors to be associated with behavior change: level of education (p = 0.002), urban living (p<0.001), knowledge of avian influenza risk (p<0.001) and disease (p<0.001), owning poultry (p<0.001), and being a government worker (p<0.001). 
 
This study had limitations but provides new insights on Laotians’ knowledge and poultry practices with regard to HPAI. Despite a high level of awareness, populations underestimated the risk, particularly those in rural areas. Most respondents were unaware of appropriate poultry-handling measures to reduce risk (6). The claimed changes were higher (more frequent and more substantial) in urban (91.8%) than in rural sites (3.8%, p<0.001), higher than changes made by their counterparts in Thailand (7), and confirmed by reports after the 2004 outbreaks (8,9). These differences between urban and rural areas might be explained not only by participant characteristics but also by a lower extent of the awareness campaign in rural areas. 
 
Failure to report poultry deaths should be addressed and has several possible explanations. Farmers are accustomed to common yearly poultry deaths, which are not reported. In the absence of an official compensation statement, farmers may fear income loss from massive poultry culling. 
 
Our results emphasize the need for more accurate information about transmission risks, notification requirements, safer behavior and practices, and compensation for losses. Focus also needs to be placed on building capacity in the veterinary system (10). These issues should be integrated in the Laos National Avian Influenza Control and Pandemic Preparedness Plan (2006–2010).


Avian Infl uenza Risk Perceptions, Laos
To the Editor: After the 2004 outbreak of highly pathogenic avian infl uenza (HPAI) in poultry in Lao People's Democratic Republic (PDR), the Ministry of Health implemented extensive virologic surveillance (1,2). Surveillance began in July 2005, and by early 2006, only sporadic cases were found. In July 2006, an outbreak of HPAI was confi rmed on 2 chicken farms in Vientiane, the capital city of Lao PDR (1,3). Most of Laos' ≈20 million chickens are kept on familyowned backyard farms; 3.2 million are on commercial farms (4). This production meets 80% of Lao poultry (chicken, duck, goose, quail) needs; imports from neighboring countries, either through legal trade or crossborder smuggling, account for the rest (3). Common poultry diseases occur frequently during the cold season, and lack of reporting of poultry deaths is of concern (4).
Until February 2007, no human cases of infl uenza A (H5N1) had been reported in Lao PDR. To learn more about Laotians' knowledge of HPAI and perceptions of their risk, we conducted a cross-sectional survey.
In March-April 2006, participants in 3 settings (Vientiane, urban; Oudomxay, semiurban; Attapeu Province and Hinheub District, both rural) were interviewed in the Lao language by means of a standardized 33-question survey. We recorded information about behavior, poultry handling and keeping practices, and poultry deaths. We used multivariate analysis (Stata, version 8; Stata Corporation, College Station, TX, USA) to analyze the factors associated with behavior changes.
Using a random sampling list of visitors and vendors, we interviewed 461 respondents in 4 Vientiane city markets (Vientiane has 114,793 households and 3,700 registered poultry farms) (5). Semiurban respondents were recruited in Oudomxay (40,987 households, 715 poultry farms), an active trading zone near the Chinese border. Rural respondents were recruited from Hinheup District and in Attapeu (19,050 households, 360 poultry farms), near the Vietnam border. Twenty villages were randomly selected, and 10 participants per village were randomly selected for interview. Approval for the investigation was obtained from the health and market authorities. Oral consent for interview was obtained from participants.
A total of 842 participants were interviewed (Table). Differences in occupation and literacy were associated with different study areas. Differences in participant sex and age were also noted because, in the rural areas, interviews took place in the home. A total of 583 (69.3%) participants were female: 302 (65.5%), 139 (68.2%), and 150 (79.3%), in urban, semiurban, and rural areas, respectively; p = 0.002, 95% confi dence interval 66-72. Mean ages for participants in these areas were 41 (range 40-43), 34 (range 32-36), and 38 (range 37-41) years, respectively; p<0.001. Animal breeding was conducted by 50% of families. Daily close exposure to poultry was common (39.6%). Few families owned a henhouse, and no special handling of poultry was reported. Rates of poultry vaccination against common poultry diseases were higher in urban and semiurban areas; veterinary surveillance was low (10.2%).
Overall, 96.9% of respondents had already heard of HPAI, mainly through television. Urban residents ranked it as the most well-known poultry disease, but rural residents ranked it fi fth. Less than half of the respondents had some knowledge of the disease signs and symptoms for humans and poultry; 28.4% could describe 1 symptom. Half of the respondents believed that they were not at risk for human avian infl uenza or that their poultry were not at risk for it. Respondents in urban and semiurban areas knew more about avian infl uenza than those in rural areas.
During the cold season, poultry deaths were higher in the north (colder) and south than in Vientiane. The poultry mortality rate during the cold season was similar to that of Cambodia (6). Behavior regarding poultry deaths differed between areas. Despite a high rate of poultry deaths, none of the interviewees had notifi ed authorities. Since hearing about HPAI, 67.1% respondents, mainly in Vientiane, claimed that they had changed behavior regarding poultry. Multivariate analysis showed the following factors to be associated with behavior change: level of education (p = 0.002), urban living (p<0.001), knowledge of avian infl uenza risk (p<0.001) and disease (p<0.001), owning poultry (p<0.001), and being a government worker (p<0.001).
This study had limitations but provides new insights on Laotians' knowledge and poultry practices with regard to HPAI. Despite a high level of awareness, populations underestimated the risk, particularly those in rural areas. Most respondents were unaware of appropriate poultry-handling measures to reduce risk (6). The claimed changes were higher (more frequent and more substantial) in ur-ban (91.8%) than in rural sites (3.8%, p<0.001), higher than changes made by their counterparts in Thailand (7), and confi rmed by reports after the 2004 outbreaks (8,9). These differences between urban and rural areas might be explained not only by participant characteristics but also by a lower extent of the awareness campaign in rural areas. Failure to report poultry deaths should be addressed and has several possible explanations. Farmers are accustomed to common yearly poultry deaths, which are not reported. In the absence of an offi cial compensation statement, farmers may fear income loss from massive poultry culling.
Our results emphasize the need for more accurate information about transmission risks, notifi cation requirements, safer behavior and practices, and compensation for losses. Focus also needs to be placed on building capacity in the veterinary system (10). These issues should be integrated in the Laos National Avian Infl uenza Control and Pandemic Preparedness Plan (2006-2010).

Norovirus GII.4 Strains and Outbreaks, Australia
To the Editor: Viral gastroenteritis affects millions of people of all ages worldwide, and some seasonality has been observed in outbreak occurrences ( (Figure). In May, the rate of norovirus detection (22.5%) was signifi cantly greater than that of any other pathogen (Fisher exact test, p<0.0001), including intestinal parasites, foodborne bacterial pathogens (Salmonella, Shigella, and Camplylobacter), and enteric viruses (rotavirus, adenovirus, and astrovirus).
In April 2006, the NSW Department of Health Public Health Realtime Emergency Department Surveillance System (PHREDSS) detected a signifi cant increase in visits for gastroenteritis. This system records cases in real time for each visit to an emergency department from patient demographic information and syndromes diagnosed according to the International Classifi cation of Diseases, version 9, Clinical Modifi cation (ICD-9-CM) (4). Information collected came Letters Letters commenting on recent articles as well as letters reporting cases, outbreaks, or original research are welcome. Letters commenting on articles should contain no more than 300 words and 5 references; they are more likely to be published if submitted within 4 weeks of the original article's publication. Letters reporting cases, outbreaks, or original research should contain no more than 800 words and 10 references. They may have one Figure or Table and should not be divided into sections. All letters should contain material not previously published and include a word count.