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*
Characteristic
Urban, n (%)
Semiurban, n (%)
Rural, n (%)
Total, n (%)
p value
95% CI
Total persons interviewed
461
192
189
842
Illiterate
175 (37.9)
60 (31.2)
181 (95.7)
416 (49.4)
<0.001
47.1–54
Occupation
Housewife
126 (27.3)
24(12.5)
94 (50)
244 (28.9)
<0.001
32–25.9
Farmer
25 (5.4)
36 (18.75)
75 (40)
136 (16.1)
<0.001
13.7–18.6
Government worker
103 (22.4)
22 (11.5)
3 (1.5)
128 (15.2)
<0.001
12.8–17.6
None
2 (4.3)
0
24 (12.6)
36 (4.2)
<0.001
2.9–5.6
Keep poultry
185 (40.2)
97(50.5)
159 (84.3)
441 (59.4)
<0.001
19 (17–20)
>1 poultry death, past 2 mo†
58 (31.3)
84 (86.5)
95 (59.7)
239 (54.1)
<0.000
49.5–58.8
Any poultry deaths, past 2 y
95 (51.3)
62 (63.9)
141 (88.6)
298 (65.5)
<0.001
63.2–71.9
Response to dead poultry (n = 399)‡
Bury dead chickens
105 (56.7)
87 (89.6)
118 (74.2)
310 (70.2)
<0.001
66–74.6
Throw out dead chickens
50 (27.0)
5 (5.1)
9 (5.6)
64 (14.5)
<0.001
11.2–17.8
Eat dead chickens
1 (0.5)
2 (2.0)
7 (4.4)
10 (2.2)
0.06
0.9–3.7
Treat other chickens
0
0
5 (2.6)
5 (0.5)
<0.001
0.07–1.1
Apply lime to backyard
0
8 (1.7)
1 (0.5)
9 (1.0)
<0.001
0.03–1.7
Sell dead chickens
0
1 (1.0)
0
1 (0.1)
0.1
0.00–0.3
Report dead chickens
0
0
0
0
NA
NA
Poultry location
Henhouse
39 (21.0)
4 (4.4)
7 (4.4)
50 (11.3)
<0.001
8.4–14.3
Inside house
8 (4.3)
1 (1.03)
2 (12.6)
11 (2.4)
0.003
1–3.9
Near house (<5 m)
78 (42.2)
59 (61)
28 (17.7)
165 (37.4)
<0.001
32.9–41.9
Far from house (>5 m)
58 (31.3)
30 (31)
114 (71.7)
202 (45.8)
<0.001
41.2–50.5
Regular poultry vaccination
81 (43.7)
54 (55.6)
19 (11.9)
154 (34.2)
<0.001
30.5–39.4
Information source
Never heard
8 (1.7)
11 (5.1)
7 (3.7)
26/837 (3.1)
0.02
1.9–4.3
Heard from television
388 (86.4)
158 (87.8)
178 (97.8)
724 (89.2)
<0.001
(86.4–90.8)
Heard from radio
19 (4.2)
12 (6.6)
4 (2.2)
35 (4.3)
0.1
(3.02–5.9)
Read in paper
6 (1.3)
1 (0.5)
0
7 (0.8)
0.003
(0.34–1.8)
Perceive risk for avian influenza
In Laos
369 (81.6)
110 (60.7)
8 (4.3)
487 (59.6)
<0.001
56.3–63
At home
293 (64.8)
72 (40.0)
5 (2.6)
370 (45.7)
<0.001
41.9–48.8
Unable to describe human disease
116 (25.6)
116 (63.7)
182 (97.5)
414 (50.7)
<0.001
47.3–54.2
Able to describe as lethal for poultry
306 (67.5)
90 (49.7)
2(1.0)
398 (48.7)
<0.0001
45.3–52.2
Behavior change‡
416 (91.8)
125 (69.0)
7 (3.8)
548 (67.1)
<0.0001
63.9–70.4
Stopped eating chicken
328 (72.4)
120 (66.2)
0
448 (54.9)
<0.000
51.5–58.3
Avoided contact
348 (76.8)
60 (33.1)
3 (1.6)
411 (50.3)
<0.000
46.9–53.8
Stopped keeping poultry
335 (73.9)
13 (7.1)
1 (0.5)
349 (42.7)
<0.000
39.4–46.2
Wore mask
338 (74.6)
10 (5.5)
1 (0.5)
349 (42.7)
<0.000
39.4–46.2
Washed hands after contact
100 (22.0)
3 (1.6)
1 (0.5)
104 (12.7)
<0.002
10.5–15
Ate well-cooked chicken
155 (34.2)
3 (1.6)
1 (0.5)
159 (19.4)
<0.000
16.8–22.2
*CI, confidence interval; NA, not applicable.
†Mean nos. of poultry deaths were 15
(range 10–19), 27 (range 22–32), and 15 (range 13–18) for urban, semiurban, and rural
areas, respectively. Total mean = 19.3; p<0.0001; 95% CI, 17.0–18.4.
‡95% CIs were
89–94, 62–76, and 1–7 for urban, semiurban, and rural areas, respectively.
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).