Since 23 January 2004, the Ministry of Public Health in Thailand has reported 9 laboratory-confirmed cases of human infection with H5N1 avian influenza. Of these, seven have died. The situation is reviewed daily by a joint team of ministry officials and WHO staff.
Preliminary epidemiological and clinical data on the first five cases were published last week by WHO. The subsequent four cases include two who have fully recovered (a 2-year old boy and a 27-year-old woman), a thirteen-year-old boy, and a four-year-old boy, who died on 3 February. All cases have been announced in previous updates.
Thai authorities are currently investigating a further 147 reports of patients admitted to hospital with suspicious symptoms. Of these, 21 are being considered as suspect cases of H5N1 infection. All have a clinical diagnosis of pneumonia. Eight have died, 8 have fully recovered, and 5 remain hospitalized.
The investigation of cases is following three lines: laboratory testing, epidemiological tracing of likely sources of infection, and examination of clinical features of disease.
Final results of laboratory testing are pending for the additional 126 patients under investigation. The results of virus isolation studies are pending. These studies, which can take up to 14 days, are used to verify and supplement the initial PCR findings. Recent enhancement of laboratory facilities at Thailand’s National Institutes of Health, including the addition of equipment for real-time PCR testing, has expedited the processing of clinical samples, thus reducing the time from notification to obtaining the initial laboratory diagnosis. In this group of 126 patients, 19 are still being investigated to obtain more details about either potential exposure to affected poultry or the clinical features of disease.
The surveillance system in Thailand is on high alert. To date, 510 reports have been brought to the attention of health authorities. Of these, 354 have been excluded from consideration following thorough laboratory, epidemiological, and clinical investigation.
The most recently announced confirmed case was a four-year-old boy from the northeastern province of Khon Kaen. His family raised chickens, and many died shortly before the onset of his symptoms.
One of the most recently reported suspect cases is a two-year-old girl from a southern province. The family’s poultry died 7 days prior to the onset of her symptoms. The case is not yet laboratory confirmed. As H5N1 infection in poultry has not been reported in this province to date, the Ministry of Agriculture has been informed and is currently investigating animal illness in the area.
To date, no evidence suggests that human-to-human transmission has occurred in Thailand.
The number of reports brought to the attention of Thai authorities has declined and the numbers this week are low. The Ministry of Agriculture is currently responding to the detection, earlier this week, of the reappearance of infection in poultry in provinces where extensive culling was previously carried out. Rapid culling in the newly affected areas is now under way to prevent further spread, and thus reduce opportunities for the disease to become endemic.
Thailand’s Ministry of Public Health, with the full support of WHO, is stressing the need for continued vigilance and intensive surveillance.
Preliminary epidemiological and clinical data on the first five cases were published last week by WHO. The subsequent four cases include two who have fully recovered (a 2-year old boy and a 27-year-old woman), a thirteen-year-old boy, and a four-year-old boy, who died on 3 February. All cases have been announced in previous updates.
Thai authorities are currently investigating a further 147 reports of patients admitted to hospital with suspicious symptoms. Of these, 21 are being considered as suspect cases of H5N1 infection. All have a clinical diagnosis of pneumonia. Eight have died, 8 have fully recovered, and 5 remain hospitalized.
The investigation of cases is following three lines: laboratory testing, epidemiological tracing of likely sources of infection, and examination of clinical features of disease.
Final results of laboratory testing are pending for the additional 126 patients under investigation. The results of virus isolation studies are pending. These studies, which can take up to 14 days, are used to verify and supplement the initial PCR findings. Recent enhancement of laboratory facilities at Thailand’s National Institutes of Health, including the addition of equipment for real-time PCR testing, has expedited the processing of clinical samples, thus reducing the time from notification to obtaining the initial laboratory diagnosis. In this group of 126 patients, 19 are still being investigated to obtain more details about either potential exposure to affected poultry or the clinical features of disease.
The surveillance system in Thailand is on high alert. To date, 510 reports have been brought to the attention of health authorities. Of these, 354 have been excluded from consideration following thorough laboratory, epidemiological, and clinical investigation.
The most recently announced confirmed case was a four-year-old boy from the northeastern province of Khon Kaen. His family raised chickens, and many died shortly before the onset of his symptoms.
One of the most recently reported suspect cases is a two-year-old girl from a southern province. The family’s poultry died 7 days prior to the onset of her symptoms. The case is not yet laboratory confirmed. As H5N1 infection in poultry has not been reported in this province to date, the Ministry of Agriculture has been informed and is currently investigating animal illness in the area.
To date, no evidence suggests that human-to-human transmission has occurred in Thailand.
The number of reports brought to the attention of Thai authorities has declined and the numbers this week are low. The Ministry of Agriculture is currently responding to the detection, earlier this week, of the reappearance of infection in poultry in provinces where extensive culling was previously carried out. Rapid culling in the newly affected areas is now under way to prevent further spread, and thus reduce opportunities for the disease to become endemic.
Thailand’s Ministry of Public Health, with the full support of WHO, is stressing the need for continued vigilance and intensive surveillance.
