Influenza Surveillance and Avian Influenza Update
Bureau of Epidemiology Bureau of Laboratories
Editor: Susan Vagasky, DVM Surveillance and Infectious Disease Epidemiology VagaskyS@Michigan.gov April 3, 2008 Vol. 5; No. 14
New updates in this issue:
• Michigan Surveillance: Overall activity decreases to local levels; influenza B activity still steady. • National Surveillance: Activity continues to decrease with 17 states reporting widespread activity. • Avian Influenza: WHO reports new human cases in Indonesia and an update on Pakistan cases from December.
Michigan Disease Surveillance System: The week ending March 29 saw aggregate flu-like illness and individual influenza reports continue to decline. Aggregate flu-like illness reports are lower than numbers seen this week last year, while individual influenza reports are consistent with last year. Emergency Department Surveillance: Emergency department visits from both constitutional and respiratory complaints continued to hold steady near last week’s levels. Respiratory complaints are slightly higher than numbers that were seen this time last year, while constitutional complaints are slightly lower than last year. Both of these categories appear to be approaching baseline levels. Seven constitutional alerts in the C(4), N(1), SE(1) and SW(1) Influenza Surveillance Regions and five respiratory alerts in the C(2), N(2) and SW(1) Influenza Surveillance Regions were generated last week. Over-the-Counter Product Surveillance: OTC product sales activity was steady or decreasing last week. Thermometers and children’s electrolyte sales slightly decreased over the last week. The remaining product sales held steady overall during the week. The indicator levels are comparable to those seen at this time last year. Sentinel Surveillance (as of April 3): The proportion of visits due to influenza-like illness (ILI) in Michigan decreased from 1.3% to 1.1% of all visits during the week ending March 29, 2008. This represents 89 cases of ILI out of 8404 total patient visits reported by 32 sentinels. Activity remained steady from last week in the North (1.4%), Southeast (1.2%), and Southwest (1.8%) surveillance regions but decreased substantially, from 1.0% to 0.4%, in the Central region. Note that these rates may change as additional reports are received. Percentage of Visits for Influenza-like Illness (ILI) Reported by Sentinel Providers, 12 Michigan Statewide and Regions 2007-2008
% ILI Statewide Central North
% of Visits for ILI
0 12-Jul 17-May 31-May 19-Apr 26-Jul 3-May 14-Jun 28-Jun 9-Aug 23-Aug 15-Dec 17-Nov 29-Dec 20-Sep 20-Oct 22-Mar 3-Nov 1-Dec 23-Feb 12-Jan 26-Jan 6-Sep 6-Oct 9-Feb 8-Mar 5-Apr
As part of pandemic influenza preparedness, CDC and MDCH highly encourage year-round participation from all sentinel providers. New practices are encouraged to join the sentinel surveillance program today! Contact Rachel Potter at 517-335-9710 or firstname.lastname@example.org for more information. Laboratory Surveillance (as of April 3): For the 2007-2008 influenza season, the MDCH Bureau of Laboratories has identified 229 influenza isolates: • 185 A/H3N2: Central (54); Southeast (48); Southwest (51); North (32) • 4 A/H1N1: Southeast (2); North (2) • 2 A subtyping unable to be performed: Southeast (2) • 38 B: Southeast (19); North (9); Southwest (5); Central (4); Indiana (1). 36 have been typed as B/Shanghai/361/2002-like and 2 are pending subtyping. The MDCH BOL is reporting decreasing specimen submissions. Sentinel laboratories are reporting decreasing or no positive influenza A’s and low but steady numbers of positive influenza B tests. Multiple sentinel laboratories are reporting only influenza B positives. RSV activity continues to be steady. ***As a reminder, the positive predictive value of influenza rapid tests decreases during times of low influenza prevalence. MDCH suggests that during periods of low influenza activity in your community, all positive rapid tests results be confirmed by sending in a specimen for viral culture; this can be arranged through your local health department. Influenza-Associated Pediatric Mortality (as of April 3): For the 2007-2008 season, there are no confirmed reports of influenza-related pediatric mortality in Michigan. ***The CDC has asked all states to collect information on any pediatric death associated with influenza infection. This includes not only any death in a child (<18 years) resulting from a compatible illness confirmed to be influenza by an appropriate diagnostic test, but also any unexplained death with evidence of an infectious process in a child. See www.michigan.gov/documents/fluletter_107562_7.pdf for the complete protocol. Please immediately call MDCH to ensure that proper clinical specimens are obtained. Congregate Settings Outbreaks (as of April 3): Congregate setting outbreaks have been reported in all regions of the state and appeared to peak in the first two weeks of February. Six outbreaks have been culture-confirmed as influenza A/H3N2 at MDCH for the 2007-2008 influenza season. National (FDA website, April 1): GlaxoSmithKline informed healthcare professionals of changes to the WARNINGS AND PRECAUTIONS sections of prescribing information for Relenza regarding information from postmarketing reports (mostly from Japan) of delirium and abnormal behavior leading to injury in patients with influenza who are receiving neuraminidase inhibitors, including Relenza. These events were reported primarily among pediatric patients and often had an abrupt onset and rapid resolution. The contribution of Relenza to these events has not been established. Influenza can be associated with a variety of neurologic and behavioral symptoms which can include seizures, hallucinations, delirium, and abnormal behavior, in some cases resulting in fatal outcomes. These events may occur in the setting of encephalitis or encephalopathy but can occur without obvious severe disease. Patients with influenza should be closely monitored for signs of abnormal behavior. If neuropsychiatric symptoms occur, the risks and benefits of continuing treatment should be evaluated for each patient. National (CDC, March 28): During week 12 (March 16 - 22, 2008), influenza activity continued to decrease in the United States. Nine hundred eighty-six (21.3%) specimens tested by U.S. World Health Organization (WHO) and National Respiratory and Enteric Virus Surveillance System (NREVSS) collaborating laboratories were positive for influenza. The proportion of deaths attributed to pneumonia and influenza was above the epidemic threshold for the eleventh consecutive week. The proportion of outpatient visits for influenza-like illness (ILI) was above national baseline levels, while the proportion of outpatient visits for acute respiratory illness (ARI) was below national baseline levels. ILI was below the region specific baselines in the West South Central and Pacific regions, but remained above regionspecific baselines in the remaining seven regions. The proportion of outpatient visits reported for ARI was below all region-specific baselines. Seventeen states reported widespread influenza activity; 30 states reported regional influenza activity; two states and the District of Columbia reported local influenza activity; and one state and Puerto Rico reported sporadic influenza activity.
To access the entire CDC weekly surveillance report throughout the influenza season, visit http://www.cdc.gov/flu/weekly/fluactivity.htm
International (WHO, March 20): During weeks 10–11, the level of overall influenza activity in the world slightly decreased. The majority of countries in the Northern Europe and United States of America reported drop of influenza activity. In Europe influenza B viruses become more abundant, but influenza A (predominantly H1N1) viruses were still circulated. In Canada and Russian Federation influenza activity remained mostly on a widespread level. Significant increase of influenza activity was observed in Hong Kong SAR China. The entire report can be found online at http://www.who.int/csr/disease/influenza/update/en/
MDCH reported LOCAL ACTIVITY to the CDC for the week ending March 29, 2008. For stakeholders interested in additional information regarding influenza vaccination and education, the MDCH publication Michigan FluBytes is available online at http://www.michigan.gov/mdch/0,1607,7-1322940_2955_22779_40563-125027--,00.html. FluBytes is published weekly during the influenza season. End of Seasonal Report
Avian Influenza Activity
WHO Pandemic Phase: Phase 3 - Human infection(s) with a new subtype, but no human-to-human spread or rare instances of spread to a close contact. International, Human (WHO, April 2): The Ministry of Health of Indonesia has announced three new cases of human H5N1 avian influenza infection. The cases are not linked epidemiologically. The first is a 15-year-old male student from Subang District, West Java Province who developed symptoms on 19 March, was hospitalized on 22 March and died on 26 March. The second case is an 11-year-old female student from Bekasi City, West Java Province who developed symptoms on 19 March, was hospitalized on 23 March and died 28 March. The third case is a 21-month-old female from Bukit Tinggi, West Sumatra Province who developed symptoms on 17 March, and was hospitalized on 22 March. She is presently recovering in hospital. The source of infection for all three cases is still under investigation. Of the 132 cases confirmed to date in Indonesia, 107 have been fatal.
International, Human (WHO, April 3): Two additional H5N1 cases were confirmed by serological testing, thus providing final H5N1 infection test results on a previously reported family cluster in Peshawar. These tests were conducted by the WHO H5 Reference Laboratory in Cairo, Egypt and the WHO Collaborating Centre for Reference and Research on Influenza in Atlanta, USA. The table below summarizes the testing results of the confirmed/probable cases in the family cluster. • • The preliminary risk assessment found no evidence of sustained or community human to human transmission. All identified close contacts including the other members of the affected family and involved health care workers remain asymptomatic and have been removed from close medical observation.
These laboratory test results support the epidemiological findings from the outbreak investigation in December 2007, and the final risk assessment that suggested limited human to human transmission likely occurred among some of the family members which is consistent with some human-to-human transmission events reported previously. This outbreak did not extend into the community, and appropriate steps were taken to reduce future risks of human infections. Relationship Onset Date Outcome Fully recovered Exposure Direct contact sick/dead poultry Close contact with Case 1, no known direct contact with sick/dead poultry Close contact with Case 1 and 2, no known direct contact with sick/dead poultry Close contact with Case 1 and 2, no known direct contact with sick/dead poultry Status Confirmed (serology) Probable (No sample available)
Case 1 (Index case) 29 Oct 07
12 Nov 07
Dead (19 Nov 07)
21 Nov 07
Dead (28 Nov 07)
21 Nov 07
National, Poultry (wjactv.com, March 20): The Pennsylvania Department of Agriculture has quarantined a poultry auction in Blair County after a backtracking investigation revealed it may have been exposed to a string of the avian influenza. Department of Agriculture officials said ducks that were up for sale at an auction in Luzerne County may have been the same ducks sold at the Farmer's Poultry and Hay Auction in Martinsburg. The ducks were carrying the low pathogen strain of the avian flu, which officials said causes no public health threat, neither direct infection nor food safety. According to officials, the ducks did not show signs of a virus. They appeared to be normal and healthy. The birds may have picked it up from wild birds, which isn't uncommon. And in this particular case they have seen no sick birds, other animals or humans. Officials at the Department of Agriculture are still taking every precaution. In the past week, under quarantine, the auction house in Martinsburg and two other auction houses in Pennsylvania have cleaned and disinfected their facilities. They are waiting for lab results and officials said if those results are negative, the quarantines will be revoked.
According to officials, other birds that passed through the Martinsburg auction house went to Maryland and the Maryland Department of Agriculture is also investigating. Officials said this case is a useful reminder to anyone who owns poultry that it is important to practice biosecurity to prevent the avian flu or any other bird disease. International, Poultry (BBC, April 2): An outbreak of bird flu is sweeping through the central province of Quang Nam, felling fowls and forcing authorities to cull a further 26,660 birds. They destroyed 7,000 eggs and 1,250 ducks Monday [31 March] after finding signs of the H5N1 virus that causes the disease. Seven communes in four districts - Nui Thanh, Thang Binh, Dai Loc and Tien Phuoc -have been affected. Nguyen Ngoc Quang, vice-chairman of the Quang Nam People's Committee, instructed local authorities to focus on disinfecting affected areas and containing the spread of the disease. Until mid-March only Nui Thanh had reported outbreaks. International, Wild Birds (Independent Online, March 27): Switzerland on Thursday [27 Mar 2008] reported its 1st case of bird flu in 2 years, after diagnosing a wild duck with the H5N1 virus, said the Swiss federal veterinary department. The virus was detected in a wild duck on Lake Sempach, near Lucerne, during a regular detection programme in which 200 specimens obtained from birds were tested. The duck shows no symptoms of the disease, said the office, adding that the detected virus is almost identical with those detected in Europe in 2007. Protective measures put in place since October 2007 remain in place, and "additional measures such as a ban on free-range poultry is not necessary at this time", said the office in a statement. The risk of transmission to farmed poultry is small, indicated the office. This case brings the total number of H5N1 cases detected in Switzerland to 33. Previous cases were detected in February and March 2006 in wild birds found dead in the Lake Leman and Lake Constance regions. Earlier in 2008, wild swans tested positive for the strain of bird flu in southwest England. International, Canine (Bloomberg News, April 2): A bird flu virus killed dogs in South Korea, showing that a pure avian strain of influenza is capable of crossing a species barrier and causing outbreaks of severe disease in mammals, a new study found. A cocker spaniel and a miniature schnauzer were among dozens of dogs in South Korea sickened by an H3N2 strain from birds, researchers said in a study published in the May issue of Emerging Infectious Diseases journal. Viruses taken from the sick canines were used in an experiment later to see if pathogens were capable of spreading from dog to dog. The findings add to scientific understanding of how flu viruses evolve in animals and the risks they pose to humans. A separate bird flu strain called H5N1 has killed 236 people worldwide by spreading primarily from birds to humans. If a deadly H5N1 strain evolved like the strain in today's study to spread from one human to another, it could kill millions. “Transmission of avian influenza A virus to a new mammalian species is of great concern because it potentially allows the virus to adapt to a new mammalian host, cross new species barriers, and acquire pandemic potential,” the Korean researchers said. The study, led by Daesub Song, Bokyu Kang and Chulseung Lee of the Green Cross Veterinary Products Co. and Daewoong Pharmaceutical Co. at Yong-in, outside Seoul, followed cases of severe respiratory disease last year in dogs at three veterinary clinics in Kyunggi province.
Tests on specimens collected from three of the dogs showed they were infected with H3N2 viruses closely resembling those found in chickens and doves in South Korea in 2003. The pathogens may have been transmitted from birds to dogs fed raw, minced meat from infected ducks and chickens, the authors said. “In South Korea, untreated duck and chicken meats, including internal organs and heads, have been widely used to feed dogs for fattening in local canine farms or kennels,” they said. Dog is regarded by some Koreans as a delicacy. Seoul city officials will ask the national government to include the animal in the legal definition of livestock, the Chosun Ilbo newspaper reported last week. A variant of the H3N2 virus causes seasonal flu in humans. A canine strain was linked to an outbreak among 13 dogs at an animal hospital and later reported at a kennel in Jeolla province, where as many as 52 canines were infected, most likely as the virus spread from dog to dog, the Korean researchers said. Avian flu viruses are known to transmit to unrelated mammalian species only rarely, the researchers said. Bird- derived H7 and H4 flu viruses were reported in seals in the early 1980s, and the H5N1 bird-flu strain was found in a dog that fed on a duck infected with the virus in Thailand in 2004, according to the study. Large cats, including tigers and leopards, kept in capacity and fed on infected poultry carcasses, have also been infected and developed severe disease. Almost two of every three human H5N1 cases were fatal, according to the World Health Organization. “This is an important and interesting study because previous avian-to-mammal influenza infection by H5 or H7 were not efficient in subsequent human-to-human or cat-to-cat transmission, whereas this study shows an outbreak of 13 dogs in addition to sporadic cases,” said Yuen Kwok-yung, a microbiology professor at the University of Hong Kong. “Efficient mammal-to-mammal transmission” of H3N2 viruses isn't unexpected since variations of the strain regularly infect humans and pigs, Yuen said in an interview today. Dogs may be more susceptible to flu strains carried by birds because both canines and birds share a specific type of virus-binding site in their respiratory systems which is less common in humans. The bird-like H3N2 virus may be capable of spreading between dogs because it was excreted in nasal discharges of experimentally infected Beagle puppies, the study found. Evidence of avian flu in pet dogs “raises the concern that dogs may be become a new source of transmission of novel influenza viruses, especially where avian influenza viruses are circulating or have been detected,” the authors said. Michigan Wild Bird Surveillance (USDA, as of April 3): For the 2007 testing season, 1998 Michigan samples have been taken so far, comprised of 100 live bird samples, 1425 hunter-killed birds, 198 morbidity/mortality samples, and 275 environmental samples. HPAI subtype H5N1 has not been recovered from any Michigan samples tested to date, or from the 94,990 birds or environmental samples tested nationwide. The 2007 testing season will run from April 1, 2007-March 31, 2008. For more information, visit the National HPAI Early Detection Data System website at http://wildlifedisease.nbii.gov/ai/. To learn about avian influenza surveillance in Michigan wild birds or to report dead waterfowl, go to Michigan’s Emerging Disease website at http://www.michigan.gov/emergingdiseases.
Please contact Susan Vagasky at VagaskyS@Michigan.gov with any questions regarding this newsletter or to be added to the weekly electronic mailing list. Contributors MDCH Bureau of Epidemiology - Sally Bidol, MPH; Edward Hartwick, MS; Elizabeth Lewis, MHS; Rachel Potter, DVM, MS MDCH Bureau of Laboratories – Patricia Clark, MPH
Table 1. H5N1 Influenza in Poultry (Outbreaks up to April 1, 2008)
(Source: http://www.oie.int/downld/AVIAN%20INFLUENZA/A_AI-Asia.htm Downloaded 4/3/2008)
Table 2. H5N1 Influenza in Humans (Cases up to April 3, 2008)
(http://www.who.int/csr/disease/avian_influenza/country/cases_table_2008_04_03/en/index.html Downloaded 4/3/2008) Cumulative number of lab-confirmed human cases reported to WHO. Total number of cases includes deaths.
Country 2003 cases Azerbaijan Cambodia China Djibouti Egypt Indonesia Iraq Lao People's Dem. Rep. Myanmar Nigeria Pakistan Thailand Turkey Viet Nam Total 0 0 1 0 0 0 0 0 0 0 0 0 0 3 4 deaths 0 0 1 0 0 0 0 0 0 0 0 0 0 3 4 0 0 0 0 0 0 0 0 0 0 0 17 0 29 46 2004 cases deaths 0 0 0 0 0 0 0 0 0 0 0 12 0 20 32 0 4 8 0 0 20 0 0 0 0 0 5 0 61 98 2005 cases 2006 2007 2008 Total
deaths cases deaths cases deaths cases deaths cases deaths 0 4 5 0 0 13 0 0 0 0 0 2 0 19 43 8 2 13 1 18 55 3 0 0 0 0 3 12 0 115 5 2 8 0 10 45 2 0 0 0 0 3 4 0 79 0 1 5 0 25 42 0 2 1 1 3 0 0 8 88 0 1 3 0 9 37 0 2 0 1 1 0 0 5 59 0 0 3 0 4 15 0 0 0 0 0 0 0 5 27 0 0 3 0 1 12 0 0 0 0 0 0 0 5 21 8 7 30 1 47 132 3 2 1 1 3 25 12 106 378 5 7 20 0 20 107 2 2 0 1 1 17 4 52 238