Influenza A (H1N1) Outbreak Update: May 8,2009

From the Center for Excellence in Disaster Management and Humanitarian Assistance

Influenza A (H1N1) Outbreak Update
May 8, 2009

Influenza A (H1N1), commonly known as swine flu, infections sharply increased on Friday (May 8) as the global count hit 3,243 cases from a previous count of 1,893 on Thursday (May 7), according to numbers from the UN’s World Health Organization (WHO) and US Centers for Disease Control and Prevention (CDC). The WHO’s daily update for Friday reports the number of US laboratory-confirmed cases as 896, which is the same as Thursday’s count, while the CDC has confirmed 1,639 US cases. The UN agency’s death toll for Mexico went up to 44 deaths, bringing the number of worldwide casualties to 46. Brazil is the latest country to confirm H1N1 flu cases, increasing the number of laboratory-confirmed countries to 25 – Mexico (1,112), US (896), Canada (201), Spain (81), the UK (32), Germany (10), Israel (6), France (5), Italy (5), New Zealand (5), Brazil (4), Republic of Korea (3), El Salvador (2), Netherlands (2), Austria (1), Switzerland (1), Denmark (1), Ireland (1), China, Hong Kong, Special Administrative Region (1), Costa Rica (1), Colombia (1), Portugal (1), Guatemala (1), Poland (1) and Sweden (1). Argentina officials have confirmed an H1N1 flu case, but it has yet to be reported by the WHO. The WHO’s tally of confirmed cases has lagged behind those that individual countries report because it has to wait for formal notification from the affected nation. Despite the WHO’s death toll lagging behind national reports, it is considered more scientifically secure, as it reflects sophisticated tests conducted in its global network of laboratories. Meanwhile, WHO officials have observed that the disease appears to be concentrated in young people, with a median age in the mid-20s, while there were few cases in anyone over the age of 60. Dr. Keiji Fukuda, assistant director-general of the WHO, said young adults catching the H1N1 flu more often than other age brackets may be attributed to this age group comprising the bulk of people who travelled to Mexico and became exposed to the virus. Another theory was that older people may have some form of immunity from an earlier infection.

The WHO today is monitoring and awaiting test results in 12 other countries possibly having the virus – Australia, Argentina, Venezuela, Peru, Chile, Japan, Belize, South Africa, Benin, Finland, Norway and Kosovo. The WHO defines “possible” as cases where the patient tested positive for Influenza A, which is the general category of strains that includes the H1N1 swine virus, and needs additional tests to verify whether they are positive for the specific virus. Fukuda said the higher totals do not necessarily mean incidence of the disease is increasing, but rather that health investigators are getting through their backlog of specimens. Several thousand samples are being analyzed. Under pressure from meat industry producers and concerned governments, the WHO last week decided to refer to the new virus strain as Influenza A (H1N1), not swine flu.

On Friday, the WHO said it was keeping its global pandemic alert level at Phase 5 as no evidence of community transmission was apparent. Dr. Fukuda was quoted as saying, “We continue to see human to human transmission, community-level transmission, primarily in North America. We are not seeing it yet anywhere else.” Last week, the WHO raised its pandemic alert level from 3 to 4 to 5 due to the transmission of the virus in Mexico, the US and Canada. Phase 5 calls for national governments to implement pandemic preparation plans, while Phase 6 would indicate a global outbreak of H1N1 flu is under way. The move to Phase 6 would also expedite efforts already under way to produce and distribute antiviral drugs and vaccines. The WHO also reported on Thursday that if the current outbreak were to amount to a pandemic, up to 2 billion people could be infected. Past experiences with flu pandemics have shown that one-third of the world’s population contracts the infection. He added that even with a mild flu, large numbers of people could develop secondary, bacterial infections resulting in pneumonia and other respiratory diseases. The UN agency’s biggest fear is the possibility the virus will mutate and be easily transmitted from human to human. Margaret Chan, WHO director-general, expressed her fear of the virus returning “with a vengeance,” as history shows that past pandemics have endured mild summer outbreaks, which were followed by a lethal second wave in the fall and winter.

UNITED STATES
According to the US Centers for Disease Control and Prevention (CDC), the number of laboratory-confirmed cases in the US on Friday surpassed the number of cases in Mexico as the total bumped up to 1,639 people from Thursday’s 896 cases. The H1N1 flu death toll in the US remains at two, with both victims dying in Texas. States confirming infections increased to 43 today as the District of Columbia, which is being counted as a state, and South Dakota both confirmed one case each. Among the affected states, 26 - Illinois (392), Wisconsin (240), New York (174), Arizona (138), California (107), Texas (93), Massachusetts (83), Michigan (49), Delaware (39), Tennessee (36), Washington (33), South Carolina (29), Indiana (29), Colorado (25), Utah (24), Virginia (14), Kansas (12), Missouri (9), Nevada (8), Rhode Island (7), Florida (6), Ohio (6), Hawaii (5), Oklahoma (4), Kentucky (3) and New Hampshire (3) - confirmed additional cases, with Wisconsin increasing the most with 214 new infections. Seventeen states – Oregon (15), New Mexico (8), Louisiana (7), New Jersey (7), North Carolina (7), Iowa (5), Alabama (4), Connecticut (4), Maine (4), Maryland (4), Nebraska, Pennsylvania (2), Idaho (1), Minnesota (1), South Dakota (1) and Washington DC (1) – reported the same number of infections as Thursday. The surge in the case count on Friday can be attributed to a backlog of likely cases that needed to be confirmed through additional testing, causing the number of cases to jump quickly day to day as more suspected cases are confirmed. US officials expect H1N1 flu to spread to all 50 states and to cause many infections ranging from mild to severe. Richard Besser, acting director of the CDC, reported on Monday that the number of infections was likely an underestimation of the total number of cases across the US due to not everyone with flu-like symptoms seeking medical attention. Besser was quoted as saying on Thursday, “We are reporting 1,823 probable and confirmed cases in 44 states,” adding that 99 percent of probable cases later turn out to be the new flu, which is a good indication of how many true cases exist. On Tuesday, federal health officials announced a change in their guidance on school closures related to the H1N1 flu outbreak. Health and Human Services Secretary Kathleen Sebelius said closing schools was no longer necessary where cases occur. Instead the agency recommends parents keep children at home individually if they become ill. The CDC’s Besser attributed the change to growing evidence that the virus was producing more mild illness than originally had been feared.

MEXICO
As scientists continue to analyze thousands of specimens suspected of having the H1N1 flu, Mexico’s confirmed case count is now less than the US’ tally, reporting 1,204 cases on Friday from 1,112 on Thursday. The death toll increased to 44, according to the WHO, but the situation seems to be slowing. Late on Wednesday (May 6), Mexican officials lowered the alert level for the flu in Mexico City, the epicenter of the outbreak, from orange, indicating elevated risk, to yellow, indicating medium risk. Earlier on Monday (May 4), officials had declared the epidemic was waning, decreasing their nation’s health alert from red, or “high,” to orange. Health Minister Jose Angel Cordova stressed that the country must remain vigilant against the outbreak despite the slowing of the epidemic. After Mexico underwent a five-day shutdown to try to curb the spread of the H1N1 virus, the country is slowly beginning to return to normal. Restaurants reopened on Tuesday, people returned to work on Wednesday, and on Thursday, high schools and universities opened their doors for the first time in two weeks after teachers and parents disinfected schools. Additionally, dance halls, movie theaters, bars and sports events resumed service. However, all businesses are required to screen for any sick customers and restaurant employees must wear surgical masks. Primary schools are scheduled to reopen next week. After the closure of about 35,000 public venues, Mexican Finance Minister Agustin Carstens estimated on Tuesday that the virus has cost the country’s tourism industry roughly US$2.3 billion. Mexican President Felipe Calderon met with former Mexican health ministers on Thursday to analyze the results of implementing initiatives to combat the H1N1 flu. Calderon announced his plans to reinforce the monitoring of the H1N1 flu epidemic in order to detect another possible wave of the outbreak, but stressed cooperation and active participation from doctors, nurses, workers of the health sector and the citizens of Mexico as fundamental factors in containing the spread of the disease. Calderon was quoted as saying, “We have been able to hold or at least reduce the rate of propagation of the virus to contain the epidemic,” The virus will be considered under control after 15 days pass without a new case reported. However, Dr. Marc-Alain Widdowson, a medical epidemiologist from the CDC, has been tracking the flu in Mexico City and has reported that the H1N1 flu seems to have a long incubation period – five to seven days before symptoms surface – meaning the virus can continue spreading by people who will not know to stay home. Health officials are reminded of the 1918 Spanish flu, as it showed a surge in the spring and then disappeared in the summer months, only to return in the autumn, eventually killing 40 to 50 million people. Sebelius noted that the real test would come when the winter flu season hits, adding that “this was no time for complacency.” UN chief Ban Ki-moon also echoed appeals for caution, noting “there is still much that is not known about this new strain and the dangers it poses.”

INTERNATIONAL RESPONSE
Some 300 guests and staff at the Metropark Hotel in Hong Kong were released after spending a week in the hotel under quarantine after a guest from Mexico who was carrying the swine flu virus stayed there. The man was Hong Kong’s first and only confirmed case thus far. The man was released from the hospital on Friday (May 8). All the guests were given health certificates by authorities as they left the hotel. On Thursday, officials had released the first batch of 35 people, most of who had come into contact with the infected man on his flight to Hong Kong from Shanghai. The move by authorities to quarantine the hotel guests was controversial, but some public health experts have supported the move.

While countries in Asia have confirmed four cases of the virus so far, the region has been taking steps to ward off the H1N1 flu virus. China lifted a seven-day quarantine for passengers who arrived in Shanghai on the same flight as a Mexican man infected with the H1N1 flu virus. China has flown back dozens of Mexicans from China, in addition to returning 100 Chinese stranded in Mexico to Shanghai, who all appeared to be healthy. In Vietnam, visitors arriving from flu-affected countries are being quarantined, while nationals are being advised not to visit affected areas. Meanwhile, in Singapore, eight people who recently returned from Mexico were ordered to stay at home for a week and have been told to monitor their temperature twice a day. Cambodian officials have established temperature screening checkpoints at the main airports in the capital, Phnom Penh, and in Siem Reap, home of the Angkor temples, a popular tourist destination. Brunei issued a temporary ban on importing pork from countries with a high number of cases, despite Thursday’s reissuing of a joint statement from the Food and Agriculture Organization, the WHO and World Organization for Animal Health, that stressed the fact that influenza viruses are not known to be transmissible to people eating processed pork or other food products derived from pigs. Bangladeshi officials reported that all travelers will be screened, while in Indonesia temperature scanners have been installed at 10 airports and ports. The country has also placed a ban on pig imports. Most countries in this region have a supply of antiviral drugs or are expanding their stockpile in case of an escalation in cases.

At the conclusion of a special two-day meeting in Bangkok, Thailand, attended by health ministers from the 10 member states of the Association of Southeast Asian Nations (ASEAN) plus China, Japan and the Republic of Korea, all agreed on five measures to cooperate in containing the spread of the virus. This would include fostering collaboration in the region to ensure sufficient and prompt sharing of information, forming regional mobile units to inspect possible cases along the borders, setting up hotlines among national health authorities for an effective response and enhancing laboratory support for the investigation and confirmation of the virus. All members have agreed to boost the stockpile of antiviral medicine and protective equipment, although the specific size of the stockpile has not been determined. A joint ministerial statement was issued, saying the grouping “should assess the potential need for and increase national stockpiling of antiviral and other essential medicines, medical supplies and personal protective equipment to the level necessary for effective response in view of the dynamics of the spread of the virus.” Japan announced it would donate 500,000 doses of antiviral medication and hundreds of thousands of sets of protective equipment for the region, should the H1N1 virus spread across Asia. Additionally, China has offered help to ASEAN countries in areas of antiviral drug and vaccine development if the virus turns into a serious pandemic. China’s Health Minister, Dr. Chen Zhu, assured Thailand’s Health Minister Witthaya Kaewparadai of his help during bilateral talks in Bangkok. The measures proposed during this special meeting will be proposed to the WHO meeting in Switzerland scheduled for May.

Elsewhere, African countries are being vigilant in case of an H1N1 flu outbreak. The WHO reported on Thursday that if the virus were to reach Africa, the world’s poorest continent, it would have a bigger impact than it has had anywhere else. Due to weaker surveillance systems and scarce resources, African ministers are now in the process of preparing for a possible outbreak, and will discuss response plans during a two-day health conference that began on Thursday at African Union headquarters in the Ethiopian capital, Addis Ababa. Tanzania has established checkpoints at major air, marine and land access locations and has dispatched doctors to monitor visitors.

There have been misunderstandings about transmission of the H1N1 virus, which has resulted in unjustified bans and widespread import restrictions on pork and pork products from major US, Canadian and Mexican agricultural regions. To try to avoid any misunderstandings on the safety of pork, the Food and Agriculture Organization, the WHO and the World Organization for Animal Health reissued their joint statement that was originally issued on April 30. The statement stressed the fact that influenza viruses are not known to be transmissible to people by eating processed pork or other food products derived from pigs. In addition, heat treatments commonly used while cooking meat will inactivate any viruses potentially present in raw meat products. Thus, any pork product handled in accordance with good hygienic practices recommended by the WHO and the OIE will not be a source of infection. The agencies have also ensured that sick and dead pigs are not processed or used for human consumption under any circumstances. On Thursday, the three North American Free Trade Agreement nations, US, Canada and Mexico, called for an end to “unscientific bans on pork imports” over the outbreak. They have urged trading partners who have imposed restrictions, most notably Russia and China, to remove bans on products immediately. Ecuador lifted its ban on imports of pigs and pork products on Thursday due to the WHO clarifying that the virus is not transmitted by consuming pork.

The US, Canada and the European Union have advised people to avoid non-essential travel to Mexico, but no travel restrictions have been implemented. Additionally, the WHO continues to advise against travel restrictions and border closures, saying such restrictions will not stop the spread of the virus and urged countries to instead boost domestic efforts to contain the spread of the virus. The UN agency did stress people who are ill to delay international travel and for people developing symptoms to postpone international travel to seek medical attention, which follows guidance from national authorities.

CDC
The CDC continues to take action and respond aggressively to the expanding H1N1 flu outbreak. Depending on local circumstances, response may vary across states and communities. The CDC also continues to issue and update interim guidance daily as the situation evolves for schools and childcare facilities on preventing the spread of the virus. Currently, the CDC recommends the primary means to reduce spread of the disease in schools are early identification of sick students and staff, staying at home when ill, good cough etiquette and frequent hand washing. Decisions regarding school closures should be at the discretion of local authorities based on the situation in the area. In conjunction with officials worldwide, the CDC’s goals include reducing transmission and illness severity and providing information to assist healthcare providers, public health officials and the public in addressing the challenges posed by the newly identified swine influenza. They urge communities, businesses, places of worship, schools and individuals to take action to slow the spread of the outbreak. In addition, the CDC stressed people who are sick to stay home from work or school and to avoid contact with others.

The CDC’s Division of the Strategic National Stockpile (SNS) completed its deployment of one-quarter of its antiviral drugs on Sunday (May 3), oseltamivir (Tamiflu) and zanamivir (Relenza), personal protective equipment and respiratory protection devices to all 50 states and US territories to help them cope with the escalating outbreak. As of Wednesday, the CDC announced that it had developed a Polymerase Chain Reaction (PCR) diagnostic test kit to detect the H1N1 flu virus and had distributed test kits to all states in the US and Puerto Rico. Test kits are also being shipped internationally. These new kits will allow states and other countries to test for the new virus. As a result, the increase in testing capacity will likely increase the number of reported confirmed cases in the country, but should provide a more accurate picture of how the disease is affecting the US.

There is no direct vaccine available for the new virus, but the federal government and manufacturers have commenced the process of developing a vaccine against it. Researchers are racing to develop a vaccine and the CDC hopes to get one to manufacturers within a month. However, the WHO director of the Initiative for Vaccine Research, Dr. Marie-Paule Kieny, said there is “no doubt” that a vaccine can be made “in a relatively short period of time,” but it would take four to six months from the time the appropriate strain is identified before inoculations would become available. As early as next week Thursday (May 14), the WHO could decide to call for international production of an Influenza A H1N1 flu vaccine. Dr. Kieny said the decision could force some vaccine manufacturers to make some lots that do not include a vaccine against influenza B viruses. The new vaccine would be created after manufacturers finish making shots for the seasonal strain. On Thursday, a WHO specialist arrived in Mexico City to start work on developing a vaccine. Researchers are also still investigating the origins of the outbreak as it would be key in future prevention. Also, they are trying to understand the virulence of the strain and why it has caused serious illness and deaths in Mexico, but mild symptoms elsewhere. The CDC on Friday reported that the new virus is “a very unusual” four-way combination of human genes and genes from swine viruses found in North America, Asia and Europe. On a positive note, CDC flu chief Dr. Nancy Cox was quoted on Friday as saying, “we do not see the markers for virulence that were seen in the 1918 virus,” which was possibly the deadliest outbreak of all time.

BACKGROUND
Swine influenza has previously been identified as a contagious respiratory disease that commonly infects pigs and is caused by a type-A influenza. The current strain is a new variation of an H1N1 virus, which is known as a mix of human and animal versions. The dangers of this strain exist when the flu spreads from human to human instead of from animals to humans, as the virus can continue to mutate, making it difficult to treat and combat because people do not have natural immunity. The H1N1 flu was first detected in Mexico City, where surveillance started picking up a surge in cases of influenza-like illness starting March 18. It was assumed by Mexican authorities to be “late-season flu” until April 21, when a CDC alert regarding two isolated cases was reported in the media. The first H1N1 flu death occurred on April 13. Symptoms are similar to the common flu, causing fever, lethargy, lack of appetite, coughing, runny nose, sore throat, nausea, vomiting and diarrhea. Also like the common flu, the virus spreads when an infected person coughs or sneezes around another person. One can also become infected by touching something with the flu virus on it and then touching their mouth, nose or eyes. The CDC recommends taking everyday precautions such as frequent hand washing, covering up coughs and sneezes and staying away from work or school if not feeling well to prevent the disease from spreading. According to the WHO, seasonal flu affects 57,000 to 96,000 people each week and leaves 4,800 to 9,600 dead. Over the last 10 days, the H1N1 flu virus has infected at least 1,480 people and killed 30 worldwide.