A study of household transmission of the novel H1N1 virus in San Antonio, Tex., during the first pandemic wave found that children were most affected and were more likely to transmit the virus to other children at rates that were generally lower than seasonal flu. The median time to illness onset between contacts was 4 days. The Emerging Infectious Diseases study found secondary attack rates of 4% for confirmed novel H1N1, compared with rates ranging from 13% to 30% for seasonal flu. [Mar 11 Emerg Infect Dis study]

Doctors writing in Clinical Infectious Diseases report the case of a 7-year-old girl infected with pandemic H1N1 flu who developed encephalopathy that led to brain death. She had had fever and malaise for 1 day but no upper respiratory symptoms. Her condition then deteriorated, and on admission to intensive care she had signs of severe neurologic compromise. Brain death was confirmed within 3 days, in the first such instance documented in the pandemic, according to the authors. [Mar 10 Clin Infect Dis abstract]

To identify risk factors, French researchers compared the frequency of preexisting health conditions in patients who had severe H1N1 flu with their frequency in the general French population. Writing in PLoS Currents, an online journal that screens content but does not use full peer review, they report that pregnancy, obesity, heart failure, and diabetes were risk factors for admission to an intensive care unit. But only obesity, heart failure, and diabetes were risk factors for death. [PLoS Currents report]

Ministers of health from Arab nations are meeting to discuss various health topics, including their response to pandemic H1N1 flu, Kuwait News Agency (KUNA) reported today. Kuwaiti Minister of Health Dr. Hilal Musaed Al-Sayer said there is full coordination among members of the Gulf Cooperation Council (GCC), especially in the seasons of pilgrimage and lesser pilgrimage, on fighting the pandemic, as well as on exchanging data and statistics related to the infections and deaths. [Mar 11 KUNA article]

The nation's colleges saw a very slight decrease in flu-like illnesses last week, but the attack rate stayed about the same as the previous 2 weeks, about 3 to 4 cases per 10,000 students, the American College Health Association (ACHA) reported today. So far the patterns don't signal a third pandemic flu wave, even on a regional level. Two more hospitalizations were reported, and the vaccination level stayed the same, at about 8%. [Mar 10 ACHA surveillance report]

India's health ministry said the country will begin vaccinating its priority groups against the pandemic H1N1 virus next week, Indo-Asian News Service (IANS) reported today. Doctors and paramedics will be among the first to receive the vaccine. India has purchased 1.5 million doses from Sanofi and had asked the company to conduct a pandemic vaccine trial in India, which it has completed and sent to the ministry. Indian companies are also working on pandemic H1N1 vaccines. [Mar 10 IANS story]

A mouse study found that earlier infection with a 1976 classical swine H1N1 virus completely protected against the current pandemic virus, suggesting modern day benefits for those who received the 1976 swine flu vaccine, according to a study in Influenza and Other Respiratory Viruses. Mice infected with either 2009 or 1940 seasonal H1N1 viruses showed partial protection, which might partly explain why older people seem to have some protection against the pandemic virus. [Mar 8 study abstract]

Turkey is negotiating with vaccine companies to return some of its unused doses of H1N1 flu vaccine, the Anatolia News Agency reported today. Health Minister Recep Akdag said the government had ordered 43 million doses of vaccine but actually purchased 17 million. Officials are talking with manufacturers about giving "a significant part" of that amount back, but will keep 2 to 3 million doses for emergencies, he said. Akdag said in January that more than 600 people in Turkey had died of H1N1. [Mar 9 Anatolia News Agency report]

Pandemic flu cases in Rwanda are starting to increase again after dropping in early February, The New Times in Kigali reported today. A health ministry official said an increase was noted in Burera district of Northern province, with six confirmed cases in the past week. He said seasonal flu cases are also being reported and that a stockpile of oseltamivir (Tamiflu) is available. He added that the flu uptick calls for more vigilance but said there is no cause for alarm. [Mar 9 New Times story]

The Dutch health ministry has signaled that it is in talks with GlaxoSmithKline to possibly return a large portion of its surplus H1N1 flu vaccine, Reuters reported. The ministry had ordered 34 million doses at a time when experts thought each person would need two doses. Of that total, 11 million doses have been administered, and the government is holding 2.2 million as an emergency reserve. [Mar 6 Reuters story]

In an effort to prevent a repeat of last year's post spring break flu spread, the American College Health Association (ACHA) and the US Centers for Disease Control and Prevention (CDC) advised students with travel plans to get the pandemic H1N1 vaccine and take other measures to protect themselves. The two groups warned in a Mar 5 letter that the virus is still circulating in the United States and abroad and that some colleges have recently reported increases in flu activity. [Mar 5 ACHA and CDC letter]

Britain's system of electronic health records made it easier for medical providers to notify people targeted for H1N1 vaccination than was the case for US providers, said CDC Director Thomas Frieden at a recent conference. While Americans mostly decided on their own if and when to get vaccinated, British providers used the electronic records to identify people with high-risk conditions and invited them to come in for vaccination, he said. [Mar 5 Reuters report]

Spain plans to donate 4 million doses of H1N1 vaccine to the countries of Latin America, the Pan American Health Organization (PAHO) announced recently. Trinidad Jimenez, Spain's minister of health, announced the donation at a Mar 4 meeting with Dr. Socorro Gross, assistant director of PAHO. [Mar 4 PAHO announcement]

The pandemic H1N1 virus continues to circulate in temperate zones of the Northern Hemisphere but is at low levels and continuing to decline in most areas, the World Health Organization (WHO) said in its weekly update today. The most active areas include Thailand, Myanmar, Russia, Bulgaria, Armenia, and Moldova. Activity is very low in North America, but Mexico and Peru have seen a slight increase in respiratory disease. Several countries in western Sub-Saharan Africa are reporting H1N1 cases. [Mar 5 WHO weekly update]

For the sixth week in a row the nation's pandemic flu activity was steady last week, with doctor's visits for flu-like illnesses below baseline and pneumonia and flu deaths up a bit but below the epidemic threshold, the US CDC reported today. One pediatric flu death was reported, in an influenza B case from last season. No states reported widespread activity, but Alabama, Georgia, Mississippi, and South Carolina had regional activity. Testing found only two seasonal flu viruses. [Mar 5 CDC weekly flu update]

The health service at Penn State University has seen several confirmed H1N1 cases over the past few weeks, offering a reminder that the virus is still circulating and that people still need to be vaccinated, the university announced yesterday. The cases were detected at the school's University Park campus. A school newspaper, the Daily Collegian, reported today that pandemic flu was recently confirmed in seven students, the first ones since the new semester began in January. [Mar 4 Penn State press release]

A genetic study of pandemic H1N1 viruses by Italian researchers today suggests that several H1N1 clades circulated early in the epidemic but that one clade (clade 7) replaced the others and has predominated through most of the pandemic. The authors concluded, however, that it's not clear whether the shift to a single-clade pattern had a clinical impact or gave the virus a transmissibility advantage. The report appears in Public Library of Science (PLoS) Currents. [Mar 4 PLoS Currents study]

The Hong Kong Centre for Health Protection (CHP) today reported a slight increase in cases of influenza-like illness (ILI). ILI cases increased from 42.8 to 55.1 per 1,000 office visits over the preceding week. The CHP also reported 23 institutional outbreaks, compared with 3 in each of the previous 2 weeks. And the number of respiratory samples that tested positive for flu rose to 85 from 44 the week before. About a fourth of the isolates were pandemic H1N1, and more than 60% were influenza B. [Mar 4 CHP report]

British vaccine advisors are considering advising those traveling to the Southern Hemisphere during its upcoming flu season to receive the pandemic H1N1 vaccine in addition to the seasonal version, Healthcare Republic, a UK-based publication, reported today. The Southern Hemisphere's flu season typically runs from May through October. The Department of Health said it is exploring ways to implement the flu vaccine advice. [Mar 4 Healthcare Republic story]

In a study today, the Department of Veterans Affairs reported that it effectively used an electronic biosurveillance system for tracking and monitoring influenza trends. The system, called Electronic Surveillance System for the Early Notification of Community-based Epidemics (ESSENCE), effectively tracked trends for seasonal flu as well as the rise in cases at the start of the H1N1 pandemic. The authors said it could serve as an important alerting tool. [Mar 4 PLoS One report]

Flu-like illness activity at US colleges decreased slightly last week, and although disease incidence was higher than it was between mid December and mid February, the American College Health Association (ACHA) sees no evidence of a third pandemic wave. The attack rate for the week ending Feb 26 was 3.3 cases per 10,000 students, down 20% from the previous week. Southeast and Gulf Coast schools showed slight increases in disease activity, with levels still lower than November's. [Mar 3 ACHA surveillance report]

The University of South Carolina in Aiken saw an increase in suspected H1N1 flu cases in February, according to The State newspaper in Columbia, S.C. After seeing few flu-like illnesses in January, the campus had 27 cases in February, said Cindy Gelinas, director of the student health center. Four sick students were tested in late February, and all had the virus. State epidemiologist Dr. Jerry Gibson said another wave of cases is likely if the pandemic follows historical precedents. [Mar 3 State report]

China's health ministry said the country's H1N1 pandemic has passed its peak, according to Xinhua. The proportion of H1N1 among all flu cases dropped from 36.6% in January to 11.1% in February. The ministry reported that 793 Chinese have died of the illness, including 18 in February. Officials estimated that 30% of the population has immunity to the virus and said a major new wave of cases is unlikely in the near term, but added that localized outbreaks in crowded settings remain possible. [Mar 3 Xinhua report]

India's government has signed an agreement with Panacea Biotec, a pharmaceutical company based in New Delhi, to produce pandemic H1N1 vaccine, the company reported today. Panacea has a manufacturing facility in Punjab that can produce 45 million doses a year. Panacea projects that its vaccine, a split-virus, egg-based product, will be available by April for emergency use. India has also signed vaccine agreements with two other companies. [Mar 3 Panacea Biotec press release]

The government of Brazil said Monday that it will launch "the largest campaign in the world" to vaccinate its citizens before the Southern Hemisphere flu season. Xinhua reported that the effort aims to give shots to 90 million Brazilians in a tiered campaign: health workers and indigenous citizens first, followed by pregnant women, young children, chronic-disease sufferers and young adults, and then the rest of the population. [Mar 2 Xinhua story]

Widespread building damage and continuing power-supply interruptions have forced authorities to suspend H1N1 and routine vaccination campaigns in Chile following the Feb 27 8.8-magnitude quake there. New deliveries of H1N1 vaccine from outside the country have been postponed for at least a week, while authorities fear existing vaccine stocks have been ruined by electricity failures that interrupt the cold-chain keeping vaccines potent. [Mar 1 Pan American Health Org update]

An analysis of complaints to the Irish Medicines Board (IMB) reveals that there have been almost 1,000 reports of adverse reactions to the H1N1 vaccine, the Irish Times reported today. Most of the reactions were injection-site swelling, gastrointestinal problems, and flu-like symptoms. In its most recent update, the IMB said it has no mechanism for separating true adverse reactions from coincidental events. [Mar 2 Irish Times story]

If pandemic H1N1 follows the same evolutionary pathway as seasonal H1N1 strains, it will likely develop the resistance to oseltamivir (Tamiflu) that has become widespread in seasonal strains, Ohio State University researchers predict in the International Journal of Health Geographics. Reassortment between pandemic and seasonal strains in areas where they co-circulate, such as China, could speed the evolution of resistance, and antiviral use must be judicious, they say. [Feb 24 Int J Health Geogr article]

Pandemic H1N1 flu hasn't ebbed as much as anticipated in Alabama, according to public health officials there. Although frequency was higher in the fall than it is currently, cases are still occurring across the state, and there were three deaths in February, a pattern unlike previous flu epidemics. The state ran a large school immunization program earlier in the winter, but school absences in the state remain higher than the typical 5%. [Mar 1 Tuscaloosa News story]

Pubic health data show that the H1N1 influenza vaccine was distributed unevenly across Los Angeles County, with the north and south sides getting disproportionately less, according to an LA Times story today. The reason for the disparity primarily lies in the lower number of healthcare providers in those areas, which translates into fewer requests for vaccine, county health officials said. They admitted that some of the efforts to ensure equal access to vaccine failed. [Mar 1 LA Times story]

Pandemic H1N1 flu virus has the intrinsic ability to cause more severe pneumonia than seasonal H1N1 flu, concludes a study in the Journal of Infectious Diseases. This ability is a key measure of a flu virus's pandemic potential. The researchers inoculated ferrets intratracheally--to model influenza pneumonia in humans--with pandemic H1N1, seasonal H1N1, or highly pathogenic H5N1 virus. Pandemic H1N1 caused pneumonia intermediate in severity between the other viruses. [Feb 26 JID study abstract]

An April 2009 outbreak of pandemic H1N1 flu in a New York City high school, reported in the Journal of Infectious Diseases, had an 11.3% attack rate of flu-like illness among household contacts. Protective factors were older age, antiviral prophylaxis, and having a family discussion of flu. Risk factors in parents included caring for the index patient and, in siblings, watching TV with the patient. Half the secondary illnesses occurred within 3 days of the index patient's illness onset. [Feb 25 JID study abstract]

Canada's IMPACT monitoring program has reported that, in the first wave of the pandemic (May-August 2009), 324 cases involving hospitalization occurred in the country's children. Of 235 for whom case details were available, 69% were older than 2, with a median age of 4.8; 40% were previously healthy; 50% received antivirals; and two died. The data show the disease course and risk groups affected to be similar to those for seasonal flu but use of antivirals to be higher. [Feb 26 Vaccine article]

Pandemic flu stayed at the same level for the fifth consecutive week last week, with no states reporting widespread activity and only three--Alabama, Georgia, and South Carolina--reporting regional activity, the Centers for Disease Control and Prevention (CDC) said today. Outpatient visits for flu-like illness were below the national baseline, and deaths from pneumonia and flu were below the epidemic threshold. Influenza B circulated at low levels. Three pediatric flu deaths were reported. [Feb 26 CDC weekly flu update]

Though overall pandemic activity waned across the globe, some active areas were seen in parts of south and southeast Asia and in a few areas of eastern and southeastern Europe, the World Health Organization (WHO) said today. Brunei Darussalam reported intensifying flu activity, and overall respiratory disease increased in some countries because of influenza B and respiratory syncytial virus activity. Low levels of influenza B and seasonal H3N2 flu circulated in parts of Africa and Asia. [Feb 26 WHO update]

Japan's National Institute of Infectious Diseases has estimated that 20 million people in Japan, mostly children, were infected with H1N1, according to an editorial in the Asahi Shimbun. But fewer than 200 people in Japan have died of the illness, "an amazingly low toll," the newspaper said. It said early diagnosis and treatment apparently helped limit deaths. But it said the health ministry was slow to prepare for the H1N1 vaccination campaign and used a flawed communication strategy. [Feb 25 Asahi Shimbun editorial]

Fifteen California women who were vaccinated against H1N1 while pregnant had miscarriages or stillbirths, a figure far below the expected rate of miscarriage for all pregnant women, California health officials told TV station KCRA 3 in Sacramento. Officials said the miscarriage rate for all pregnancies is about 15%, but the miscarriage rate among vaccinated women is only a fraction of 1%. Officials said no link between the vaccine and the pregnancy outcomes has been found. [Feb 24 KCRA3 report]

In the first study describing the course of pandemic H1N1 infection in patients with cystic fibrosis, researchers from an Australian cystic fibrosis center for adults reported that most patients had a mild illness and were managed with antiviral treatment as outpatients. More severe disease was seen in those who presented for treatment late. The findings appear in BMC Pulmonary Medicine. [Feb 25 BMC Pulm Med abstract]