Thursday, April 29, 2010

H1N1 Lessons Learned Resource

CIDRAP has issued the first of a series of articles reviewing the world's experience with pandemic H1N1 influenza and what lessons have been learned in the past year.

This first issue covers geographic expectations, wave pattern, impacts on populations, as well the stresses of H1N1 on health systems. The resource also talks about clinical components of illness related to H1N1, as well as about high risk populations.

Source: CIDRAP

International Group Renews Push to Fight Avian & Pandemic Influenza

Apr 22, 2010 – An international avian and pandemic flu meeting in Hanoi concluded yesterday, with health ministers and top officials from more than 70 countries agreeing on a set of strategies for responding to future disease threats.

The agreement, titled the Hanoi Declaration, includes national measures to identify new diseases that cross from animals to humans and quickly deploy public health responses, the United Nations (UN) said yesterday in a press release. Documents related to the meeting are available on the Web site of the Seventh International Ministerial Conference on Animal and Pandemic Influenza, where the Hanoi Declaration will be posted shortly, according to the group.

The ministerial conference was hosted by the Vietnamese government and organized by the United States, the European Union, UN groups, and other global health organizations. It was the latest in a series of high-level meetings over the past 4 years to tackle international avian and pandemic flu issues.

Clouds of volcanic ash hampered travel to the 3-day meeting over Europe, which blocked about a fifth of the delegates from attending the meeting, the UN said. China's earthquake limited that country's participation. "The severity of these natural occurrences, and the suddenness with which they struck, reminded delegates about the swift and unpredictable spread of new hazards that can emerge from the animal world," the UN release said.

The meeting also took place in the wake of warnings from several global organizations about the continued risk of H5N1 avian influenza. Countries where the disease is endemic, such as Egypt and Vietnam, have reported several outbreaks in poultry this year, along with a spate of human cases.

A few weeks in advance of the meeting, organizers released a draft report on how to sustain momentum in the fight against animal and pandemic flu. The report was slated to be finalized when the group met in Hanoi. Some of the topics include broad-based prevention and control, incentives, measuring progress, and building financial and technical assistance.

The health officials rejected an effort put forth by Poland to include in the declaration a statement on pharmaceutical company conflict of interest and their responsibility for vaccine side effects, Deutsche Presse-Agentur (DPA) reported yesterday. The Polish government did not purchase a stockpile of pandemic vaccine, in part because it objected to liability limits on companies' pandemic vaccines.

David Nabarro, the UN's system influenza coordinator, said in the press release that the global capacity to collaborate in response to disease threats has improved over the past 5 years, but the conference helped identify areas that can enhance the world's security during future emerging disease threats.

At the closing ceremony yesterday, Bui Ba Bong, Vietnam's vice-minister of agriculture and rural development, said the world needs to continue responding to H5N1 and pandemic H1N1 while preparing for other diseases that move from animals to humans. "In Vietnam's experience, this calls for good human and animal health services, excellent communications, and whole of society responses," he said.

Source: CIDRAP

Accelerated 2009 H1N1 Infection Rates in Bangladesh

According to recent reports, Bangladesh has directed health officials across the country to remain on alert after finding that the 2009 H1N1 influenza virus has spread rapidly this month.

They said the disease had been remaining at lower levels in Bangladesh from January-March of 2010, but this month it has spread hastily, infecting many across the country, posing a fresh threat of a massive outbreak.

"So, we've asked all officials concerned to remain on alert," Mahmudur Rahman, Head of the country's Institute of Epidemiology, Disease Control and Research (IEDCR) under the Health Ministry, told Xinhua Tuesday.

As to whether there is a possibility of major outbreak of the disease in the country in the coming months, Rahman said the possibility is very low, as they have adequate preparations to contain the spread of the disease.

"The virus sustained at a lower level in Bangladesh during January-March period but it showed rising trend since the beginning of this month," he said, adding this is not something unusual as April-September period is considered to be the peak season of the disease.

He did not cite the exact number of people infected by the disease so far this month but said that the April's figure is not something negligible compared to the first three months of 2010 and confirmed that no one died due to the flu this year.

According to the official record of the Bangladesh Health Ministry, the 2009 H1N1 death toll in the country in 2009 rose to 6.

A 35-year old female flu positive patient in Aug. 31, 2009 died in Dhaka which was first fatality the country has had since recording its first A(H1N1) case on June 18. Three people died until the first week of October, 2009 since June while three other died in the later October and early November period.

Rahman also said that Bangladesh will very shortly launch flu vaccination program as part of its efforts to protect people.

"As part of our strengthening measures we're now collecting flu samples from 28 points of the country instead of 14 earlier," he said, adding there is nothing to be much worried following the disease's rapid outbreak this month as there is also huge supply of medicines in the Health Ministry's stock.

The country's Health Ministry had already permitted the marketing of 2009 H1N1 flu vaccine in the country.

Currently, the Bangladeshi government has asked hospitals and clinics in the country to immediately treat anyone who displays symptoms of H1N1 rather than to spare time by having to test them first.



Balita News flu-infection-accelerates/?date=042110

Vaccine Shortage Threatens 2009 H1N1 Control in Nigeria

Despite the recent outbreak of the pandemic 2009 H1N1 virus in Ghana, Nigeria is yet to receive stocks of vaccine to prepare for a possible outbreak in the country.

Two Nigerians have so far died of the virus and 11 cases have been confirmed by the Federal Ministry of Health (FMOH). A nine-year-old American girl was the first case of HINI in Nigeria, which was reported in November 2009.

Experts are worried that the scenario may threaten efforts to control the virus, especially in developing countries. They said the demand for the vaccine worldwide has outstripped the supply, which coupled with the high cost of the vaccine, has made it difficult to obtain.

Former Health Minister, Prof. Babatunde Osotimehin, has been elected Vice Chair, International Health Regulations (IHR) Review Committee, which was set up by the World Health Organisation (WHO) to assess the global response to the pandemic H1N1.

Source: Nigerian Guardian Newspaper

US Global Funds for Avian & Pandemic Influenza Reach $1.5 Billion

From CIDRAP News - April 20, 2010

Lat week, the US delegation to the International Ministerial Conference on Animal and Pandemic Influenza (IMCAPI) meeting in Hanoi, Vietnam, noted the country has spent more than $1.5 billion to combat global avian and pandemic influenza. This figure represents $627 million invested since the previous 2008 IMCAPI conference held in Sharm el-Sheikh, Egypt, according to a Department of State press release.

The additional US funding will be allocated to multilateral organizations, such as the World Health Organization, as well as to bilateral and regional programs. This investment includes the donation of 10% of the US H1N1 vaccine supply to developing countries, as well as in-kind assistance such as personal protective equipment, laboratory and decontamination kits, technical and humanitarian assistance, and vaccine research. The 3-day conference, was hosted by Vietnam with support from the US Agency for International Development, the United Nations, and the European Commission.

Source: CIDRAP

Friday, April 16, 2010

Humanitarian Pandemic Preparedness (H2P): Red Cross Annual Report

The International Federation of Red Cross and Red Crescent Societies (IFRC) is supporting National Societies with financial and technical support, to prepare for, and respond to, an outbreak of pandemic influenza in their countries.

Essential to the program's success is ongoing collaboration and coordination with multiple implementing partners, including NGOs (including CARE), UN agencies, local governments and Movement partners. National Societies implementing H2P projects are developing pandemic preparedness and response plans, training staff and volunteers, providing consistent messages to their communities, in addition to the ongoing in-country coordination with all stakeholders. Health, Food Security, Livelihoods and Communications working groups consisting of IFRC and partner organizations have developed tools, materials, guidelines and a website for pandemic preparedness and response efforts

View the full annual report at$File/full_report.pdf, and visit the H2P website at for more information on pandemic preparedness.

Renal Complications Common with Pandemic Flu

According to an article published in Renal & Urology News, acute kidney injury (AKI), acute renal failure (ARF), and the need for dialysis are common complications in critically ill patients with 2009 H1N1, and are associated with an increased death risk, according to Canadian researchers.

Manish M. Sood, MD, and colleagues at the University of Manitoba in Winnepeg, prospectively studied 50 patients with 2009 H1N1 admitted to one of seven ICUs in Manitoba. Subjects had a mean age of 35.5 years and 72% were women.

AKI developed in 66.7% of the patients for whom this complication could be determined. Eleven patients (22%) required dialysis; of these, 10 recovered. Eight patients (16%) died. AKI and kidney failure were associated with a 5.7 and 11 times increased risk of death. The need for dialysis was associated with a 21% increased risk.

In addition, patients requiring dialysis had a significantly increased ICU stay compared with those not requiring dialysis (mean 33.3 vs. 19.3 days).

The researchers concluded that critically ill patients with H1N1 infection suffer a high rate of kidney injury, kidney failure, and the need for dialytic therapies. Kidney injury was also strongly associated with mortality.

The researchers also stress that longer ICU stay for patients needing dialysis could significantly stress hospital resources in the event of a future outbreak.

Source: Renal & Urology News

Egypt: Confirmed H5N1 Infection in Donkeys

A new study investigating H5N1 in mammalian hosts has confirmed that the virus was found in donkeys in Egypt.

Nasal swabs were collected from donkeys suffering from respiratory distress. Phylogenetic analysis showed that the virus clustered within the lineage of H5N1 from Egypt, closely related to 2009 isolates. It harbored few genetic changes compared to the closely related viruses from avian and humans. The neuraminidase lacks oseltamivir resistant mutations.

These findings extend the host range of the H5N1 influenza virus, possess implications for influenza virus epidemiology and highlight the need for the systematic surveillance of H5N1 in animals in the vicinity of backyard poultry units especially in endemic areas.

Source: Journal of Biomedical Science

Bangladesh: Confirmed H5N1 Outbreaks in Poultry, Narayangonj and Mymensingh

Following active surveillance, outbreaks of H5N1 were observed:
  1. On 7 April 2010 in Mymensingh District, Dhaka division,where 4 out of 123 backyard poultry died. The rest of the poultry were culled.
  2. On 11 April 2010, when three outbreaks occurred at threebackyard poultry in Araihazar Upazila. Narayangonj District, Dhaka division and 3,136 out of 10,700 died. The rest of the chickens were culled.
The farms are clustered in the same area (the distance from each other being 10-15 meters).

Narayangonj District last reported four outbreaks in March 2007.


Thursday, April 15, 2010

New UN study urges sustained momentum to tackle human, animal influenza threats

14 April 2010 While there has been substantial global progress towards pandemic preparedness in recent years, it is vital to maintain that momentum to respond effectively to existing and possible future threats, according to a new study by the United Nations and the World Bank.

“Continued global vigilance for infectious disease outbreaks and pandemics is of critical importance for health security and well-being,” says the report, entitled “Animal and pandemic influenza: a framework for sustaining momentum.”

The report notes that an estimated 75 per cent of new human diseases originate in animals and an average of two new animal diseases with cross-over capabilities emerge every year. We have to find ways to put the work on bird flu and on pandemics more into the routine business of ministries of health and ministries of agriculture
The emergence of three major epidemiological events into the first decade of the new century – SARS, H5N1 avian influenza and H1N1 pandemic influenza – is an indication of the rate at which threats may continue to arise, it adds.

“Sustaining momentum,” states the report, “will require a strategic use of resources and a move away from emergency response-driven projects and special, single-focus initiatives, to long-term capacity-building.”

The report will be taken up by delegates from over 80 countries when they meet at the International Ministerial Conference on Animal and Pandemic Influenza, which will be held in Hanoi, Viet Nam, from 20 to 21 April.

“This is a really significant conference,” David Nabarro, Senior UN System Influenza Coordinator, told reporters in New York, noting that the gathering will take stock of where the world is with regard to bird flu and the H1N1 virus, review preparedness and consider lessons learned from countries with successful control efforts.

The threats from bird flu and H1N1 are not over yet, he noted, stressing the need for further measures to ensure an effective global response.

“We have to find ways to put the work on bird flu and on pandemics more into the routine business of ministries of health and ministries of agriculture, into the routine work of disaster preparedness units in countries,” he stated. “And so an important element of the discussions in Hanoi will be the way forward.”

Part of the work in Hanoi, he added, will be to consider whether or not extra preparedness is necessary to ensure that those who look after animal health and those that look after human health are working together well enough to prepare for disease threats that come from animals.

A key question, he noted, is: “Are we well enough organized as a world to be prepared for diseases that can jump from the animal kingdom and lead to sickness and possibly quite widespread suffering among humans?”

Find this story at Scroll down to Topics: Health, Poverty, and Food Security

Wednesday, April 14, 2010

Outbreak Study: Satellite Tracking Reveals How Wild Birds May Spread Avian Flu

For the first time, migratory birds marked with satellite transmitters were tracked during an outbreak of highly pathogenic H5N1 avian influenza virus (H5N1) in Asia, providing evidence that wild birds may be partly responsible for the spread of the virus to new areas.
In the study, scientists from the USGS Alaska Science Center and the University of Tokyo attached satellite transmitters to 92 northern pintail ducks several months before the H5N1 virus was discovered in dead and dying whooper swans at wetlands in Japan.
They found that 12 percent of marked pintails used the same wetlands as infected swans and that pintails were present at those sites on dates the virus was discovered in swans. During the first week after they become infected with H5N1, ducks such as pintails can shed the virus orally or in their feces, potentially contributing to the virus’ spread.
Researchers found that some of the marked pintails migrated 700 miles within four days of leaving the outbreak sites; marked pintails ultimately migrated more than 2,000 miles to nesting areas in eastern Russia. The study’s discovery that northern pintails made long-distance migrations during the period when an infected duck would likely shed the virus offers insight on how H5N1 could be spread by wild birds across large areas.
The research, published in the journal Ibis, does not prove the marked pintails were actually infected with the H5N1 virus or that they definitively contributed to its spread. However, it does demonstrate that pintails satisfied two requirements necessary for migratory birds to spread the virus: they used outbreak sites at times when the virus was present and some birds migrated long distances within a week of using the sites.
Jerry Hupp, Ph.D., a U. S. Geological Survey scientist and one of the lead authors of the study, noted that the H5N1 virus has been found in wild birds, including northern pintails, which show no visible signs of illness. Also, laboratory studies have shown that pintails and some other wild birds remain healthy when infected with H5N1.
“Consequently,” said Hupp, “infected wild birds that do not become ill, or birds that shed the virus before they become ill, may contribute to the spread of H5N1.”
The extent to which the virus has been spread via the wild bird trade, wild bird migration, and shipping of infected poultry or poultry products has been the focus of debate. “Studies of the movements of wild birds during H5N1 outbreaks can help scientists evaluate the overlap between migratory pathways and the occurrence of the virus,” Hupp said.
The region in eastern Russia that pintails migrated to is also an important migration and nesting area for many North American birds. Mingling of Asian and North American migrants in Russia can result in exchange of influenza virus genes. Previous USGS studies have demonstrated that northern pintails in Alaska often carry low pathogenic influenza virus genes that can be linked to Asian sources.
“Because northern pintails in Alaska exchange influenza viruses with Asian birds, movement of the H5N1 virus into eastern Russia would increase the risk for its transmission to North America via wild birds -- such as the northern pintail -- that migrate between continents,” said Hupp.
The study also noted that Japanese wetlands where the H5N1 virus was found are important migration habitat for other waterfowl, including as many as 11,000 Eurasian wigeon and 8,000 greater scaup, demonstrating the potential for large numbers of wild birds to pass through sites where the H5N1 virus is present if outbreaks occur during migration.
Although the highly pathogenic H5N1 virus has not been discovered in North America, it continues to plague the poultry industry throughout Eastern Europe, Asia and Africa and is a serious health threat to humans.
Satellite-tracking of northern pintail during outbreaks of the H5N1 virus in Japan: implications for virus spread was published in Ibis (February 2010, Volume 152) and was authored by Noriyuki Yamaguchi (University of Tokyo), Jerry Hupp (USGS), Hiroyoshi Higuchi (University of Tokyo), Paul Flint (USGS), and John Pearce (USGS).
For more information on avian influenza research, visit the USGS Alaska Science Center.

Monday, April 12, 2010

WHO Global Influenza Update: Distribution, Spread and Resistance

Though pandemic flu activity stayed stable in most parts of the world, Chile is reporting new detections of the pandemic virus in at least three regions in advance of the start of its flu season, with other hot spots occurring in Bangladesh and parts of Africa, the World Health Organization (WHO) reported today.

Localized pandemic flu transmission is persisting in Tanzania and Rwanda. Several countries in the tropical zones of the Americas are reporting localized flu activity as well, including Cuba, Guatemala, Peru, and Bolivia. WHO said in its weekly flu report that the significance of the rise in pandemic flu in parts of Chile to the rest of its flu season is unknown.

Data from Mexico suggest that several states reported localized activity throughout March, particularly in Federal district, an area that has reported recent spikes in severe and fatal pandemic H1N1 infections, the WHO said. Brazil, which has reported increased levels of influenza-like illnesses over the past month, has reported that most of the severe and fatal pandemic H1N1 infections are occurring in the country's northern regions.

In some parts of the world, including China and European countries such as Italy, flu activity is occurring at expected levels, much of which is influenza B. Other countries reporting increased detections of influenza B strains include Hong Kong and Chinese Taipei. Some parts of Africa, such as Cameroon, are also reporting influenza B illnesses.

Small number of seasonal H3N2 viruses have been detected in West and East Africa, the WHO said. Indonesia is still the most active area for seasonal H3N2 transmission, though activity is leveling off there, the WHO said.

In addition, the seasonal H1N1 virus has been reported sporadically by the Russian Federation.

Most pandemic virus samples that countries have submitted to WHO collaborating center laboratories are closely related to the strain recommended for pandemic influenza vaccines.

Ten more cases of oseltamivir-resistant pandemic H1N1 were reported last week, most of which occurred in the last quarter of 2009, WHO said. All 278 samples so far have the H275Y substitution, and all remained sensitive to zanamivir. Most cases were linked to treatment or postexposure prophylaxis or occurred in severely immunocompromised patients. Only 7% had no known association to treatment.

In addition, WHO said it has received preliminary notification about a pandemic H1N1 isolate that has reduced sensitivity to neuraminidase inhibitors.

So far more than 213 countries and overseas territories or communities have reported lab-confirmed pandemic H1N1 cases, the WHO said. The agency has received reports of more than 17,700 deaths, a number it says greatly underestimates the true burden of the disease.

Source: CIDRAP


Friday, April 9, 2010

FAO: Egypt one of five countries where H5N1 still persists

Via H5N1 (Crofsblogs) and Daily News Egypt Excerpt:

"Egypt is listed as one of five countries where the H5N1 virus, or avian influenza, still persists, said a statement by the Food and Agriculture Organization of the United Nations (FAO).

The H5N1 virus has been combated in 135 countries while an outbreak remains a threat in Egypt, China, Bangladesh, Indonesia and Vietnam.

'Unfortunately, H5N1 may have slipped off the radar screen for some people, but it continues to be a major problem, especially in Egypt and parts of Asia, where it is having a huge impact on food security and the livelihoods of farmers and local communities,' said Juan Lubroth, FAO's chief veterinary officer.

Bangladesh, Indonesia and Vietnam reported bird flu outbreaks resulting in the deaths of thousands of birds thus far while Egypt reported more human cases.
Poor farm biosecurity and trading of infected poultry are the main causes of the disease spread, according to the FAO.

Last Sunday, Egypt’s Ministry of Health announced the 34th bird flu-related death in the country; an 18-year-old woman from Fayoum. The number of bird flu cases witnessed a hike in 2010; the 18-year-old is the seventh reported this year.

A total of 109 cases have been reported since the virus first appeared in Egypt in 2006."

News source:

No adverse effects to influenza antiviral medications in pregnancy: Maternal and neonatal outcomes after antepartum treatment of influenza antiviral m

Via CIDRAP News:

Researchers from the University of Texas Southwest Medical Center report that neither oseltamivir nor amantadine/rimantadine caused any adverse events in pregnant women treated at the medical center during the H1N1 influenza pandemic. The 104 women given amantadine or rimantadine and the 135 women given oseltamivir had the same rates of preterm birth, premature rupture of membranes, gestational diabetes, and preeclampsia as the 82,097 women who did not receive antivirals.

Thursday, April 8, 2010

FAO says Avian Influenza Pandemic Still Evident in Nigeria

The Avian influenza (AI) pandemic is not yet over in Nigeria says the Food and Agricultural Organization (FAO).

Chief Technical Adviser of the Emergency Centre for Trans-boundary Animal Diseases (ECTAD) of FAO Dr. Tesfia Tseggai said this in Abuja during the launching of products from FAO-media fellowship project.

He said despite successes recorded in bringing the disease under control, AI can still be found in some very remote rural settlements.

"Media fellowship is about giving voice to ordinary Nigerians especially rural dwellers to talk to the media on their experiences with birds and Avian influenza," he said.

Country Representative of FAO in Nigeria Dr. Helder Muteia said many countries are still battling with Avian influenza but Nigeria has been able to bring it under control and has not recorded any new outbreak since July 2008.

Muteia observed that history has shown that successes must be recorded and properly managed for sustainability.

Media products that were launched included documentaries, in photograph, film and radio.

"There are documentaries that reveal the complex relationship between birds and their human neighbors, there are radio and television programs that reveal the immense contribution of birds to the livelihood of Nigerians and pictures as well," he said.

Participants visited selected communities across Nigeria affected by the disease and documented the experiences of the locals and cultural practices involving the use of birds in Nigeria.

Ten media persons were awarded fellowship certificates after participating in the project.


H5N1 Avian Influenza Outbreak in Tien Phong commune, Yen Hung district, VIetnam

Quang Ninh province has officially confirmed a new outbreak of H5N1 in Tien Phong commune, Yen Hung district. Information released on April 7 by the Chairman of the Yen Hung district People’s Committee, called for urgent measures to prevent the spread of H5N1 Avian Influenza (AI).

On March 19, Quang Ninh province also declared bird flu recurrence in Dong Mai commune, Yen Hung district. Local farmers claimed that although their poultry had been vaccinated they were still infected by bird flu virus.

The provincial Veterinary Department has introduced urgent measures to quarantine infected areas and sterilize breeding farms. The Department has also banned the transport and trading of sick poultry.


Possible H1N1 Outbreak in Ghana

The National Disaster Management Organisation (NADMO) and the Ghana Health Service, in conjunction with the Ministry of Health have warned of a threat of possible outbreak of 2009 H1N1 in Ghana.

A statement signed by the NADMO Coordinator, Kofi Portuphy, said the threat was heightened by the recent sporadic outbreaks of the disease in a number of schools in some regions leading to their closure.

Those affected include Merton Primary School, Tema Parents Association, Achimota Basic School, Lincoln Community School and American International School, all in the Greater Accra Region.

Others are Okuapeman Secondary School in the Eastern Region, Nankpanduri Senior High School in the Northern Region and Nfantsipim School and Ayipey in the Central Region.

The statement said minors and children were the vulnerable groups, and added that those from the affected schools might be incubating the disease without showing any signs or symptoms and could easily infect others.

Due to the mode of transmission, crowding at social events, especially for children coming from different schools, would be highly fertile grounds for easy spread of the disease to family members, friends, and the community,? it said.

The statement, therefore, cautioned the general public to minimize crowding at social events, especially those meant for children.

It reminded the public that transmission of the disease was from human to human, through droplets released during coughing, sneezing and touching surfaces contaminated with body fluids secreted by infected persons and touching the eyes nose and mouth without washing hands.

The signs and symptoms of the disease include coughing, sneezing, fever, chits, running nose, headache, vomiting, sore throat and body aches, and complications may lead to pneumonia and difficulty in breathing.

The statement said an effective way of preventing infection was through observance of good personal hygiene by washing hands with soap and water as often as possible, especially after touching surfaces and hand shakes.

Meanwhile from Mpraeso, Agnes Opoku Sarpong reports that the pandemic has broken out at the Mpraeso Senior High School in the Eastern Region with two students confirmed as having the virus, out of 33 suspected cases.

Source: GhanaWeb

Thursday, April 1, 2010

Entry Screening to Delay Local Transmission of 2009 H1N1

After the WHO issued the global alert for 2009 H1N1, many national health agencies began to screen travelers on entry in airports, ports and border crossings to try to delay local transmission.

The authors of this study reviewed entry screening policies adopted by different nations and ascertained dates of official report of the first laboratory-confirmed imported H1N1 case and the first laboratory-confirmed untraceable or ‘local’ H1N1 case.

Screening policies adopted by countries included:

  • Temperature checks onboard aircraft prior to disembarkation.
  • Health declaration forms collected from every traveler or all travelers from countries identified with confirmed H1N1 cases.
  • Arriving travelers were observed by alert staff for influenza symptoms (e.g. cough).
  • Travelers were scanned for elevated body temperature by thermal scanners.
Of the nations looked at in the study, two (China and Japan) implemented all four tools. Five nations did not implement any of the four. Overall, implementation of the four tools alone or in combination were associated with on average additional 7-12 day delays in local transmission compared to nations that did not implement entry screening.

The authors' results suggest that entry screening did not lead to substantial delays in local H1N1
transmission which is consistent with theoretical results from previous modeling studies and findings from previous pandemics. While longer delays in local transmission to the summer in countries in the Northern hemisphere could have substantially aided pandemic mitigation, due to seasonal factors and school vacations leading to lower peak attack rates, the observed delays in the present pandemic suggest entry screening provided around 1-2 weeks of additional time for
preparation and planning.

While this study focused on the impact of entry screening, some nations also implemented other containment and mitigation measures, such as isolation of suspected or confirmed cases, quarantine of their contacts with or without antiviral chemoprophylaxis, school closures or other social distancing measures, and public health campaigns to improve hygiene. Most nations enhanced their influenza surveillance. If countries that expended greater effort into entry screening also had more effective containment and mitigation measures in the general population, these might have led us to overestimate the effect of entry screening.

Conversely, if countries that expanded greater effort into entry screening also tended to have better influenza surveillance and were able to identify local transmission earlier, we may have underestimated the effect of entry screening. Other differences between countries in laboratory capacity and availability of public health resources may also have confounded our evaluation, and all of these factors are limitations of our study.

Previous mathematical modeling studies have questioned the value of entry screening, since it could only delay rather than prevent local epidemics. However, most models assumed that source countries would conduct exit screening and infectious cases would not travel. In such a scenario it is not surprising that entry screening would add little benefit, since most journeys are shorter than the average 1.5-2 day incubation period for influenza A virus infections. Screening is unlikely to identify 100% of ill travelers, while some might use antipyretics to reduce a fever prior to passing through thermal scanners, or fail to report symptoms on declaration forms. Many individuals with subclinical or asymptomatic illness would not be identified, and could initiate outbreaks after arrival. In Hong Kong, only one third of confirmed imported H1N1 cases were identified through screening on entry to Hong Kong, the majority of imported cases were
identified through the local health care system after arrival. A similar experience has been reported in Singapore.

Nevertheless, entry screening could act as a deterrent to traveling when ill or lead to other indirect benefits such as improving public awareness of the pandemic. For entry screening to be successfully employed, substantial resources are required to identify the small fraction of travelers who may have H1N1 infection. Further resources may be needed to isolate identified cases, and trace and quarantine close contacts.

The authors go on to discuss other caveats that may limit the accuracy of their model.

Source: BMC Infectious Diseases