Effect Measure

There may not have been much news at the CDC briefing, but it is coming thick and fast now. The CDC works through state health departments and defers to them on information about what is going on in their localities. Hence all questions about this were deflected at the 1 pm CDC briefing. I think I understand the thinking behind this but it doesn’t serve the goal of getting the information out there quickly. CDC needs to be the information clearing house for all the swine flu news going on around the country and they need to do with absolute transparency. Here’s what has developed since that briefing.

Kansas: According to AP and other sources, Kansas Department of Health and Environment has confirmed two cases of swine flu. Details yet to come.

New York City (Queens): About 100 students at St. Francis Preparatory School have come down with a febrile respiratory illness with sore throat and myalgia. There were 200 absentees at the school at the time. The NYC Health Department is saying that the illness is influenza A that is untypable in their laboratories (see here for more explanation of the testing routine). This is the way the current swine flu virus appears when seen by most laboratories, so confirmation that it is the same virus as in Mexico will require use of a special diagnostic primer now available in the CDC labs in Atlanta. Definitive results due tomorrow, but this is almost certainly swine flu with person to person spread. The incubation period seems very short, 1 – 2 days. All illnesses are said to be mild with no hospitalizations. Again the contrast with Mexico is striking. Previous reports said that one or more of the students had recently been in Mexico. No details were given in the NYC Health Department briefing.

World Health Organization (WHO): For the first time since the International Health Regulations started coming into force two years ago, WHO convened its Emergency Committee to advise the Director General, Dr. Margaret Chan, whether the developing swine flu situation constitutes “a public health emergency of international concern.” WHO has announced that the Committee has indeed made this judgment. Such a declaration allows WHO to ask for various disease control measures, including travel advisories and even border controls. Under international law prior to passage of the IHR WHO was not permitted to call for any measures that might infringe on the national sovereignty of a member state (see this post and the links there at the end of the first paragraph for more explanation).

So far, so good. There is another part to this, though. On the basis of such a declaration the Committee through the Director General may change the pandemic threat level from phase 3 to phase 4, (or, some would argue, even more appropriately to phase 5). According to a statement released by WHO hours ago, the Committee and the DG are declining to do so at this time:

Based on this advice, the Director-General has determined that the current events constitute a public health emergency of international concern, under the Regulations.

Concerning public health measures, in line with the Regulations the Director-General is recommending, on the advice of the Committee, that all countries intensify surveillance for unusual outbreaks of influenza-like illness and severe pneumonia.

The Committee further agreed that more information is needed before a decision could be made concerning the appropriateness of the current phase 3. (WHO)

The failure to change the threat level reveals what many people have being saying for some time: the WHO threat levels are totally irrelevant and meaningless. The definition of phase 4 is significant spread with a novel flu virus. There may be reasons — practical, political or even scientific — not to say we are in phase 4, but a failure to describe the current situation isn’t one of them. In other words, the WHO threat level descriptions are meaningless and have nothing to do with what is happening on the ground. Failure to recognize this by overhauling the criteria to match the facts, is a guaranteed way to send what is left of WHO’s credibility down the toilet.

When asked about this at the CDC briefing, the very sensible response was that CDC will do what it needs to do regardless of what WHO says the threat level is. I’m sure WHO would make the same response. If so, who needs the WHO threat levels?

There are now lots of terrific bloggers and sites active on this. None of us can cover it all. Here are some (but not the only) good ones: H5N1, FluWiki, DemFromCT, Avian Flu Diary, CIDRAP, Aetiology. Apologies to those I am leaving out (lots of great flu forums that are the best source for what the rest of us haven’t reported yet; Crof’s H5N1 sidebar has a pretty complete list).

Comments

#1 Phila
April 25, 2009

The Crof and Avian Flu Talk links are broken.
#2 george
April 25, 2009

Thanks, Revere, for staying on top of this.

Is it possible that the CFR is lower in the US because patients are being given antivirals and this wasn’t the case in Mexico? If so, then does that mean the true CFR is closer to the Mexican numbers? Would that mean that we will need a lot of antiviral meds if this goes pandemic, and do we have enough?
#3 phytosleuth
April 25, 2009

So who gets hurt by NOT raising the pandemic phase level? What are the consequences of that inaction? (you GO Revere!)
#4 Grace RN
April 25, 2009

Well, there we have it. When it was time to step up, Chan/WHO stepped back. I was very pleased to hear the CDC say they will continue to work hard at this, not tying their response to a WHO phase.
#5 revere
April 25, 2009

Thanks, Phila. Fixed.

george: I think only one of the US cases got Tamiflu. The US cases are mild and antivirals aren’t much used, so that’s not the answer. Two possibilities: biased ascertainment (Mexico only looking at hospitalized and seriously ill cases, US looking at community cases not in hosptial); or some co-factor, like infection with another virus common in Mexico but not common here. We’re all guessing, but this is the number one question at the moment.
#6 Carolyn Russ
April 25, 2009

Revere, I have read your blog for several years and and feel lucky I can turn to you for up to date info. Thank you for all you do.
#7 chezjake
April 25, 2009

Revere, links are *not* fixed — both give me:
http://scienceblogs.com/effectmeasure/2009/04/%3C/a%3E

At any rate, thanks again for being so prompt, honest, and reliable on this situation.
#8 bern
April 25, 2009

Maybe I’m being too cynical, but I can’t help but wonder if it wasn’t a coincidence that this story broke on a Friday…
#9 GermTheory
April 25, 2009

Could we be seeing illness severity differences by age group? Perhaps illness is most severe in the 25-45 age group,thus they are hospitalized,more likely to be tested and thus counted than younger mild cases in the community who never make it to the hospital.
#10 Tony P
April 25, 2009

From what I’m seeing if you’re not very young, very old or immuno-compromised you’ll live. I wonder why the virus is so deadly in Mexico?

This one moves fast though, 1 to 2 day incubation? Damn!
#11 revere
April 25, 2009

chezjake: Thanks. Fixed now.

GermTheory: In epi terms, that would be confounding by age. Not likely in this case. Flu rarely kills this age group, so this is not only unusual but hallmark of a pandemic virus. We really don’t have enough data to make judgments about the descriptive epidemiology of this virus yet. That will take days or weeks, but it must be done.
#12 Edmund
April 25, 2009

GermTheory, I’ve been wondering the same thing. The NY school cases would all obviously be quite younger than 25. Is that why there have been no hospitalizations (yet)?
#13 Anonymous
April 25, 2009

The CFR for this flu in Mexico seems too high. Perhaps many more people have the flu than is being reported…which would seem logical. On the other hand, as is possible in the NYC case..lots of people get it easily. Yet, young people are being killed by this flu in Mexaco. Curious and early.
#14 Pork Flu
April 25, 2009

I still think that if there are deaths from swine flu in the US that they are not going to let the general public know about it for fear it will cause panic. I’ll wait to see if other countries get this and what their mortality rate is.
#15 Phila
April 25, 2009

Revere, I have read your blog for several years and and feel lucky I can turn to you for up to date info. Thank you for all you do.

Seconded.
#16 revere
April 25, 2009

Anonymous: Undoubtedly there are many missed cases and inapparent infections in Mexico. How many? I wish I knew.

Pork Flu: Who are “they”? Vital statistics in the US isn’t in any one person’s hands or any single agency. It is mainly local (aggregated step by step) and there would be no way to hide it. You are in tin foil hat territory. But when things get scary, I lot of people here are in tin foil hat territory, just not all in the same territory. Sometimes a flu outbreak is just a flu outbreak. In fact most of the time, it is. In fact, all of the time it is. Right now we have other fish to fry. Like coping with whatever this is and whatever it will become. If we’re lucky, it will burn itself out. But then there’s next flu season . . . Remember wave 2 in 1918?
#17 Dylan
April 25, 2009

Revere, do you have any information on the clinical presentation at the more advanced stages of infection? Such as when it is clear that a fatal result is imminent? I’m sure that there have been many, many autopsies conducted, by now. I haven’t seen anything, anywhere, that mentions anything beyond death from “atypical pneumonia.”
#18 concerned
April 25, 2009

Revere, thanks again for all the info. Question: this year’s influenza vaccine has an A(H1N1) component, do you think there’s any degree of protection against this swine flu for people who received that vaccine ?
#19 GermTheory
April 25, 2009

Edmund:

I understand that the 1918 Pandemic and human cases of H5N1 Avian flu show this same age-linked severity.

Having worked in infection control in US hospitals for many years, I can attest to the fact that little testing to identify influenza is done in many hospitals in the US. Thus, cases have always been underreported.

The CDC has now asked clinicians and hospitals to test.

In addition to lack of testing, there are many ill people who do not seek medical care, or, who are misdiagnosed, also contributing to underreporting.

In the 1918 pandemic, the second and third waves of illness were more severe than the first.
#20 revere
April 25, 2009

Dylan: I’ve seen no pathology info on the Mexican cases. I don’t know what their autopsy rate is. In the US it is a dismal 12% of all deaths and going down. Likely the results look like acute distress syndrome or secondary bacterial infection.

concerned: The degree of cross-reactivity with the H1 component of the season flu vaccine is unknown. CDC says the H1 is antigenically quite different but we know little about antibody response repertoire (see our post here that discusses the basic science).
#21 Anonymous
April 25, 2009

It is not 1918. Transport the 1918 flu to today.
#22 M. Randolph Kruger
April 25, 2009

Just in from one of those printouts… possible case in UK.BA flight attendant is symptomatic. Mild symptoms.
#23 Snowy Owl
April 25, 2009

April 24, 2009
Swine Flu in Mexico- Timeline of Events

Introduction

At Veratect, we operate two operations centers based in the United States (one in the Washington, DC area and one in Seattle, WA) that provide animal and human infectious disease event detection and tracking globally. Both operations centers are organizationally modeled after our National Weather Service using a distinct methodology inspired by the natural disaster and meteorology communities. Our analysts handle information in the native vernacular language and have been thoroughly trained in their discipline, which include cultural-specific interpretation of the information. We are currently partnered with 14 organizations that provide us with direct ground observations in 238 countries. We are a multi-source, near-real time event detection and tracking organization with years of experience in this discipline.

March 30

Veratect reported that a 47-year-old city attorney for Cornwall was hospitalized in a coma at Ottawa General Hospital following a recent trip to Mexico. Family members reported the individual voluntarily reported to the hospital after gradually feeling ill upon returning from his trip on 22 March. The source stated that the hospital did not know the cause of illness. The case was reportedly on a respirator and awaiting a blood transfusion, but sources did not provide symptoms or a suggested cause of illness. This information was available in our web portal to all clients, including CDC and multiple US state and local public health authorities, however no one had connected this man’s illness with a potential crisis in Mexico.

April 2

Local media source Imagen del Golfo reported that state health officials recorded a 15% increase in disease over an unspecified period in the highland areas of Veracruz, which includes La Gloria. The increase was primarily due to higher levels of upper respiratory disease and gastroenteritis. Specifically, officials noted an increase in pneumonia and bronchial pneumonia cases. Health officials attributed the increase to seasonal climate changes.

April 6

Veratect reported local health officials declared a health alert due to a respiratory disease outbreak in La Gloria, Perote Municipality, Veracruz State, Mexico. Sources characterized the event as a “strange” outbreak of acute respiratory infection, which led to bronchial pneumonia in some pediatric cases. According to a local resident, symptoms included fever, severe cough, and large amounts of phlegm. Health officials recorded 400 cases that sought medical treatment in the last week in La Gloria, which has a population of 3,000; officials indicated that 60% of the town’s population (approximately 1,800 cases) has been affected. No precise timeframe was provided, but sources reported that a local official had been seeking health assistance for the town since February.

Residents claimed that three pediatric cases, all under two years of age, died from the outbreak. However, health officials stated that there was no direct link between the pediatric deaths and the outbreak; they stated the three fatal cases were “isolated” and “not related” to each other.

Residents believed the outbreak had been caused by contamination from pig breeding farms located in the area. They believed that the farms, operated by Granjas Carroll, polluted the atmosphere and local water bodies, which in turn led to the disease outbreak. According to residents, the company denied responsibility for the outbreak and attributed the cases to “flu.” However, a municipal health official stated that preliminary investigations indicated that the disease vector was a type of fly that reproduces in pig waste and that the outbreak was linked to the pig farms. It was unclear whether health officials had identified a suspected pathogen responsible for this outbreak.

Local health officials had implemented several control measures in response to the outbreak. A health cordon was established around La Gloria. Officials launched a spraying and cleaning operation that targeted the fly suspected to be the disease vector. State health officials also implemented a vaccination campaign against influenza, although sources noted physicians ruled out influenza as the cause of the outbreak. Finally, officials announced an epidemiological investigation that focused on any cases exhibiting symptoms since 10 March.

This information was available in our web portal to all clients, including CDC and multiple US state and local public health authorities.

April 16

Veratect reported the Oaxaca Health Department (SSO) indicated that an unspecified number of atypical pneumonia cases were detected at the Hospital Civil Aurelio Valdivieso in Reforma, Oaxaca State, Mexico. No information was provided about symptoms or treatment for the cases. NSS Oaxaca reported that rumors were circulating that human coronavirus was spreading at the hospital; sources did not provide any response to these statements from the hospital or health officials.

Laboratory samples were sent to Mexico City for analysis; results were expected to be released sometime next week. According to NSS Oaxaca, health officials had intensified preventive measures aimed at mitigating further spread of the disease. Sources reported that the SSO also implemented a sanitary cordon around the hospital.

This information was pushed to CDC and several US state and local public health authorities in an email alert notification provided by Veratect.

April 20

Veratect was urgently asked to provide access to the VeraSight Global platform on 20 April by a client in the US public health community, and indicated they had received word from their counterparts in Canada that Mexican authorities had requested support. This client speculated whether notification of all southern U.S. border states’ public health authorities should be done and were confused as to why the CDC had not issued an advisory. Veratect contacted the CDC Emergency Operations Center to sensitize them about the situation in Mexico. CDC indicated they were already dealing with the crisis of recently detected H1N1 swine influenza in California and possibly Texas.

April 21

Veratect reported the Oaxaca Health Department (SSO) confirmed two adults died from atypical pneumonia at the Hospital Civil Aurelio Valdivieso in Oaxaca, Oaxaca State, Mexico. One of the cases was a 39-year-old female; the other case was an adult male of unspecified age. After the deaths, the hospital established a quarantine in the emergency room due to initial concerns that avian influenza was responsible for the cases. However, the SSO subsequently stated that neither avian influenza nor coronaviruses, including that which causes severe acute respiratory syndrome (SARS), were the source of infection. Additionally, the SSO denied the cases represented an epidemic. According to local sources, the SSO indicated that the atypical pneumonia cases were caused by an unspecified bacterial pathogen and were treatable with antibiotics. Sources indicated a total of 16 additional patients exhibited signs of respiratory infection; none of these patients exhibited complications.

Veratect sources indicated the 39-year-old female was treated at the hospital for five days before dying on 13 April. This case was reportedly immunocompromised; in addition to acute respiratory symptoms, she also had diabetes and diarrhea. The SSO contacted 300 people that had been in contact with the woman; sources stated that between 33-61 contacts exhibited symptoms of respiratory disease, but none showed severe complications. The SSO characterized the incident as an “isolated case;” they noted that over 5,000 cases of pneumonia occur annually in Oaxaca.

Another local source reported the SSO launched surveillance measures in the former residential areas of the two fatal cases and in other targeted geographic areas. No additional information was provided regarding the second fatal case at the hospital.

Veratect reported that the Oaxaca State Congress Permanent Committee on Health had undertaken an investigation into the cases. The committee inspected the Hospital Civil Aurelio Valdivieso on 20 April. The director of the medical school at the University Autónoma “Benito Juárez” de Oaxaca (UABJO), along with other medical academics, publicly requested that national health authorities investigate the cases of atypical pneumonia. No information was provided indicating that national health authorities plan to investigate the matter. The director of the medical school also requested the SSO furnish evidence showing that the cases were negative for avian influenza, SARS, and other severe pathogens; his request was echoed by readers commenting on an online user forum.

Veratect also reported the National Ministry of Health issued a health alert due to a significant increase in influenza cases during the spring season in Mexico. Officials indicated that there have been 14 influenza outbreaks throughout the country. The most heavily affected states are Baja California, Chihuahua, Distrito Federal (Mexico City), Hidalgo, Tlaxcala, and Veracruz. Local case counts were not provided.

Officials stated that 4,167 probable cases of influenza, 313 of which were confirmed, have been reported throughout the country in 2009. Case counts for suspected and confirmed influenza cases have tripled in 2009 as compared to the equivalent time period in 2008. The National Institute of Respiratory Diseases recorded two fatal cases of influenza in 2009, but specific dates and locations were not provided.

Health officials stated they were unsure precisely why the incidence of influenza had increased. However, they believed the increased presence of influenza B, in combination with influenza A, was a contributing factor. In response, officials advised anyone exhibiting influenza symptoms to avoid self-medication and seek medical care immediately. Officials had also enhanced epidemiological surveillance for influenza. Lastly, health officials had focused efforts on providing antiviral medications and influenza vaccinations to the most vulnerable segments of the population. According to the Mexican Ministry of Health, 44.3% of the national population was vaccinated against influenza in 2005-2006.

Veratect sensitized the International Federation of Red Cross who in turn requested broader access be provided to the Pan-American Disaster Response Unit (PADRU). Veratect moved to notify several US state and local public health authorities, providing the caveat the situation in Mexico remained unclear due to pending laboratory results. Veratect reached out to World Health Organization (WHO) operations, informing them the Veratect team was on an alert posture and available for situational awareness support. They indicated they and their subordinate, the Pan American Health Organization (PAHO) were now aware of the situation but had no further information. Veratect also extended contact to the British Columbia Center for Disease Control and offered assistance in tracking the events in Mexico. All contacts indicated laboratory results were pending.

April 22

Veratect reported the Oaxaca Health Department (SSO) indicated 16 employees at the Hospital Civil Aurelio Valdivieso in Oaxaca, Oaxaca State, Mexico had contracted respiratory disease. However, the SSO denied these cases were connected to the recently identified cases of atypical pneumonia at the hospital. No information was provided indicating how many employees work at the hospital or whether the number of respiratory disease cases was higher than average. The source reported that “fear” persisted among hospital physicians concerning the possible presence of a deadly bacteria or virus circulating in the hospital. One anonymous hospital employee criticized hospital management as “unfair” for not providing clear information regarding the first fatal atypical pneumonia case.

An additional source reported the cause of the atypical pneumonia cases remained unknown; it stated that bacteria or virus could have caused the cases. In contrast, according to an 18 April report, the SSO indicated that the atypical pneumonia cases were caused by an unspecified bacterial pathogen and were treatable with antibiotics. The reason for this discrepancy was unclear at this time.

The Instituto Mexicano del Seguro Social (IMSS), a national health entity, had now joined the SSO in responding to the cases; reports did not indicate the Mexican National Ministry of Health had joined in the response efforts. The IMSS extended the sanitary cordon surrounding the hospital. Patients exhibiting flu-like symptoms would be sent to the hospital’s epidemiology department for further study. IMSS instructed physicians to hospitalize respiratory disease patients immediately if they meet certain standards for severity of symptoms. Lastly, the hospital’s emergency room would remain closed for an additional 15 days so that cleaning and preventive disinfection could be carried out.

Veratect also reported the Mexican Ministry of Health indicated that an “unusual” outbreak of laboratory-confirmed influenza caused five deaths from 17-19 April 2009 in Mexico City, Mexico. The deaths occurred at the following three hospitals: el Hospital de la Secretaría de Salud (2), el Institute Nacional de Enfermedades Respiratorias (2), and el Hospital Ángeles del Pedregal (1). According to unofficial sources, the fatal case count was higher than that provided by officials. There were currently 120 influenza cases hospitalized throughout Mexico City. National health officials indicated that influenza vaccines were sold out in Mexico City and that they were attempting to acquire additional supplies of the vaccine.

At this point, the Mexican Health Secretary reportedly stated there was an influenza epidemic in Mexico City and throughout the rest of the county. In response to the cases, the official stated health authorities would launch a public awareness and vaccination campaigns. He stated that 400,000 vaccines would be administered, primarily to medical staff; it was unclear whether these efforts would be focused on Mexico City or any other geographic area. Health officials also ordered the provision of special masks, gloves, and gowns for medical personnel that were in contact with influenza cases.

A total of 13 fatal cases of influenza were reported in Mexico City in the past three weeks. However, several other media sources reported that the 13 deaths were recorded since 18 March 2009; the reason for this discrepancy was unclear. Sources reported a total of 20 fatal cases of influenza throughout Mexico over the disputed timeframe. The other cases were located in San Luis Potosí (4), Baja California (2), and Oaxaca (1). The Director of Epidemiology at the National Center for Epidemiological Surveillance and Disease Control characterized the outbreak as “quite unusual.”

No information was provided indicating that the strain of influenza itself was unusual. Rather, several sources indicated that it was “unusual” to record this many fatal influenza cases during this time of year. Influenza cases normally peak from October to February, while these cases had occurred during Mexico’s spring season.

Canada announced a national alert for travelers returning from Mexico with respiratory disease, beginning a campaign of public media announcements. Potentially ill contacts were identified returning from Mexico and isolated in Canada. Internet blogs begin to spin up. CDC indicates concern about the events unfolding in Mexico. Veratect sensitizes the US community physician social network managed by Ozmosis.

April 23

Veratect reported the Secretary General of the Oaxaca Ministry of Health Workers Union confirmed that a doctor and a nurse from the Hospital Civil Aurelio Valdivieso in Oaxaca, Oaxaca State, Mexico were under observation for suspected “atypical” pneumonia. This contradicted statements made by the Oaxaca Health Department (SSO) on 22 April that 16 hospital employees contracted respiratory disease, but none of the cases exhibited atypical pneumonia.

The union official stated that a review by the Oaxaca State Board of Medical Arbitration indicated that the hospital faced serious difficulties caused by overcrowding; he stated that overcrowded conditions created a “breeding ground” for the spread of various epidemics. According to the official, the hospital has 120 beds but the number of patients hospitalized had at times surpassed 240.

Other sources reported that the Department of Livestock, Fisheries, Rural Development, and Feed (SAGARPA) declared on 20 April that Oaxaca, Mexico was free of avian influenza. SAGARPA stated that authorities should remain vigilant in monitoring for the disease among birds.

Canadian local health officials stated that a Rouge Valley resident with influenza-like illness was being monitored at Scarborough Centenary Hospital in Scarborough, Ontario. The precaution was being taken in accordance with an alert issued by the Ministry of Health asking hospitals to watch for severe respiratory illnesses in travelers returning from Mexico. Despite the warning, the Ministry had indicated that evidence is not suggestive of a novel pathogen or influenza strain, according to the source. A representative for the Rouge Valley Health System stated that this case is being monitored related to the alert. The source did not specifically indicate symptoms or that the person had traveled to Mexico. No additional information regarding the case, including age or health status, was reported.

The source stated that hospital employees were asking any patients admitted to the hospital if they had recently traveled to Mexico, which according to the source was a popular tourist destination for Durham-region residents.

Additional Canadian sources indicated Southlake Regional Health Centre officials treated a patient with influenza-like illness (ILI) who recently returned from Mexico. The Ministry of Health recently notified Southlake, in addition to health units across the country, that an outbreak of severe respiratory disease was affecting areas of Mexico; ill travelers returning from that region with ILI symptoms were encouraged to be monitored. Sources did not provide any specific information about the case, including age or current treatment status. Information regarding the individual’s travel to Mexico was also not provided, including destinations and duration of time in country.

The Public Health Agency of Canada (PHAC) noted that an Ontario resident who returned from Mexico on 22 March experienced severe respiratory illness, but has fully recovered and was not considered connected to the current situation. Veratect recently reported on 30 March that a public official from Cornwall, Ontario was hospitalized with an unknown illness following a trip to Mexico; however, it is unclear if the cases are related, or if this was the case referenced by PHAC officials.

Veratect assesses the situation and notes the following:

Affected areas:

Oaxaca, Distrito Federal, San Luis Potosí, Baja California

Distance to nearest international airport:

• Oaxaca airport, located approximately 150 miles from Reforma, is connected via non-stop air traffic to Houston
• Mexico City (Distrito Federal) airport is connected via non-stop air traffic to many cities in the US, Canada, Europe and Latin America, with the most outbound traffic to Los Angeles, Frankfurt, Houston, Dallas, and Amsterdam
• San Luis Potosí airport is connected via non-stop air traffic to Dallas and Houston
• Mexicali airport in Baja California is connected via non-stop traffic to Los Angeles
• Veracruz airport is connected via non-stop air traffic to Houston

Large mass gatherings:

Semana Santa (April ~April 3 – 12, Palm Sunday to Easter Sunday), which is Mexico’s second largest holiday. Mexico’s population is approximately 90% Catholic, which results in substantial population migration patterns during this time period. For instance, in Ixtapalapa (in Mexico City), one million people visit for Semana Santa. Other well-known sites for the holiday include Pátzcuaro, San Cristobal de las Casas (Chiapas), and Taxco. Veratect notes substantial population migration has just occurred that could facilitate the spread of respiratory disease.

Civil Unrest:

The recent surge in organized crime and drug-related violence in Mexico, including homicides, kidnappings, extortion, and theft, has disproportionately impacted Mexican states along the Pacific Coast and U.S.-Mexico border. This factor may confound situational awareness of respiratory disease in Mexico and contribute to problems in epidemiological investigation and response measures. Baja California is one of five states within this region that currently accounts for more than 75 percent of Mexico’s drug-related homicides, and has recorded high levels of drug seizures and police corruption cases. Veracruz, a state with high drug cartel activity in the Gulf of Mexico, has recorded little violence, while the state of Oaxaca to the southwest, recently recorded the assassination of a political party leader. Mexico City, in the center of the country, recently arrested a major drug cartel leader, and recorded few homicides this month. The levels of unrest in Hidalgo, San Luis Potosi, and Tlaxcala, however, are very low, and have not reported a single homicide related to organized crime in the past month.

Veratect issues notification to additional public health authorities in two states. Veratect reaches out to the Pan American Health Organization emergency operations team but is unable to establish contact. Veratect notes no publicly available English language reporting from ProMED, HealthMap, FluNET, CDC, ECDC, or WHO about the unfolding events in Mexico. Many of Veratect’s clients, including Canadian, ask why an alert has not been issued by the US to sensitize their healthcare community.

April 24

Veratect continues to process a dramatic increase in reporting on the situation in Mexico.

WHO requests access to the Veratect system. Veratect is aware of laboratory samples from Mexico are positive for “swine flu” H1N1, a novel virus. World media are now aware of the situation in Mexico. CDC issues a press statement, as does WHO.

Veratect notifies the private US clinical laboratory community and activates a Twitter feed (twitter.com/veratect) to enable more rapid updating of information.

http://biosurveillance.typepad.com/biosurveillance/2009/04/swine-flu-in-mexico-timeline-of-events.html
#24 Phila
April 25, 2009

In addition to lack of testing, there are many ill people who do not seek medical care, or, who are misdiagnosed, also contributing to underreporting.

I’d assume that most people haven’t been seeking medical care. My wife was at a conference a couple of weeks ago. About two days in, she ended up coming down with what seemed to be the flu (fever, upper respiratory symptoms, muscle aches), although it had the unusual (for her) additional symptom of vomiting. I ended up getting it too, about a day later, though not as severely. I know a bunch of other people who’ve had the same thing lately…they were pretty miserable, but like us, they never thought of going to the doctor.

I’m sure a lot more people will be flocking to clinics and ERs now, though, given the coverage….
#25 Lisa the GP
April 26, 2009

Er, I think in the interest of brevity I’ll just give the link…Huffington post has a rather obnoxious alarmist banner on its front page, but this article about the state of pig farming in the region around Mexico City is calm and informative:

http://www.huffingtonpost.com/david-kirby/swine-flu-outbreak—-nat_b_191408.html
#26 anon
April 26, 2009

we’re probably (>50%) going to get a pandemic with
millions of deaths, right ?

why isn’t it being told to the public this way ?
#27 anon
April 26, 2009

is it ethical from scientists and politicians
to continue by not saying what they really think
and estimate ?
#28 K
April 26, 2009

Recent research has shown that the health of the mother or grandmother can have effects on children or grandchildren. I don’t know if there is any research on this with the flu, but healthy young Mexicans probably had parents or grandparents that had less food or even were at times close to starving, and poor pre-natal care.

http://www.timesonline.co.uk/tol/news/uk/health/article5029679.ece

http://www.sciencedaily.com/releases/2008/10/081030110959.htm

I believe that the book “The Great Mortality” offers the theory that a famine some 20 or 30 years before the Black Plague of the early 1300′s was a factor in the spread and mortality.
#29 anonymous
April 26, 2009

Historically, Native Americans have had high vulnerability to flu. Maybe it is a host factor that accounts for the death rate in Mexico–could the victims with severe illness have a higher proportion of native blood?

If so, the threshold for initiating Tamiflu should be lower for people with that ethnic background.
#30 pb
April 26, 2009

10 possible cases in New Zealand. School kids just returned from a trip to Mexico.

http://www.stuff.co.nz/national/2364487/Ten-influenza-results-confirmed-in-New-Zealand-teens
#31 D. C. Sessions
April 26, 2009

Two possibilities: biased ascertainment (Mexico only looking at hospitalized and seriously ill cases, US looking at community cases not in hosptial); or some co-factor, like infection with another virus common in Mexico but not common here.

I’ll add a third: there are two strains in Mexico, one which is relatively mild and widespread (and which made it to the USA) and another which is more virulent but is so far confined to Mexico. For instance, the second (more virulent) is a new variant on the first.

My understanding is that we don’t yet have full sequencing of the lethal cases in Mexico, so this particular hypothesis is due for falsification RSN.