The Haiti Epidemic Advisory System (HEAS)

Village Level Cholera Forecast Validation

Below are the results of our assessment of forecast validation for Artibonite Province, Haiti.  We are quite pleased with the results from an operational perspective.

This is the area:



Basically, the forecasts vs. the actual outcomes for:

 

1)    Anse-Rouge was outstanding with three peaks in both, and with both the timing and the amplitudes of the 2^nd and 3^rd peaks right on.

 

2)    Govaives was solid with three peaks in both but only okay as the timing and amplitude of the 1^st and 3^rd peaks are off while that of the 2^nd peak was right on.

 

3)    Marmelade was solid with three peaks in both and okay as the timing and amplitude of the 1^st and 3^rd peaks are right on while that of the very broad 2^nd peak was off.

 

4)    TerrNeuve was off in the timing of the peaks, but the amplitudes of the peaks were solid and the number of peaks, with six predicted and six occurring, was outstanding.

 

5)    Ennery was very good as both the timing and amplitudes of the actual and predicted 5^th peaks were right on, however while the forecast was for four peaks and there were five actual, the predicted 3^rd  peak fell between the 3^rd and 4th actual peaks, the agreement was not too bad overall. Additionally, considering the relatively high and low numbers of actual and predicted cases, the comparison is very good.

 

6)    Grosmorne was okay considering the low number of cases.

 

7)    St. Michel shows a mixed outcome as the only one peak was predicted and the timing and amplitude of that peak vs. the actual realization was outstanding, however the forecast missed the 2^nd and 3^rd peaks entirely.

 

So why did the model do well in some cases and not so well in others?

 

We believe that there are several fundamental reasons.

 

On the positive side, there is good structure and momentum in the individual and collective time series. As such the memory in the systems is capable of being carried forward in a probabilistic sense. So, one can conclude that there are individual and distinct signals which can be and have been separated from the noise in each of the time series.

 

Albeit, one must recognize that the forecasts are totally probabilistic and not deterministic. Moreover. and this point cannot be overstated, the time series are very short (~2 years) in all cases, so there are very few data points. Also, there have not been any correlative analyses done with other likely relevant parameters and variables, other then the cross correlations that we conducted between the stations. 

 

The challenge created by the short time series can be briefly summarized with a simple example. To wit, if Dave left his office to walk across campus and the first two students he saw were wearing NC State tee shirts, then what would he guess, probabilistically speaking, that the next student would be wearing; an NC State tee shirt or not; 50/50?

 

Again, probabilistically speaking, if Bob found that using 117 years of hourly temperature data that the coldest two weeks of the year occur during the 2^nd and 3^rd weeks of January, then what about the forecast for 2013? What are the odds that it would necessarily be those two weeks or could it end up being the 4th week of January and the 1^st week of February, et cetera? As such, probabilistic forecasts are not deterministic.

 

In terms of the timing and amplitude, while we have several observations, they cover only a bit over 1 year so we have had only one look at a pattern that is not necessarily going to repeat the next year. The 117 year example gets at the idea of probabilistic forecasting but our case is much worse, having seen not 117 instances of a yearly pattern but only a bit over 1. 

In our forecasts we did not account for any of the external variables that the different regional facilities are located in, such as: relationships to weather and climate factors, with the former and latter including such conditions as warm and humid conditions, altitude, arid versus no-arid conditions, thus low or high low precipitation, transportation availability, water contamination, the ability of the stricken to get to the hospitals, the exposure of the populace to disease carrying hosts, such as outsiders carrying the disease into the locale(s), polluted water, and so on.

 

So the solution to the improvement of forecasts would be to have longer time series at individual and multiple locations which document incidence and also to be able to conduct correlative analyses with other factors that may be conditional and or causal in nature. We actually showed the power of such studies and analyses with our cross-correlations between station to station cholera data and also our cross-correlation study of the other diseases and medical conditions. These powerful relationships, or lack therein, were in the report as well. 

 

All of that said, the results are very encouraging, especially given the paucity of data, suggesting that highly reliable relationships can be created given appropriate data sets, and sufficient time and effort.   

 

 

Operational Forecasting of Cholera in Artibonite, Haiti

The Praecipio International infectious disease forecasting team, sponsored by Direct Relief International and thanks to HEAS partner efforts in sharing data, has just completed the first phase of an extensive statistical review of epidemiological data for cholera in Artibonite.  We have had the honor and benefit of working with some of the world's experts in meteorological forecasting, including three National Academy of Science members.  All of these individuals were excited to have the opportunity to support the People of Haiti. 

We went through this exercise to get our hands around the question of "what seasonality is cholera settling into"?  While we have often seen media reports of association with rainfall, which makes sense based on prior experience in countries like Bangladesh, we needed to make sure of this in Haiti. 
 
The bottom line is we have identified a target signature pattern for Artibonite that is now testable in the humanitarian theater.  Obviously, we would be more sure of our conclusions if we had 10-20 years of reliable data, but with 2 years of baseline it is the best we have at the moment.  It appears that in Artibonite, the peak weeks for transmission are Epidemiological Weeks 27 (first week of July) and 46 (second week of November), respectively.  This means we would issue forecasts for Artibonite at 60 and 30 day intervals prior to all of the Haitians and NGOs operating in this area.  We are in the process of determining whether variation in these signatures exist from village to village.
 
We will now be executing live forecasts from this point forward.  The crucial next step is validation, of course, of these forecasts.  Validation contributes to refinement of the forecast libraries.
 
One of the other observations made was a statistically significant decrease in overall rates of cholera transmission, which of course makes sense as the disease is settling into an endemic state.  We are planning to publish this as an academic paper for the world's benefit.
 
This is just the beginning….

Words of Thanks For Helping to Save Pestel

Hello [HEAS partners],
 
First, let me thank you for all the work you've done on behalf of the people of Pestel, Haiti.  I've been following Dr. Carroll's blog posts on his experiences in that area over the past week.
 
I have been engaged in Pestel since 2007, usually going out several times a year.  I have a good working relationship with Dr. Seneque Philippe.  As you know, Pestel is one of those remote areas that has gotten little attention in the past, and I'm grateful to see the amazing response over these past couple of weeks.  Your ability to mobilize quickly a large number of resources toward this awful problem of cholera has been truly impressive.

- An American physician who has donated countless hours of his time over the years to the people of Pestel, now an HEAS partner

HEAS Operations Update

We currently have several “onion layers” of operations in-place now to facilitate the movement of alerts to response.  These layers follow the steps we have to go through before getting emergency aid to a site in need:

Initial report.  This is the first report of a site either reporting cases of cholera for the first time, sudden surge, or “first contact” mortality.  The degree of alarm to us is related to this sequence.  That said, we prefer to engage as quickly as possible to avoid “first contact” mortality, however this is often difficult to a number of factors such as degree of site isolation (i.e. a community’s access to communications), pre-contact awareness there is a cholera disaster in-country (we have had communities who had no awareness of the epidemic!), and social thresholds of tolerance for adverse clinical outcomes.  The general rule of thumb is people typically alert for mortality, not non-mortal cases.  We encourage reporting of at least “first surge” or the window of opportunity to avert unnecessary fatalities may be lost.

Verification of event features.  We generally see the majority of reports validate, however the actual case counts may vary tremendously between the HEAS reporter, the officials, and any on-site NGO(s).  We want to make it clear that accuracy in case counts is not important to us.  What IS important is verification of impact such as the ability of local medical responders (if there are any) to manage the demand of patients.  This is important to because we are looking for specific, prioritized items of need involving materiel or personnel (see below).  Collapse of a clinic or high daily clinic mortality is associated with a distinct psychosocial impact on the involved community that does play a role in civil stability dynamics.  In short, we seek verification of impact first, accuracy of case counts last.

There are several key caveats to keep in mind.  There MUST be a false positive rate when reporting or we are not doing our job.  While we as warning analysts are very tolerant of false positive reporting, those that manage deployment of response are NOT.  This highlights the crucial importance of verification as an operational bridge.

Now, we do monitor sources of reporting and will “dial back” reports from a source to the HEAS if we observe a high rate of unverifiable reporting.  We see this rarely, but it does happen.  There is also a triage of reporting, where sources unknown to us typically require more attention to verification than trusted sources.  That said, we have observed many instances where highly trusted, credible sources have either misinterpreted their information or were simply wrong.  It happens to the best of us, as we are all human.

When verifying information, we are seeking to pin down several aspects of event information.  The name of the site is often problematic for us, as there are often different names for the same site in Kreyol versus French or English.  GPS coordinates or Google map links are also very problematic, especially for the rural areas, because these sites are often not even well known to NGOs who work in the region unless they have worked there directly.  We have found this can be problematic to lock down even for indigenous Haitians.  The effect of multi-source reporting often distorts information as elements are passed from person to person.  In general, the more steps you are away from direct ground observation, the more probable distortion has occurred above and beyond the basic limits of human observation.  And of course, two people standing at the same site observing the same thing will often come away with two different interpretations based on life experiences, for instance.  If multiple NGOs are managing a given community’s needs, we often see conflicting reporting depending on the relationship between those NGOs. 

Bottom line, verification can be a difficult and time-consuming process.

The firehose of information now streaming through the HEAS community is at once an incredible accomplishment for the community but also a challenge from an information management perspective.  To address this, we have broken off a much smaller group of HEAS partners that manage event reports, verification, triage of those reports to the HEAS Community Watchboard as potential sites for response consideration, and ground logistics and response.  Events on the HEAS Community Watchboard are triaged according to a simple scale of need:

Level 1= Request For Emergency Assistance triggered; requires IMMEDIATE attention via deployment of emergency supplies or personnel (time delta= hours-48 hrs)

Level 2= Request For Emergency Assistance triggered; requires URGENT attention via deployment of emergency supplies or personnel (time delta= multiple days)

Level 3= No Request For Emergency Assistance triggered yet, but Request For Verification triggered

Level 4= Awareness of active cholera treatment noted but no action required at this time

Validation of emergency need is often entwined with the verification process.  Here we ask for a strict prioritization of need, which sometimes indicates how much trouble a site is in.  For instance, a site requesting supplies but no personnel appears less urgent to us than a site requesting body bags over other supplies and “as many people as we can spare”.  There is an implied anxiety level in the requesters that we also monitor.

Some use a case count cut-off of 50 cases or above to prompt mobile response.  We have struggled with this guideline because we are looking at the psychosocial dynamic from the viewpoint of expected local capacity: i.e. the local medical clinic.  One community, as mentioned above, may have a high psychosocial tolerance for morbidity but become tremendously anxious upon observation of 5 fatalities.  Another community may be very resistant to high fatalities and wait to report until the last possible moment.  This is of course due to a whole range of factors.  Bottom line, it is a difficult and terrible triage to decide which site, all things considered, should be prioritized for response.

We have observed now several instances where the HEAS core team did not need to directly push for response, but the HEAS community self-triggered response on its own, offline from the main group communications.  This is a tremendous positive development and indicates the "living entity" that is the HEAS.  Response coordination, however, has been a serious challenge for us in that we have seen a general trend of no response report from organizations planning to mobilize to a site.  The problem arises when multiple organizations arrive with duplicative assets due to lack of communication. This becomes a tremendous problem because when organizations perceive possible duplication of effort, hesitation results.  Hesitation may cost lives. This is the purpose of the HEAS Google group and Community Watchboard: to assist in coordination.  So, the HEAS is experiencing "growing pains" that we are addressing as they arise.

Grid level response has been tricky at times due to grid overload.  That said, we HAVE seen an increased awareness on the ground that 2/3 of Haiti is likely under-supported due to extreme terrain and lack of access or communications.  Thus, there has been a concerted effort on our part to emphasize the consideration of helo and rapid mobile medical team support.  This has been tremendously challenging, as many of the mountain sites do not have a suitable landing zone for helo support, resulting in a many-hour hike across terrain that makes hauling mass quantities of IV fluids impossible.  As we have seen so many times throughout the world, the more isolated a community is, the more likely one sees adverse outcomes in the context of an infectious disease crisis or disaster.

We conclude with an important observation: that the HEAS has now evolved into a self-regulating, distributive, complex, adaptive, net-centric warning and response community.  This is a major, positive development as we continue to struggle to support the people of Haiti.

Notes From The EpiCenter: We Are Out Of... Everything

I am sad to report that things have worsened significantly and in 3 camps (St. Marc being the hardest hit that I have seen yet) have 76 known cholera deaths and 1,709 confirmed cases.  The death toll of 76, I received yesterday from [REDACTED] was the count over approximately (the last) ten days in one camp.  There are many more deaths from other camps and although some of us traveling to the rural areas are trying to remain in contact, it is nearly impossible.  We are out of ORS - oral rehydration solution, pedialyte, IV fluids and tubing -- everything.  The situation in the tent camps/cities is already full of unspeakable horrors and now for those with cholera the sight is just gruesome.  

The rural camps, hardest hit by cholera are in the worst situation because there is NO relief aid presence and no UN presence.  During this last trip it would take almost 5 hours to drive from St. Marc back to Port au Prince to try and secure supplies.  We are purchasing ORS, water, and pedialyte (now absent from stores because we are buying so much of it).  [REDACTED] gave me 10 cases of pedialyte and some other supplies, which is all they could afford because they feared an outbreak in Port au Prince.  Finally, after running out of medications, fluids, etc. and being turned away from most all sources for medical supplies, including the UN, there was no way to help those suffering from cholera.  It was simply too difficult to watch another baby die of dehydration and I came home to recover from the worst week I'd experienced in Haiti since the earthquake. 

I cannot begin to explain how much worse the situation is in Haiti and how there is very little coordination of any relief aid or the NGO's.  The following is the mission statement of the UN for its mission in Haiti.  It is not being carried out now during this cholera outbreak and has not been carried out since the earthquake, which is more than a failure to the Haitian people.

"The mission of the United Nations Office for the Coordination of Humanitarian Affairs (OCHA) is to mobilize and coordinate effective and principled humanitarian action in partnership with national and international actors."

I have shared all my findings with the CDC in order to give them as much data as I can gather for their investigators.  I have also given our findings to the MOH and OCHA - mainly for informational purposes because I've given up the hope of obtaining necessary supplies.  I wish the news was better and sadly the deaths will continue because there is little to no support available for those providers in rural areas.  There is very little available in the way of supplies even in the larger cities now facing patients with cholera.  I am contacting organizations here at home to try and get the ORS, which comes in small packets, donated so I can take it back on my next trip.   

Again, for everyone attending today's demonstration - thank you and it is with much appreciation that people are standing up to demand accountability for Haiti. There are not words in any language to describe life for her people or the heart wrenching feeling watching them die of neglect and indifference.  It is why I continue asking the question, "When does indifference become a crime against humanity." 

I will be attending the January 8th demonstration and sadly, I do not expect to have better news - I expect it will continue to worsen.  Please know that I have spoken with [REDACTED] and several of my friends, this morning to tell them about your demonstration - and they send their love, appreciation, and prayers to each of you on behalf of the Haitian people.  

 

"First Contact" Effect on Cholera Mortality in Haiti

Official statistics are often quoted in terms of total aggregated case counts and total aggregate deaths at the national or departmental level.  For example, as of today, there have been 16,700 cases and 1,034 fatalities with a case fatality rate-apparent of 6.2%.  From an operational perspective, this yields little information to guide rapid medical support deployment. 

Once we have been sensitized to report of sudden inundation of a clinic with suspect cholera cases, subsequent examination of epidemiological data offers insight into how a clinic is progressing.  Acquisition of epidemiological data usually happens several days after "first contact" with cholera due to the operational distraction of managing the sudden influx of patients.  Progess is determined by effective management of the balance between patient demand, medical response resources (i.e. personnel and materiel), and positive adaptation over time of processes, procedures, and experience to streamline efficient diagnosis and care of the patients. 

Clinics experiencing "first contact" with cholera are usually observed to have dramatically high daily mortality as they adapt to the sudden challenge, as shown in the below examples of Cap Haitien city, Plaisance, and Limbe (green boxes).  This is particularly true for clinics unprepared or staffed with personnel with little experience recognizing and treating cholera, as is was the case in the Cap Haitien region.

It is notable that Cap Haitien experienced later surge than Plaisance and Limbe and was better resourced when they experienced first contact, which may explain the lower daily mortality.  This is a strong argument for near-real time, network-centric situation awareness as facilitated by the HEAS.  At the Plaisance and Limbe facilities, daily mortality declined despite an increase in case counts.  At the Cap Haitien facility, however, we are concerned about the persistenly high daily clinic mortality.  MSF is mobilizing to assist them now.

The argument for prior experience and forewarning is further supported by examination of the data from MSF cholera treatment centers in Port au Prince, where daily clinic mortality has not breached 10%.  MSF as an organization has experience treating cholera in other parts of the world and also was sensitized by a combination of their experience in Artibonite and sensitization to warnings issued about the entry of cholera into Port au Prince.

 

 

 

 

Timeline of the Haiti Cholera Epidemic

Selected highlights of HEAS involvement in warning, forecast, and rapid medical response functions during the Haiti cholera epidemic below. 

The HEAS provided forecast warning of threat to Cite Soleil and Port au Prince 7  and 18 days in advance of first reported cases without travel history in both locations, respectively.

 

Day 0 (Oct 20).  First suspect cholera case reported to MSPP by MSF.

 

Day 1.  HEAS reactivates, as the 250+ member network has become active with reporting about fatal diarrheal disease in Artibonite (St Marc and Mirebalais).  “Cholera” as a diagnosis believed to be highly unlikely based on no cholera reported in Haiti for years.  Significant medical facility strain reported in St Marc.  MSPP announces to the press laboratory confirmation of cholera.  HEAS assesses situation to represent IDIS Category 5 conditions.  HEAS observes potential for activation of the International Health Regulations (IHRs).  Single case of cholera reported in Lafito, with possible linkage to a local market.  Direct threat to Cite Soleil identified, with implication for spread into Port au Prince.

 

Day 2.  Second case of cholera reported in Lafito. Direct threat to Cite Soleil again identified, with implication for spread into Port au Prince.  Confirmed cholera reported in Arcahaie.  “It is now clear the coastal highway is a major transit corridor for the potential introduction of cholera into Port au Prince.”  Suspect cholera cases reported in Croix des Bouquets and Port au Prince itself; 2 suspect cases reported at HUEH (PaP General Hospital).  “We do not believe the epidemic is contained within the Artibonite Valley at this time and are now concerned the disease is within Port au Prince.”

 

Day 4. Lafito now identified as a new focus of transmission.  “We urge immediate investigation of this site by the Health and WASH Clusters given the implications for further introductions of cases to Port au Prince”.

 

Day 5.  Emergency Appeal to support the HEAS issued.

 

Day 6.  First report of community outcry blaming Nepalese MINUSTAH deployment in Mirebalais as the source of the epidemic.  HEAS aware of serovar match with Nepal strains and reports of cholera activity in Nepal preceding incept of epidemic.  HEAS calls for activation of the International Health Regulations given the implications for regional spread.  “There is no need to close the borders or restrict travel or trade because a neighboring country has cholera.”  Anti-clinic protest reported in St Marc.

 

Day 7.  Realization that Health Cluster assertions the epidemic was under control was inaccurate.

 

Day 8.  Cholera reported in Cite Soleil- case had no travel history from Artibonite. 

 

Day 14.  Large outbreak identified in Hinche region.  HEAS joined by partner with meteorological experience; cholera risk assessments considered with meteorological data for Tropical Storm Tomas. 

 

Day 15.  Alert posted for regionalized transmission of cholera in the Cap Haitien area with evidence of medical infrastructure strain.  Large outbreak in Gros Morne reported with evidence of medical infrastructure strain.  Warning Forecast issued for post-Tomas cholera activity levels.

 

Day 17.  Gonaives reports fatalities.  Port de Paix and other northern areas report high patient loads with medical response strained.  Lafito reports medical response collapse due to supply depletion.

 

Day 18.  47 cases of cholera reported in Cite Soleil.  “Port au Prince is directly at risk of epidemic cholera.  All assertions that the situation is ‘under control’ or epidemic surveillance and control activities ‘are adequate’ should be viewed with skepticism.”  Large outbreak reported in St Louis du Nord.

 

Day 19.  Suspect cases reported in multiple southern peninsula sites, one confirmed as cholera.  Grand and Petit Goave reporting suspect cases.  Confirmed cholera case inside Port au Prince without a travel history.

 

Today.  MSF: “All of the hospitals in Port au Prince are overflowing.”

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Cholera Transmission Risk in SouthEast Haiti

[Our tremendous thanks to UNDP DINEPA for sharing this crucial information.]

Colleagues,

Since 2006 UNDP and DINEPA (before SNEP) work together in a program of water supply and sanitation department on the Southeast. Since 2008 the program has begun a comprehensive inventory and a survey of the sector throughout the EPA Southeast.

Result of this work we (UNDP DINEPA) have developed maps by county (10 cards) that represent the theoretical risk of transmission of cholera in all localities (approximately 900 locations / homes) in the south-east from the water drinking.  We hope the map will be useful for planning actions. At the end of
this week a similar card on the department Centre will be available.  Maps of South-east will be improved during the week with data we have on the hydrographic network, schools, health facilities and roads.  Attached herewith the 10 cards.

Good work and good day.

Ovidio López-Ibáñez
Draft EPA Southeast
Environment Unit
UNDP-Haiti

Maps attached below.

Download AnseaPitre

Download Bainet

Download BelleAnse

Download BelleAnse

Download CayesJacmel

Download CotedeFer

Download GrandGosier

Download Jacmel

Download LaVallee

Download Marigot

Download Thiotte

Suspected, Confirmed, and Response Priorities in the Haiti Cholera Epidemic

Regarding the issue of SUSPECTED versus CONFIRMED, the operational reality is it often takes days to have laboratory confirmation, and in most cases you simply do not have it.  This is the case in nearly every infectious disease crisis we have been involved in over the years in more than 200 countries including the US.  Obviously, healthcare providers respond to demands by their patients for treatment regardless of suspect versus confirmation status.

Rapid medical response, as demonstrated by the HEAS community, must be enabled despite the status of laboratory confirmation, and hence the problem we have with information management.  The other reality is the public health community and apparatus used to investigate outbreaks is (and has been for some time now) overwhelmed in Haiti.  This is identical to what happened during the 2009 H1N1 influenza pandemic, where the number of outbreaks and samples submitted overwhelmed public health capacity to rapidly investigate and interpret every report and every sample. 

We simply cannot wait for laboratory confirmation to contemplate site verification or rapid response.  That said, we are in discussions with Haitian civil society, governmental and international organizations about directing human and financial resources toward prioritized mission critical gaps to save lives and stem the spread of cholera through additional agile rapid response teams.

This is the difference between operational biosurveillance and traditional public health surveillance.  Operational biosurveillance is concerned with rapid event detection, verification, and immediate coupling to rapid medical response.  Note the priority in response is medical; public health response operates on an entirely different time scale.  As medical responders have already swarmed personnel and materiel to a site to treat patients, public health may or may not be able to investigate the site. In other words, medical treatment used to save lives often does not depend on the results of laboratory testing or forensic epidemiological investigation.

We operate in the near-real time to prevent or mitigate unnecessary loss of life.  Determination of epidemic attribution (i.e. source), forensic epidemiological investigation, and dealing with water / sanitation issues are not the emphasis, although all key tasks being performed by others and collectively, all save lives.

One analogy is 911 dispatch.  Another would be the National Weather Service.  Still another might be emergency medical services (EMS).  The best analogy would be a hybrid of all three.

 

Current Map of Cholera-Affected Areas

We will adjust this map as more information becomes available. 

Updates: Official stats, estimates of true case loads, updated map.

While the UN OCHA maps and official MSPP reporting tends to focus on Artibonite and points north, there are other areas routinely not included on the OCHA maps that have reported cholera.  We opt on the side of "cholera until proven otherwise" or when political sensitivity is such that full disclosure and transparency allows.

Current official stats are more than 72,017 cases that have sought treatment and 1,648 fatalities.  We note large discrepancies between HEAS partner information and officially reported statistics, reflective of official under-reporting.

• Case fatality rates such as the most recent Health Cluster report of 2.3% is representative of gross national level aggregation of information available to officials, which represents a substantial bias towards CTC/CTUs staffed by experienced teams such as MSF.  What is not reflected is the continually documented "first contact" pattern of daily clinical mortality seen by rural communities and urban environments such as Gonaives several weeks ago reported by officials do not reflect the true impact of cholera at the community level.  The daily mortality we have documented on multiple occasions may range from 10 to 100%.  We often see sudden overwhelming of local capacity to the point of backloading corpses for burial, having run out of body bags.
• Conservative estimates therefore suggest more than a quarter-million cases of cholera in Haiti to-date, the majority of which were subclinical. 
• In some areas of Haiti, we have confirmation that in-patient statistics are under-reported by as much as 400%. In many areas of Haiti, we are documenting outbreaks that are not being accounted for in the official statistics.  We therefore estimate the upper bound of estimated total (subclinical and clinically apparent) case counts to be nearly one million.  From a practical operations point of view, these estimates are academic.  The bottom line is the epidemic continues to spread completely out of control.
  
• Although PAHO projections use an attack rate of 2% of a total estimated Haiti population of 10 million to estimate 200,000 total clinically apparent infections, the true community load will be closer to 800,000 if subclinical infections are counted. 
  
• We err on the side of over-estimating because this is a "virgin soil" epidemic and expected to aggressively spread throughout the country and across the border into the Dominican Republic to cause massive disruption.
• We are now pursuing answers to the question of uptake by indigenous zooplankton and spread along oceanic currents that pass west of the Gonave Gulf, which is where the Artibonite River discharges, north and west along the northern Cuban coastline and north to the waters east of Florida.   
  
• We assess the elections on the 28th facilitated further spread.  To what degree remains uncertain.
  
• Multiple healthcare worker infections have been reported on the ground in Haiti with one report of a worker returning to the United States infected.
• There will be more cases in the United States; we believe it likely more cases are inside the US unreported.  Implications for the United States are neglible.

The below represents areas of specific concern and active monitoring by the HEAS:

 

• Red- where we continuously receive emergency requests for assistance due to "first contact" high mortality and have facilitated several mobile emergency responses.
• Orange- where we occasionally receive notification of "first contact" high mortality but confirmation is difficult; we suspect there is far greater mortality in these mountains but it goes unreported because of very low NGO presence and difficulty of access.
  
• Yellow- where we have confirmed cholera activity at multiple sites throughout the southern peninsula, however the majority of international response is focused on PaP, Artibonite, and recently the north… the south is left relatively untouched in terms of response.  As with the orange areas, we suspect far more activity that is what reported because of very low NGO presence.  We also note very large time lags in official reporting from this area.  The southern peninsula is the next battle front, where we expect the 'war' to go very badly given the low availability of response assets.

 

 

View Overall Haiti Cholera Epidemic Map in a larger map