Haiti: Operational Biosurveillance Priorities For Potentially Disruptive Infectious Disease Events

UPDATED 0410 GMT 17 JAN 2010- UPDATED INFORMATION HIGHLIGHTED IN RED

Summary

 

We consider anthrax, dengue, diarrheal disease, and pandemic influenza to be key diseases of potential for generating acute disruption in the context of the current disaster response operation in Haiti.

 

Introduction

 

On 1/12/2010 at 10:19:57 PM UTC (26 minutes after the event), the team received a Red Alert from GDACS regarding a 7.3M earthquake in Haiti.  The team immediately activated operational biosurveillance support activities.

 

Figure 1.  Earthquake impact zone in Haiti.

 

Figure 1 displays the impact zone.  The focus of this assessment pertains to this figure and is concerned with operational biosurveillance issues which may or may not overlap what are considered public health priorities.  In this assessment we recognize the following key points about earthquake disasters:

 

1.    Large-scale epidemics are not typically triggered by earthquakes.  However, seasonal disease baselines are still observed such as malaria and dengue in the case of Haiti that may complicate response operations.

2.    Corpses do not typically trigger large-scale epidemics.

 

In operational biosurveillance, we adopt a conservatively aggressive posture when it comes to monitoring.  Here our purpose is to provide high-level analysis of the situation to identify potential disease-related occurrences that will further challenge the response efforts.  Several of the diseases mentioned in this report have the capacity to generate crises and disasters in their own right under the current conditions in Haiti.

 

Prioritized Diseases for Operational Biosurveillance During Disaster Response in Haiti

 

Here we focus on those diseases that pose the greatest challenge to response operations.  Diseases marked with an asterisk are the prioritized diseases we are monitoring closely due to probability for causing an acutely disruptive outbreak in the disaster response theater.

 

Table 1.  Operational biosurveillance priorities during disaster response operations in Haiti.  Important caveats: it is acknowledged that large-scale epidemics are rarely triggered by earthquakes.  Our operational posture is one of conservatism to anticipate unexpected events.  The bias is towards those infectious diseases capable of generating crises or disasters in their own right.

 

AIDS. The prevalence of HIV infection is estimated to be 4.5% (1.8%-7% in pregnant women).  The prevalence of chronic infection with Hepatitis B is moderate (2%-7%).  Prevalence of AIDS relates to TB prevalence (see below).

 

Anthrax*.  Considered “hyperendemic” in Haiti.  In the 1700s, it is believed Haiti was the site of the world’s largest epidemic of anthrax.  Of note, this  epidemic was thought to have been triggered by an earthquake on June 3, 1770 that led to massive destruction of civil infrastructure on the western end of Haiti and a resultant food crisis.  Slaves at the time were compelled to eat indigenous contaminated beef, as trade regulations prohibited importation of meat or fish.  Within 6 weeks, 15,000 fatalities were observed.  The last outbreak involving human cases of anthrax was documented on August 14, 2009, an unspecified number of human anthrax cases including one fatal case in Calumette, Bell-Anse commune. The source of the infection was suspected to be contaminated meat.  Calumette is an area east of Port-au-Prince that reported “moderate” perceived shaking.  It is believed the majority of anthrax cases are reported in southeast Haiti.  Currently, there is a efflux of refugees from Port-au-Prince to rural areas.  At this time, we do not know if refugees are migrating to this specific area of Haiti, however.   

 

Cholera.  “Some” activity may exist in the northwest portion of Haiti, but is not projected to be a concern.  We have not seen reports of cholera in the last 12 months in proximity to the disaster zone.  The next rainy season is not expected to begin until March, with typical seasonal peak in May.  Sewer and water lines are disrupted in the disaster zone.  Access to safe drinking water and proper sanitation facilities is crucial.

 

Dengue*.  The Dominican Republic and Haiti reported the tail end of a dengue fever epidemic with fatalities due to Dengue Hemorrhagic Fever (DHF) as recently as late December.  This epidemic had strained local medical infrastructure with the volume of cases numbering in the thousands.  The air temperature and humidity profile in Haiti is essentially optimized year-round; however, vector mosquito increases are typically seen following rainy periods. The next rainy season is not expected to begin until March, with typical seasonal peak in May.  Mosquito control under the present circumstances will be extremely difficult. 

 

Diarrheal and Waterborne Disease Not Otherwise Specified*.  Diarrheal disease is a serious and immediate concern.  The next rainy season is not expected to begin until March, with typical seasonal peak in May.  Sewer and water lines are disrupted in the disaster zone.  Access to safe drinking water and proper sanitation facilities is crucial to avoid outbreaks of diarrheal disease.

 

Diphtheria*.  On October 15, 2009, 11 cases were reported in the municipalities of Cap-Haitien to Pilate (4 deaths), Milot, Borgne, in the north of Gros Morne Gonaives in the Artibonite and Port-au-Prince.  Since the beginning of 2009, 19 cases with 9 deaths were reported throughout the country.  Diphtheria outbreaks have been reported since at least as far back as 1980 in Haiti.  In 2005 and 2006, more than 400 cases were reported.

Influenza*.  The primary concern here is pandemic H1N1.  Haiti has not experienced the same level of intense transmission as the temperate areas of the world, presumably due to its tropical climate and other factors.  That said, overcrowding of refugees in camps offers opportunity for outbreaks to evolve.  Intensive care capacity is minimal.  Therefore, high case fatality rates may be observed as have already been observed in multiple areas of the world among those with poor access to healthcare services.  Vaccination for pandemic influenza among the survivors is an important consideration.

 

Leptospirosis*.  Small scale outbreaks have been reported in past years during the same time period.  Dislocation of the rodent population may pose increased risk for an outbreak.  Leptospirosis has been associated with periods of heavy rain and flooding. The next rainy season is not expected to begin until March, with typical seasonal peak in May.

 

Malaria.  Highest rates of infection are observed from May to November.  Plasmodium falciparum accounts for nearly 100% of cases and is considered endemic to 75% of the land area in Haiti.

 

Measles.  Low herd immunity exists in Port-au-Prince.  The potential for a measles epidemic following introduction was demonstrated in 2000, where 992 cases were documented in Artibonite and Port-au-Prince following introduction from the Dominican Republic.  We believe a measles epidemic could be triggered if introduced.

Rabies.  There has been less than 5 canine cases of rabies reported in Haiti per year over approximately the last ten years.  Concern has been raised by veterinarians familiar with the situation in Haiti that dislocated companion animals will form roving packs, facilitating greater transmission of rabies among canine populations and perhaps place them in conflict with humans in their search for food.

Tuberculosis.  A high percentage (estimates as high as 50%) of Haitians with tuberculosis have AIDS.  Multi-Drug and eXtremely-Drug Resistance TuBerculosis (MDR- and XDR-TB) prevalences are unknown.  USAID considers Haiti to be associated with the highest per capita tuberculosis prevalence in the Latin American and Caribbean region.  With approximately 33,000 cases of active pulmonary tuberculosis believed to be in Haiti, tuberculosis is the country's greatest infectious cause of mortality after HIV.  The destruction of the prison and escape of 4,500 prisoners as well as the destruction of the Grace Children's Hospital, a 60-bed inpatient ward devoted to the treatment of pediatric tuberculosis, in Port-au-Prince may represent an influx of active tuberculosis into the community.

 

Typhoid.  Last outbreak in 2003 (200 cases, 40 fatalities) in Grand Bois.  More current data is unavailable, and risk is difficult to assess.

 

Endemic Disease Considerations in Haiti (Credit: GIDEON)

 

Aeromonas & marine Vibrio infx. (Latest Outbreak: 1976 - 386 cases)

AIDS

Amoeba - free living

Amoebic colitis

Angiostrongyliasis

Anthrax (Latest Outbreak: 2009 – multiple human cases)

Ascariasis

Blastocystis hominis infection

Brucellosis

Cholera

Cryptosporidiosis

Cyclosporiasis

Cysticercosis

Dengue

Diphtheria (Latest Outbreak: 2009 - 24 cases)

Escherichia coli diarrhea (Latest Outbreak: 1976 - 386 cases)

Filariasis - Bancroftian

Giardiasis

Gonococcal infection

Hepatitis B

Hepatitis C

Hepatitis E (Latest Outbreak: 1995 - 4 cases)

Histoplasmosis

Hookworm

Hymenolepis nana infection

Influenza (Latest Outbreak: 2010 – 92 pH1N1 cases reported, likely underreported)

Isosporiasis

Leptospirosis

Listeriosis

Malaria

Mansonelliasis - M. ozzardi

Measles (Latest Outbreak: 2000 - 992 cases)

Meningitis - bacterial (Latest Outbreak: 1994 - 100 cases)

Mumps

Pertussis

Poliomyelitis (Latest Outbreak: 2000 - 8 cases)

Rabies

Rubella

Salmonellosis (Latest Outbreak: 1976 - 386 cases)

Schistosomiasis - mansoni

Shigellosis (Latest Outbreak: 1976 - 386 cases)

Syphilis

Taeniasis

Tetanus

Trichinosis

Tuberculosis

Tungiasis (Latest Outbreak: 2004)

Typhoid and enteric fever (Latest Outbreak: 2003 - 200 cases)

West Nile fever

Yaws

 

Meteorological Baselines (Credit: Weather.com)

 

Port-au-Prince Seasonal Monthly Precipitation

 

Port-au-Prince Seasonal Monthly Temperatures

 

Further Reading and References           

 

1.  GIDEON.  http://www.cyinfo.com

2.  CDC. http://emergency.cdc.gov/disasters/earthquakes/healthconcerns_haiti.asp

3.  PAHO.  http://new.paho.org/disasters/

4.  Meteorological Information.  http://www.srh.noaa.gov/mfl/?n=haiti_support

5. WHO Preliminary Assessment.  Note this reflects general public health priorities which are slightly different than that presented by our team here.  http://www.reliefweb.int/rw/rwb.nsf/db900SID/DKAN-7ZRMLR?OpenDocument