Infectious Diseases After Natural Disasters Christian Sandrock, MD, MPH California Preparedness Education Network Funded by HRSA Grant T01HP01405
Infectious Diseases After Natural Disasters
Christian Sandrock, MD, MPH
California Preparedness Education Network
Funded by HRSA Grant T01HP01405
calPEN at COMMUNITY HEALTH PARTNERSHIP
• Covers the 9 San Francisco Bay Area counties
• It is a program of the Health Education and Training Center (South Bay AHEC), a division of the Community Health Partnership
• Community Health Partnership is a consortium of community clinics that works to strengthen the healthcare safetynet for the medically underserved
HOUSEKEEPING
• Folder contents
• Sign-in sheet with degree/job function and license number (if applicable)
• Please FILL OUT the participant data form and the evaluation form and TURN IN by the end of the presentation
OBJECTIVES
1. Recognize the risk of infectious diseases after natural disasters
2. Recognize the indications of infectious diseases after natural disasters
3. Meet immediate care needs of patients
4. Alert appropriate authorities
5. Participate in response
Overview
• The role of infectious diseases in natural disasters
• Factors leading to a disease outbreak after a disaster
• Review some of the common and rare diseases after a natural disaster
Background
• Historically, infectious disease epidemics have high mortality
• Disasters have potential for social disruption and death
• Epidemics compounded when infrastructure breaks down
• Can a natural disaster lead to an epidemic of an infectious disease?
• If so, how?
Western K Tropical Public Health, London School of Hygiene and Tropical Public Health
Phases of Disaster
• Impact Phase (0-4 days)– Extrication– Immediate soft tissue infections
• Post impact Phase (4 days- 4 weeks)– Airborne, foodborne, waterborne and vector
diseases
• Recovery phase (after 4 weeks)– Those with long incubation and of chronic
disease, vectorborne
Factors for Disease Transmission After a Disaster
• Environmental considerations
• Endemic organisms
• Population characteristics
• Pre- event structure and public health
• Type and magnitude of the disaster
Environmental Considerations
• Climate– Cold- airborne – Warm- waterborne
• Season (USA)– Winter- influenza– Summer- enterovirus
• Rainfall– El Nino years increase malaria– Drought-malnutrition-disease
• Geography– Isolation from resources
Endemic organisms
• Infectious organisms endemic to a region will be present after the disaster
• Agents not endemic before the event are UNLIKELY to be present after
• Rare disease may be more common
• Deliberate introduction could change this factor
Endemic Organisms
• Northridge Earthquake– Ninefold increase in coccidiomycosis (Valley
fever) from January- March 1994
• Mount St. Helens– Giardiasis outbreak in 1980 after increased
runoff in Red Lodge, Montana from increased ash
Population Characteristics
• Density– Displaced populations– Refugee camps
• Age– Increased elderly or children
• Chronic Disease– Malnutrition– DM, heart disease– transplantation
Population Characteristics
• Education– Less responsive to disaster teams
• Religion– Polio in Nigeria, 2004
• Hygiene– Underlying health education of public
• Trauma– Penetrating, blunt, burns
• Stress
Pre-event resources
• Sanitation• Primary health care and nutrition• Disaster preparedness• Disease surveillance• Equipment and medications• Transportation• Roads• Medical infrastructure
Type of disaster
• Earthquake– Crush and penetrating injuries
• Hurricane (Monsoon, Typhoon) and Flooding– Water contamination, vector borne diseases
• Tornado– Crush
• Volcano– Water contamination, airway diseases
• Magnitude– Bigger can mean more likelihood for epidemics
Howard et al, Emergency Medicine Clinics in North America 1996 14 (2)
Flooding
• Missouri 1993– Increase reports if E.D. visits due to illness– 20% respiratory,17% GI
• Iowa 1993– No reports of GI or respiratory increase due to
sanitation measures
• Florida – Hurricane Andrew– Heavy mosquito spraying lead to no change
in encephalitis rates
Bissell, RA J Emerg Med 1983 1 (1):59-66
Dominican Republic, 1979
• Hurricane David and Fredrick on Aug 31 and Sept 5th 1979
• >2,300 dead immediately• Marked increase in all diseases measured
6 months after the hurricane– Thyphoid fever– Gastroenteritis– Measles– Viral hepatitis
S.F. 1907 Fire Plague Quarantine failure
Duluth, MN 1918
Forest Fire Influenza Crowding, epidemic
Haiti, 1963 Hurricane Malaria Vector control stopped
Italy, 1976 Earthquake Salmonella Carriers
Water sanitation stopped
Epidemics after Disasters
Epidemics after Disasters
Dominican Republic, 1979
Hurricane Thyphoid, GI, hepatitis, measles
Crowding, flooding, chronic disease
Popaya, Colombia 1983
Earthquake Viral hepatitis
Water sanitation
Equador, 1983
Flooding Malaria Vector increase
Summary of Factors
• Many factors play a role in disease development and outbreaks
• Change of disease not likely to play role
• Change and cessation of public health measures play a big role
Post-Impact Phase Infections
• Crush and penetrating trauma– Skin and soft tissue disruption (MRSA)– Muscle/tissue necrosis– Toxin production disease– Burns
• Waterborne– Gastroenteritis– Cholera– Non-cholera dysentery– Hepatitis– Rare diseases
Post-Impact Phase Infections
• Vector borne– Malaria– WNV, other viral encephalitis– Dengue and Yellow fever– Typhus
• Respiratory– Viral– CAP– Rare disease
• Other– Blood transfusions
Recovery Phase Infections
• These agents need a longer incubation period– TB– Schistosomiasis– Lieshmaniasis– Leptospirosis– Nosocomial infections of chronic disease
What effects skin and soft tissue infections?
• Crush and penetrating injuries– ABC’s
• Establish airway• Circulation
– Stabilize• BP support• Respiratory support
– Diagnose extent of injuries• Radiology• Diagnostic procedures
– Corrective action• CT, fracture stabilization, transfusion• Surgery if necessary
What effects skin and soft tissue infections?
• Post-traumatic Care– Hypoxia from pulmonary contusion, ARDS, VAP– Coagulopathy– Renal failure– DVT/PE– Ulcer disease– Soft tissue infections
• Cellulitis • Necrotizing fasciitis• Post op wound infection• Burn care
Cellulitis
• Skin infection involving the subcutaneous tissue
• Predisposing factors– Lymphatic compromise– Site of entry– Obesity– DM– Dirty/contaminated wound
Cellulitis- Microbiology
• Streptococcus• Staphylococcus (MRSA)
– Worse in shelters
• Special circumstances– Water exposure
• Aeromonas (MMWR 2005 Sept;54(38):961 and Clin Infect Dis 2005 Nov;41(10):93)
• Vibrio vulnificus (MMWR 2005 Sept;54(38):961)
• E coli, Klebsiella, Pseudomonas (Lakartidningen 2005 Nov;102(48):3660)
• Myroides, Bergeyella, Sphingomonas• Mucormycosis (Ann Acad Med Singapore 2005)
Cellulitis- Microbiology
• Animal bites– Pasteurella multocida
• DM– Other gram negatives
• Asia– Increased resistance (Lakartidningen 2005 Nov;102(48):3660)
• Leprosy (Emerg Infect Dis 2005 Oct;11(10):1591-3)
• Chemical dermatitis (MMWR 2005 Sept;54(38):961)
Cellulitis
• Pathogenicity– Not well understood– Venous and lymphatic compromise– Bacterial invasion with endo/exotoxin release– Cytokine release
• Symptoms– Systemic- F/C/M– Redness, swelling– Tenderness, edema– May have ulcer or abscess
Cellulitis
• Treatment– Antibiotics (MRSA)
• B-lactam• TMP/SMX• Clindamycin• Linezolid• Vancomycin
– Limb elevation– Systemic support– Surgical consultation
• Abscess• Occular• Necrotizing fasciitis evaluation
Necrotizing Fasciitis
• Fulminant destruction of tissue
• Systemic toxicity
• Very high mortality
• Much larger bacterial load than cellulitis
• Travels through fascial plain
• Much less inflammation from necrosis, vessel thrombosis, and bacterial factors
Necrotizing Fasciitis
• Two types– Type I
• Largely mixed aerobic and anaerobic infection• Seen in post surgical patients• DM, PVD big risk factors• Examples
– Cervical necrotizing fasciitis (Ludwig’s angina)– Fournier’s gangrene
– Type II• Group A strep • Large exotoxin production or M protein• Any age group or without portal of entry
Diagnosis
• Pain– May mimic post surgical changes
• Skin changes– Thick or “woody” in nature– Minimal erythema– Bullae
• Systemic symptoms– Fevers, chills– Rapid sepsis
Treatment
• Surgical Debridement!!!!!!!!– aggressive and explorative– Wide tissue excision
• Antibiotics– B- lactam antibiotics– Clindamycin for toxin production– Gram negative/anaerobic coverage
• Hyperbaric O2• Supportive care
Toxin Diseases
• Tetnus– Rare due to vaccination
– 1 Million die per year in developing world– 4 clinical patterns
• Generalized
• Local
• Cephalic
• Neonatal
Tetanus
• Spores of C. tetani enter the tissue
• Produce metalloprotease, tetanospasmin
• Retrograde movement into CNS
• Blocks neurotransmission by cleaving protein responsible for neuroexocytosis
• Disinhibition of motor cortex
• Extensive spasm
Tetanus
• Needs the right factors to produce– Penetrating injury with spore delivery
– Co-infection with other bacteria– Devitalized tissue– Localized ischemia– Can have water contamination as part of entry
(Ann Acad Med Singapore 2005;34(9):582)
Tetanus Treatment
• Wound management– Halts toxin production
• Tetanus antitoxin and vaccine– Neutralized unbound toxin
• Benzodiazepines and paralytics– Treats spasms
• B-blockers– Treats autonomic dysfunction of late disease
• Supportive care
Waterborne disease
• Viral gastroenteritis– Norovirus (MMWR 2005 Oct;54(40):1016)
• Cholera– Gram negative bacterium Vibrio cholerae
– Severe water diarrhea with 50% mortality if untreated– 190 serrotypes but only O1 and O139 cause human
epidemics– Bacterial model for toxin mediated disease– 2 cases isolated after Katrina with minimal disease
(MMWR Nov 2005)
Cholera pathophysiology
• Enter the small bowel and colonize– Pilus required– Hemagglutanins
– Acessory colonizing factor
– Porin like proteins
• Produces toxin– A with 5 B subunits– A cleaves to A1, activates adenylate cyclase
– Leads to increase Cl secreation and decreased Na absorption
Cholera-symptoms
• Majority are asymptomatic
• Some with develop rapid diarrhea
• Diarrhea most severe days 1-2, stops by day 6
• May loose 100% body weight in 2 days
• Children, elderly at risk
• Death in 2 -48 hours (18 average)
Cholera Treatment
• Oral rehydration- per liter– 3.5g NaCl– 2.9g NaHCO3– 1.5g KCl– 20g glucose
• IV rehydration• Antibiotics- not necessary
– Lessens diarrhea by one day
• Vaccine- no evidence• Public health prevention
Non cholera dysentery
• Giardia• E. Coli• Toxin Mediate food poisoning• Salmonella• Shigella• Campylobacter• Yersinia• Viral hepatitis• Viral Gastroenteritis
Respiratory Illness
• Viral– Most common cause of infectious illness after
Midwest floods over past 20 years– More common is shelter setting (unpublished)
• TB– 25% mortality in camps in Africa and Asia– Worsened by drought
• Community acquired bacterial pneumonia– Mainly theoretical, no data
Recent experiences
• Meliodosis (Emerg Infect Dis 2005 Oct;11(10):1639)
• Necrotizing pneumonia• Multidrug resistant TB (Emerg Infect Dis 2005 Oct;11(10):1591-3)
• Atypical mycobacterial pneumonia (Emerg Infect Dis
2005 Oct;11(10):1591-3)
Vector borne disease
• Malaria– Common after flooding (Prehospital disaster Med 2002;17(3):126)
– Brackish water increases Anopheles (Malar J 2005;4(1):30)
– Well controlled with mosquito abatement
• Encephalitis– No documented increase in US but heavy
abatement programs– West Nile?
General disaster reminders
• Vaccinations are the mainstay of outbreak control in many situations
• Dead bodies pose little to no infectious disease risk (Rev Panam Salud 2004;15(5):297-9)
• Early surveillance and hygiene can stem outbreaks
Conclusions
• Infectious diseases may play a role in the post disaster period
• These diseases will vary depending on many factors
• If the disease if not present before the disaster, it will not be there after
Conclusions
• Early recognition of certain diseases in disaster setting important
• Halting infrastructure and response has led to most increases in infectious diseases
• If deployed, know where you are going and what is endemic
QUESTIONS?
• Please remember to complete:
– Personal data sheet
– Evaluation
– Sign-in sheet (include your degree or job function AND your license number if applicable to receive CEUs)