COUNTY OF ORANGE - HEALTH CARE AGENCY

VOLUME 54, NUMBER 2
Summer-Fall 2005

This Issue …

Blast injuries may result from terrorism - Page 1

Pertussis (whooping cough)—Still with us - Page 2

State promotes pesticide illness reporting - Page 2

Multi-drug resistant tuberculosis in OC - Page 3

California Reportable Disease List revised - Page 4

Childhood Lead Poisoning Prevention Program - Page 5

Blast injuries may result from terrorism

Derived from Centers for Disease Control and Prevention information

The increasing threat of terrorism and the recent attacks on public transportation systems in London, England serve as reminders that health care providers may be called upon to treat victims of terrorist attacks using conventional explosives. Explosions can produce unique patterns of injury seldom seen outside combat. When they do occur, they have the potential to inflict multi-system life-threatening injuries on many persons simultaneously.

The injury patterns following such events are a product of the composition and amount of the materials involved, the surrounding environment, delivery method (if a bomb), the distance between the victim and the blast, and any intervening protective barriers or environmental hazards. Because explosions are relatively infrequent, blast-related injuries can present unique triage, diagnostic, and management challenges to providers of emergency care.

Few U.S. health professionals have experience with explosive-related injuries. Vietnam era physicians are retiring, other armed conflicts have been short-lived, and until this past decade, the U.S. was largely spared the danger of terrorist attacks.

Selected Blast Injuries

Lung Injury

"Blast lung" is a direct consequence of the High-Order Explosives over-pressurization wave. It is a common cause of death among initial survivors. Signs of blast lung are usually present at the time of initial evaluation, but they have been reported as late as 48 hours after the explosion.

Severe blast lung is characterized by the clinical triad of apnea, bradycardia, and hypotension. An early sign is decreasing oxygen saturation on pulse oximetry. Pulmonary injuries vary from scattered petechiae to confluent hemorrhages. Blast lung should be suspected for anyone with dyspnea, cough, hemoptysis, or chest pain following blast exposure. Symptoms of air embolism may be seen. Blast lung produces a characteristic "butterfly" pattern on chest X-ray. A chest X-ray is recommended for all exposed persons and a prophylactic chest tube (thoracostomy) is recommended before general anesthesia or air transport is indicated if blast lung is suspected. Pneumothoraces are common. If mechanical ventilation is necessary, high peak airway pressures should be avoided and permissive hypercapnia may be employed.

Ear Injury

Primary blast injuries of the auditory system cause significant morbidity, but are easily overlooked. Injury is dependent on the orientation of the ear to the blast. Tympanic membrane (TM) perforation is the most common injury to the middle ear. Signs of ear injury are usually present at time of initial evaluation and should be suspected for anyone presenting with hearing loss, tinnitus, otalgia, vertigo, bleeding from the external canal, TM rupture, or mucopurulent otorrhea. All patients exposed to blast should have an otologic assessment and audiometry. Rupture of the TM is predictive of other blast injuries and should be assessed in all blast victims.

Abdominal Injury

Gas-containing sections of the GI tract are most vulnerable to primary blast effect. This can cause immediate bowel perforation, hemorrhage (ranging from small petechiae to large hematomas), mesenteric shear injuries, solid organ lacerations, and testicular rupture. Blast abdominal injury should be suspected in anyone exposed to an explosion who has abdominal pain, nausea, vomiting, hematemesis, rectal pain, tenesmus, testicular pain, unexplained hypovolemia, or any findings suggestive of an acute abdomen. Clinical findings may be absent until the onset of complications.

Brain Injury

Primary blast waves can cause concussions or mild traumatic brain injury (MTBI) without a direct blow to the head. Consider the proximity of the victim to the blast particularly when given complaints of headache, fatigue, poor concentration, lethargy, depression, anxiety, insomnia, or other constitutional symptoms. The symptoms of concussion and post traumatic stress disorder can be similar.

(Continued on Page 3)

PUBLIC HEALTH Bulletin
VOLUME 54, NUMBER 2

Pertussis (whooping cough)—Still with us

Pertussis (whooping cough), caused by the bacterium Bordetella pertussis, has been in the news recently—for negative and positive reasons. First, the negative. The reported incidence of pertussis has been increasing [see graph] in Orange County, California and the United States. Nationally, pertussis is up 20.2% compared to last year at this time ¹. While some of the increase may be due to better recognition of pertussis in adolescents and adults, many experts think there has been a real increase in disease incidence. Pertussis remains a potentially deadly disease for very young children—20 children aged 0-2 months died from pertussis in California from 1995 to 2004.

Now the positive. The Food and Drug Administration (FDA) recently licensed the first pertussis vaccines for use in adolescents and adults. These booster vaccines are combined with booster doses of tetanus and diphtheria (Tdap): BOOSTRIX^®, was licensed by the FDA on May 3, 2005, for use in adolescents 10 through 18 years of age; ADACEL™, was licensed on June 10, 2005, for persons 11 through 64 years of age.

The Advisory Committee on Immunization Practices (ACIP) to the Centers for Disease Control and Prevention (CDC) recommended on June 30, 2005, that adolescents 11 and 12 years of age be given Tdap in place of the tetanus-diphtheria (Td) booster currently given to adolescents. The committee also recommended that Tdap be given to adolescents 13 to 18 years old who missed the 11 to 12 year dose of Td. Adolescents 11 to 18 who have already been vaccinated with Td are encouraged to receive a dose of Tdap to further protect against pertussis.²

Why vaccinate adolescents and adults against pertussis? Pertussis vaccination is approximately 85% effective in preventing infection after 3 doses. That protection only lasts 5-10 years. Adolescents and adults are the source of infection for infants and young children who are at greatest risk of serious complications and death. Pertussis also causes significant illness in adults and adolescents—20% - 30% of cough illness lasting more than 2 weeks in this age group is from pertussis³. While illness in adults and adolescents is often milder than in children, whooping and paroxysmal cough can occur. More than 50% of adults and adolescents with pertussis cough for at least 1 month and more than 40% cough for at least 9 weeks⁴.

It is important to consider pertussis in any person with a prolonged cough. Unfortunately, laboratory confirmation of pertussis is often difficult. Culture of nasopharyngeal secretions has been the gold standard; however, by the time the diagnosis is entertained the degree of shedding has decreased and the patient often has had antibiotic treatment so the yield on culture is low. Also, nasopharyngeal specimens must be transported with special media or transport tubes and cultured on special media. The organism is fastidious, grows slowly and must be incubated for a prolonged period. A negative culture does not rule out pertussis. Two alternatives to culture, direct fluorescent antibody (DFA) staining of nasopharyngeal secretions and serology, cannot be relied upon for diagnosis. The DFA test currently available has very low sensitivity and specificity and provides only presumptive identification of the organism. A negative DFA does not rule out pertussis. Serologic tests use a variety of antigens; none has been standardized and the results are not reliable. Polymerase chain reaction (PCR) has significant advantages—the results are rapid and the test can remain positive for a longer period than culture. Diagnostic testing should include PCR and culture⁵.

The key to control of this serious infection is prevention since it is easily transmitted and difficult to diagnose. Although recommendations for use of Tdap in adolescents have been made, the official recommendations for adults are not yet available; adults who are at risk of frequent exposure to pertussis and who could expose infants to pertussis, such as health care workers and pregnant women would be prime candidates.

Pertussis is a reportable disease, and the requirement to report includes suspected cases. Don't wait for laboratory results to report suspected cases to Orange County Epidemiology at 714-834-8180 or fax 714-834-8196. Close contacts of clinically suspected and laboratory confirmed pertussis cases should receive prophylactic treatment (see table).

Recommended Treatment and Chemoprophylaxis*

Drug

Erythromycin

Infants and Children-
40-50 mg/kg/day- div.q6h po or iv (max 2 g/d) x 14 days days

Adults-
1-2 g/day - div.q6h po or iv (max 2 g/d) x 14

If person cannot tolerate erythromycin or compliance is questionable:

Trimethoprim/Sulfamethoxazole (TMP-SMX)
Infants and Children-
trimethoprim 8 mg/kg/day, sulfamethoxazole 40 mg/kg/day - div.q12h po x 14 days
Adults-
trimethoprim 320 mg, sulfamethoxazole 1600 mg - div q12h po x 14 days [1 double strength (DS) po BID)]

Clarithromycin
Infants and Children-
15-20 mg/kg/day - div.q12h po (max 1 g/d) x 7days
Adults-
15-20 mg/kg/day - div.q1 2h po (max 1 g/d) x 7 days

Azithromycin
Infants and Children-
10-12 mg/kg (max 500 mg/d) po day 1
5-6 mg/kg/d (max 250 mg/d) days 2-5
Adults-
500 mg/day day 1
250 mg/day days 2-5
*Initiating treatment ≥3 weeks after cough onset has limited benefit to patient or contacts and initiating chemoprophylaxis ≥3 weeks after exposure has limited benefit for the contact. The dosages for treatment and prophylaxis are the same.

¹ CDC. Provisional cases of selected notifiable diseases, United States, weeks ending August 13, 2005, and August 14, 2004 (32nd Week). MMWR 2005. 54(32);811.

² National Immunization Program, CDC. Press release. http://www.cdc.gov/nip/pr/pr_tdap_jun2005.htm. Accessed July 11, 2005.
³ Dworkin MS. Adults are Whooping, but Are Internists Listening? Ann Intern Med. 2005;142:832-35.
⁴ Blumberg, DA. CHOC Grand Rounds. June 22, 2005.
⁵ Hewlett EL, Edwards KM. Pertussis—Not Just for Kids. NEJM. 2005;352:1215-22.

PUBLIC HEALTH Bulletin
SUMMER-FALL 2005

for-phys.htm#Physicians.
For more information on WNV

• OC Epidemiology website: www.ochealthinfo.com/epi/wnv/
• State website: www.westnile.ca.gov/
• CDC website: www.cdc.gov/ncidod/dvbid/westnile/
• Clinical trials for WNV: http://www.ochealthinfo.com/epi/wnv/WNVtrials.pdf
• Insect repellant: http://www.ochealthinfo.com/epi/wnv/Repellent.pdf

ORANGE COUNTY REPORTED CASES OF SPECIFIED NOTIFIABLE DISEASES

Second Quarter (Weeks 1-26)
Number of Cases by Year of Report
DISEASE 2005 2004 2003 2002

AIDS¹ 68 107 139 107
AMEBIASIS 6 7 3 8
CAMPYLOBACTERIOSIS 77 103 110 118
CHLAMYDIA 4,773 2,934 2,691 2,887
CRYPTOSPORIDIOSIS 3 3 8 4
E-COLI O157:H7 1 4 2 1
FOOD POISONING OUTBREAKS 8 16 19 38
GIARDIASIS 39 47 52 56
GONOCOCCAL INFECTION 708 436 324 360
H-FLU, INVASIVE DISEASE 3 3 2 2
HANSEN'S DISEASE, LEPROSY 0 0 0 0
HEPATITIS A (acute) 19 21 41 60
HEPATITIS B (acute) 5 15 14 30
HEPATITIS B (chronic) 272 499 631 651
HEPATITIS B (perinatal, acute & chronic)²279 514 645 681
HEPATITIS C (acute) 0 4 3 2
HEPATITIS C (chronic) 63 736 786 841
HEPATITIS OTHER/UNSPECIFIED 1 2 3 8
HIV³172 285 364 N/A
KAWASAKI DISEASE 14 11 17 12
LISTERIOSIS 3 7 1 8
MALARIA 5 6 2 7
MEASLES (RUBEOLA) 0 0 0 2
MENINGITIS, TOTAL 91 211 147 132
ASEPTIC MENINGITIS 74 192 124 103
MENINGOCOCCAL INFECTIONS 6 13 3 5
MUMPS 1 1 2 5
NON-GONOCOCCAL URETHRITIS 237 273 292 407
PERTUSSIS 34 41 35 40
PELVIC INFLAMMATORY DISEASE 25 22 20 40
RUBELLA 0 0 0 0
SALMONELLOSIS 80 118 87 121
SHIGELLOSIS 38 36 45 47
STREP, INVASIVE GROUP A 24 13 30 36
SYPHILIS, TOTAL 154 144 140 179
PRIMARY 15 5 8 9
SECONDARY 27 13 8 6
EARLY LATENT 25 11 7 19
LATENT 4 7 7 1
LATE LATENT 82 106 109 142
CONGENITAL 1 2 1 2
NEUROLOGICAL 0 0 0 0
TUBERCULOSIS 46 59 56 90
TYPHOID FEVER, CASE 3 0 7 2

¹Source: CDC HARS Reporting System NA= Not Available
²Previously included in Hepatitis B acute or chronic totals. Separate reporting started in 2002.
³Source: CEC HARS Reporting System. 2002 numbers are from July-December. Orange County officially began HIV case reporting July 1, 2002; data is unavailable for previous years.

COUNTY OF ORANGE ^-HEALTH CARE AGENCY

Public Health Bulletin is published by the County of Orange Health Care Agency, Quality Management/Public Information under the direction of:

Mark Horton, MD, MSPH, Health Officer

Editorial Board:
Hildy Meyers, MD, MPH, Medical Director
Epidemiology & Assessment
Amy Dale, MPH, Division Manager
Health Promotion
Steven Wong, REHS, MPH, Director
Environmental Health Services

Editors:
Howard Sutter
Public Information
Pat Markley
Public Information

Public Health Bulletin provides up-to-date information on public health issues affecting the Orange County medical community. PHB welcomes your ideas, comments, and article submissions. Please direct all comments and/or questions to:
County of Orange Health Care Agency
Public Health Bulletin/QM
P.O. Box 355
Santa Ana, CA 92702
(714) 834-3166

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COUNTY OF ORANGE - HEALTH CARE AGENCY
QUALITY MANAGEMENT
P.O. BOX 355
SANTA ANA, CA 92702

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Second Quarter (Weeks 1-26) Number of Cases by Year of Report DISEASE 2005 2004 2003 2002

Second Quarter (Weeks 1-26)
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