In the United States, malaria transmission was eliminated in the 1940s,
and malaria eradication was certified in 1970.1 Since then, 60
small localized outbreaks of probable mosquito-transmitted malaria have been
reported to CDC.2-6 Before 1995, the number of imported malaria
cases reported to the Suffolk County (New York) Department of Health Services
ranged from zero to eight per year. Since 1995, seven to 17 cases per year
have been reported. In all of these cases, a history of residing in or traveling
to an area with endemic malaria outside the United States was confirmed. This
report describes the investigation of two cases of Plasmodium
vivax malaria that occurred in Suffolk County in August 1999; the patients
had no history of travel outside of the United States.
On August 18, an 11-year-old boy residing in Suffolk County was seen
by his physician with a 5-day history of fever, rigors, abdominal pain, arthralgias,
and vomiting. Intracellular parasites consistent with P.
vivax were noted on a complete blood count. The patient was admitted
to a local hospital on August 21 with a temperature of 102.0 F (38.9 C), hepatosplenomegaly,
and several healing maculopapular bite lesions. Initial laboratory examinations
revealed leukopenia (white blood cell count: 2,800/mm3 [normal:
4,500-13,500/mm3]), anemia (hemoglobin: 9.8 g/dL [normal: 11.5-15.5
g/dL]), and severe thrombocytopenia (platelet count: 21,000/mm3
[normal: 150,000-400,000/mm3]). Serology was negative for Lyme
disease and babesiosis. Serum electrolytes and chest radiograph were normal.
Urinalysis demonstrated a slightly elevated urobilinogen. Examination of peripheral
thick and thin blood smears at the New York State Department of Health (NYSDH)
and CDC confirmed P. vivax infection. The patient
was treated with chloroquine phosphate, quinine, clindamycin, and primaquine
and was discharged from the hospital on August 25.
The patient's parents reported he had never traveled to a malarious
area or had a history of a blood transfusion or organ transplantation. During
August 1-7, the patient spent 1 week at a summer camp 20 miles from his hometown.
He slept in a tent and went swimming in the camp pond. After his return home
on August 7, the patient attended another camp in Massachusetts for 2 days.
On August 22, an 11-year-old boy residing in Suffolk County was seen
by his physician for a 12-day history of vomiting, diarrhea, fever, chills,
and fatigue. On August 27, a complete blood count showed malarial ring forms;
the boy was admitted to a hospital the following day. Physical examination
on admission revealed a temperature of 100.0 F (37.8 C), no splenomegaly,
and multiple healing maculopapular bite lesions. Initial laboratory examinations
revealed leukopenia (white blood cell count: 4,300/mm3), severe
anemia (hemoglobin: 8 g/dL), and thrombocytopenia (platelet count: 134,000/mm3). Routine blood and urine cultures were negative. Serology was negative
for babesiosis. Urinalysis and chest radiograph were normal. Examination of
peripheral thick and thin blood smears at NYSDH and CDC revealed intracellular
parasites consistent with P. vivax (less than 1% parasitemia). The patient
was treated with chloroquine phosphate and primaquine and was discharged from
the hospital on August 29.
His parents reported he had never traveled to a malarious area or had
a history of a blood transfusion or organ transplantation. The boy spent the
same week at the same summer camp as case 1, which is 15 miles from his hometown.
During the week he slept in a tent and participated in numerous outdoor activities.
On August 10, he began having fevers ranging from 101.0 F to 104.0 F (38.3
C to 40.0 C) with rigors and sweats.
No other unexplained cases of malaria were reported to NYSDH during
July 1-August 31, 1999. To identify potential unreported cases, a field investigation
was conducted that included 1155 telephone interviews with boys who attended
the camp, members of their families and the camp staff, and interviews with
residents living within 1 mile of the camp. Sixty-three of 375 boys who attended
the camp and members of their families who were interviewed reported having
a fever during the defined time period. Fourteen of these persons had unexplained
fevers; however, no malaria parasites were shown on peripheral blood smears
on any of these persons. Two of the approximately 150 residents who lived
within a 1-mile radius of the camp who were interviewed reported a fever during
the specified time period. No malaria parasites were shown on their peripheral
blood smears. Of 52 farm workers interviewed who had immigrated from Mexico,
Guatemala, Honduras, El Salvador, and Bangladesh and who resided in three
farms near the camp, three reported a recent history of fever; their blood
smears did not reveal parasites.
Routine mosquito trapping by the Suffolk County health department for
eastern equine encephalitis during early August (the time these cases would
have been transmitted) from sites 7 miles from the summer camp yielded Anopheles quadrimaculatus and An. punctipennis. Trapping from the campsite in eastern Long Island from August 24
to 31 yielded primarily An. quadrimaculatus and a
few An. punctipennis. No mosquitoes (222 of 248 were
tested) from the campsite or the boys' hometowns tested positive for Plasmodium species. Mosquito control measures to kill larvae
and adults were performed at the camp. The adjacent state park was closed
temporarily by the health department until surveillance indicated low numbers
CB Bradley, MD, MH Zaki, MD, DG Graham, MD, M Mayer, MD, V DiPalma,
MSN, SR Campbell, PhD,'s Kennedy, Suffolk County Dept of Health Svcs, Hauppauge,
New York. MA Persi, DO, Dept of Preventive Medicine, State Univ of New York
at Stony Brook, Stony Brook, New York. A Szlakowicz, MA, P Kurpiel, J Keithly,
PhD, J Ennis, P Smith, MD, State Epidemiologist, New York State Dept of Health.
O Szlakowicz, Mayo School of Medicine, Rochester, Minnesota. Malaria Epidemiology
Br (proposed), Entomology Br, Biology and Diagnostics Br, Div of Parasitic
Diseases, National Center for Infectious Diseases; and an EIS officer, CDC.
The two cases presented in this report represent the third episode of
possible mosquito-borne malaria in New York during the preceding 7 years4,5,7 and the 24th episode in the United States since 1985. The possibility
of autochthonous (i.e., locally acquired) mosquito-borne malaria transmission
in the United States remains a concern because of the frequency of international
travel, the presence of gametocytemic persons (i.e., persons with malaria
parasites in the blood stream that can infect mosquitoes) in the United States,
the presence of competent mosquito vectors, and the occurrence of environmental
conditions that favor transmission. This investigation confirmed two epidemiologically
linked cases of P. vivax infection in children residing
and camping in Suffolk County, who probably acquired their infections in eastern
Long Island through the bite of one or more locally infected Anopheles mosquitoes, a competent vector for malaria.
Neither patient had risk factors for the acquisition of malaria infection,
such as travel to a disease-endemic area or history of intravenous drug use.
Neither had ever had a blood transfusion or organ transplantation. Other potential
sources of infective mosquitoes, such as international airports, were too
distant from the presumed site of infection. However, Anopheles mosquitoes were identified in the recreational area that both patients
had visited during the month of August 1999. In addition, potentially gametocytemic
persons were living near this recreational area, and environmental conditions
were suitable for the development of the parasite in the mosquito (sporogonic
cycle) and larvae into adult mosquitoes. Although case finding and contact
tracing activities did not identify persons with malaria who might have been
the source of the infection, this does not preclude local transmission, which
may have occurred weeks before the investigation.
Suffolk County is one of the most heavily mosquito-infested areas in
the northeast. In 1999, the northeastern United States experienced one of
the warmest and driest summers in history.8 However, heavy rainfall
shortly before the two boys arrived at the camp may have resulted in a large
population of adult female mosquitoes. Dry weather followed by heavy rains,
in addition to resulting in conditions conducive for mosquito breeding, could
have reduced the mosquito predator population.
Gametocytemic persons still may be present in the community and constitute
a potential reservoir for future episodes of mosquito-borne malaria. Thousands
of travelers return to the United States each year from areas where malaria
is endemic, and many fail to take adequate chemoprophylaxis. Reintroducing
malaria transmission on a small scale in selected areas in the United States
is possible. This cluster underscores the need for ongoing surveillance for
vector-borne diseases, including malaria. Prompt recognition and adequate
treatment of malaria, including improved access to diagnosis and treatment
for migrant populations, rapid reporting of malaria cases to public health
authorities, and implementation of appropriate control measures, are indicated.
Finally, malaria should be considered in the differential diagnosis of illness
in any patient with unexplained fevers, regardless of travel history.
During the summer months, persons should follow personal protective
measures that reduce contact with potentially infective mosquitoes. These
include the use of protective clothing and insect repellants, and sleeping
in screened or air-conditioned enclosures. Repellant products containing N,N-diethylmetatoluamide
(DEET) are more effective than other compounds.
References: 8 available
To control indoor flying insects, restaurants and other businesses commonly
use pyrethrin and pyrethroid insecticides sprayed from automatic dispensing
units. Usually placed near entrances, these units are designed to kill flying
insects in food service or work areas. On May 18, 1999, the Florida Department
of Health (FDH) was notified by the Florida Department of Business and Professional
Regulation (DBPR) that during May 12-17, three persons developed pesticide-related
illnesses associated with improperly placed automatic insecticide dispensers.
After FDH conducted a follow-up investigation and notified CDC's National
Institute for Occupational Safety and Health (NIOSH) of this event, surveillance
data were reviewed to identify additional cases of pesticide-related illnesses
associated with automatic insecticide dispensers. Data were provided by the
Toxic Exposure Surveillance System (TESS), the California Department of Pesticide
Regulation (CDPR), the Montana Department of Agriculture (MDA), the National
Pesticide Telecommunications Network (NPTN), and the Washington State Department
of Health (WSDH).* This report describes cases, summarizes surveillance data
for pesticide-related illnesses associated with automatic insecticide dispensers,
and provides recommendations for safe dispenser use.
A 42-year-old cook working at a Florida restaurant developed a sore
throat, dyspnea, headache, and dizziness on May 12, 1999, after a several-hour
exposure to mist released from insecticide dispensers in the food preparation
area. The insecticide dispensers had been installed on May 10, but it is unknown
on what day the cook was first exposed. The cook removed the dispensers on
May 12 and noted relief of his symptoms. However, the restaurant management
reinstalled the dispensers on May 14, and on May 15, a 40-year-old male customer
developed headache and shortness of breath within 1 hour of entering the restaurant.
These symptoms lasted approximately 4 hours. On May 17, approximately 45 minutes
after leaving this restaurant, a 47-year-old male customer experienced a sharp
burning sensation in his left eye and noted swelling, redness, and irritation
of the eyelid that persisted approximately 24 hours. The implicated pesticide
dispenser was within 6 feet of the booth where this customer had been sitting,
and it faced his left eye. This person reported his symptoms to DBPR on May
18. None of the three persons sought medical attention for their symptoms.
The active ingredients released by these dispensers were pyrethrin and piperonyl
On August 20, 1995, a 17-year-old male restaurant employee in California
was changing the cartridge of an automatic insecticide dispenser. When he
closed the dispenser panel, the firing mechanism was activated and discharged
a pyrethrin-containing mist into his right eye. The employee immediately experienced
burning in the eye and promptly sought medical attention at the emergency
department of a local hospital. He was diagnosed with chemical conjunctivitis
and treated symptomatically.
TESS is maintained by the American Association of Poison Control Centers
and collects poisoning reports submitted by approximately 85% of U.S. poison
control centers.1 A review of TESS data from 1993 through 1996,
the most recent years for which data are available, identified 54 cases of
pesticide-related illnesses associated with automatic insecticide dispensers;
suicides and intentional misuse/abuse were excluded. Among the 42 cases for
which specific age information was available, the median age was 22.5 years
(range: 3-73 years). Among the 53 cases for which sex was known, 27 (50%)
were male. Twenty (37%) cases were work-related. In all cases, pyrethrin/piperonyl
butoxide was the responsible insecticide.
During 1986-1999, 43 cases of acute pesticide-related illnesses associated
with automatic insecticide dispensers were reported to CDPR (32 cases), MDA
(four cases), FDH (three cases), NPTN (two cases), and WSDH (two cases). Age,
sex, and state of occurrence for these cases were compared with those from
the TESS database, and no overlap with TESS data was found. Thirty-five (81%)
of these cases were in persons exposed while at work, including seven whose
exposure occurred during dispenser cartridge replacement or attempts to service
faulty dispensers. Seven (16%) cases were in persons exposed while they were
customers in restaurants, and one was a movie theater customer. For the 27
with age data available, the median age was 40 years (range: 17-68 years);
for the 38 with information on sex, 23 (61%) were women. Resmethrin, a pyrethroid
insecticide, was implicated in three cases; the remaining 40 were exposed
to pyrethrin/piperonyl butoxide. Most insecticide dispenser-related illnesses
identified in the non-TESS data† occurred when the dispensers were
improperly placed too close (i.e., less than 12 feet) to food handling, dining,
or work areas; were placed where ventilation currents entrained the mist to
such areas; and/or were serviced by persons unfamiliar with proper maintenance
of these units.
Among the 94 pyrethrin/piperonyl butoxide-exposed cases in the combined
surveillance data, signs and symptoms for 36 (38%) involved the eye; 34 (36%),
the neurologic system; 26 (28%), the respiratory system; 23 (24%), the gastrointestinal
system; 20 (21%), the nose and throat; 10 (11%), the skin; and eight (9%),
the cardiovascular system. Some persons experienced signs and symptoms in
more than one system. Among the three resmethrin-exposed cases, reported signs
and symptoms included pruritus, throat irritation, nausea, vomiting, diarrhea,
headache, burning sensation in the lungs, and cough.
O Shafey, PhD, Bur of Environmental Epidemiology, Florida Dept of Health.
L Mehler, MD, California Dept of Pesticide Regulation. L Baum, Pesticide and
Surveillance Section, Washington State Dept of Health. Office of Pesticide
Programs, US Environmental Protection Agency. Div of Environmental Hazards
and Health Effects, National Center for Environmental Health; Div of Surveillance,
Health Evaluations, and Field Studies, National Institute for Occupational
Safety and Health; and an EIS Officer, CDC.
This report is the first to document pesticide-related illnesses attributable
to automatic insecticide dispensers. Automatic insecticide dispensers are
registered by the U.S. Environmental Protection Agency (EPA) for use in the
restaurant industry and in other public settings, including schools, hotels,
offices, supermarkets, hospitals, day-care centers, and long-term-care facilities
(e.g., nursing homes). When used properly, automatic insecticide dispensers
reduce the number of flying insects. However, given the dispensers' widespread
use and potential for malfunction and/or improper use or maintenance, these
units may pose a public health hazard.
Insecticide dispensers of the type described in this report are typically
calibrated to spray automatically a fine mist of 50-100 mg of insecticide
(consisting of approximately 0.5%-1.85% pyrethrin or resmethrin, along with
other active and inert ingredients) every 15 minutes, 24 hours per day. Pyrethrins
are insecticides derived from the oleoresin extract of dried chrysanthemum
flowers (pyrethrum).2 Piperonyl butoxide (either alone or combined
with n-octyl bicycloheptene dicarboximide) often is added to pyrethrin products
to inhibit microsomal enzymes that detoxify pyrethrins.2 Although
pyrethrins (classified by EPA as acute toxicity category III compounds‡)
have little systemic toxicity in mammals, they possess irritant and/or sensitizing
properties that can induce contact dermatitis, conjunctivitis, and asthma.2,3 Anaphylactic reactions2 and gastrointestinal symptoms4 related to inhalation of and cutaneous exposure to pyrethrin also
have been reported; however, no previously published reports were identified
associating pyrethrin exposure with reported cardiovascular (i.e., tachycardia,
chest pain, and palpitations) or neurologic (i.e., headache, dizziness, malaise,
altered taste, and lip numbness/burning) signs and symptoms. Resmethrin is
a pyrethroid, a class of synthetic insecticides chemically similar to natural
pyrethrins2 and is classified in acute toxicity category III. Pyrethroids
are reported to induce abnormal skin sensation, dizziness, salivation, headache,
fatigue, vomiting, diarrhea, irritability to sound and touch, and other central
nervous system effects.2,5
The findings in this report are subject to at least two limitations.
First, the surveillance systems that identified cases are passive and may
have missed some acute pesticide-related illnesses. Second, lack of detailed
information on incidents recorded in the surveillance data may have precluded
identification of additional risk factors for insecticide dispenser-related
Effective flying insect control can be achieved through nonchemical
integrated pest management practices (e.g., proper sanitation practices by
employees and installation of air curtains and screens). However, if automatic
insecticide dispensers are used, they should be installed according to manufacturer
labeling instructions. Warning stickers on dispensers should be considered,
installation near supplied-air ducts should be avoided, and timers should
be set to dispense insecticide during nonbusiness hours.6 Dispensers
used in locations frequented by the public should be installed and serviced
by commercial pest control operators. Although they are not required by EPA,
persons servicing these devices should use personal protective equipment (i.e.,
chemical-resistant gloves and goggles designed to provide splash protection).
References: 6 available
On May 25, 2000, the Surgeon General issued Oral Health
in America: A Report of the Surgeon General. The report identifies
the essential role of oral health in overall health and well-being. Although
oral health has improved since 1950, disparities in oral health status and
access to care affect many persons, including those with low income and members
of racial/ethnic minority groups. Safe and effective measures for preventing
oral disease such as the use of fluoridated water or dental sealants are underutilized.
Actions called for by the report include increasing awareness of the importance
of oral health as part of general health; accelerating the building of the
science base and applying it more effectively to improve oral health; strengthening
the local, state, and federal capacity to perform core public health functions;
removing barriers between people and receipt of oral health services; and
using public-private partnerships to improve the oral health of those who
still suffer disproportionately from oral diseases.
Additional information, a copy of the report, and ordering information
are available on the World-Wide Web at http://www.surgeongeneral.gov. Additional information is available on the Web at http://www.cdc.gov/nccdphp/oh/, or by telephone at (887) 232-2020.
The Draft Public Health Action Plan to Combat Antimicrobial
Resistance became available for public comment on June 22, 2000. Comments
must be submitted in writing by August 4, 2000, to the Office of Health Communication,
National Center for Infectious Diseases, CDC, Mailstop C-14, 1600 Clifton
Rd., N.E., Atlanta, GA 30333; fax, (404) 371-5489; e-mail, email@example.com; or the World-Wide Web, http://www.cdc.gov/drugresistance/actionplan/.
Requests for copies of the plan should be submitted to the Office of
Health Communication, National Center for Infectious Diseases, CDC, Mailstop
C-14, 1600 Clifton Rd., N.E., Atlanta, GA 30333; fax, (404) 371-5489; e-mail, firstname.lastname@example.org; or the Web, http://www.cdc.gov/drugresistance/actionplan/. Copies can be downloaded from the Web site.
Probable Locally Acquired Mosquito-Transmitted. JAMA. 2000;284(4):431-432. doi:10.1001/jama.284.4.431