Malaria Cases in Alameda County, California

Malaria has once again become the formidable disease that it was prior to the development of mosquito control programs and DDT. The World Health Organization estimates that there will be between 300 and 500 million cases of malaria this year and that between one to two million persons will die from this disease.

California's association with this disease has been more recent starting sometime around 1829-1832 with the fur trade. About the turn of the century it was estimated that California had approximately 5,000-6,000 cases per year.

Endemic malaria in California has been rare since the second world war with sporadic episodes primarily due to returning military personnel and migrant farm labor. With the upsurge of malaria worldwide during the past few years, the potential for reintroduction of malaria into California has increased.

In 1990, the Alameda County Mosquito Abatement District developed and implemented a malaria surveillance and response program in recognition of these changes occuring worldwide with malaria. The program developed was adapted from a report by Dr. William Reisen that recommended increased surveillance and a prepared response program should endemic malaria cases be identified. What follows is a summary of the Alameda County Program with statistics on number of cases, point of origin and type of malaria diagnosed in Alameda County for the past 12 years.

District Malaria Program

The current malaria program of the Alameda County Mosquito Abatement District is summarized as follows:

There will be continuous monitoring and control of the larval and adult Anopheline mosquito populations in Alameda County. Sources producing vector Anopheline mosquitoes will be recorded and mapped for day to day use and emergencies.

Upon receipt of a Malaria Case Surveillance Report, an investigation by District personnel will be made to determine the origin of the case.

Upon determination that a malaria case has arrived in Alameda County, but has not been transmitted in the County, the Zone technician handling the area where the case resides will be notified. If Anopheline species are found in this area the Zone Technician will monitor and control as needed until satisfied that no further chance exists for local transmission. This will be done with the advice and consent of the Entomologist.

If a malaria case is determined to have been locally transmitted by a mosquito vector, the emergency malaria response plan will be immediately implemented. See the descriptions of the duties of personnel.

Malaria Case Surveillance Report

Malaria Case Surveillance Reports are received by the Alameda County Mosquito Abatement District from the Department of Health Services.

District personnel will contact the attending physician or if necessary the person being treated for malaria to determine that they are under treatment, taking their medication or have completed treatment, and to determine the origin of the infection.

The technician who handles the zone where the malaria case resides will receive a copy of the report and a computer print out of Anopheline mosquito sources in that area of his/her zone.

The technician in consultation with the Entomologist will determine if there is a chance for malaria to have been picked up in the mosquito population and what control measures may be necessary.

If this is a locally contracted case, the emergency malaria response plan will be activated.
All Case reports will be recorded in the District data base.

The District will complete the surveillance report and submit the completed report to the County Public Health Department

Emergency Personnel Duties

In the event of a local transmission of malaria and the declaration of an emergency, District personnel will be called upon to fulfill duties not normally involved in the normal day-to-day job duties. The information about job duties is provided in the event that the persons normally handling these jobs are unavailable. Below is a description of positions and duties to be accomplished by District personnel in a malaria emergency:

District Manager

Oversee the Emergency Malaria Control program.

Coordinate District activities with Federal, State, and other local agencies.

Assign District personnel to emergency duties.

Environmental Specialist/Public Information

Organize and prepare emergency information for the media, the general public, and the population residing in the emergency control area.

Prepare and release information to the media.

Be available to talk to the public residing in the control area.

Coordinate the door to door information distribution in the control area.

Talk to the media as District spokesperson.

Coordinate media coverage of District personnel and field operations.

Entomologist

To coordinate the monitoring of adult and larval populations upon determination of a local transmission.

To oversee the control program and field operations against the mosquito population.

To coordinate with the Manager, Environmental Specialist and Historian positions.

To assign technicians to assist in field operations in the control area.

To ensure that District policies and safety procedures are followed during the declared emergency.

Outbreak Historian (To be assigned)

To preserve and maintain information specific to the malaria control program during an indigenous outbreak. Information to include inspection reports, news articles, official documents, source maps, treatment records, and other information.

To co-ordinate production of information needed for field operations that can be generated from current computerized records.

Upon completion of the emergency, to prepare the collected information for use in critiquing the program to help improve the Emergency Response Program for any future outbreaks.

Zone Technician / Assisting Technicians

To carry out field monitoring and control operations.

To directly contact the persons living within the control area.

To assist with public information and information gathering as required by circumstances.