1. Provide epidemiologic data to define the extent of, and risk factors for botulism intoxication in ROG.

Botulinum intoxication causes a sever neuroparalytic illness often requiring prolonged mechanical ventilation and expensive antitoxin treatment. The incidence of foodborne botulinum intoxication in ROG has increased seven-fold from about 0.2/100,000 in the early 1980's to about 1.3/100,000/year in the past 4 years, with a peak of 3.5/100,000 in 1994. The current incidence is over 100-fold that of the U.S. Incomplete epidemiologic data, attrition of laboratory diagnostic capacity, and shortages of antitoxin hamper control efforts. Infant botulism has never been reported in ROG; high incidence of foodborne botulism, indicating the presence of C. botulinum in the environment, suggests this is a surveillance failure. Low mortality rates for botulism in ROG, despite strains on the medical system, suggest the predominance of less virulent strains of C. botulinum strains in ROG compared to the US.

Proposed project: we will review the existing surveillance system and available data and revise the system and standardized instruments as necessary, and enhance outbreak-management capacity by emergently investigating botulism outbreaks. We will also design and implement active surveillance for infant botulism in ROG. We will design and execute case-control studies to establish risk factors for foodborne botulism in ROG, and based on the findings of these studies we will design, implement and evaluate a foodborne botulism control program. As foodborne botulinum intoxication is due to consumption of contaminated foods packaged in ways conducive to the anaerobic conditions that favor the growth of C. botulinum, we anticipate that the disease control program will entail studying specific food preparation and storage practices in ROG; devising adaptations to render these practices safer; and implementing and evaluating interventions targeted to groups at risk, utilizing education and low-cost, sustainable interventions. If infant botulism, never reported in ROG, is detected, we will produce an educational program for pediatric caregivers about this conditions. Laboratory diagnosis of botulism is made with a biological assay involving the injection of patient serum or stool culture supernatant into mice and observing symptom development. Determination of toxin type requires a similar challenge to animals, accompanied by injection of protective serum. These assays are time-consuming, and, because of the need to maintain large animal colonies, exceedingly expensive. Commercially produced ELISA kits for diagnosis and toxin-type determination have recently become available; if validated, such kits would significantly decrease the cost and the delay in obtaining laboratory confirmation and toxin typing. We will validate the ELISA kit for clinical use by measuring its sensitivity and specificity against the gold-standard mouse assays using clinical specimens, and re-establish diagnostic capacity in ROG using the most cost-effective methodology.

Botulinum antitoxin is the only therapeutic intervention for botulinum intoxication; studies have shown that it reduces the need for mechanical ventilation or its duration, thereby significantly diminishing the burden of illness. We will refurbish the national antitoxin stock and case-notification-linked-release mechanism in ROG and create a mechanism for resupply in accordance with need.

The variable rates of mortality and ventilator dependence in different regions of the world irrespective of the quality of medical care suggest a spectrum of pathogenicity among strains of C. botulinum, although the question has not been studied formally. The low mortality rates in ROG despite deficiencies of the healthcare system suggest a biological difference of strains between those in ROG and the USA. We will compare toxin types in the laboratory, and clinical presentation in patients, from both countries in order to better understand the variable pathogenicity of microbial strains. Additionally we will perform molecular subtyping by Pulsed-Field Gel Electrophoresis on clinical isolates from ROG and the US to explore correlation of molecular subytpe and pathogenicity.

The information gained from our collaborative research will:

– improve control of botulism in ROG;

Additionally the project will create the basis for further exchange, research and public health action, benefiting the practice of public health in both countries.