Haff disease outbreak investigation - Amazonas, Northern region of Brazil, 2021
- Other
- Environmental Health (Including Water & Sanitation)
- One Health
- Toxicology
Background
Between August-October/2021, in the Northern region of Brazil, an increase in cases of Haff disease, a rare syndrome caused by an unknown toxin, responsible for a rhabdomyolysis condition in 24 hours after fish ingestion was observed. An epidemiological investigation was conducted to identify risk factors associated with the illness.
Methods
Case-control study (1:1.02) conducted between August 20th and October 16th 2021, in three municipalities of the state of Amazonas, Brazil. Cases were defined as individuals with sudden onset muscle changes and elevated serum creatine phosphokinase (at least five times the upper limit of the reference value). Controls: individuals who ingested the same fish as the case, but did not get sick. A semi-structured questionnaire and chart analysis were used as data sources. Adjusted odds ratios (aOR) and confidence intervals were calculated using multivariate logistic regression.
Results
Of the 83 people who shared fish, 41 cases and 42 controls were identified. Most were male (n=47;56.6%), 40 to 59 years old (n=27;32.5%), brown (n=64,77.1%), urban and periurban residents (n=54;65.1%). The most consumed fish was Tambaqui (Colossoma macropomum) and all were free-living. The attack rate was 49.4%. Statistical differences were observed for comorbidities (OR=3.11; 95%CI:1.05-9.14); daily fish intake (OR=2.71; 95%CI:1.02-7.13); amount of fish eaten (OR=4.17;95%CI:1.63-10.70); fish intake with garnish (OR=2.49; 95%CI:1.01-6.13) and fish head consumption (OR=6.05; 95%CI:1.97-18.60). After adjustment only fish head consumption (aOR=5.36; 95%CI:1.65-17.32) and the amount of fish eaten (aOR=3.41; 95%CI:1.25-9.25) remained associated.
Conclusion
This study provides information to understand the epidemiology of Haff's disease and generates evidence for future investigations. The risk factors associated with the outcome may indicate a dose-response relationship regarding the ingestion of contaminated fish. It was recommended to collect biochemical samples in a timely manner for toxin identification and to develop research on specific part of the fish.
Between August-October/2021, in the Northern region of Brazil, an increase in cases of Haff disease, a rare syndrome caused by an unknown toxin, responsible for a rhabdomyolysis condition in 24 hours after fish ingestion was observed. An epidemiological investigation was conducted to identify risk factors associated with the illness.
Methods
Case-control study (1:1.02) conducted between August 20th and October 16th 2021, in three municipalities of the state of Amazonas, Brazil. Cases were defined as individuals with sudden onset muscle changes and elevated serum creatine phosphokinase (at least five times the upper limit of the reference value). Controls: individuals who ingested the same fish as the case, but did not get sick. A semi-structured questionnaire and chart analysis were used as data sources. Adjusted odds ratios (aOR) and confidence intervals were calculated using multivariate logistic regression.
Results
Of the 83 people who shared fish, 41 cases and 42 controls were identified. Most were male (n=47;56.6%), 40 to 59 years old (n=27;32.5%), brown (n=64,77.1%), urban and periurban residents (n=54;65.1%). The most consumed fish was Tambaqui (Colossoma macropomum) and all were free-living. The attack rate was 49.4%. Statistical differences were observed for comorbidities (OR=3.11; 95%CI:1.05-9.14); daily fish intake (OR=2.71; 95%CI:1.02-7.13); amount of fish eaten (OR=4.17;95%CI:1.63-10.70); fish intake with garnish (OR=2.49; 95%CI:1.01-6.13) and fish head consumption (OR=6.05; 95%CI:1.97-18.60). After adjustment only fish head consumption (aOR=5.36; 95%CI:1.65-17.32) and the amount of fish eaten (aOR=3.41; 95%CI:1.25-9.25) remained associated.
Conclusion
This study provides information to understand the epidemiology of Haff's disease and generates evidence for future investigations. The risk factors associated with the outcome may indicate a dose-response relationship regarding the ingestion of contaminated fish. It was recommended to collect biochemical samples in a timely manner for toxin identification and to develop research on specific part of the fish.