Case report universally required by International Health Regulations
RATIONALE FOR SURVEILLANCE
Disease endemic in many countries and often has epidemic potential. Plague is transmitted to humans through flea bites or direct exposure to respiratory droplets or infected animal tissues. Surveillance of human and animal disease is important to predict and detect epidemics and to monitor control measures.
Case report universally required by International Health Regulations.
RECOMMENDED CASE DEFINITION
Disease characterized by rapid onset of fever, chills, headache, severe malaise, prostration, with
• bubonic form: extreme painful swelling of lymph nodes (buboes)
• pneumonic form: cough with blood-stained sputum, chest pain, difficult breathing
Laboratory criteria for diagnosis
Note: Both forms can progress to a septicaemic form with toxaemia: sepsis without evident buboes rarely occurs.
• Isolation of Yersinia pestis in cultures from buboes, blood, CSF or sputum or
• Passive haemagglutination (PHA) test, demonstrating an at least fourfold change in antibody titre, specific for F1 antigen of Y. pestis, as determined by the haemagglutination inhibition test (HI) in paired sera.
Suspected: A case compatible with the clinical description May or may not be supported by laboratory finding of Gram stain negative bipolar coccobaccili in clinical material (bubo aspirate, sputum, tissue, blood).
Probable: A suspected case with
• Positive direct fluorescent antibody (FA) test for Y. pestis in clinical specimen or
• Passive haemagglutination test, with antibody titre of at least 1:10, specific for the F1 antigen of Y. pestis as determined by the haemagglutination inhibition test (HI) or
• Epidemiological link with a confirmed case.
Confirmed: A suspected or probable case that is laboratory-confirmed.
RECOMMENDED TYPES OF SURVEILLANCE
In all situations: Immediate case-based reporting of suspected cases from peripheral level to intermediate and central level. Laboratory-based reporting of all confirmed cases required in all situations.
During an outbreak: Intensified surveillance: active case-finding and contact-tracing should be undertaken in order that treatment start for cases and contacts; targeting environmental measures; community education. A daily report of the number of cases and contacts as well as their treatment status and vital status must be produced. A weekly report must summarize the outbreak situation, the control measures taken, and those planned to interrupt the outbreak.
International: Mandatory reporting of all suspected and confirmed cases to WHO within 24 hours.
RECOMMENDED MINIMUM DATA ELEMENTS
Case-based data at peripheral level for investigation and reporting
• Case classification (suspected/probable/confirmed), unique identifier, name, geographical information, age, sex, clinical syndrome, history of contact with rodents, presence of flea bites, household or face-to-face contacts for previous seven days, names and geographical location of contacts
Case-based data at central and regional level
• Case classification (suspected/probable/confirmed)
• Unique identifier, age, sex, geographical area, number of contacts identified, number of contacts treated
RECOMMENDED DATA ANALYSES, PRESENTATION, REPORTS
Cases by week/month, geographical area, age, sex.
PRINCIPAL USES OF DATA FOR DECISION-MAKING
• Detect trends in sporadic and endemic disease patterns
• Identify high risk areas
• Give early warning of outbreak
• Detect clusters of cases and outbreaks
• Confirm the impact of control measures and the end of an outbreak
• Periodical surveys of rodent populations and of their fleas, and monitoring of plague activity in these populations; this alerts public health authorities to increased human plague risks, thus allowing prevention and control measures to be implemented before human cases occur
• Serological surveillance of wild carnivore and outdoor-ranging dog and cat populations is recommended in zones surrounding endemic ones
• Ports close to endemic areas should be placed under surveillance and require periodic sanitation to prevent increases in rodent populations.
Countries with endemic areas must have a risk assessment policy for every new development work that could affect local ecology (e.g., roads, dams, agriculture)
See Regional Communicable Disease contacts on section "Communicable disease contacts in Regional Offices".
Headquarters: 20 Avenue Appia, CH-1211 Geneva 27, Switzerland
Communicable Diseases Surveillance and Response (CSR)
E-mail: email@example.com / firstname.lastname@example.org
Tel: (41 22) 791 2656/2850/2111
Fax: (41 22) 791 4878/0746 attn CSR