We had hoped to have better information about the possible cluster of bird flu cases in remote West Java, but the situation remains murky and unresolved. Nothing especially reassuring has yet happened to ease the discomfort of health authorities regarding whatever is happening there, at any rate. Reporting by The Jakarta Post is typical:
The new patient, a five-year-old boy identified as R, is a resident of Rancamareme hamlet and the brother of a young girl also identified as R, who died two weeks ago after showing bird flu symptoms. No blood test was conducted on the girl to confirm that she had died of the disease.
Head of the West Java Health Office, Yudi Prayudha, said there were a total of 10 patients from five hamlets in Cikelet and Cigadog villages, located some 130 kilometers south of Garut city who had shown symptoms of bird flu. (The Jakarta Post)
Blood samples of about 40 contacts were said to have been obtained (for what purpose, it isn’t clear, since evidence of H5N1 antibodies would not be epxected to appear so quickly). Several deceased cases were originally diagnosed as “typhoid” and no testing was done. There is now some question as to whether they were bird flu cases. Two other children were said to have negative PCR tests for H5N1 (we reported them in an Update to our previous post) but the tests are being repeated. This suggests there is reason to doubt the negative tests.
Not to worry, though. The ever unreliable Minister of Health, Siti Fadilah Supari assures us this does not represent a cluster. Her reasoning is given by a subordinate:
Meanwhile, Director General for Disease Control and Sanitation in the ministry I. Nyoman Kandun said that the Garut cases could not be categorized as a cluster case because it happened in separate places and was not simultaneous.
“It happened on different days and are far from each other,” Kandun said on Saturday. (Xinhua)
This is either deliberately misleading or Nyoman Kandun doesn’t understand the concept of clusters. Cases closer together in space or time (or both) are of interest only for what they can tell us about what is going on about disease transmission and occurrence. If many people are infected within a few days by a common source in a small geographic area (a time-space cluster) it could indicate a common source (e.g., poultry) infected with a virus that is passing more easily to humans. On the other hand, people falling ill a week or so apart might indicate person to person transmission if they have had direct or indirect contact with each other. Communicable disease travels on social networks.
Different days or different locations are not criteria that rule clusters in or out. Only good epidemiological investigative work can do that. Indonesia has been conspicuously bad at that kind of follow-up.