Day 7: Epidemiology of Diarrheal Diseases

Source: IK Jamal Osman of Communicable Diseases Control (CDC) Unit, Sik DHO

The CDC in Sik is under the umbrella of the Health Inspectorate and is manned by IK Jamal and a PKA (General Health Assistant).

Diarrheal diseases form the epicenter of the CDC in Sik District. This focus may be surprising to a few as it doesn’t extrapolate to other wealthier states in Malaysia where food and water borne diseases have taken a backseat to other communicable diseases like TB and HIV. The paradox is attributable to the lack of clean water supply (most of the water from Sik’s three dams are channeled to Kota Star and Kuala Muda), sanitation services, migrant population and the general poverty in the district (being the poorest but second largest district in Kedah).

The diarrheal diseases which come under the purview would be Acute Gastroenteritis (AGE), food poisoning, cholera, typhoid, dysentery and Hepatitis A. Fortunately in the previous year the last four were zero in incidence though suspected typhoid (2) and dysentery (10) cases were ruled out. However outbreaks of the first two were there and their investigation closely ties with Outbreak Management (refer to the blogpost by Karyn). There were no diarrheal deaths. Diarrheal diseases strike mostly in institutions like training institutes, schools and hostels.

A typical return for AGE would be the above. They are done on a weekly basis. Most outbreaks occur during school holidays (all the spikes correspond to this) when people hosts feasts. Spike 1 would be the March school holidays, Spike 2 Hari Raya and Spike 3 Hari Raya Haji. The lack of a proper industrial kitchen and cooking in open spaces along with the exposed food volume and unsanitary food handling seem to translate into the above figures. The other occurrences are plainly attributed to improper food storage where food is often cooked 9 hours before serving as in hostels and the Food Supplement Programme.

Though it comes as a surprise that no specific programme is conducted routinely to address the issue of diarrheal diseases and the interventions are based on the causes identified by outbreak investigation and managed by the Health Promotions Unit. Typically food handlers are subjected to a food handling course especially at hostels and schools. The State Health Department is often involved in this. Furthermore AGE monitoring is collated with the similar time frame of previous years i.e. comparing incidences of the same week between a run of 5 years. This gives a better picture of management and control of the problem as well as to highlight the need for newer interventions.

Even so, the indicators used in the 1990 Revised WHO Diarrheal Control Programme are not monitored here. The difficulty in monitoring these indicators and lack of deaths seem to be the reason though other indicators of food quality control (premises) are used. It is unique to note while in global guidelines the identification of the organism is not a priority, here it is otherwise where stool samples (if obtainable) are cultured and interventions are specific to the organism. An example would be proper food storage in case of Bacillus cereus.

Unfortunately managing diarrheal diseases remain a challenge. The average number of AGE cases in Kedah have exceeded the maximum average and is identified in the Health Action Plan of 2011. The difficult in obtaining stool samples as well as the attitude of the public superimpose on inherent factors. These stem on socioeconomic reasons as most cases are institutional and a reporting-co-investigation could possibly bring disrepute and loss of tenders.

Hence, future intervention should tie in a continuous programme to address the inherent problems (collaboration with BAKAS to improve water and sanitation) and food handling practices to institutions with regular auditing.

RavivarmaRao