Transmission of infection among household contacts of cholera patients in the 1978 outbreak in Perak

In the outbreak of cholera in Perak in 1978, a study on 179 cholera patients (cases) from 8 health districts in the state indicated that those afflicted with the disease were from the rural areas, belonged to the lower socio-economic class and had little or no formal education. Under such conditions, it is expected that personal hygiene may not be satisfactory and person to person contact could play an important role in the transmission of the disease especially among those living in close contact. 34.2 percent of the 164 households of the cholera patients contained injected household contacts. From 1 to 6 infected household contacts per household were found for household size ranging from 2 to 18. Ninetyjive (8.6 percent) of the total 1101 household contacts were injected. Only 8 of these 95 infected household contacts developed clinical symptoms giving a ratio of 1:12 symptomatic to inapparent injections. While most of the contacts probably acquired their infection from the patient who constitutes the index case, the role of the asymptomatic carrier in the transmission ofinjection cannot be underestimated.