CHOLERA OUTBREAK IN HONDAT, KIEN GIANG PROVINCE IN 2002 AND ITS RELATIONSHIP TO THE CLIMATE CHANGE

Le van Tuan(*), Nguyen Manh Cuong (**)

(*) HCM Pasteur institute

(**) Kien Giang Provincial Preventive Medicine Center

In the year 2002, after the Cholera positive case of Rach Gia town, Kien giang province, the index case of Cholera in Hon Dat district was detected on 23rd April 2002. Ten days later cholera really broke out and it’s stretched up to mid- June. Seven out of eight commune were affected by 16 cases positive, 111 cases cholera suspected (diarrhea like-cholera) and 422 cases acute diarrhea. Attack Rate (AR) was 0.01 and the AR highest was 0.026% at Nam Thai Son commune. Case Fatality Rate (CFR) = 0, no death case was reported. Respectively, the proportion age distribution of the out break was 25%, 18.75%, 31.25% and 25% for ages <5, 5-9, 10-15 and 16-49. The distribution cases by gender were 1:1 (8 cases: 8 cases). The proportion of positive samples was 14,29% account for 16 cases positive out of 112 stool samples be collected from the suspected patients. Vibrio cholera O1 of the Eltor biotype, Inaba serotype was implicated relative to this out break causation and was confirm by the Microbiological Laboratory of the HCM Pasteur institute. Anti-microbial susceptibility of V. cholera O1 isolates was sensitive to the most of common antibiotic such as Nalidixic Acid, Tetracycline, Chloramphenicol, Bactrim, Cipro, and Doxycycline and also showed the effectiveness in clinical treatment. According data of Meteorology in March 2002, the pre-epidemic period, the average of air temperature at Hon Dat was 2.4°C higher than average of the last 3 years (1998 -2001), and also comparing to the average 3 years (1998-2001) the mean rainfall (mm) at Hon Dat in March - April 2002 reduced over 50%. In addition, acute diarrhea cases exceeded the threshold of average 5 years 1.56 folds. Therefore the relationship between climate change and outbreak cholera epidemic relate potentially.

Cholera outbreak re-emerging after 20 years in Hon Dat, V cholera O1 serotype Inaba positive cases was sporadic, but spread over 90% this area. Based on the regular surveillance system of acute diarrhea this epidemic was detected promptly. The strict measures recommended by WHO to control such outbreak were taken immediately by health staffs in collaboration with the local authorities. Therefore, after 20 days the epidemic was under control effectively. In order to have a sensitive epidemic early warning system, beside the regular surveillance, a deeper study on correlation between climate change and cholera outbreak should be carried out in the future.