Geographically Isolated and Depressed Area(GIDA) Malaria Outbreak within the City -̶ Southern Philippines, 2010

Background: On July 6, 2010, the National Epidemiology Center received a report of increasing malaria cases in a remote village in Davao City, accessible only by an 8-hour helicopter ride. There were no reported case since 2005. An FETP team was sent to conduct an epidemiological investigation to verify the outbreak, identify the risk factors, and recommend control and preventive measures.

Methods: An unmatched case-control study was done. Cases were village residents who got sick and were positive for malarial parasites on microscopy from May 7 to July 19, 2010. Controls were well residents of the village who were malarial parasite negative on microscopy. Entomological and ocular surveys were done.

Results: There were 60 cases and 81 controls. Age of cases ranged from 1-78 years (median 11). Most (47%) affected was the 1-10 years age-group. Thirty-six (60%) were female. One died (CFR=1.7%). Blood smear showed Plasmodium falciparum 55 (92%) Plasmodium vivax 3 (5%) and mixed infection 2 (3%). Carabao Bait Trap showed presence of Anopheles flavirostris and Anopheles maculatus, Univariate analysis showed that living in unscreened houses (OR=20.92, 95%CI=8.14-55.39, p= 0.000), spending time outdoors at night (OR=7.78, 95%CI=3.22-19.15, p=0.000), sleeping outdoors (OR=6.36, 95%CI=2.64-15.62, p=0.002), taking a bath in makeshift bathroom (OR=5.20, 95%CI=1.23-25.18, p=0.008) and bathing in the river (OR=12.65 95%CI=5.27-31.02, p= 0.000) were risk factors.

Conclusion: There was a malaria outbreak in Gumitan, brought about by the presence of malaria vectors, suitable breeding sites, and breakdown in health services delivery. Malaria surveillance system was re-established and strengthened. The tribesmen' elders initiated stream-clearing of breeding areas near the creek. Insecticide-treated nets were distributed. Indoor residual sprayings were done. 

Author (s): 

Melanie M. del Prado, N. Jalani, M. Mapue II, J. Lopez, E. Tayag

Presenter (s): 
del Prado
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