The monthly average ovitrap index rose to 13% in July from 11% in June, the Food & Environmental Hygiene Department said today.

Six districts recorded readings at or above the alert zone of 20%, including Diamond Hill (25.9%), Tsim Sha Tsui (24.1%), Sheung Shui (22.2%), Tung Chung (22.2%), Ma On Shan (20.4%) and Pok Fu Lam (20%).