City hospitals and clinics recorded 2,576 cases of dengue from January to June this year, a more than fourfold increase compared to the same timeframe in 2016. Of the total, one death had been recorded.
Most of the infected had already fully recovered, except for an estimated 270 that are still under treatment at area hospitals and clinics, said the health officials.
The spike in dengue cases were described as very alarming by Nguyen Nhat Cam, head of the municipal Hanoi Centre for Preventive Medicine. He also expected the number to rise further.
Dengue is a viral infection transmitted by the bite of an infected mosquito. There are four closely related but antigenically different serotypes of the virus that can cause dengue (DEN1, DEN 2, DEN 3, DEN 4).
Dengue has a wide spectrum of infection outcome (asymptomatic to symptomatic). Symptomatic illness can vary from dengue fever (DF) to the more serious dengue haemorrhagic fever (DHF).
Dengue Fever (DF) is marked by an onset of sudden high fever, severe headache, pain behind the eyes, and pain in muscles and joints. Some may also have a rash and varying degree of bleeding from various parts of the body (including nose, mouth and gums or skin bruising).
Dengue Haemorrhagic Fever (DHF) is a more severe form, seen only in a small proportion of those infected. DHF is a stereotypic illness characterized by three phases; febrile phase with high continuous fever usually lasting for less than seven days; critical phase (plasma leaking) lasting one-two days usually apparent when fever comes down, leading to shock if not detected and treated early; convalescence phase lasting two-five days with improvement of appetite, bradycardia (slow heart rate), convalescent rash (white patches in red background), often accompanied by generalized itching (more intense in palms and soles), and diuresis (increase urine output).
There is no specific medication for treatment of a dengue infection, medical personnel can only treat the symptoms. A better option is to eradicate the mosquitoes transmitting the disease, said Mr Hanh.
At present, the prevention campaign faces some difficulties as local people feel reluctant to cooperate with authorities in tackling the problem and spray chemicals to kill the mosquitoes that carry the potentially deadly disease.