July to September 2006

 

WHO’s latest record shows that the Philippines led six countries in South East Asia with the most number of dengue cases from January to October last year with 21,537 cases with 280 deaths.

Bites that kill

kagat lamokEleven year-old Sherilyn Casurian of Morong, Rizal will no longer finish 5th grade.
Playmates and schoolmates will surely pine for her sparkling giggles. Teachers will miss the girl sitting at the corner of the room who often eagerly raises hand for questions asked. And gone is the cheery daughter who wraps her tender arms around Tatay when he comes home from the day’s work.

In another town of the same province, chubby five year-old Mona Manados is sorely missed, too. Her grief-stricken grandmother almost can’t believe it happened.

Last August 11, Sherilyn and Mona succumbed from high fever. Indeed mosquito nets, fumigation, and other government aids arrived too late.

Barely a month later on September 7, the same tragedy claimed three other children—one from Teresa town in Rizal, and two from a Quezon City district.

At the end, warm blood oozed from their cramped bodies’ eyes, noses, and ears. These young shattered lives were the latest death counts from the deadly virus that causes dengue hemorrhagic fever that now wrecks public health mayhem across Southeast Asia.

The Department of Health’s National Epidemiology Center said that 167 mostly children died from 13,468 dengue fever cases registered from January to August this year alone.

The DOH-NEC also reported that the National Capital Region registered the highest number of cases with 4,222 followed by Central Luzon with 1,989 and Central Visayas with 1,752 cases.
Last September 8, the Rizal LGU with the recommendations of DOH’s Provincial Health Office declared a dengue epidemic in Rizal because of extraordinary rise in the number of cases and fatalities – 9 in Rodriguez; 5 each in Teresa and San Mateo; 4 in Morong; 3 in Cardona; and one each in Angono, Antipolo, Tanay, and Taytay.

The World Health Organization’s latest record shows that the Philippines led six countries in South East Asia with the most number of dengue cases from January to October last year with 21,537 cases with 280 deaths. Thailand had 7,200 cases with 12 deaths; Indonesia had 80,000 cases with 800 deaths; Malaysia had 33,203 but no number of deaths reported; Singapore had 14,248 cases with 12 deaths; and Australia with only two reported cases).

Deciphering the Deadly Virus
Dengue fever or its potentially fatal form known as dengue hemorrhagic fever (DHF), is a febrile viral disease that affects countries in tropical and sub-tropical regions where warm temperature and high relative humidity favor the breeding and proliferation of Aedes aegyti mosquitoes, also known as tiger mosquitoes.

Dengue fever is caused by four serologically related virus types i.e., dengue 1, dengue 2, dengue 3, and dengue 4 under the Family Flaviviridae. The disease is transmitted by day-biting female Aedes aegypti mosquitoes that have previously bitten persons and have the virus in their blood stream. These persons may or may not show any sign of illness but are unknowingly ready sources of infection.

Outbreaks resembling the signs and symptoms of dengue disease have been reported throughout medical history. Benjamin Rush coined the term breakbone fever during its first reported case in 1789 due to the victims manifested physical symptoms such as myalgia (muscle pains due to overstretching) and arthralgia (joint pains).

Dengue (pronounced as DENG–gae) is a term derived from the phrase “ki denga pepo”, meaning “cramp-like seizure caused by evil spirit”. The term was an attempt to describe victims of the then still unknown disease during outbreaks in Swahili, East Africa, and in the Caribbean in 1880s.

DHF epidemics were first experienced in SE Asia in the1950s. By 1975, DHF had become a primary cause of death among children in the region. Spanning the 1980s to late 1990s, dengue was the most notorious mosquito-borne viral disease-affecting humans after malaria.
This notoriety led to collaborative efforts of scientists and epidemiologists around the world in understanding dengue’s viral etiology (study of causation) and transmission.

By the latter part of 20th century, dengue’s etiology and transmission by Aedes aegypti mosquito were decoded. However, transmission and maintenance of the virus from the mother mosquito to its offspring through a process known as transovarian transmission (via eggs) has yet to be linked as a possible part of the epidemic cycle.

The Dengue Attack and Life Cycle
The spread of dengue is attributed to the expanding geographic distribution of the four flaviviruses by Aedes aegypti and Aedes albopictus mosquitoes, the WHO explained.

In urban areas like in Metro Manila and some districts of Quezon City, Aedes aegypti is the most predominant species of mosquito vector.

Filipino scientist Nelia P. Salazar, currently a consultant of DOH’s Research Institute for Tropical Medicine said that Aedes aegypti breeds in different ubiquitous water-holding containers such as unused or junk tires, drums, jars, bottles, tree holes, roof gutter, and flower vases among others. She added that unclean urban areas are generally the favorite habitat of these virus carriers although these can also be found in better residential districts, schools, and other public places.

More so, crowding contributes to increased man-vector contact since the mosquitoes prefer to stay in domestic and peridomestic habitats. Humans are the main amplifying hosts of the viruses.

Transmission of this lethal virus actually begins with a dengue-infected person.

The person will have virus circulating in the blood that lasts about five days, a condition that is called viremia. During this viremic period when an uninfected Aedes aegypti mosquito bites and feeds on the blood of an unsuspecting but infected person, ingestion of the blood containing the dengue virus takes place. Within the mosquito’s system, the virus replicates—reproducing and multiplying—and incubates for eight days (extrinsic incubation). When this vector bites a susceptible person, the virus is transmitted through its saliva, Dr. Salazar added.

This agent of death will continue to spread the virus for the rest of its lifetime. According to www.wildlifeinformation.org, Aedes aegypti mosquito survives up to 10 days. But with favorable condition it can survive up to 3 weeks. The website likewise describe this species to be a small, dark mosquito with lyre-shaped silver-white lines on the thorax and white bands on the tarsal segments.

Once the virus enters the victim’s body, the virus settles and replicates in various target organs like lymph nodes (responsible for cleansing human body tissues and associated with the reproduction of white blood cells that fight foreign bodies like bacteria and viruses) or liver (an important organ of digestive system).

Upon release from these organs, the virus spreads through the blood infecting the white blood cells and causing the release of substances that trigger a chain of physiological reactions affecting the capillaries (the smallest blood vessels). The capillary walls become prone to bleeding or hemorrhage in various tissues and organs. Blood platelets and coagulation factors are mobilized by the body to contain the bleeding, hence, the depletion of platelets as one of DHF’s clinical manifestations.

Dengue victim then suffers fever reaching 106oF or 41.11oC with severe headache, joint and muscular pains, and rashes (red spots) lasting a few days.

WHO statistics show that during dengue epidemics, attack rates among those at risk (mostly children 10 years below are observed to be the most susceptible age bracket) are often 40–50% but may reach 80–90%. An estimated 2.5% of the cases will be fatal. Without proper and immediate medical supportive therapy, the rate could reach as high as 20%.

The repression and mitigation of this viral Infection is yet to be accomplished. It will continue to be a threat to human lives.

The Challenge
Despite all these, national agencies and local governments react only when DHF cases reach alarming numbers.

On the other hand, LGUs still seek financial assistance from the National Dengue Control Program for an irregular implementation of dengue control measures concentrating on merely on preventive fogging. But public health experts believe that success of the dengue control program depends on a holistic strategy.

In the Philippines, few laws exist that mandate LGUs to involve themselves in disease control programs such as the Code on Sanitation (1975), Local Government Code (1993), Clean Air Act (1999), Ecological Solid Waste Management (2000), and the Clean Water Act (2004).  In addition, there are administrative orders regarding dengue control activities, and memoranda of agreement with various national agencies regarding the prevention and control of dengue outbreaks. 

But the real first big challenge for government officials, lawmakers, and other stakeholders is to implement these laws and policies firmly and sustain the initiative. STP