Dengue menace lurking in the wings

Dengue is an arbovirus disease caused by any one of four closely related viruses that do not provide cross-protective immunity; a person can be infected as many as four times, once with each serotype. Dengue viruses are transmitted from person to person by the Aedes aegypti mosquito in the domestic environment. Periodic epidemics have occurred in the Western Hemisphere for over 200 years. In the past 20 years, however, dengue transmission and frequency of epidemics have increased greatly in most tropical countries of the American, African and Asian region. As this has occurred, dengue hemorrhagic fever (DHF) has emerged and produced epidemics in many countries of the region.


  • 1. History of Dengue
  • 2.Dengue spreading in Dhaka, Bangladesh, Kolkatta,  India
  • 3.Aedes aegypti mosquito
  • 4. Symtoms of Dengue Fever
  • 5. Treatment of Dengue Fever
  • 6. How to avoid Dengue
  • 7. Death Trap for Diseases in Bangladesh
  • 8. Frequently Asked Questions
  • 9. Future Outlook
  • Dengue strikes in city

    dengue patientThe number of patients diagnosed with dengue is increasing at an alarming rate which the Dhaka City Corporation (DCC) fears might turn into an epidemic. A survey report of the DCC dengue control section revealed that around 150 government hospitals and private clinics in the capital are presently treating at least 230 dengue patients. Around 408 patients were diagnosed with dengue in the last 22 days in the capital. .
    With the death of a dengue patient in the city, and more than 60 patients having been admitted to different city hospitals, it is obvious that the disease is spreading. It took a heavy toll of human lives six years ago when neither the city fathers nor the doctors were aware of how to contain or manage it. But things improved in the following years with people in general becoming a lot more conscious about the problem. Drive against the aedes mosquito gained momentum and it appeared that the campaign against dengue was making progress. But after all these years it seems the preparedness to face the menace has slackened. There is no visible anti-mosquito drive and people are apparently oblivious of the measures like not allowing water logging in flower vases or any empty container that they have to adopt to stop breeding of aedes mosquito.

    Most hospitals are not really well equipped to manage the disease which can turn fatal if timely medical support is not provided to the patients. So the fight against dengue which will ensure that it doesn't assume menacing proportions must be conducted at three levels. The City Corporation has to launch a vigorous anti-mosquito drive, targeting the areas known as breeding grounds of aedes mosquito. Sadly, we witnessed in the past that this important task was never performed with due urgency. Then there is the need for awareness-building which proved to be effective in the past. Both the electronic and print media have a role to play in his respect.

    Finally, the hospitals should open dengue units to handle the situation, lest it turned worse. But there is, of course, no reason to be panicked; what we need is sound planning, better sanitation and prompt delivery of medical services in case of affliction on the basis of which the situation can be tackled. It is obvious that dengue visits us almost annually. The planners should concentrate on how this painful malady can be eradicated, and for the time-being steps will have to be taken to prevent it from spreading. Source: The Daily Star, July 09, 2006.

    1.History of Dengue

    The first reported epidemics of dengue fever occurred in 1779-1780 in Asia, Africa, and North America; the near simultaneous occurrence of outbreaks on three continents indicates that these viruses and their mosquito vector have had a worldwide distribution in the tropics for more than 200 years. During most of this time, dengue fever was considered a benign, nonfatal disease of visitors to the tropics. Generally, there were long intervals (10-40 years) between major epidemics, mainly because the viruses and their mosquito vector could only be transported between population centers by sailing vessels.

    A global pandemic of dengue began in Southeast Asia after World War II and has intensified during the last 15 years. Epidemics caused by multiple serotypes (hyperendemicity) are more frequent, the geographic distribution of dengue viruses and their mosquito vectors has expanded, and DHF has emerged in the Pacific region and the Americas. In Southeast Asia, epidemic DHF first appeared in the 1950s, but by 1975 it had become a leading cause of hospitalization and death among children in many countries in that region

    In 1997, dengue is the most important mosquito-borne viral disease affecting humans; its global distribution is comparable to that of malaria, and an estimated 2.5 billion people live in areas at risk for epidemic transmission (Figure 3). Each year, tens of millions of cases of dengue fever occur and, depending on the year, up to hundreds of thousands of cases of DHF. The case-fatality rate of DHF in most countries is about 5%; most fatal cases are among children and young adults.

    The reasons for this dramatic global emergence of dengue/DHF as a major public health problem are complex and not well understood. However, several important factors can be identified. First, effective mosquito control is virtually nonexistent in most dengue-endemic countries. Considerable emphasis for the past 20 years has been placed on ultra-low-volume insecticide space sprays for adult mosquito control, a relatively ineffective approach for controlling Ae. aegypti

    Second, major global demographic changes have occurred, the most important of which have been uncontrolled urbanization and concurrent population growth. These demographic changes have resulted in substandard housing and inadequate water, sewer, and waste management systems, all of which increase Ae. aegypti population densities and facilitate transmission of Ae. aegypti-borne disease

    Third, increased travel by airplane provides the ideal mechanism for transporting dengue viruses between population centers of the tropics, resulting in a constant exchange of dengue viruses and other pathogens.

    Lastly, in most countries the public health infrastructure has deteriorated. Limited financial and human resources and competing priorities have resulted in a "crisis mentality" with emphasis on implementing so-called emergency control methods in response to epidemics rather than on developing programs to prevent epidemic transmission. This approach has been particularly detrimental to dengue control because, in most countries, surveillance is (just as in the U.S.) very inadequate; the system to detect increased transmission normally relies on reports by local physicians who often do not consider dengue in their differential diagnoses.

    As a result, an epidemic has often reached or passed transmission before it is detected.

    Outbreaks of dengue fever follow regular cycles

    Outbreaks of dengue fever, the potentially fatal mosquito-borne disease that affects millions of lives each year, appear to follow predictable cycles, an insight that should help combat the virus, researchers say. American and Thai researchers tracked the location of 850,000 cases of dengue haemhorragic fever (DHF), the severest form of the disease, that occurred in 72 provinces of Thailand between 1983 and 1997.

    The epidemics unfolded in three-year cycles that initiated in Bangkok and spread out like a wave, moving across the country at the average rate of 148 kilometres (95 miles) a month, they found. Previous research has already established an array of factors that determine when DHF outbreaks can erupt. These include environmental and climatic factors such as temperature and humidity, the proximity of a human host and available breeding grounds for the Aedes aegypti mosquito that carries the virus, as well as the type of virus itself.

    The researchers believe that Bangkok''s preponderant size and its status as Thailand''s commercial hub could be a previously unremarked additional factor - the virus'' spread could be helped by people''s movement when the conditions are right. Between 50 and 100 million people around the world catch dengue fever each year, of which 200,000-500,000 cases are DHF, which is life-threatening. Big outbreaks of DHF can often overwhelm health systems and inflict a crippling blow to economic life. The study, led by Donald Burke of the Johns Hopkins Bloomberg School of Public Health in Baltimore, Maryland, was published Thursday in the British weekly Nature. In another valuable piece of dengue research, likewise published in Nature, US researchers shed light on how the virus is able to lock on to host cells, the first step towards penetrating them.

    The process is similar to that used by the influenza virus and human immunodeficiency virus (HIV), which have "fusion proteins" on the fatty membranes that encase them. To reproduce, these "enveloped" viruses fuse their membrane coat with that of the cell, locking onto a gateway, called a receptor, on its surface. They then spew genetic material into the cell, effectively hijacking it.

    The new study, led by Stephen Harrison of the Children''s Hospital and Harvard Medical School, reports on a structure of one of the fusion proteins in dengue and reveals aspects of the fusion process. This - in the future - could lead to new drugs to block the viral entry, they hope (Agence France Presse, The Financial Express, January 22, 2004).

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    2.Dengue spreading in Dhaka, Bangladesh, Kolkatta, W. Bengal, India

    Dengue reappears, August 2005

    Dengue fever, which has claimed lives of a considerable number of people over the past several years, has come back. It causes worries as dwellers of the capital city are being afflicted with the disease. The Independent reported yesterday that the number of patients getting admitted to the city's hospitals and clinics is increasing progressively. The news item adds that the dengue situation is worsening day by day in Dhaka and other parts of the country. Dengue Control Room record says that 10 patients have been undergoing treatment at different government hospitals; but unofficial figure is higher.

    The solution lies in vigorous anti-mosquito drives, but in the past the Mayor of Dhaka spoke of insufficient resources at his disposal to carry on such effort adding that many outlying areas of the city remain outside the DCC's jurisdiction. Both these issues need to be urgently addressed by the Ministry of Local Government to make DCC a more effective body. Disappointed by the apathy of the ministry, the Mayor even once went to the extent of suggesting -- without any justification, of course -- that the DCC should become part of the bureaucracy of the Prime Minister's Office, surrendering its prestigious status as the country's topmost local government institution. Such dismay has been ventilated by all mayors and administrators but with little success because of the refusal of the controlling ministry to allow any more autonomy to the country's system of local government.

    The reason why the fever is dreaded much is that a type of dengue is fatal. It is a matter of real concern that no vaccine for dengue is available yet, and there is no specific treatment for this killer disease. Hence Dengue Fever (DF) or Dengue Haemorragic Fever (DHF) control is primarily dependent on the control of Aedes Aegypti mosquito which breeds in small collection of clean water in residential houses. However vexatious the conflict between the mayor and his controlling ministry may be, the people in a frightful life-and-death situation would be left with little appetite to enjoy such a fun. They would like all the agencies of DCC and of the government to gear up for action to control dengue and other diseases that may erupt in an epidemic form. Immediate action by the authorities brooks no delay (Independent,August 18, 2005).

    Dengue is spreading in the city at an alarming rate, bringing increasing number of people to hospitals with infection. Official sources yesterday said since mid-June 427 dengue patients, including those coming from outside, have been hospitalised in the city, with 128 under treatment at the moment. According to health directorate records, dengue seized 486 people and killed 10 last year, 6,132 and 58 in 2002, 2,430 and 44 in 2001, and 5,551 and 93 in 2000. But Dhaka City Corporation (DCC) pays little or no attention to the scare, keeping virtually mum on mosquito control issue, experts alleged and pointed to the need for a survey on Aedes mosquito population which the mayor, however, calls unessential. (Daily Star, July 4, 2004).

    Dengue, a mosquito-borne brain fever, is sweeping through south Kolkata, the capital of Indian state West Bengal, neighbourhoods besides the suburbs. The death toll from dengue fever has already risen to 13 in the city and on the outskirts on Thursday.

    Hundreds of Bangladeshi used to travel the affected areas everyday. Therefore, the health offices in Bangladesh advised its citizens to take precaution in this regard while travelling Kolkata and its outskirts. However, the West Bengal health minister, Suryakanta Misra, said the situation was under control. Health experts said more than 100 people suffering from fever are showing symptoms of dengue, which often causes death when the fever reaches the brain. Sources said Lake Gardens, Golf Green, Dhakuria, Jodhpur Park, Tollygunge, Santoshpur and Jadavpur of Kolkata are among the worst affected areas (New Age, August 26, 2995).

    Deluge fallout turns dengue full-blown- August 2004

    Dengue turns full-blown in Dhaka, infecting 66 people a day on average in the wake of floodwater run-off as the deluge released a disease epidemic. As many as 1,540 people have been taken ill with dengue this monsoon dengue-breeding season, according to the health directorate control room. Apart from the vector of dengue, Aedes mosquito, Culex mosquitoes have also increased because of stagnated floodwaters, turning the city into a virtual mosquito-breeding ground.

    "Mosquitoes bite not only at night, but in the day as well," said Mazharul Islam, a Basabo resident, adding: "We can't go out because of filthy floodwaters, nor can we stay at home because of the mosquito menace." Like Islam, many residents of Khilgaon, Sabujbagh, Madartek, Badda, Gulshan, Banani and Dhanmondi accused the DCC of inactivity. Last week, a ward commissioner in Demra, also blamed the corporation in public for the mosquito menace.

    The deadly dengue has landed at least 300 people in the city's hospitals and clinics for treatment and killed nine since July 15. Two-year-old Dyuti diagnosed with dengue at Lab Aid was crying in pain when she was taken to the diagnostic centre for blood test for the fifth time. Her parents were also crying and asked the lab assistant not to inject her again -- a common scene at diagnostic centres.

    She (Dyuti) cannot stand it," said Dyuti's mother Bilkis, tears rolling down her cheeks.
    Ibne Sina, another diagnostic centre, found 1,073 people infected with acute dengue from early July to August 4, Lab Aid diagnosed 1,309, Popular Diagnostic Centre 1,114 and Medinova 986.

    Despite the alarming situation, the DCC remains silent on mosquito control, experts alleged, pointing to the need for a survey on aedes population.  (Sultana Rahman, August 8, 2004)

    New strain of dengue virus

    A new form of dengue virus may have either evolved in or been imported to Bangladesh, warn doctors. Three of four known types of dengue virus have been detected so far in the country but symptoms of some recent dengue patients have experts suspicious of the fourth type or a new genetically mutated virus. The virus is very to difficult diagnose, as patients do not complain of "bone-breaking pain" or pain around eyeballs, typical symptom of dengue fever, although potency to develop complications remains the same.

    As a result, patients and doctors in most cases take infection of the dengue virus for flu, said experts. Mahbuba Chowdhury, a 70-year-old woman, died of dengue in Samorita Hospital a few days ago. Her daughter Dr Ferdous Ara Chowdhury, an associate professor of microbiology, did not even suspect that her mother had been infected by dengue. A doctor related to the family said Mahbuba had fever for only a day and her body temperature was below 101 degrees Fahrenheit. "Neither body ache nor any other symptoms of dengue fever were there."

    Mahbuba went into shock two days after the fever had subsided. Doctors initially suspected that she might have had a heart attack but subsequent investigations proved them wrong. Her routine blood count incidentally showed very low platelet count and doctors found internal haemorrhage while doing tracheotomy, a surgical procedure to create an opening in the trachea (windpipe) so that one can breathe. Doctors eventually confirmed dengue as the cause of her death.

    Professor FM Siddiqui of medicine at the Dhaka Medical College said many dengue patients this year have concurrently been afflicted with diarrhoea. "Diarrhoea and other symptoms the dengue patients have displayed are unusual. A new strain of dengue virus may have developed." Dr AKM Shahidul Islam, an associate professor of microbiology at the Sir Salimullah Medical College, said many dengue patients displayed flu-like symptoms. "It has made diagnosis more difficult for clinicians and patients. Although the degree of fever is low, such complications as haemorrhage and shock remains the same."

    The Type 4 dengue virus or a new form of virus may be responsible but it is not possible to confirm without virus detection under microscope. Professor Abul Kalam Azad, director of the Institute of Epidemiology, Disease Control and Research, says he does not know anything about change in symptoms of dengue as no physician has so far reported it to the institute. "Not many blood specimens of dengue infected patients are coming to the IEDCR laboratory nowadays but I will look into the matter." The institute is, however, not equipped to detect virus at the molecular level (K. K. Das, september 25, 2004).

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    3.Aedes aegypti mosquito

    Experts say intermittent but lingering rain is causing Dengue fever because that is instrumental in proliferating the Aedes mosquito. Dengue fever occurs due to the bite of Aedes mosquitoes. Dengue hence spreads during the rainy season as Aedes mosquito proliferates during this season.These mosquitoes gather around stagnant water. Hence, it is common for a surge in reports of dengue infections just after the monsoon. The mosquito lays eggs on the clear stagnant water logged in the flower vessel, water jar, tub, freeze, unused basin, green coconut's shell and the like. People should be made aware of this. As the monsoon is running the Ministry of Health and the Dhaka City Corporation may make use of the media to raise awareness among people which will help them to become alert, and inspire them to destroy the breeding.

    World Health Organisation (WHO) statistics says that about 2.5 billion people around the globe are at risk from four kinds of dengue viruses. These are Den-1, Den-2, Den-3 & Den-4. Of these, the last two are dangerous; they cause Hemorrhagic Dengue. Traditional dengue fever is not very serious as is thought of. It is curable in seven days.

    The mosquito Aedes aegypti has a world-wide distribution in tropical and semitropical zones. It is important because it is a vector for yellow fever and dengu fever. The distribution of the mosquito is sharply limited by latitude and temperature
  • 10° C is lethal to adults and larvae
  • The egg stage is more resistant to low temperatures and in some areas, Aedes aegypti can overwinter as eggs.
  • In the temperate zone eggs can overwinter but relatively low summer temperatures cause the adults to develop slowly and females die before they reach maturity and lay eggs.
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    4. Symtoms of Dengue Fever

    The symptoms of the traditional dengue fever are high fever, vomiting, stomach pain and acute headache, pain at joint of bones, waist and rear side of the eyes. The symptoms of Hemorrhagic dengue fever are like those of traditional Dengue but there is bleeding from the gum and the nose; congealed blood and reddish circles are seen under the skin and in the eyes. Black blood goes with the excrement and internal bleeding occurs often causing death of the patient. Careful people may take lesson to manage the disease out of these information

    Two-stage fever: having a fever for 3 days, becoming normal for one day and the temperature going up again

    There are two types of dengue:

  • Classical Dengue Fever: Infected person complains of high fever, intense headache, muscle and joint pain, bitter taste, insomnia, anorexia, retro orbital pain and photophobia. Instances of it proving fatal are extremely low.
  • Dengue Haemorrhagic Fever or Dengue Shock Syndrome: Infected person complains of high fever, bleeding from nose, gums, ears, skin. May go into shock due to blood loss.

    Clinical Diagnosis

    Classic dengue fever is characterized by acute onset of high fever, frontal headache, retro-orbital pain, myalgias, arthralgias, nausea, vomiting, and often a maculopapular rash. In addition, many patients may notice a change in taste sensation

    Symptoms tend to be milder in children than in adults, and the illness may be clinically indistinguishable from influenza, measles, or rubella. The disease manifestations can range in intensity from inapparent illness to the symptoms described. The acute phase of up to 1 week is followed by a 1- to 2-week period of convalescence which is characterized by weakness, malaise, and anorexia. Treatment emphasizes relief of these symptoms.

    Dengue Hemorrhagic Fever/Dengue Shock Syndrome

    During the first few days of illness, dengue hemorrhagic fever (DHF), a severe and sometimes fatal form of dengue, may resemble classic dengue or other viral syndromes. Patients with DHF may have fever lasting 2 to 7 days and a variety of nonspecific signs and symptoms. At about the time the fever begins to subside, the patient may become restless or lethargic, show signs of circulatory failure, and experience hemorrhagic manifestations. The most common of these manifestations are skin hemorrhages such as petechiae, purpura, or ecchymoses, but may also include epistaxis, bleeding gums, hematemesis, and melena. DHF patients develop thrombocytopenia and hemoconcentration, the latter as a result of the leakage of plasma from the vascular compartment.

    The condition of these patients may rapidly evolve into dengue shock syndrome (DSS), which, if not immediately corrected, can lead to profound shock and death. Advance warning signs of DSS include severe abdominal pain, protracted vomiting, marked change in temperature (from fever to hypothermia), or change in mental status (irritability or obtundation). Early signs of DSS include restlessness, cold clammy skin, rapid weak pulse, and narrowing of pulse pressure and/or hypotension. Fatality rates among those with DSS may be as high as 44%. DHF/DSS can occur in children and adults.

    Dengue is also known as Break Bone Fever. If the infection is treated on time, the mortality rate is less then 15%. The fever comes within eight days of the mosquito bite.

    How to detect if you are infected:

  • Serological test to detect IgM, IgG antibodies: IgM antibodies appear in blood at the end of eight days and persist for 1-3 months. It indicates acute infection. This is the test that most people undergo. It has an accuracy of 80-90% and is referred to as the preliminary test.
  • Isolation of virus in blood: This is a sophisticated test, conducted only by the Pune-based National Institute of Virology. Can be undertaken 10 days after the first blood test. Quite expensive, but it can confirm if the person is infected by dengue.
  • Polymerized Chain Reaction: This test involves amplification of the DNA (Deoxyribo Nucleic Acid). Very expensive and hence, undertaken only in rare cases.

    Unequivocal diagnosis of dengue infection requires laboratory confirmation, either by isolating the virus or detecting specific antibodies. For virus isolation, a serum specimen should be collected as soon as possible or within 5 days after onset of symptoms.

    For serologic diagnosis, a convalescent-phase serum specimen obtained at least 6 days after onset of symptoms is required. These specimens may be tested for anti-dengue antibodies by enzyme-linked immunosorbent assay (ELISA).

    Acute-phase samples for virus diagnosis may be stored indefinitely on dry ice (-60°C) or, if delivery can be made within 1 week, stored unfrozen in a refrigerator (4°C).

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    5. Treatment of Dengue Fever


    Fortunately, DHF/DSS can be effectively managed by fluid replacement therapy, and if diagnosed early, fatality rates can be kept below 1%. It is very important, that physicians and other health care providers learn to recognize this disease. Once a person acquires dengue, the key to survival is early diagnosis and appropriate treatment.

    To manage the pain and fever, patients suspected of having a dengue infection should be given acetaminophen preparations rather than aspirin, because the anticoagulant effects of aspirin may aggravate the bleeding tendency associated with some dengue infections

    The dreaded dengue fever session is back with a fear of an extensive outbreak if measures to stem the viral infection are not taken immediately, say experts. Experience of the past four dengue infection sessions show that June, July and August are the months when the highest numbers of dengue cases were diagnosed. Though no incidence of dengue has so far been reported to the department of disease control this year, experts could not exclude a pre-monsoon outbreak.

    Due to infrequent rains, stagnant water sources have increased markedly in the city areas where aedes mosquitoes, the vector for dengue virus breed. The number of mosquitoes is also increasing and the virus lurking to strike. "Though we cannot predict an outbreak now but we cannot also exclude it," said Professor Abul Kalam Azad, director of the institute of epidemiology disease control and research.

    The IEDCH has begun dengue surveillance in all out-patients departments of the major hospitals in the city since May 22. Of the 1,000 or so patents tested, three patients were found positive for dengue infection. Azad termed the cases sporadic and not an outbreak. Experts feared that if an outbreak occurred this year, it would be severe and widespread. Dengue incidences showed a waxing and waning relationship of disease severity and immunological response of people.

    According to Department of Public Health of the Health Directorate, Dengue was first scientifically documented through the formal national survey in 1996-1997 which revealed blood sample positive in 13.7 per cent of fever cases without focal signs. These heralding features foresaw future outbreaks and incidence of Dengue Hemorrhagic Fever but ignored until year 2000 when an epidemic occurred. The documentations also revealed that there is a cyclical phenomenon of the outbreaks with a periodicity at alternate years with about three-fold increase in the blood test (sero-positivity) rates with increasing incidence and a case fatality rate hovering between 0.9 to 2.1 per cent

    According to the dengue study group of the department of Disease Control of Health Directorate, this mosquito vector borne communicable infectious viral febrile disease is an emerging public health problem in Bangladesh since the first outbreak in 2000. "There are 5 no's which make dengue a dreaded disease: there is no specific (pathognomic) clinical feature, no user friendly quick lab test, no specific anti viral therapy and no specific preventive tool."

    In 2000 some 93 people died and 5,223 others were admitted in hospitals in the dengue epidemic. In 2001 total reported number of death in dengue were 44 out of 2387 infected. In 2002, a total of 58 people died in dengue and 6318 patients were hospitalised. In 2003 an unusual post-monsoon outbreak of dengue killed at least 10 people and infected thousands most of whom were treated in private clinics and hospitals. Government record shows that about 100 people were admitted to the hospitals.

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    6. How to avoid Dengue

    How to avoid Dengue

  • Water from flower pots should be changed at least once a week
  • All containers storing water should be covered with a tight lid
  • Water stored in barrels, drums etc should be replaced by fresh stock (at least) once a week
  • All large water tanks, like those in buildings, should have single piece cast iron, tight fitting cover. A suitable ladder should be provided to enable civic staff to climb and examine the tanks at frequent intervals. The overflow pipe should be protected by a net that can keep away mosquitoes.
  • Discarded container-like objects like tyres, coconut shells, bottles, etc should be disposed off or destroyed.
  • Water fountains should be kept dry once a week
  • Surface wells should be well-maintained so that mosquitoes do not breed in the vicinity
  • Rain water collected on terraces/roofs should be cleared (at least) once a week
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    7. Death Trap for Diseases in Bangladesh

    A dangerous life on the water's edge: Pollution poisons Bangladesh's riverside slums

    slum,dhakaIf you try to ignore the excrement floating beneath her floorboards, the view from Mrs Sefali's shack could almost be regarded as idyllic. At sunset, green dragonflies hover outside her back door, which leads directly to a turquoise lake. Along the narrow lane in front of her flimsy bamboo home, rickshaw drivers carry exhausted women back from sweatshops where they make clothes for poverty wages.

    This is Dhaka - probably the most squalid, wretched, and perversely beautiful city on earth. The capital of Bangladesh is home to 12 million people, a quarter of whom live in slums, in conditions of unimaginable filth. They include Mrs Sefali, who moved into one of the city's numerous illegal slums, Mirpur, 10 years ago. Her tiny two-roomed bamboo shack has been constructed next to dozens of others. With so little land available, settlements like Mirpur have sprung up above Dhaka's many emerald-green lakes.

    "Seven days ago there was heavy rainfall and the water came up through the bottom of my house. It rose up to my legs," Mrs Sefali said. But it is not just the floods that transform life for the slum-dwellers of Mirpur into a watery hell. It is the sanitation: there isn't any. Mrs Sefali and her family do not have a toilet. Instead they use a hole in the bottom of their shack that leads directly into the lake below.

    Some of her neighbours have devised a system of "hanging latrines" - precarious bamboo platforms raised a few feet above the water and screened by rags. The tiny alley to Mrs Sefali's house goes past four or five other shacks, where families of up to 10 people live packed together. The smell is appalling: just outside her front door, human faeces sitting in nearly a metre of water bob up to meet you.

    All the slum-dwellers are forced to use the lake as a collective latrine. They use the same water to clean their cooking pots, to wash clothes, and to bathe in. "We know this water is not good for washing ourselves in. But what can we do?" Mrs Sefali asked. "We don't have much choice." It is hardly surprising that the inhabitants of Dhaka's sprawling slums suffer from a variety of diseases. In the rainy season they got jor - a debilitating fever. And then there is diarrhoea, dysentery and tuberculosis. Both of Mrs Sefali's children have scabies - a universal complaint - while her husband has TB.

    "My neighbour's child died recently of diarrhoea," Mrs Sefali said. Only the carp that feed off the excrement floating in the city's slum-ponds appear healthy. Bangladesh is one of the poorest, most squalid, most corrupt, and most densely populated countries on earth. Millions of people face the same problem as Mrs Sefali and her neighbours.

    There is an abundance of water in Bangladesh. Most of the country is a vast delta fed by the Ganges and Brahmaputra rivers, which flow via a series of lagoons and shifting islands into the bay of Bengal. But much of this water is polluted.

    There is an abundance of water in Bangladesh. Most of the country is a vast delta fed by the Ganges and Brahmaputra rivers, which flow via a series of lagoons and shifting islands into the bay of Bengal. But much of this water is polluted.

    The country has also suffered from bad luck. Since Bangladesh won independence in 1971, western donors have funded the construction of thousands of wells, especially in rural areas. In the early 1990s, however, many were found to be contaminated with naturally occurring arsenic. Nobody knows exactly how many people have died, but as many as 50 million may have been affected by arsenic poisoning. The west has hardly noticed.(Guardian Foreign Pages . December 15, 2002)

    A river is a large stream of water flowing in a bed or channel and emptying into the ocean, a sea, a lake, or another stream; a stream larger than a rivulet or brook. Transparent and sparkling rivers, from which it is delightful to drink as they flow, says Macaulay in praise of the river. But look at the pitiable plight of the Buriganga river: why cannot we even protect the lifeline of Dhaka city? Why are the Dhaka City Corporation and the government itself are so inert or powerless? If the government cannot take action against a few dozen swindlers who have outright grabbed the Buriganga river, the lifeline of Dhaka city, then how can they govern the country?

    The river is further polluted by discharge of industrial effluents into river water, indiscriminate throwing of household, clinical, pathological and commercial wastes, and discharge of fuel and human excreta. In fact, the river has become a dumping ground of all kinds of solid, liquid and chemical waste of bank-side population. A survey in 1999, says the BAPA, revealed that the water of Buriganga, Turag, Dhaleshwari, Balu, and Narai flowing around the greater Dhaka city had been completely polluted. The report concluded that the water of these rivers posed a serious threat to public life and was unfit for human use. People, living near the rivers, use the water because they are unaware of the health risks and also having no other alternative. This causes incidents of water borne and skin diseases.

    We have already begun to lament about what we had and what we are left with. We blame industries, the unscrupulous people living in the city, the helpless people of the slums, RAJUK and WASA but hardly ourselves. At this juncture in our endeavour to save our ponds (are there any left?) and lakes, rivers and waterways, it is perhaps apt to question what one is doing at the individual level. Or are we behaving like egocentrics when our petty personal interests are threatened even if were ill begotten?

    For those of you who thought Dhaka was an unplanned City perhaps did not know that this one of the most populated cities in the world was planned at its installation in the early 17th C, and later on as many as four occasions in the last century, but alas little or naught have been put into practice. Even the stupendous sums of money spent on foreign consultants have gone down the drain without needing any help whatsoever from the sewerage staff of Dhaka WASA. But the lack of political will to implement the plans has clogged almost every avenue for the sustainable development of a city that is crying for help, your help.

    In 1610, Islam Kha Chisti declared Dhaka as the provincial capital of Bengal and it was named Jahangirnagar according to the name of Delhi's ruler Emperor Jahangir. At that time, the only means of travelling internally to and from Dhaka was through the water route. Naturally, all major business activities began to grow around the Buriganga and important constructions like the Lalbagh Fort and the Ahsan Manjil also rose on its banks. Even 50 years ago, people could rush to the Buriganga for leisure and entertainment. Boat trips from the Swarighat to the Buckland embankment were a real treat. Can we even dream of something like that now?

    In the past, industrial wastes from lakes used to flow into the rivers. But that's not the case anymore. In Tejgaon alone, 1600 metre cube of industrial waste is disposed off everyday; 1200 metre cube of waste is disposed off daily in the Hazaribagh tannery area. These wastes cannot find their way to the rivers these days and stay confined. Tejgaon's wastes get cramped at Barogram off Trimohoni.Hospital waste and solid waste carry a lot of chemicals that are deadly for the fish and aquatic life

    In all these plans since 1610, the waterways and water bodies, and flooding have been given extreme importance. Even in the 1917 plan, it was said that the waterways and water bodies have to be protected and flooding should be allowed. As Dr. Shahidullah puts it, Flood water will recede in time. If you want to block it, problems will arise. The 1959 and 1980 plans echo the same concept. Even in the 1917 plan, it was said that the waterways and water bodies have to be protected and flooding should be allowed.

    We have some 25 khals (natural canals led to river)in Dhaka and we need to look into ways to recover those khals. We've already filled up most of them. Take the example of Bangkok and what they did.... unbearable foul smell came out of that water. But with the help of the World Bank, they reclaimed their khals and now, although the water is dirty, but it's very much navigable and the waterway transports passengers.

    Chemical waste from tanneries in Hazaribagh being siphoned to Buriganga from the temporary dumping ground as monsoon rainwater overflows the city water bodies. According to the environment department, up to 40,000 tonnes of tannery waste flows untreated into the Buriganga a day.

    As the Buriganga River could not escape their clutches despite its being the lifeline of the capital the situation in the rest of the country can be well imagined. While the immediate adverse effects of river grabbing can be felt by the poor fishermen and peasants it is the environmental aspects which will hurt the most in the long run. In fact some of the effects are already being felt. Many of the rivers have become lean and the situation is getting progressively worse. It would be unwise to put the blame solely on barrages set up in foreign countries though of course those too have played a part. The rivers of the country are also being polluted at an alarming rate. The grabbing of the rivers must stop and stern steps should be taken against the responsible persons.

    stagnent dirty water, dhakaBut the situation in Dhaka is deteriorating day by day through destruction of link canals, wet land and ill planned city structure:

  • Most of the major roads of the city were flooded due to torrential rainfall since early Monday morning. Many of the water choked major thoroughfares and link roads that have innumerable potholes became a deathtrap for those moving around the city
  • WASA tries to maintain the 220 KM of surface drains as well as underground and saucer drains around the city that fall under their juristiction. But there is at least 2000 KM of drainage system belonging to DCC, that remains in bad shape most of the time. "It hampers the de watering system of WASA," complained an official of WASA on condition he should not be named. Moreover, carpeting of roads by DUTP throughout the city is preventing proper drainage.
  • Some 20 lakh inhabitants of Matuail have been marooned for the last two weeks following water-logging caused by stagnant rainwater. The area, protected against floodwater by the DND embankment, is now wallowing in it own watery wastes as the drainage network has collapsed. Back to Content

    8. Frequently Asked Questions

    Q. What is dengue?
    A. Dengue (pronounced den' gee) is a disease caused by any one of four closely related viruses (DEN-1, DEN-2, DEN-3, or DEN-4). The viruses are transmitted to humans by the bite of an infected mosquito. In the Western Hemisphere, the Aedes aegypti mosquito is the most important transmitter or vector of dengue viruses, although a 2001 outbreak in Hawaii was transmitted by Aedes albopictus. It is estimated that there are over 100 million cases of dengue worldwide each year.

    Q. What is dengue hemorrhagic fever (DHF)?
    A. DHF is a more severe form of dengue. It can be fatal if unrecognized and not properly treated. DHF is caused by infection with the same viruses that cause dengue. With good medical management, mortality due to DHF can be less than 1%.

    Q. How are dengue and dengue hemorrhagic fever (DHF) spread?
    A. Dengue is transmitted to people by the bite of an Aedes mosquito that is infected with a dengue virus. The mosquito becomes infected with dengue virus when it bites a person who has dengue or DHF and after about a week can transmit the virus while biting a healthy person. Dengue cannot be spread directly from person to person.

    Q. What are the symptoms of the disease?
    A. The principal symptoms of dengue are high fever, severe headache, backache, joint pains, nausea and vomiting, eye pain, and rash. Generally, younger children have a milder illness than older children and adults.

    Dengue hemorrhagic fever is characterized by a fever that lasts from 2 to 7 days, with general signs and symptoms that could occur with many other illnesses (e.g., nausea, vomiting, abdominal pain, and headache). This stage is followed by hemorrhagic manifestations, tendency to bruise easily or other types of skin hemorrhages, bleeding nose or gums, and possibly internal bleeding. The smallest blood vessels (capillaries) become excessively permeable (“leaky”), allowing the fluid component to escape from the blood vessels. This may lead to failure of the circulatory system and shock, followed by death, if circulatory failure is not corrected.

    Q. What is the treatment for dengue?
    A. There is no specific medication for treatment of a dengue infection. Persons who think they have dengue should use analgesics (pain relievers) with acetaminophen and avoid those containing aspirin. They should also rest, drink plenty of fluids, and consult a physician.

    Q. Is there an effective treatment for dengue hemorrhagic fever (DHF)?
    A. As with dengue, there is no specific medication for DHF. It can however be effectively treated by fluid replacement therapy if an early clinical diagnosis is made. Hospitalization is frequently required in order to adequately manage DHF.

    Q. Where can outbreaks of dengue occur?
    A. Outbreaks of dengue occur primarily in areas where Aedes aegypti (sometimes also Aedes albopictus) mosquitoes live. This includes most tropical urban areas of the world. Dengue viruses may be introduced into areas by travelers who become infected while visiting other areas of the tropics where dengue commonly exists.

    Q. What can be done to reduce the risk of acquiring dengue?
    A. There is no vaccine for preventing dengue. The best preventive measure for residents living in areas infested with Aedes aegypti is to eliminate the places where the mosquito lays her eggs, primarily artificial containers that hold water.

    Q. How can we prevent epidemics of dengue hemorrhagic fever (DHF)?
    A. The emphasis for dengue prevention is on sustainable, community-based, integrated mosquito control, with limited reliance on insecticides (chemical larvicides and adulticides). Preventing epidemic disease requires a coordinated community effort to increase awareness about dengue/DHF, how to recognize it, and how to control the mosquito that transmits it. Residents are responsible for keeping their yards and patios free of sites where mosquitoes can be produced.

    Back to Content

    9. Future Outlook

    Aedes breeds in clean, still and stagnant water usually discarded tyres, water tanks and storage appliance are the ideal sites for breeding. Aedes is a voracious bloodsucker, which helps more virus transmission during blood meal. Biting occurs throughout the day especially marked at 8:00 A.M to 13:00 P.M and between 15:00 P.M to 17:00 P.M. therefore, late risers and late evening sleepers are more susceptible to mosquito bites. The mosquito sucks blood many times and therefore, it can infect many persons.

    Female Aedes mosquitoes are the vector of the virus and are peridomestic in nature. The tropical zone of the world between 350N and 350 S latitude and area not over 1,000 ft. above sea level is the usual habitat, the area are marked by monsoon-rains. The breeding of the mosquitoes is highest during pre and post-monsoon periods. The foremost essential step regarding the prevention of this deadly dengue is the identification and mode of Aedesmosquito breeding and the method of spraying insecticide/larvaecide at the appropriate sites.

    No dengue vaccine is available. Recently, however, attenuated candidate vaccine viruses have been developed in Thailand. These vaccines are safe and immunogenic when given in various formulations, including a quadrivalent vaccine for all four dengue virus serotypes. Efficacy trials in human volunteers have yet to be initiated. Research is also being conducted to develop second-generation recombinant vaccine viruses; the Thailand attenuated viruses are used as a template. Therefore, an effective dengue vaccine for public use will not be available for 5 to 10 years.

    New dengue virus strains and serotypes will likely continue to be introduced into many areas where the population densities of Ae. aegypti are at high levels. With no new mosquito control technology available, in recent years public health authorities have emphasized disease prevention and mosquito control through community efforts to reduce larval breeding sources.

    It was recently found in the internet that papaya leaf juice and Papaya Juice could be given to the dengue patients as it may reduce the heartiness in one's body and the fever as well. (Not recommended by a physician or a journal publication) (August, 2006).

    Last Modified: September 3, 2006.

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