Dengue as a cause of acute undifferentiated fever in Vietnam.

[Snowy Owl]

Dengue as a cause of acute undifferentiated fever in Vietnam.
BMC Infectious Diseases 2006, 6:123 doi:10.1186/1471-2334-6-123

<table class="smalltext" cellpadding="0" cellspacing="0"><tbody><tr><td>Published</td> <td width="25"> </td> <td>25 July 2006</td></tr></tbody></table>http://www.biomedcentral.com/1471-2334/6/123/abstract

Abstract (provisional)

The complete article is available as a provisional PDF. The fully formatted PDF and HTML versions are in production.

Dengue is a common cause of fever of fever in the tropics but its contribution to the total burden of febrile illnesses that is presented to primary health facilities in endemic regions such as Vietnam, is largely unknown.


Background
To report the frequency of dengue as a cause of fever in Binh Thuan Province, to describe the characteristics of dengue patients, and analyze the diagnostic accuracy of the health care workers and the determinants of the diagnostic process.


Methods
All patients presenting with acute undifferentiated fever at twelve community health posts and one clinic at the provincial malaria station, Binh Thuan Province, a dengue endemic province in southern Vietnam, were included. Record forms were used to fill in patient and diseases characteristics, pre-referral treatment, signs and symptoms, provisional diagnosis and prescribed treatment, referral and final outcome. Serum samples were collected at first presentation and after 3 weeks for serologic diagnosis.


Results
2096 patients were included from April 2001 to March 2002. All 697 patients with paired serum samples were tested for dengue virus IgM and IgG. Acute dengue was found in 33.6% cases and past dengue virus infections were found in 57.1% cases. Acute primary infections were more common among children under 15 years old than among adults (7.7% vs. 3.5%, p value < 0.001). Younger age significantly predicted acute dengue (RR per increasing year of age (95 % CI): 0.986 (0.975-0.997, p value = 0.014). 48.9% of cases with clinical diagnosis of acute dengue were serologically confirmed and 32.5% of cases without clinical diagnosis of acute dengue were positive by serology after all (OR = 1.981, p value 0.025, 95% CI: 1.079 - 3.635). Tourniquet test was not a predictor for dengue diagnosis.


Conclusions
Dengue is responsible for one third of the fevers presented to the public primary health services in Binh Thuan, southern Vietnam. It presents as a highly unspecific illness and is hardly recognized as a clinical entity by primary physicians

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Re: Dengue as a cause of acute undifferentiated fever in Vietnam.

Int J Infect Dis. 2002 Jun;6(2):118-24. Related Articles, Links


Comment in:
Int J Infect Dis. 2003 Sep;7(3):231-2.

Effect of age on outcome of secondary dengue 2 infections.

Guzman MG, Kouri G, Bravo J, Valdes L, Vazquez S, Halstead SB.

Department of Virology, PAHO/WHO Collaborating Center for Viral Diseases, Tropical Medicine Institute of Havana, Cuba.

OBJECTIVE: Dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) is a growing global health problem. It is not known how age affects the outcome of secondary dengue infections. In an island setting, a large DHF/DSS outbreak in Cuba occurred in 1981. Involved were individuals, 3-40 year old, whose only lifetime dengue exposure was to DEN-1 in 1977 and DEN-2 in 1981. In this report we calculate age-specific DHF/DSS hospitalization and death rates based on secondary DEN 2 infections. METHODS: Published and unpublished hospital and seroepidemiologic data from the 1981 DHF/DSS outbreak were used for the analysis. RESULTS: Children, aged 3 and 4 years, with secondary DEN-2 infections were found to have a high death rate (25.4/10 000 secondary DEN-2 infections). The death rate fell with increasing age, being 15.9-fold lower in the 10-14-year age group. The death rate for children aged 3-14 years was 14.5-fold higher than in young adults aged 15-39 years. The death rate rose somewhat in adults aged 50 years and older. DHF/DSS hospitalization rates showed the same trend as death rates. CONCLUSIONS: Age is an important variable in the outcome of secondary DEN-2 infections. DHF/DSS case fatality and hospitalization rates are highest in young infants and the elderly. The risk that a child will die during a secondary DEN-2 infection is nearly 15-fold higher than the risk in adults.

PMID: 12121599 [PubMed - indexed for MEDLINE]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Abstract&list_uids=12121599

[kent nickell]

Re: Dengue as a cause of acute undifferentiated fever in Vietnam.

Dengue The Deadly Killer

http://www.sdnbd.org/dengue_fever.htm

excerpts:

Dengue haemorrhagic fever (DHF), a potentially lethal complication, was first recognized during the 1950s and is today a leading cause of childhood mortality in several Asian countries. There are four distinct, but closely related, viruses which cause dengue. Recovery from infection by one provides lifelong immunity against that serotype but confers only partial and transient protection against subsequent infection by the other three. Indeed, there is good evidence that sequential infection increases the risk of more serious disease resulting in DHF.

The global prevalence of dengue has grown dramatically in recent decades. The disease is now endemic in more than 100 countries in Africa, the Americas, the Eastern Mediterranean, South-East Asia and the Western Pacific

During epidemics of dengue, attack rates among susceptibles are often 40 ? 50%, but may reach 80 ? 90%.
An estimated 500 000 cases of DHF require hospitalisation each year, of whom a very large proportion are children and roughly 5% die.
Without proper treatment, DHF case fatality rates can exceed 20%. With modern intensive supportive therapy, the rate can be reduced to less than 1%.
The spread of dengue is attributed to expanding geographic distribution of the four dengue viruses and of their mosquito vectors, the most important of which is the predominantly urban species Aedes aegypti. A rapid rise in urban population is bringing ever greater numbers of people into contact with this vector, especially in areas which are favourable for mosquito breeding

Dengue fever is a severe, flu-like illness that affects infants, young children and adults but rarely causes death. The clinical features of dengue fever vary according to the age of the patient. Infants and young children may have a non-specific febrile illness with rash. Older children and adults may have either a mild febrile syndrome or the classical incapacitating disease with abrupt onset and high fever, severe headache, pain behind the eyes, muscle and joint pains, and rash. Dengue haemorrhagic fever is a potentially deadly complication that is characterized by high fever, haemorrhagic phenomena

Vaccine development for dengue and DHF is difficult because any of four different viruses may cause disease, and because protection against only one or two dengue viruses could actually increase the risk of more serious disease.

Haemorrhagic symptoms

Bleeding, particularly in skin (petichiae), occaisionally in gunms and nose increased vascular permeability, resulting in leakage of plasma into extravascular spaces and which leads to hypovolaemia haemorrhagic symptoms reduced blood pressure vascular changes and coagulopathy circulatory shock vomiting and abdominal pain lymphadenopathy and hepatomegaly may occur presence of blood in stools, vomitus, urine

ANTIBODY RESPONSE

Infection will result in lifelong immunity to that serotype, but only temporary immunity to other serotypes

Primary Infection

IgM antibodies appear approximately 5 days after onset of symptoms and rise for the next 1-3 weeks
IgM antibodies detectable for up to 6 months
IgG are detectable at approximately 14 days after onset of symptoms and are maintained for life
Secondary Infection

Approximately 5% patients do not produce detectable levels of specific IgM

IgM titre can be slower to rise in secondary infection
IgG appears approximately 2 days after symptoms appear
IgG titre significantly higher in secondary infection