DENGUE & CHIKUNGUNYA VIRUS FEVER OUTBREAKS IN DELHI, IG-M SEROLOGY STATUS - A RECENT EXPERIENCE
←
→
Page content transcription
If your browser does not render page correctly, please read the page content below
National Journal of Basic Medical Sciences Volume - II, Issue - 4
DENGUE & CHIKUNGUNYA VIRUS FEVER OUTBREAKS IN DELHI,
IG-M SEROLOGY STATUS - A RECENT EXPERIENCE
1 2 3 4
Balvinder Singh Arora , Sonia Chugh , B. Gupta , K.C. Aggarwal
ABSTRACT been epidemic in several part of India, including city of
Dengue and Chikungunya virus illness affects tropical and Delhi, with interspersed epidemics being reported from
2,9,10,
subtropical regions around the world including India. In various places. Chikungunya fever (CHIKF), an
Delhi, a highly populous city, as recently as in the year arthropod-borne virus (arbovirus), of the family
2010, several cases of fever with clinical picture similar to togaviridae almost disappeared in 1973 and since then no
that of dengue and chikungunya virus infection reported cases reported till the end of 2005 when it re-emerged
6,7
in our Vardhman Mahavir Medical College & associated after a gap of more than three decades. Since 2005,
Safdarjang Hospital, New Delhi. Cases of fever started quite a few outbreaks have been reported from different
28
reporting in late June, 2010 but from September onwards parts of India . Clinically, CHIKV infection is marked by
also emerged cases of chikungunya. On clinical basis severe joint pains contorting its victim into unusual
3
alone, especially during mixed outbreaks, it is generally posture . It has been observed that in Asia - CHIKV
7
difficult to differentiate between the two, in particular affected area overlap with dengue virus endemic areas.
when dengue fever does not manifest as DHF. Serology Clinical similarities with dengue fever make chikungunya
for dengue and chikungunya was performed by Mac ELISA fever diagnosis difficult. It may lead physician to
test with the aim as detection of specific IgM antibodies. misdiagnose or under-diagnose chikungunya infection as
In cases of dengue fever from late June till end August – dengue virus infection. Therefore, it is believed that the
2010, the IgM seropositivity was found to be 38.3%. From incidence of chikungunya virus may actually be higher
3, 6
September, 2010 onwards and till December end, in cases than currently believed .
of chikungunya virus fever the IgM seropositivity was In the current study, on retrospective basis, analysis of
found to be 65.11% and that of dengue as 37.86%. Also, in dengue IgM seropositivity over a period from June to
cases from Sep to Dec, 2010, which presented with August 2010 and that of both i.e. dengue and
clinical pictures suggestive of both types of viral chikungunya from September to December 2010
infections, revealed that the seropositivity for dengue outbreaks in Delhi and NCR, is presented here, with
declined to 8.36%, and for Chikungunya increased to special reference to its serology status .
41.46%. In conclusion, the dengue outbreak, especially in
MATERIALS AND METHODS
city Delhi, may get overwhelmingly replaced by
chikungunya virus fever cases with both the dominant During the period from June-December 2010, dengue
viruses' co circulating in the community. Detection of IgM and chikungunya serology was performed by ELISA test
antibodies against dengue and chikungunya by ELISA with the aim of detecting specific IgM antibodies of cases
during the mixed outbreak appears to play important role clinically diagnosed as suffering from dengue fever or
for distinguishing the two, and reinforces clinical chikungunya fever or both. Majority of these patients
diagnosis, and, hence, helps initiate proper medical care. presented on the third to fifth post onset day of fever. The
serum samples were received in our microbiology
Key words: Dengue, chikungunya, IgM serology
laboratory at VMMC, Safdarjang Hospital, New Delhi In
INTRODUCTION patients who presented with mixed clinical picture, the
Dengue illness, an acute mosquito- borne infection with IgM specific antibodies were detected against both viral
dengue virus, is due to four antigenically distinct infections using a specific IgM antibody capture-ELISA
serotypes, which don't offer cross protection. Clinical method employing kits provided by Arbovirus
manifestations of dengue viral infection range from - Diagnostics, NIV, Pune, India.
'asymptomatic cases to nonspecific febrile illnesses or Quality Control
classical Dengue Fever (DF) or Dengue Hemorrhagic Fever
Each time two positive and two negative controls were
(DHF), or else as Dengue Shock Syndrome (DSS)'. It has
1
Professor, 2Senior Resident, Department of Microbiology, 3Professor & Head, Department of Medicine,
4
Professor & Head, Department of Paediatrics, VMMC, Safdarjang Hospital, New Delhi.
Website : www.njbms.com 336National Journal of Basic Medical Sciences Volume - II, Issue - 4
put up for the validation of the kit supplied. The expected infection, in current times, is best made by detection of
values for the positive and negative were – Positive: OD virus specific antibodies because of ease and simplicity of
5, 17, 21
values more than or equal to 0.5 and negative as OD the procedure. .
values less than or equal to 0.18. Interestingly, it was observed that cases of dengue started
Interpretation of the result: appearing in late June 2010 and cases continued to be
If the OD value of the sample tested exceeds OD of the reported till August end but from September 2010
negative control by a factor of 4.0 (Sample OD ≥ Negative onwards the presentation of the cases suggested it to be
OD x 4.0), the sample was considered as positive. that of not Dengue, but, clinically suspected, as that of
chikungunya. These cases were soon confirmed by NCDC,
RESULTS New Delhi, India as that of DENV 1 – Genotype III and that
From June end till last week of Aug, 2010, the of 'East Central South African genotype of CHIKV' based
seropositivity for Dengue IgM was found to be 38.3% on duplex reverse transcriptase–polymerase chain
(Table 2). However, from September 2010 onwards, the reaction (D-RT–PCR) - dengue/chikungunya through
clinical presentation of the cases suggested it to be not sequencing of CprM and E1 genes of dengue and
dengue but that of chikungunya and it was also confirmed chikungunya viruses by NCDC. Many cases presented
by NCDC, New Delhi. The seropositivity for chikungunya with clinical pictures suggestive of both types of viral
was found to be 65.11%.(Table 4) During the same period infections.
some cases presented with clinical pictures suggestive of Serology on a total of 1957 sera aimed at detecting IgM
both types of viral infections. In such cases, 287 in antibodies against dengue virus performed by Dengue
number, the IgM specific serology performed by ELISA for IgM capture ELISA revealed an overall positivity for
both the viral infections revealed that the seropositivity dengue specific IgM antibodies as 38.3%. % (Table 2). It is
for dengue alone was 8.36% and for Chikungunya alone it comparable with other studies from India (31.3%).
9,10,11,15
.
was 41.46%. Interestingly, during this period it was also Whereas from the month of Sep, 2010 onwards and till
found that 15.33% cases were positive for both and end Dec 2010 - IgM serology on a total of 5765 sera from
34.84% were negative for both (Table5). The picture dengue fever cases revealed a positivity of 37.36% while
reflected that the outbreak that initially started as in 1158 sera from CHKV fever cases, the IgM seropositivity
dengue was gradually replaced by chikungunya virus, was 65.11 % (Table 4). In 287 sera from cases that
and, at the same time many patients were also infected presented with mixed picture of dengue and chikungunya
with both viruses suggesting that both the dominant - the IgM serology performed by ELISA for both the viral
viruses co- circulated simultaneously in the community. infections revealed that the seropositivity for dengue
DISCUSSION alone was 8.36% and for Chikungunya it was 41.46% (
Table 5). Of these 287 cases, 44 sera (15.33%) were,
The worldwide large scale reappearance of dengue viral
however, positive for both. If this positivity is taken
fever for the past few decades has turned this disease into
4, 5. together then 23, 69 % cases had dengue infection either
a serious public health problem in India. The symptoms
alone or with CHKV infection whereas 56.79% cases had
of chikungunya are most often clinically indistinguishable
CHKV fever alone or with dengue as well. The picture
from those observed in dengue fever. Although, in
reflected that the outbreak that initially started as
contrast to dengue, hemorrhagic manifestations are
dengue was gradually replaced by chikungunya virus, and
relatively rare in chikungunya infection, but the
later both the viruses became dominant and co-
simultaneous isolation of both dengue and chikungunya
circulated simultaneously in the community. Findings of
virus from the sera of same patient has previously been
17,18,19. previous studies – have reported – seropositivity in the
reported indicating a dual infection. Therefore, 9, 11, 14, 19, 22 , 29.
range of 40 - 62% for CHKV in mixed outbreaks.
laboratory confirmation of chikungunya virus infection is
critical, especially in dengue endemic areas. Although, Serological diagnosis of dengue and chikungunya virus
the most straight forward diagnosis of a recent infection is infection is not without complications for several reasons,
achieved by the detection of the virus in the patient' for example - patients may have multiple and sequential
blood, either by virus isolation in susceptible cell culture
18
infections with the four dengue virus serotypes due to
or by identifying the viral RNA with PCR technique but lack of cross protective neutralizing antibodies and
laboratory diagnosis of dengue and chikungunya original antigenic sin (i.e. when many B cell clones that
337 Website : www.njbms.comNational Journal of Basic Medical Sciences Volume - II, Issue - 4
were responsible for the first flavivirus infection undergo the community. Despite these challenges, in present
re-stimulation to synthesize the early antibody with a times, the E/M – specific capture IgG and IgM ELISA has
greater affinity for the first infecting virus than for the become the most powerful assay for the sero-diagnosis of
present infecting virus in every subsequent flavivirus dengue virus infection due to its high sensitivity,
infection). In endemic areas where two or more specificity, simplicity, and feasibility for automation.
flaviviruses keep circulating, IgG antibodies have high Although demonstration of a fourfold increase in dengue
degrees of cross reactivity to homologous and virus IgG antibody titer between the acute and
heterologous flavivirus antigens and the serodiagnosis of convalescent phase sera is diagnostic, however, obtaining
past, recent and present dengue virus infections is paired sera is usually impractical. Alternatively, the
difficult due to the long persistence of IgG antibodies (≥ demonstration of IgM antibodies in acute-phase sera is
10 months as measured by E/M specific capture IgG used in instances where paired sera cannot be collected.
ELISA, or life long as measured by E/M antigen coated Therefore, the most commonly used test is IgM capture
23, 24
indirect IgG ELISA). Therefore, among the viral infections (MAC-ELISA). In the remaining cases, it is presumed
that can be diagnosed by serology, dengue virus that the IgM antibody levels were lower and
infections is among the most challenging and it becomes undetectable. It is well documented that anti – dengue
especially so when dominant viruses are co-circulating in virus IgM antibody is produced transiently during primary
Table 1 : IgM serology status of 9167 Dengue and Chikungunya fever patients from June to December2010 - of which
7722 patients were tested for Dengue from June to August, 2010; and 1158 tested for chikungunya from Sep to
Dec, 2010, ; and 287 patients tested for both i.e. Dengue as well as Chikungunya during the same period.
Website : www.njbms.com 338National Journal of Basic Medical Sciences Volume - II, Issue - 4
and secondary infection. In patients with primary dengue
virus infection IgM antibodies develop rapidly and are
detectable on days 3 to 5 of illness in half of the patients.
Studies of the dynamic antibodies response have shown
that anti – dengue virus IgM antibody levels peak at about
2 weeks post infection and then decline to undetectable
levels over 2-3 months (whereas anti-dengue virus IgG
17,24
appears shortly afterwards and persists longer). Also Table 2 : Dengue IgM serology - month wise distribution
noteworthy is the observation that in patients with of 1957 cases clinically diagnosed as dengue fever for the
secondary dengue virus infection, while the kinetics of period from June to August, 2010.
IgM production are similar to those observed in patients
with primary infection, the anti-IgM levels peak at about 2
weeks post infection and then begin to wane thereafter
and are detectable in about 30% of patients two months
after the onset of symptoms. Therefore, the present
analysis reveals that during mixed outbreaks of dengue
and chikungunya virus outbreaks IgM serology by ELISA
continues to be significant in supporting the clinical
diagnosis. Table 3 : Dengue IgM serology - month-wise distribution
For the age group affected, well known is the observation of 5765 dengue fever cases from September to
that dengue, worldwide, affects humans of all age groups. December, 2010.
In the current study maximum positivity rate was found in
the age group of 21-40 years (65 %) (Table 6). In the
patients below 10 years of age serology was positive in
23%. Similar findings have been reported by previous
14, 15
workers . In gender analysis, males (63%) showed
predominance over females (37%) which conform to
8,14
similar observation made by others . Maximum cases
8, 9,11.
(74%) were outdoor patients. In cases of chikungunya Table 4 : Chikungunya IgM serology - Month-wise
- for the gender affected, in the present analysis, distribution of 1158 fever cases from Sep –Dec, 2010 only
predominance in sero-positivity was seen among females
and most of the cases were outdoor (Table7). But the
female preponderance in the present study is statistically
13,14,15,16,30
insignificant as also observed in other studies.
Chikungunya fever affects all age groups and both
8-12, 17
genders are affected equally. In this retrospective
analysis, maximum case were reported among 20-40
years of age group (Table7) which is similar to various
6,7 ,27 , 14,16,28.
other studies reported previously.
Keeping in view that the early symptoms of dengue fever
mimic other diseases often prevalent in areas which are
endemic for other illnesses such as chikungunya, malaria
17
and leptospirosis, it is worthwhile, at the earliest
possible, to detect anti dengue virus IgM antibodies by
capture ELISA as an aid to clinical diagnosis since it is
crucial for the initiation of right line of treatment and Table 5 : IgM serology status of 287 cases tested for both
17, 24
institute proper patient care. Dengue and Chikungunya from Sep – Dec, 2010.
339 Website : www.njbms.comNational Journal of Basic Medical Sciences Volume - II, Issue - 4
8. Kirte RC,Naik DB,Khamgoankar MB.Clino epidemiological Profile of
Fever Cases Admitted during Epidemics of Chikungunya Fever. J Comm
Dis.2007; 39 (1):33-35.
9. JainM,RaiS,ChakravartiA.Chikungunya:areview.TropDoct2008;3:70-72.
10. Myers RM, Carry DE. Concurrent isolation from patients of two
arboviruses, Chikungunya, and Dengue type 2. Science 1967; 157:
1307-08.
11. Simon F, Savini H, Parola P. Chikungunya: a paradigm of emergence
and globalization of vector-borne diseases. Med Clin North Am 2008;
92: 1323-43.
12. Sudeep AB, Parashar D. Chikungunya: an overview. J Biosci 2008; 33:
443-49.
Table 6 : Gender and Age group distribution of 2932 cases 13. Innis BL .Dengue and dengue hemorrhagic fever. In Kass handbook of
of dengue and 757 cases of Chikungunya (IgM Sero- infectious diseases: Exotic virus infections edited by Posterfield JS.
London: Chapman and Hall Medical. 1995:103-46
positive). (By ELISA test) from June – Dec, 2010.
14. Powers AM, Logue CH. Changing pattern of chikungunya virus: re-
emergence of a zoonotic arbovirus. J Gen Virol 2007; 88: 2363-77.
15. Hati AK. Studies on dengue and dengue hemorrhagic fever (DHF) in
West Bengal State, India. J Commun Dis. 2006;38(2):124-9
16. Khan E, Kirat M, Khan N et al. Demographic and clinical features of
Dengue fever in Pakistan from 2003-2007; A retrospective cross-
sectional study. PLoS One. 2010;5(9):e12505
17. Ramalingaswami V: Presentaion to participant: The changing
paradigm of dengue. Dengue outbreak in Delhi: Round table
conference series: Ranbaxy science foundation.1996:7-9
Table 7 : Distribution of patients' visits to our hospital 18. Kabra SM, Verma IC, Arora NK, Jain Y, Kabra V. DHF in children in Delhi.
BULL WHO.1992;45:105-8
either in OPD or admission in ward.
19. Bandyopadhyay S, Jain DC, Datta K: Reported incidence of
CONCLUSION dengue/DHF in India 1991-1995.Dengue Bulletin.1996;20;33-4
20. Dar L, Broor S, Sengupta S, Xess I, Seth P: The first major outbreak of
Dengue and chikungunya as mixed outbreaks are not dengue haemorrhagic fever in Delhi, India. Emerg Infect Dis. 1999; 5:
31,
uncommon in our kind of eco-epidemiological settings 589-90
21. Gupta E, Dar L, Narang P, Srivastava VK, Broor S: Serodiagnosis of
The present analysis reveals that during this mixed dengue during an outbreak at a tertiary care hospital in Delhi. Indian J
outbreak when it usually casts shadows, clinically as well Med Res. 2005; 121:36-8
as laboratory analysis wise, whether the case is 22. Ukey PM, Bondade SA, Paunipagar PV, Powar RM, Akulwar SL. Study of
sero-prevalence of dengue fever in central India. Indian J Community
chikungunya or dengue or a mixed infection, detection of med. 2010; 35:517-19
specific IgM antibodies by Mac ELISA test if done, as early 23. Gupta E, Dar L, Kapoor G and Broor S. The changing epidemiology of
as possible, puts a clinician on more firm footing. It also dengue in Delhi, india.Virology Journal. 2006; 3:92
24. Monath TP and Tsai TF. Flaviviruses In: Richman DD, Whitley RJ,
helps laboratory physicians to be precise and objective Hayden FG (Eds.). Clinical Virology, New York Churchil Livingstone Inc,
and contribute to better and effective management of 1997: 1133-86.
such outbreaks by reducing morbidity and mortality by 25. Henchal EA and Putnak JR. The dengue viruses. Clinical Microbiology
Reviews. 1990; 3: 376-96.
instituting right line of treatment and proper medical care 26. Lanciotti rs, Calisher CH, Gubler DJ, Chang GJ and Vorndam AV. Rapid
at the earliest possible. detection and typing of dengue viruses from clinical samples by using
reverse transcriptase –polymerase chain reaction. Journal of clinical
REFERENCE Microbiology. 1992; 30: 545-51.
1. Munasinghe DR, Amarasekera PJ, Fernold CF. An epidemic of dengue- 27. Henchal EA, Polo SL, Vorndnam V, Yaemsiri c, innis BL and Hoke ch.
like fever in Ceylon (chikungunya- a clinical and haematological study. Sensitivity and specificity of a universal primer set for the rapid
Ceylon Med. 1996; 11(4):129-42. diagnosis of dengue virus infection by polymerase chain reaction and
2. Lall R, Dhandav V. Dengue haemorrhagic fever, and dengue shock nucleic acid hybridization. American Journal of Tropical Medicine and
syndrome in India. Natl Med J India. 1996;9:20-3 hygiene. 1991; 45: 418-25.
3. Teixeira OG, Corta MCN, Guerra Z, Barreto ML. Dengue in Brazil: 28. Innis BL, Nisilak A, Nimmannitya S, Kusalerdchariya S, Chongswadi v,
Sitation-2001 and trends. Dengue Bull. 2002;26: 70-6 Suntayakorn S, chongswadi v, Suntayakorn S, Puttisri P and Hoke Ch.
4. Sukri NC, Laras K, Wondra T, Didi S, Larasati RP, Rachdyatmaka JR: An enzyme-linked immunosorbent assay to characterize dengue
Transmission of epidemic dengue haemorrhagic fever in easternmost infections and Japanese encephalitis co-circulate. American Journal of
Indonesia. Ann J Trop Med Hyg 2003;68(5): 529-35 Tropical Medicine and Hygiene. 1989; 40: 418-27.
5. Mc Bribe WJ, Bielefeldt-Ohmann H: Dengue viral infections: 29. Nawa M, Takasaki T, Yamada K, Akatsuka T, and Kurane I.
Pathogenesis and epidemiology. Microbes infect. 2002;2:1041-50 Development of Dengue IgM-capture enzyme-linked
6. Shah KV, Gibbs CJ Jr, Banerjee G. Virological investigation of the immunosorbent assay with higher sensitivity using Monoclonal
epidemic of hemorrhagic fever in Calcutta. Isolation of three strains of detection antibody. J Virol Methods. 2001; 92: 65-70.
chikungunya virus. Indian J Med Res 1964; 52: 676-83. 30. Yamada K, Nawa M, Takasaki T, Yabe S, and Kurane I. Laboratory
7. Ravi V. Re-emergence of chikungunya virus in India: India J Med diagnosis of Dengue virus infection by reverse transcriptase
Microbiol 2006; 24: 83-84. polymerase chain reaction (RT-PCR) and IgM-capture enzyme-linked
immunosorbent assay (ELISA). Jpn J Infect Dis. 1999; 52:150-2.
Website : www.njbms.com 340You can also read
