5 months ago
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Last year, Tamil Nadu logged its highest dengue caseload, crossing the 20,000 people for the archetypal clip since the erstwhile highest successful 2017. Though lawsuit numbers person risen steadily this twelvemonth arsenic well, doctors and nationalist wellness experts constituent retired that a stronger knowing of the disease, targeted surveillance strategies, greater nationalist consciousness and well-defined protocols person improved aboriginal diagnosis and helped trim complications and mortality.
Previous peaks
The State, successful its two earlier peaks successful 2012 and 2017, had recorded 13,204 cases with 66 deaths and 23,294 cases with 65 deaths, respectively. In the years that followed, some lawsuit numbers and deaths declined, until 2024, erstwhile the fig of cases again surged. Though the nonstop fig of cases and deaths this twelvemonth could not beryllium ascertained, wellness officials confirmed that determination are astir 23,000 to 24,000 cases of dengue truthful acold but fewer deaths than past year.
A. Somasundaram, Director of Public Health and Preventive Medicine, said that communicable diseases person some seasonal and cyclic trends. While flu is seasonal, immoderate diseases travel a cyclic pattern. In these cycles of 5 to 7 years, the illness builds its capableness to origin much superior infections. When this coincides with susceptible oregon susceptible groups being contiguous successful ample numbers, much terrible illness tin occur, helium said
“The nationalist wellness strategy is geared to instrumentality preventive measures. We usage a triangulation approach. We absorption connected areas wherever the larval scale is precocious and person identified locations that are traditionally dengue hotspots. We besides behaviour mosquito pooling, an workout successful which mosquito samples are collected and tested for dengue viruses utilizing RT-PCR. This attack has helped america trim some cases and mortality,” helium said.
Endemic successful India
Dengue is endemic successful India, a elder doc added. “It was an exotic microorganism successful the precocious 1990s. But this is nary longer the case. Cases of dengue increases aft rains and decreases erstwhile determination are nary rains. This follows the dynamics of the mosquito cycle. We tin power dengue with definite checks and balances. It has a unsocial pattern. Dengue outbreaks thin to hap erstwhile successful 5 years erstwhile the dispersed is rapid, with the classical examples being outbreaks successful 2012-2013 and 2017 erstwhile mortality was high,” helium explained. He added that an outbreak was expected during 2021 - 2022 but did not hap owing to the COVID-19 pandemic. “In fact, dengue cases were debased during that period,” helium said.
Interestingly, the Directorate of Public Health and Preventive Medicine did a dengue serosurvey to find the reasons for debased prevalence of dengue during the pandemic owed to imaginable viral interference. Dengue is caused by 4 serotypes of dengue microorganism (DENV 1 - 4). The survey was conducted during the midle of the pandemic successful December 2021 to comparison the antibody levels (seroprevalence) against DENV and SARS-CoV-2, and recovered that seroprevalence of dengue was precise debased successful the assemblage with 4.12% for DENV IgM and 6.4% for DENV IgG. Only 3.76% of pistillate Aedes mosquito pools were affirmative for DENV. It said that portion anti-SARS-CoV-2 IgG antibody levels remained precocious astatine 87.3%, the diminution successful dengue incidence and/or prevalence during the pandemic (2020-2022) appears to beryllium attributed to imaginable viral interference and neutralising effect of SARS-CoV-2 IgG against DENV.
“Tamil Nadu has a robust vector surveillance system implemented by the Directorate of Public Health and Preventive Medicine, nether which detection of dengue microorganism successful field-caught mosquito excavation samples is done by RT-PCR crossed the State. This surveillance enables aboriginal recognition of hotspots and due nationalist wellness measures,” helium said.
What has worked
While the dengue alarm is sounded each year, doctors accidental that aboriginal diagnosis and punctual referrals person improved arsenic a effect of which complications and deaths person reduced.
Janani Sankar, aesculapian director, Kanchi Kamakoti CHILDS Trust Hospital, Chennai, said the infirmary has been continuously seeing children with dengue since July, but determination were nary Intensive Care Unit admissions, nary earnestly sick cases and nary deaths. “Early diagnosis has decidedly improved. About 25 to 30% of children did not necessitate hospitalisation. If they resided adjacent by, we educated the parents connected the informing symptoms and asked them to study successful 24 hours to cheque their captious parameters. If they were from distant location, we did not privation to instrumentality chances and admitted them. They were discharged successful a fewer days,” she said.
The severity of the cases has decidedly travel down, she said, adding: “Improved consciousness levels, including connected the informing signs, among the nationalist arsenic good arsenic doctors has helped to a large extent. Children are besides referred to the infirmary earlier. The knowing of the illness is amended now.” She added that though lawsuit numbers usually autumn by the extremity of the year, they present spot sporadic cases passim the twelvemonth - though tiny successful numbers - dissimilar before, erstwhile cases are usually reported aft July.
Soumya Sridharan, consultant, infectious diseases, Kauvery Hospital, Alwarpet, Chennai, said that post-COVID, consciousness connected immoderate fever has accrued among the public. “The complications are not alarming and determination has been nary strain connected the healthcare system. Proactive measures from the State authorities person reduced mortality owed to dengue,” she noted.
Dr. Soumya further explained: “When determination is aboriginal detection and adjacent monitoring, absorption is better. In at-risk patients, dengue could origin complications. Monitoring helps to observe aboriginal signs of deterioration oregon complications. A cascade sets successful erstwhile dehydration occurs successful the febrile signifier of dengue. If fluid absorption is not done appropriately, it could pb to daze and terrible dengue erstwhile haematocrit levels emergence and platelet number falls and organ dysfunction could occur. The humor unit drops and bleeding manifestations whitethorn occur. Any organ specified arsenic the brain, heart, lung and kidney could beryllium affected.”
S. Chandrasekar, prof and head, section of medicine, Government Stanley Medical College Hospital, Chennai, said successful dengue, abrupt abrupt onset of fever, myalgia and symptom down the eyes is typically seen successful patients. “Nearly 95% of dengue cases are self-limiting. We tin measure its severity by definite parameters - driblet successful achromatic humor compartment number followed by autumn successful platelet number and emergence successful haematocrit levels. We should show these 3 changes.”
While these manifestations could alteration each season, what has been observed successful the past six months is radical coming successful with daze syndrome, debased BP, debased platelet count, and liver dysfunction markers, Dr. Chandrasekar said. Elaborating connected however the infirmary focused its attraction strategy, helium said, “Patients required prolonged infirmary enactment and intensive care. So, we decided to show these parameters for each patients with dengue. All liver parameters including serum albumin are checked, and if immoderate changes occur, we alteration our attraction strategy. The dengue microorganism incites an immunological absorption successful the body. It tin effect successful a cytokine storm. So, we commencement to dainty patients focusing connected fluid absorption successful summation to mitigating the inflammation and organ dysfunction.”
Extended dengue fever
A authorities doc successful Chennai said that fever with debased platelet number is usually connected the emergence this clip of the year. “It tin beryllium caused by a plethora of tropical infections - astir commonly associated with dengue, chikungunya, immoderate viral illness, malaria, leptospirosis oregon adjacent scrub typhus. Identifying underlying illness and starting aboriginal attraction is the cornerstone to cure,” helium said.
Usually successful dengue, fever stops by time 5 to 8 and the play pursuing defervescence is crucial. “We telephone it the immune signifier during which platelet levels driblet and complications commencement to develop. The antithetic inclination we person seen for the past mates of years is that fever continues good beyond 10 days and platelet drops simultaneously with fever continuing. We telephone this extended dengue fever. It tin beryllium rather challenging to marque a diagnosis successful this phase. We spot rather a batch of patients successful the teen and younger property radical with debased platelet counts alternatively than older patients,” helium said.
In Chennai, migrant workers, including those moving successful operation sites, are commonly seen with complications and they besides contiguous precocious successful the illness, making it hard to dainty and get a affirmative outcome, helium said. “Mortality seems to beryllium low, and complication rates, erstwhile compared to erstwhile years, are besides low,” the doc added.
A ‘man-made’ disease
Dr. Chandrasekar said that successful Tamil Nadu, the wide cognition astir dengue has improved and patients are managed arsenic per protocols. “We person charts successful each fever wards and doctors are alert of the protocols. The mortality is debased arsenic of present this year, and cases volition usually hap till the extremity of February,” helium said.
Aedes mosquitoes breed successful caller cleanable water, and so, cases commencement to emergence aft the rains erstwhile h2o collections successful containers and unused items specified arsenic pots, tyres and coconut shells crook into a breeding crushed for mosquitoes. Though transmitted by mosquitoes, dengue is simply a much man-made disease, helium said.
