Dengue is currently affecting half of the world population. Several factors such as globalization, travel, trade, socioeconomics, and climate change have played a vital role in dengue transmission and expansion. The largest number of dengue cases ever reported globally was in the year 2019 when several countries were affected.
Dengue has emerged as a major health concern for Pakistan since 2010 where 10,416 cases with 51 deaths were reported. According to data of the National Institute of Health (NIH) Islamabad, over 2700 cases with 370 deaths in 2011, 8546 cases with 33 deaths in 2013, 24,807 cases with 69 deaths in 2017, over 3200 cases with 34 deaths in 2018, 53,498 cases with 95 deaths in 2019 and 3442 cases in 2020 were reported. Now, in November 2021, the dengue outbreak is again rearing its head in different cities of Punjab. More than 48,906 cases with 183 deaths have been recorded till 25 November 2021.
It is considered among one of the major outbreaks of the world. Dengue infection is being caused by the dengue virus that is a small spherical particle and exists in four serotypes namely DENV1 to DENV4. Recently the fifth serotype has also been identified in Malaysia. Dengue virus is transmitted to the humans by the bite of female mosquito that belongs to species within genus Aedes principally, Aedes aegypti and Aedes albopictus.
Dengue infection has been classified into three classes i.e., dengue fever (DF), dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS), according to the severity of disease by the World Health Organisation (WHO). DF is an acute onset of febrile illness that lasts for 2-7 days and patient suffers from two and more of the following symptoms: myalgia, headache, retro-orbital pain, arthralgia, rash, and petechiae. Patients suffer from thrombocytopenia, liver injury, multi-organ haemorrhages, circulatory failure and neurological disorders. DHF/DSS patients can die within 4-6 hours if proper supportive treatment is not provided in time.
Early detection of the dengue virus is essential for the proper treatment of patients as well as for clinical and epidemiological surveillance. The PCR is the most widely used molecular tool for dengue diagnosis, as it is a quick, cost-effective and most reliable method for early detection of dengue virus. Reduction in morbidity and better care of dengue patients depends upon the early diagnosis of disease as the first 48 hours are important for the patient treatment. Severe cases of dengue (DHF/DSS) require rapid medical intervention for victim survival. Dengue virus infects different organs of the body and deranges various haematological and biochemical parameters. Some of these parameters can predict that patient will develop a severe form of infection.
Scientists at the University of Veterinary & Animal Sciences, Lahore conducted a study on dengue patients, to explore a set of parameters that could easily be investigated in the clinical laboratory and could be used as indicators of dengue severity. The investigation of the complete blood count of dengue patients revealed that thrombocytopenia and leucopenia were common among dengue patients.
The deranged hematocrit levels were associated with the severity of the disease. The elevated levels of liver function enzymes, low levels of total protein and serum albumin in DHF and DSS patients revealed that the dengue virus affects liver function. Acute kidney injury is documented in some patients of DHF/DSS. According to this study, elevated levels of hematocrit, transaminases, bilirubin, urea, creatinine, triglycerides, VLDL, LDH, and CK-MB were associated with the severity of the disease.
Similarly, low hematocrit due to excessive blood loss, leukocytosis, thrombocytopenia, hyponatremia, hypokalemia and hypocalcemia are also indicators of poor prognosis and patients with these features need proper and timely medical care. Therefore, the regular monitoring of these parameters can be used to predict and manage dengue disease severity and can help to provide proper and in time treatment to the patients.
NUSRAT BANO AND DR MUHAMMAD TAYYAB
LAHORE
