Almost all States/UTs of the country are affected by COVID-19. Given the seasonal pattern of epidemic prone diseases observed every year in our country, it diseases like Dengue, Malaria, Seasonal Influenza, Leptospirosis, Chikungunya, Enteric fever, etc. can not only present as a diagnostic dilemma but may co-exist in COVID cases. This poses challenges in clinical and laboratory diagnosis of COVID , and have a bearing on clinical management and patient outcomes.
As per the World Health Organization (WHO) case definition, a COVID case may present with: 1) Acute onset of fever AND cough; OR 2) Acute onset of ANY THREE OR MORE of the following signs or symptoms: fever, cough, general weakness/fatigue, headache, myalgia, sore throat, coryza, dyspnoea, anorexia/nausea/ vomiting, diarrhoea, altered mental status. This case definition, although sensitive, is not very specific. Seasonal epidemic prone diseases, as cited in the foregoing paragraphs may all present as febrile illness, with symptoms that mimic COVID-19. If there is a co-infection, then apart from the febrile illness there may be constellation of signs and symptoms that may lead to difficulty in diagnosis
A high index of suspicion must be maintained for epidemic prone diseases (e.g. Dengue, Malaria, Chikungunya, Seasonal influenza, Leptospirosis) prevalent in a particular geographic region during monsoon and post-monsoon seasons. Bacterial co-infections must also be suspected in moderate or severe cases of COVID-19 not responding to treatment
While each of these infections are antigenically distinct with specific serological responses, yet in the eventuality of co-infections, cross-reactions (resulting in false-positive /false negative results) cannot be totally ruled out, especially if the testing kits used are not having requisite sensitivity and specificity. Hence the tests recommended by ICMR (for COVID-19) and that recommended by the concerned programme divisions (NVBDCP for vector borne diseases [Malaria, Dengue, Chikungunya]) and NCDC (Seasonal Influenza, Leptospirosis, Scrub Typhus)] needs to be followed. Availability of rapid diagnostic kits for malaria, dengue, scrub typhus should be ensured in such COVID treatment facilities. The table below summarizes the various (confirmatory) test to be undertaken for possible coinfections.
Management of co-infection of COVID-19 with dengue, Influenza and bacterial co-infections may however be challenging and are dealt with in greater detail here.
If the patient is in a primary care setup, the following criteria should be monitored to assess patients clinical progress. Early warning signs for referral to higher centre are:
A concerted effort is required in prevention, surveillance, behaviour change communication and management of such cases. Alert vigil, a high index of suspicion and constant awareness of the possibility of co-infections can help physicians avert the adverse outcome of cases with coinfection and improve clinical outcomes.
| COVID 19 | Dengue | Malaria | Chikungunya | Leptospirosis | Seasonal Influenza | |
|---|---|---|---|---|---|---|
| Onset | IP: 2-14 days. (onset of symptom average 5-7 days). Acute onset of low to moderate grade continuous fever | IP: ranges from 3- 14 days (onset of symptom average 4-7 days). Acute onset of high-grade continuous fever | P. Falciparum (IP: 9-14 days) P.vivax (IP 10-14 days). Acute onset of high-grade intermittent fever | IP: 1-12 days (Onset of symptom average 3-7 days) Acute onset of moderate to high grade continuous fever | IP: 2-26 days (onset of symptom Average- 6-10 days) Acute onset of moderate to high grade c | IP: 1-4 days (onset of symptom average - 2 days). Acute onset of moderate to high grade continuous fever |
| Symptoms | Cough Dyspnoea Fever Myalgia Headache Sore throat Diarrhoea Abdominal pain Rhinorrhoea | Fever, Headache, Nausea Vomiting retro-orbital pain myalgia arthralgia rash bleeding | Fever, chills, malaise, fatigue, diaphoresis (sweating), headache, cough, anorexia, nausea, vomiting, abdominal pain, diarrhea, arthralgias, and myalgias | Fever Rash Malaise Arthralgia Myalgia Red Eyes | Fever, rigors, myalgia, headache, Conjunctival suffusion, nausea, vomiting, and diarrhoea | Fever, cough, sore throat, and nasal discharge, headache, myalgia and malaise, |
| Signs | Tachypnea, Decreased oxygen saturation, Multi organ involvement | Signs of hypotension and shock, hemorrhagic manifestations (petechiae), positive | Pallor Palpable spleen | Swelling and tenderness of joints, | Subconjunctival Haemorrhages, Red eyes, Muscle tenderness, Splenomegaly, Hepatomegaly, Muscle rigidity Skin rash | pharyngeal wall hyperemia, Cervical lymphadenopathy |
| Warning signs | Respiratory distress SpO2<94 % | Persistent vomiting, Abdominal tenderness, Fluid Accumulation | Persistent high grade intermittent fever, vomiting, lethargy, low urine | High grade fever, progressive increase of myalgia and arthralgia. | High grade fever, LFT derangement | Respiratory distress SpO2<94 % |