ABSTRACT
Background & objectives: Vaccination against COVID-19 induces spike protein-binding IgG antibodies, a robust correlate of protection against COVID-19. This study was undertaken to assess the humoral response after completion of both the doses of ChAdOx1 nCoV vaccine in healthcare workers (HCWs) at a tertiary care health centre in India. Methods: A cross-sectional COVID-19 vaccine-induced antibody study was conducted among HCWs. IgG antibodies against spike protein were measured at least 28 days after the first dose and the second dose of vaccination in both SARS CoV-2 naïve and recovered HCWs. Mean and median antibody titre following each dose of vaccine and its association with age, gender, co-morbidities and factors such as exercise, stress and sleep deprivation were also explored. Results: Among the 200 vaccine recipients, 91.5 per cent showed seroconversion after the first dose and 99.5 per cent after the second dose. The mean titre after the second dose was significantly higher when compared to the first dose (12.68±4.17 vs. 9.83±6.3, P=0.001). More than half (54%) had high antibody titre ?12 S/Co (Signal/cut-off). Previous COVID-19 infection was the single most important factor influencing antibody production, where the mean titre just after a single dose [mean-17.81±5.94, median-20.5 (interquartile range [IQR]-3.7)] surpassed the titre after the second dose in SARS CoV-2 naïve individuals [mean-12.29±4.00, median-12.8 (IQR-3.7), P=0.001]. Furthermore, 28 per cent of vaccinees showed a reduction in titre after the second dose. The mean fall in titre was 2.25±1.40 and was more pronounced in males, the younger age group and those with previous COVID-19 infection. Interpretation & conclusions: ChAdOx1 nCov-19 vaccine after two doses elicited an excellent immune response. However, greater immunogenicity after the first dose was seen among those with previous COVID-19 infection, even surpassing the titre achieved by the second dose of vaccine in SARS CoV-2 naïve recipients. A fall in antibody titre after the second dose is a matter of concern and requires further studies.
ABSTRACT
Scarabiasis or Canthariasis or Beetle disease is an ectoparasitic infection of the gastrointestinal tract, in which the beetles temporarily infest the digestive tract and rarely the urinary tract. Dung beetle belongs to Scarabiaediae family.' It is mostly seen in children aged between 2 to 5 years, who play outdoor for prolonged hours without undergarments. It is a temporary infestation in which early stages of development of beetle takes place in the anus and the adult beetle flies, out of the anus while defecation. A boy aged 3 years and four months presented to the pediatric OPD with complaints of peri umbilical abdominal pain, vomiting, nausea, mucus in stool along with 'black insects' in his stool. The clinical examination revealed that the pulse rate, blood pressure and temperature were normal. Per rectal examination and ultrasound of the abdomen was normal. Routine examination of stool and urine was also found to be normal. The beetle was identified by the medical entomologist as dung beetle belonging to family Scarabidae. This report implies that the boy had an infestation with the larvae of dung beetle in the gastro intestine. The family belonged to the high range area of Mundakayam. Agriculture is the main source of income for people and main plantation being Rubber. Natives breed cattle for their livelihood and agriculture. During contact with mud or while playing outdoors naked, he would have come into contact with the eggs or the beetle, which hatched into larvae and caused canthariasis.