Pathogens (Sep 2021)

Dry Post Wintertime Mass Surveillance Unearths a Huge Burden of <i>P. vivax,</i> and Mixed Infection with <i>P. vivax</i> <i>P. falciparum</i>, a Threat to Malaria Elimination, in Dhalai, Tripura, India

  • Ipsita Pal Bhowmick,
  • Tulika Nirmolia,
  • Apoorva Pandey,
  • Sarala K. Subbarao,
  • Aatreyee Nath,
  • Susmita Senapati,
  • Debabrata Tripathy,
  • Rocky Pebam,
  • Suman Nag,
  • Rajashree Roy,
  • Dipanjan Dasgupta,
  • Jayanta Debnath,
  • Kongkona Gogoi,
  • Karuna Gogoi,
  • Lakhyajit Borah,
  • Rajdeep Chanda,
  • Arup Borgohain,
  • Chelapro Mog,
  • Ujjwal Sarkar,
  • Phiroz Gogoi,
  • Bishal Debnath,
  • Jyotish Debbarma,
  • Dibya Ranjan Bhattacharya,
  • Pyare Lal Joshi,
  • Harpreet Kaur,
  • Kanwar Narain

DOI
https://doi.org/10.3390/pathogens10101259
Journal volume & issue
Vol. 10, no. 10
p. 1259

Abstract

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With India aiming to achieve malaria elimination by 2030, several strategies have been put in place. With that aim, mass surveillance is now being conducted in some malaria-endemic pockets. As dry season mass surveillance has been shown to have its importance in targeting the reservoir, a study was undertaken to assess the parasite load by a sensitive molecular method during one of the mass surveys conducted in the dry winter period. It was executed in two malaria-endemic villages of Dhalai District, Tripura, in northeast India, also reported as P. falciparum predominated area. The present study found an enormous burden of Rapid Diagnostic Test negative malaria cases with P. vivax along with P. vivax and P. falciparum mixed infections during the mass surveillance from febrile and afebrile cases in dry winter months (February 2021–March 2021). Of the total 150 samples tested, 72 (48%) were positive and 78 (52%) negative for malaria by PCR. Out of the 72 positives, 6 (8.33%) were P. falciparum, 40 (55.55%) P. vivax, and 26 (36.11%) mixed infections. Out of 78 malaria negative samples, 6 (7.7%) were with symptoms, while among the total malaria positive, 72 cases 7 (9.8%) were with symptoms, and 65 (90.2%) were asymptomatic. Out of 114 samples tested by both microscopy and PCR, 42 samples turned out to be submicroscopic with 4 P. falciparum, 23 P. vivax, and 15 mixed infections. Although all P. vivax submicroscopic infections were asymptomatic, three P. falciparum cases were found to be febrile. Evidence of malaria transmission was also found in the vectors in the winter month. The study ascertained the use of molecular diagnostic techniques in detecting the actual burden of malaria, especially of P. vivax, in mass surveys. As Jhum cultivators in Tripura are at high risk, screening for the malarial reservoirs in pre-Jhum months can help with malaria control and elimination.

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