Laboratory Capacity for Surveillance of Infectious Diseases in Gujarat: Quantity, Quality, Effects and Way Forward

Abstract

Background: India carries one of the largest burdens of infectious diseases in the world. To estimate this, laboratory confirmation is vital. We estimated the lab capacity and effectiveness in the state of Gujarat for Enteric Fever, Infectious Hepatitis, and Dengue. Methods: We estimated the number of labs in the state through telephonic surveys and physical screening of a representative sample of labs. We created four levels of tests, Level-0 being no test and 3 being the best confirmatory test available in the state. For the profusion of rapid diagnostic test kits (RDTKs), we constructed Effective Diagnostic Scores (EDS) calculated from their sensitivity and specificity at disease prevalences specified in the literature. Tests with EDS > 0.51 were level-2 tests, and EDS < 0.50, level-1 tests. Results: Our analysis showed that there are 4293 labs in the state (1765 public and 2528 private), 7/100,000 population. However, only 2878 labs contributed to a total pooled Effective Lab Diagnostic Score (ELDS) of 6776 in the state. Strikingly, 94% of the lab effectiveness lay in RDTs (level-2 and 1 tests) which are essentially screening tests. Ninety-six percent of the overall lab effectiveness of Gujarat existed in private and only 4% in public labs. Contrarily, the level-3 confirmatory testing effectiveness, through ELISA and culture constituted only 4% of private and 36% of public lab effectiveness. More than half of the private lab effectiveness was located in eight Tier 1 cities. Level-3 confirmatory testing effectiveness was present only in Tier 1 and 2 towns. Hepatitis B testing contributed 34% of the total ELDS, followed by Dengue (30%), Enteric Fever (26%) and Hepatitis A and E (10%). Conclusion: Our study has established that the capacity and effectiveness of the lab network in Gujarat lie predominantly in RDTKs. We need to adapt our systems to capture this data in a manner that will allow us to monitor the burdens of these diseases.