CM8.1-7 | Disease Epidemiology and Control — Glossary

UNAIDS global HIV targets: 90% of PLHIV know their status; 90% of those diagnosed are on ART; 90% of those on ART are virally suppressed.

Annual Blood Examination Rate; percentage of the endemic population tested for malaria by blood smear or RDT per year; target ≥10% in high-endemic districts.

Sudden onset of flaccid (non-spastic) limb weakness in a child under 15 years; a polio-alert condition requiring immediate notification to the District Surveillance Officer — not weekly S-form submission.

Annual Parasite Incidence; confirmed malaria cases per 1000 population per year; used to stratify malaria endemicity by district.

Overweight defined as BMI ≥25 kg/m² and obesity as BMI ≥30 kg/m² for South Asians; lower than standard WHO cut-offs because Asian populations accumulate harmful abdominal fat at lower total BMI.

Number of cases divided by total exposed or at-risk population, expressed as a percentage; measures what proportion of the exposed population developed disease.

A framework tracking the proportion of a target population at each step from screening to outcome control (screened → diagnosed → treated → controlled); used to identify programme gaps.

Standardised clinical (and/or laboratory) description of what counts as a case in an outbreak investigation; enables consistent case-finding across time and geography.

Deaths from a disease divided by total confirmed cases, expressed as a percentage; measures case lethality — the risk of death given disease has occurred.

Cartridge-Based Nucleic Acid Amplification Test (GeneXpert); rapid molecular test diagnosing TB and detecting rifampicin resistance within 2 hours; mandated at PHC level under NTEP.

Public health strategy targeting shared behavioural risk factors (tobacco, diet, inactivity, alcohol) simultaneously, achieving efficiency across multiple NCDs through one programme.

Outbreak where all cases share a single exposure source; epidemic curve shows a sharp, symmetrical single peak; all cases appear within one incubation period of the exposure.

The legal requirement for healthcare providers to report specified communicable diseases to public health authorities; in India, governed by the Epidemic Diseases Act 1897 (amended 2020) and NTEP TB notification policy.

Classification of individuals into low/moderate/high/very high 10-year cardiovascular risk using validated risk charts (e.g. WHO CVD risk chart); guides pharmacotherapy intensity.

The ongoing systematic collection, analysis, and interpretation of outcome-specific data, essential to the planning, implementation, and evaluation of public health practice (WHO definition).

Directly Observed Treatment, Short-course; the strategy of providing anti-TB treatment under observation to ensure adherence; now daily (not intermittent) under NTEP.

District Vector Disease Management System; NVBDCP's reporting platform for malaria, dengue, and filariasis case surveillance and vector control activities at district level.

Occurrence of cases of a disease in a community in numbers clearly exceeding the expected level based on past experience.

A histogram plotting number of cases on the y-axis against time on the x-axis; shape (sharp single peak vs prolonged/multi-modal) distinguishes common-source from propagated outbreaks.

Indian law empowering state (and after 2020, central) governments to take special measures to prevent spread of epidemic disease, including mandatory isolation, inspection, and detention of contacts.

The three interacting components — agent, host, and environment — whose balance determines whether disease occurs in a population.

Blood glucose measured after ≥8 hours of fasting; diagnostic for diabetes mellitus if ≥126 mg/dL on two separate occasions per standard diagnostic criteria.

The mechanism by which analysis of surveillance data is shared back with reporting facilities (PHCs, sub-centres), creating accountability and demonstrating how local data influences national decisions.

Grade 2 Disability Rate; percentage of new leprosy cases with visible deformity at diagnosis; reflects late detection in the programme.

Glycated haemoglobin; reflects average blood glucose over 2–3 months; diagnostic for diabetes if ≥6.5%; target for diabetic patients on treatment is typically <7%.

Proportion of a population that must be immune to prevent epidemic spread; calculated as HIT = 1 − (1/R0); for measles R0≈15, HIT≈93.3%.

The five-phase health information system process: data collection → processing → analysis → dissemination → action; the feedback loop (sending analysis back to reporting units) is the most commonly missing phase.

Health Management Information System; MoHFW's integrated national health data platform aggregating programme reports from PHC to national level.

Integrated Disease Surveillance Programme; India's national disease surveillance system using S (syndromic), P (presumptive), and L (laboratory-confirmed) reporting forms.

Information, Education, Communication; a public health strategy for health promotion that combines mass communication, individual counselling, and community participation to change health behaviours.

International Health Regulations 2005; WHO legal framework requiring member states to detect, assess, notify, and respond to public health emergencies; defines Public Health Emergency of International Concern (PHEIC).

A tabular record of all cases in an outbreak with one row per case, including: name/ID, age, sex, onset date, symptoms, exposure history, address, and outcome.

Mass Drug Administration; annual administration of DEC 6 mg/kg + albendazole 400 mg to all eligible persons in filariasis-endemic districts on National Filaria Day.

Multi-drug therapy for leprosy: paucibacillary (PB) = rifampicin + dapsone for 6 months; multibacillary (MB) = rifampicin + clofazimine + dapsone for 12 months.

Intensified immunization campaign under NHM targeting unimmunized and partially immunized children and pregnant women; now in its 4th phase (IMI 4.0).

National AIDS Control Organisation; runs ICTC (testing), ART centres, and PPTCT (prevention of parent-to-child transmission) programmes.

New Case Detection Rate; new leprosy cases per 100,000 population per year; target for elimination is <1 case per 10,000 population.

Web-based patient management system for NTEP; records all TB notifications, treatment details, contact tracing, and treatment outcomes in real time.

Direct benefit transfer scheme under NTEP providing Rs 500 per month nutritional support to all notified TB patients for the duration of treatment.

National Leprosy Eradication Programme; delivers multi-drug therapy (MDT) — 6 months for PB leprosy, 12 months for MB leprosy.

National Programme for Prevention and Control of Cancer, Diabetes, Cardiovascular Diseases and Stroke; India's umbrella NCD programme operating at PHC level in all districts.

Non-structural protein 1 of dengue virus; detectable in blood in the first 5 days of illness; used as the PHC-level rapid diagnostic test for early dengue infection.

National Tuberculosis Elimination Programme; India's TB control programme renamed from RNTCP in 2020, targeting TB elimination (< 1 case/million population) by 2025.

National Vector Borne Disease Control Programme; integrates control of malaria, dengue, chikungunya, kala-azar, Japanese encephalitis, and lymphatic filariasis.

Systematic screening of patients who present to a health facility for any reason, regardless of their presenting complaint; the primary mechanism for NCD case detection at PHC level.

Prevention of Parent-to-Child Transmission; NACO programme ensuring all HIV-positive pregnant women receive ART from 14 weeks of gestation to prevent vertical HIV transmission.

Outbreak spread person-to-person; epidemic curve shows a gradual rise with multiple modal peaks each separated by approximately one incubation period.

Average number of secondary cases generated by one infectious case in a fully susceptible population; determines epidemic growth potential (R0 >1 = growth; R0 <1 = decline).

14-day course of primaquine for P. vivax malaria that eliminates hepatic hypnozoites and prevents relapse; G6PD status must be assessed before prescribing.

A district-level multidisciplinary team activated by IDSP alerts to investigate and control disease outbreaks; coordinated by the District Surveillance Officer.

Average number of secondary cases in a population with existing immunity and control measures; must be driven below 1.0 to control an epidemic.

Proportion of expected facilities that submitted reports in a given period; calculated as (facilities reporting / total expected) × 100; a core data quality indicator.

Syndromic surveillance form submitted weekly by community health workers (ASHA/ANM) based on observed illness clusters; the earliest alert layer in IDSP.

New cases among close contacts divided by total susceptible close contacts, expressed as a percentage; measures household or close-contact transmissibility.

Structured lifestyle advice for NCD patients: Salt restriction, No tobacco, Activity (150 min/week), Prudent diet.

WHO STEPwise Approach to Surveillance; standardised NCD risk factor survey method collecting questionnaire, physical measurement, and biochemical data.

NACO policy introduced in 2017 mandating ART initiation for ALL persons living with HIV regardless of CD4 count; replaces earlier CD4-threshold-based eligibility.

Percentage of newly bacteriologically confirmed TB cases that achieve treatment success (cured + treatment completed); NTEP target is ≥90%.

Universal Immunization Programme; India's national schedule providing free vaccines (BCG, OPV, pentavalent, PCV, IPV, MR, JE) to all children from birth through childhood.

Visual Inspection with Acetic Acid; PHC-feasible cervical cancer screening test where 3–5% acetic acid is applied to the cervix and acetowhite plaques indicate suspicious lesions.

Visual Inspection with Lugol's Iodine; alternative to VIA for cervical cancer screening; non-iodo-philic (non-staining) areas on application indicate suspicious lesions.

Submission of a report with zero cases for the reporting period; a positive quality indicator showing the facility is actively engaged in surveillance even when no disease is detected.