Weekly IDSR Bulletin
Epidemiological Week 23 (1-7 June, 2026)
Editorial Team
I. Performance & Surveillance
Reporting Completeness & Timeliness Analysis
The national reporting performance for Epidemiological Week 23 has achieved a highly positive trajectory, registering 96.0% for reporting completeness and an encouraging 93.0% for reporting timeliness on the One Health Surveillance Platform (OHSP). This performance demonstrates the robust capacity of our integrated tracking systems to capture facility data with minimal informational latency. Out of the 33 designated national reporting sites, 85.0% (28 sites) successfully met the minimum target of >= 80% for both completeness and timeliness. This widespread platform adoption provides public health decision-makers with real-time situational awareness across the territory.
When evaluated against the previous historical baseline in Epidemiological Week 22, which achieved 95.8% completeness and 95.2% timeliness, Week 23 displays a general improvement in completeness but a minor drop in timeliness. Completeness rose by 0.2 percentage points, while timeliness fell by 2.2 percentage points. This positive trend was primarily anchored by Central Hospitals (100.0% on both metrics) and the South West Zone (99.5% completeness and 98.4% timeliness). However, administrative delays persist at the district level: Zomba DHO (72.0% completeness, 60.0% timeliness), Dowa DHO (73.0% completeness, 68.0% timeliness), and Balaka DHO (78.0% completeness, 78.0% timeliness) failed to surpass the reporting minimum targets of >= 80% for both indicators in the current cycle, presenting minor tracking blind spots. Additionally, Nkhotakota DHO and Karonga DHO failed to meet the minimum target for timeliness.
To address these remaining gaps and maintain optimal surveillance parameters, the National IDSR Secretariat recommends immediate administrative follow-up. Zomba, Dowa, and Balaka DHOs must prioritize targeted administrative interventions to resolve database entry delays. IDSR coordinators and Zonal Epidemiology Officers must ensure timely verification and validation of clinical data immediately after facility focal points submit weekly forms to safeguard platform responsiveness. Additionally, Nkhotakota and Karonga must focus specifically on improving timeliness.
II. Disease Morbidity
Malaria Morbidity & Mortality
Malaria remains the dominant priority clinical condition under active surveillance in Malawi, with Epidemiological Week 23 recording an immense burden of 30,305 cases (29,701 OPD and 604 IPD) alongside 1 associated inpatient death. This volume of clinical cases indicates intense transmission dynamics, placing constant pressure on primary care facilities, diagnostic laboratories, and essential antimalarial drug inventories. High-burden districts like Blantyre (3,324 cases), Chikwawa (2,024 cases), and Mangochi (2,638 cases) continue to represent key transmission hotspots requiring sustained public health intervention.
When contrasted with the previous baseline in Epidemiological Week 22, the malaria data reveals a downward trajectory in both morbidity and inpatient mortality. Total malaria cases decreased by 17.1%, dropping from 36,561 cases in Week 22 to 30,305 cases in Week 23. Confirmed inpatient deaths also fell sharply from 13 down to 1. This decline in fatal outcomes suggests improving clinical therapeutic timing or effective supportive inpatient protocols, yet environmental factors continue to support vector propagation across high-burden districts.
To address this transmission trend, the National Malaria Control Program must coordinate immediate antimalarial supply chain audits to ensure uninterrupted buffer stocks of Artemisinin-based Combination Therapy (ACTs) and Rapid Diagnostic Tests (RDTs). Clinical teams must conduct rigorous mortality audits on the recorded death to identify potential delays in administering intravenous artesunate. Concurrently, Health Surveillance Assistants (HSAs) must scale up risk communication campaigns to emphasize immediate care-seeking behaviors for all febrile illnesses.
Enteric Diseases (Typhoid & Diarrhoea)
The surveillance of waterborne enteric pathogens in Epidemiological Week 23 has flagged a significant clinical concern, with Typhoid fever cases recorded at 56 (36 OPD and 20 IPD) and Bloody Diarrhoea cases totaling 667 (663 OPD and 4 IPD). Waterborne disease transmission remains a persistent threat, highlighted by the recent enteric illness outbreak in Nkhatabay (Usisya Health Facility, T/A Mbwana), which cumulatively resulted in 131 diarrhoea cases, including 24 bloody diarrhoea cases, and 6 suspected deaths. Environmental risk factors in Nkhatabay include unsafe water sources, poor sanitation, and reliance on traditional medicine.
When compared to the baseline figures from Epidemiological Week 22, the enteric profile shows a significant downward trajectory. Bloody Diarrhoea cases fell by 7.6%, moving from 722 cases in Week 22 down to 667 cases in Week 23. Typhoid fever cases also experienced a decline, dropping from 60 down to 56 cases. The last reported cases for the Nkhatabay outbreak were recorded on 2 June 2026, and the last death was reported on 25 May 2026, indicating that the outbreak is currently stabilizing.
Based on these findings, we recommend that Blantyre, Mchinji, Dedza, and Kasungu DHOs deploy rapid response teams to conduct water safety interventions and targeted environmental monitoring to curb Typhoid. For the Nkhatabay outbreak, continuing risk communication, water safety interventions, and hygiene monitoring remain essential. Clinical teams must ensure stool and blood cultures are collected from suspected cases to monitor antimicrobial resistance patterns and guide precise therapy, while municipal authorities must prioritize water safety in hard-to-reach areas.
III. Critical Alerts & Mortality
Cholera and Mpox Status
Epidemiological Week 23 recorded 126 suspected Cholera cases, of which 11 were laboratory-confirmed cholera cases and 115 were epidemiologically linked, alongside a commendable zero-death record. This stable survival rate reflects the high quality of supportive rehydration and prompt case management within established Cholera Treatment Units (CTUs). On the zoonotic disease front, Mpox surveillance detected zero (0) new confirmed cases and zero (0) alerts, keeping the cumulative national total stable at 158 confirmed cases and 4 cross-border cases since April 2025, with Lilongwe representing 75.8% (119 cases) and a case fatality rate (CFR) of 0.63%.
A comparison with Epidemiological Week 22 shows that the Cholera outbreak experienced an upward trend in case reporting, climbing from 85 suspected cases in Week 22 to 126 cases in Week 23. On the Mpox front, transmission was completely inactive, dropping from 1 confirmed case and 2 alerts in Week 22 down to absolute zero in Week 23. Geographically, 26 of Malawi’s 29 districts have reported at least one suspected cholera case since the start of the season on 1 November 2025, with a national cumulative total of 776 cases and 5 deaths (0.65% CFR).
To counter this Cholera threat, the National Incident Management System must continue to direct emergency water, sanitation, and hygiene (WASH) resources to high-incidence hotspots. Oral Cholera Vaccine (OCV) campaigns in selected hotspot districts have achieved a total of 612,477 doses administered (101.3% coverage). For Mpox, the District Rapid Response Teams (DRRTs) must maintain active cross-border screening and coordination with Mozambique and Tanzania to ensure any imported cases are detected and managed promptly.
SARI & Respiratory Mortality
Severe Acute Respiratory Infections (SARI) presented 66 clinical cases and 1 inpatient death during Epidemiological Week 23. The severe respiratory burden continues to affect central districts, with Kamuzu Central Hospital (KCH) reporting 32 SARI cases (48.5% of the national SARI burden) and the only SARI-associated death. This consistent concentration highlights the need for continuous sentinel respiratory surveillance and clinical preparedness within tertiary facilities to handle sudden influxes of acute respiratory cases.
When evaluated against the baseline from Epidemiological Week 22, the SARI surveillance data displays a significant decrease in respiratory morbidity and mortality. National SARI cases dropped by 50.7%, falling from 134 cases in Week 22 down to 66 cases in Week 23. SARI-associated deaths also decreased, declining from 4 down to 1. Despite this positive trend, clinical teams must continue to monitor severe cases to identify seasonal respiratory pathogens such as Influenza A/B or RSV.
We recommend that clinical teams at Kamuzu Central Hospital and other sentinel hospitals continue to systematically collect nasopharyngeal swabs from SARI patients for PCR diagnostic analysis. Healthcare facilities must ensure that pediatric oxygen delivery systems, clinical nebulizers, and essential respiratory therapeutics remain fully functional. Furthermore, clinicians must continue to document and report SARI cases on the OHSP, allowing public health teams to identify and respond to any new respiratory anomalies quickly.
IV. Vaccine Preventable Diseases
Measles & VPD Surveillance Distribution
Vaccine-Preventable Disease (VPD) surveillance remains a high-priority public health activity. From Week 1 to Week 23 of 2026, Malawi cumulatively reported 1,543 alerts, including 414 confirmed measles-rubella cases. Laboratory-confirmed measles cases totaled 287 across 23 districts, with Balaka reporting the highest proportion at 20.2% (58 cases) and Kasungu at 15.3% (44 cases). Under the IDSR framework, Acute Flaccid Paralysis (AFP) surveillance recorded 14 cases this week, and Meningococcal meningitis recorded 6 cases, highlighting the need for sustained immunization coverage and active case searching.
When compared to Epidemiological Week 22, the Measles weekly alerts fell from 79 down to 48 cases in Week 23, reflecting a 39.2% weekly decline. Conversely, AFP alerts rose significantly from 4 to 14 cases, reflecting a major increase in weekly paralysis reporting. Suspected Meningococcal meningitis cases remained relatively stable, moving from 4 cases in Week 22 to 6 cases in Week 23. Polio outbreak containment remains a high priority following the confirmation of 16 environmental sewage isolates since January 2026.
We recommend that the Expanded Programme on Immunisation (EPI) continues targeting high-burden districts, particularly Balaka and Kasungu, with supplemental vaccination and outreach. For the 14 reported AFP cases, dual stool samples must be collected and sent to the laboratory under strict cold chain conditions. To prevent poliovirus spread, preparation for the upcoming Round 3 vaccination campaign (scheduled for 16-19 June 2026) must be prioritized alongside active community-level surveillance.
V. Summary of Recommendations
1. Reporting Quality & District Targets
Zomba, Dowa, and Balaka DHOs must implement immediate data validation procedures to improve completeness and timeliness back to target levels of >= 80%, while Nkhotakota and Karonga must focus specifically on improving timeliness.
2. Enteric & Outbreak Targeted Interventions
Blantyre, Mchinji, Dedza, and Kasungu DHOs are directed to implement targeted interventions against Typhoid fever, while Nkhatabay DHO must continue environmental sanitation, risk communication, and active surveillance to suppress further enteric transmission in Usisya.
3. AEFI Safety Investigation
Mzimba North and Nkhatabay DHOs are directed to perform detailed vaccine safety investigations on the reported Adverse Events Following Immunization (AEFI) to maintain high community trust in routine childhood immunizations.