Pakistan’s dengue crisis has reached a scale that official figures alone may have failed to capture.
A major study led by Aga Khan University estimates that the country’s dengue burden rose from around 100,000 cases in 2012 to 3.28 million in 2022 — an increase of more than 3,000 percent.
The findings, published in PLOS ONE and reported by Dawn in September 2026, expose the distance between the disease’s estimated spread and the numbers reflected in routine surveillance.
They also raise difficult questions about Pakistan’s ability to track infections, manage urban environments and protect people from a disease that has become a recurring public health emergency.
The figures do not represent a simple count of individually confirmed infections.
Researchers used statistical modelling and laboratory data to estimate the wider incidence of dengue, accounting for differences in healthcare-seeking behaviour, diagnostic testing and laboratory use.
That distinction matters, but it does not diminish the warning. Instead, it highlights a fundamental weakness: a country cannot accurately assess the scale of a public health threat if its routine reporting systems capture only part of the burden.
A decade of escalating infections
The Aga Khan University-led study examined dengue incidence between 2012 and 2022, using laboratory-confirmed data from three nationwide diagnostic laboratory networks. Its estimates suggest that the disease spread far more extensively than official surveillance figures indicated.
The national estimate climbed from approximately 100,000 cases in 2012 to 3.28 million in 2022. The researchers found that the burden varied considerably across provinces and districts, with the sharpest rise among adults aged 15 to 49.
The findings challenge the perception that dengue is merely a short-lived seasonal outbreak that can be managed through occasional fumigation campaigns.
The scale of the estimated increase also exposes a problem with how the disease has been understood and monitored.
When the figures generated by research differ substantially from routine surveillance, questions arise over whether health authorities have a sufficiently complete picture of transmission, the communities most affected and the pressure placed on healthcare facilities.
Pakistan has faced dengue outbreaks for years. Yet repeated seasonal surges have not prevented the disease from spreading across wider areas or becoming entrenched in urban settings. The latest research suggests that the public health burden may be considerably greater than the official record has conveyed.
Sindh bears the heaviest burden
The geographical distribution of dengue presents another troubling dimension. According to the study, Sindh recorded an estimated 2.63 million cases in 2022, making it the province with the highest disease burden.
The estimated incidence reached 45.63 cases per 1,000 people, while Balochistan recorded approximately 6,785 estimated cases.
At district level, Karachi East registered the highest estimated incidence.
The concentration of infections in Sindh, particularly in densely populated urban areas, raises questions about the effectiveness and consistency of disease surveillance, sanitation management and mosquito-control activities.
Karachi’s size, crowded neighbourhoods, drainage problems and uneven municipal services create conditions in which public health threats can spread rapidly.
Stagnant water, uncovered containers and poorly maintained public spaces provide breeding opportunities for mosquitoes. Where waste collection and drainage systems fail to function effectively, the consequences extend beyond inconvenience and become a direct health concern.
The contrast between provinces also illustrates the limitations of treating dengue as a uniform national problem.
Disease transmission varies by location, population density, environmental conditions and access to healthcare. A surveillance system that fails to identify these differences in sufficient detail risks leaving the heaviest-burden communities exposed while the scale of the problem remains obscured by national aggregates.
Underreporting clouds the crisis
The difference between the research estimates and routine reporting is one of the most consequential findings. The study’s authors used laboratory data and statistical adjustments to estimate infections beyond those captured by ordinary surveillance.
The resulting figures indicate that the actual burden could be substantially higher than official records suggest.
This does not mean that every estimated infection was a laboratory-confirmed case recorded by a government department.
Rather, the researchers sought to account for infections that routine systems may miss because people do not seek medical attention, testing is unavailable, or cases never enter formal reporting channels.
Nevertheless, the gap highlights a serious public health problem. Incomplete data can distort the understanding of an outbreak, weaken assessments of local risk and complicate decisions about where medical resources are most urgently needed.
It also makes comparisons between districts and years less reliable when changes in testing and reporting are not fully accounted for.
The World Health Organisation has repeatedly stressed the importance of stronger dengue surveillance and laboratory capacity in Pakistan.
During the 2022 outbreak, the WHO reported that 25,932 confirmed cases and 62 deaths had been recorded by 27 September. It noted that 74 percent of those confirmed cases had been reported in September alone.
Those figures and the later research estimates measure different things over different periods and should not be directly compared as if they were equivalent.
Their contrast nevertheless demonstrates why surveillance methods and the definition of reported cases matter. A count of confirmed cases is not necessarily a complete measure of the disease circulating in a population.
Climate and urban neglect
Dengue transmission is closely linked to environmental conditions. Rainfall, humidity and temperature influence mosquito breeding, while flooding and inadequate drainage can leave standing water around homes and public infrastructure.
Pakistan’s vulnerability to extreme weather adds another layer to an already persistent health problem.
The 2022 outbreak occurred amid devastating monsoon floods that displaced millions of people and damaged infrastructure.
In October that year, the WHO warned that stagnant water following the floods created favourable mosquito-breeding habitats and heightened the risk of disease transmission.
However, environmental conditions alone cannot explain the persistence of the crisis.
The scale of dengue transmission also reflects the conditions in which people live and the capacity of local authorities to manage waste, drainage and potential breeding sites. In densely populated neighbourhoods, the failure to address standing water can leave entire communities exposed.
The seasonal pattern has also become less reassuring.
The Aga Khan University study found signs of sustained transmission throughout the year, even though cases continued to surge during the post-monsoon period. Lead author Dr Zarmeen Nasim said the disease was no longer just a seasonal threat.
That finding complicates a response centred on emergency action after cases begin to rise.
If transmission continues beyond the traditional outbreak period, a system that mobilises primarily during seasonal peaks risks responding after the disease has already gained ground.
A health system under pressure
Dengue places demands on several parts of the healthcare system at once. Patients need timely diagnosis, monitoring and appropriate clinical management, particularly when symptoms progress towards severe disease.
Laboratories must be able to test suspected infections, while hospitals need sufficient capacity to manage periods of high demand.
The WHO notes that dengue can cause severe complications and that timely detection, recognition of warning signs and appropriate care are essential to reducing deaths.
There is no specific antiviral treatment for dengue, making early clinical assessment and careful management particularly important.
When testing is scarce or delayed, patients may struggle to establish the cause of a fever. Incomplete reporting can also make the scale of the outbreak difficult to assess, while sudden surges can place additional pressure on hospitals and frontline healthcare workers.
These weaknesses compound one another: poor surveillance obscures demand, while limited diagnostic and clinical capacity makes the disease harder to manage.
The research does not establish that every shortcoming in Pakistan’s healthcare system caused the estimated increase in infections. It does, however, expose the consequences of a public health system that has struggled to measure the disease burden accurately despite repeated outbreaks.
Cost of repeated failure
The dengue figures are more than a statistical warning. They point to a disease burden that affects working-age adults particularly heavily, varies sharply between regions and appears to extend beyond the limits of conventional seasonal surveillance.
For families, dengue can mean days or weeks of illness, lost income, medical expenses and uncertainty over whether symptoms will deteriorate.
For public hospitals, a surge in patients can strain beds, diagnostic services and staff. Where people face barriers to testing or treatment, the consequences of an outbreak can be more difficult to measure and manage.
Pakistan’s repeated encounters with dengue have made the disease familiar, but familiarity has not removed its threat.
The estimated rise from 100,000 cases in 2012 to 3.28 million in 2022 raises serious questions about the reach of disease monitoring and the effectiveness of the country’s public health response.
The central warning from the Aga Khan University research is that dengue’s true scale may have remained hidden behind incomplete surveillance.
When a recurring infection spreads across millions of people while official records capture only a fraction of its estimated burden, the problem is no longer confined to mosquitoes or monsoon rainfall. It also concerns the capacity of public institutions to recognise, measure and respond to a persistent threat to public health.
Comment