Urban Malaria in Pakistan: Rising Threat

A dangerous shift is underway in Pakistan’s battle against malaria, one that challenges long-held assumptions about where the disease thrives. Traditionally associated with rural areas and stagnant irrigation channels, malaria is now finding a new foothold in the very heart of Pakistan’s cities. The culprit is Anopheles stephensi, a highly adaptive mosquito species that has evolved to exploit urban environments. Unlike rural mosquito species, which rely on open water bodies, An. stephensi breeds in man-made structures—rooftop water tanks, uncovered storage drums, clogged drains, and even cracks in densely packed housing. This adaptation is transforming Karachi, Lahore, and other metropolitan centers into year-round malaria risk zones.

The consequences of this urban shift are alarming. Cities, already struggling with dengue outbreaks, now face the double burden of two major mosquito-borne diseases. Public health systems, designed with seasonal and rural malaria patterns in mind, are ill-prepared for continuous urban transmission. Traditional responses such as fogging or spraying provide only temporary relief, often failing to reach hidden breeding sites within homes and buildings.

Containing this threat requires more than reactive measures; it demands structural change. Urban planning must integrate vector control, with building codes that mandate covered water storage, proper drainage, and mosquito-proof designs. Water supply systems need upgrading to reduce the reliance on rooftop tanks, while municipal waste and sewage management must be prioritized to eliminate breeding grounds. At the same time, public awareness campaigns should encourage households to adopt preventive practices, such as covering containers and maintaining sanitation.

Ultimately, the rise of An. stephensi underscores a harsh truth: malaria in Pakistan is no longer just a rural disease. Without urgent reforms in urban governance and infrastructure, the nation risks an entrenched public health crisis at the core of its economic hubs.

A New Kind of Malaria Threat

In Pakistan’s urban clinics, a troubling new pattern is emerging. Children and adults alike are increasingly being misdiagnosed with dengue when, in fact, they are suffering from malaria. What was once a rural disease has firmly established itself in the cities. The shift is stark: in 2022 alone, Pakistan recorded 1.6 million confirmed malaria cases, with a large share originating from urban and peri-urban areas (Pakistan National Malaria Control Program, 2023). This urban resurgence signals not just a health crisis but also a transformation in how malaria spreads and sustains itself.

At the center of this shift is Anopheles stephensi, a mosquito uniquely adapted to urban life. Unlike traditional malaria vectors that thrive in fields, ponds, or rice paddies, An. stephensi prefers artificial containers. In cities like Karachi, where water supply is irregular, millions of households rely on rooftop tanks and underground “tankas” for storage. These water reservoirs have become ideal breeding grounds. In Lahore, a recent survey revealed that over 40% of sampled water storage containers harbored An. stephensi larvae (Khan et al., 2024). Because these structures are used year-round, the mosquito enjoys a continuous breeding cycle, ensuring that malaria never fully subsides, even in cooler months.

The international experience offers a sobering warning. When An. stephensi invaded Djibouti City, malaria cases skyrocketed from just 27 in 2012 to more than 70,000 within a decade. The World Health Organization (WHO, 2023) has since flagged its spread as a severe threat to elimination of malaria across Africa, where it endangers decades of progress. For Pakistan, the message is clear: the presence of An. stephensi in urban centers is not a seasonal nuisance but a structural, long-term challenge that demands urgent public health and urban planning reforms before the country risks a full-scale urban malaria crisis.

Why Fogging is a Failing Strategy: Toward Integrated Urban Malaria Control

The widespread reliance on fogging as Pakistan’s first line of defense against malaria, particularly in urban centers, is proving dangerously inadequate against the advance of Anopheles stephensi. While fogging offers a visible and politically convenient response, its practical effectiveness is severely compromised. As one public health entomologist observed, “Fogging a street for a night is easy; keeping mosquitoes out of water tanks and homes is the real work.” The persistence of malaria transmission in Karachi, Lahore, and other major cities underscores the shortcomings of this reactive approach.

There are two central reasons for its failure. First, insecticide resistance has eroded the power of chemical interventions. A 2023 study in Punjab revealed that more than 78% of An. stephensi tested were resistant to pyrethroids, the most widely used class of insecticides for fogging and bed nets (Ali et al., 2023). This resistance dramatically reduces kill rates and renders repeated fogging campaigns increasingly futile. Second, fogging cannot penetrate the hidden breeding sites unique to this urban vector. An. stephensi thrives in rooftop tanks, underground tankas, and domestic water containers locations shielded from outdoor sprays. Larvae continue developing undisturbed, and adult mosquitoes retreat indoors, where fogging trucks cannot reach.

Relying on fogging alone is thus not only wasteful but also misleading, creating a false sense of security while the vector silently entrenches itself deeper into urban systems. A reimagined defense must integrate health policy, housing standards, and municipal infrastructure into a coordinated strategy.

The first step is to seal the water sources that serve as breeding hubs. Mandatory mosquito-proof lids for rooftop tanks and underground reservoirs, enforced through building codes, could dramatically reduce infestation. Evidence from Rajasthan, India, showed that replacing leaky lids with sealed covers eliminated tank breeding and reduced local mosquito densities by 70% (Singh et al., 2021).

Second, homes must be redesigned with mosquito-proofing in mind. Simple measures such as screened windows, sealed vents, and closed eaves create physical barriers. A 2023 meta-analysis found that house screening reduced malaria infection odds by nearly half (Tusting et al., 2023), underscoring its preventive power.

Third, urban governance must integrate mosquito control into core sanitation duties. Fixing water pooling points, lining open drains, and embedding larval surveillance into municipal routines can reduce habitats.

Finally, insecticides should be deployed intelligently. Next-generation tools, such as piperonyl butoxide (PBO)-treated nets, have proven more effective against resistant vectors. Rotating insecticide classes for Indoor Residual Spraying (IRS), guided by local resistance data, ensures sustainability.

Conclusion

The emergence of Anopheles stephensi in Pakistan’s cities signals a profound shift in the country’s malaria landscape. Once regarded as a rural and seasonal disease, malaria has now entrenched itself as a year-round urban threat, exploiting man-made water storage systems, poor drainage, and fragile municipal infrastructure. The alarming rise in cases, coupled with the mosquito’s proven resistance to commonly used insecticides, demonstrates that conventional measures such as fogging are inadequate and unsustainable.

This evolving challenge calls for a paradigm shift in both public health policy and urban governance. Malaria control must move beyond short-term chemical interventions to long-term structural reforms that integrate housing standards, water management, and sanitation into disease prevention. Building codes that mandate mosquito-proof tanks, urban planning that prioritizes drainage, and municipal services that embed larval surveillance are no longer optional they are essential. At the same time, households must be mobilized through awareness campaigns to adopt preventive measures within their own environments.

Pakistan’s cities stand at a crossroads. By embracing integrated, evidence-based strategies, the country can prevent a full-scale urban malaria crisis. Failure to act decisively risks not only overwhelming public health systems but also undermining economic stability in the nation’s urban hubs.

References: Ali et al; Khan et al; NMCP; Singh et al; Tusting et al; WHO.

Please note that the views expressed in this article are of the author and do not necessarily reflect the views or policies of any organization.

The writers are affiliated with the Department of Entomology, University of Agriculture, Faisalabad Pakistan and can be reached at h.bashir@uaf.edu.pk

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