How unseasonal rains are extending malaria transmission windows

New transmission windows emerge

While malaria is showing up unannounced, the district health department awaits guidelines for using a new compound for Indoor Residual Spraying (IRS) from the Department of Family and Health Welfare. IRS is recommended by the NCVBDC as a mosquito control measure and involves coating walls and other surfaces with an insecticide. DDT or dichloro-diphenyl-trichloroethane, which was the compound of choice for the purpose for decades, was phased out last December.

In May, as heatwave alerts were sounded in the district, Dharmendra Srivastava was at a malaria medical camp in Makra. The District Malaria Officer had been happy to note that bed nets were widely used, but added that, “till last year, DDT spraying was carried out twice a year, between May 15-June 30 and then again between September 15-October 15. For this year, we haven’t yet received any guidelines about the new insecticide.”

IRS is carried out during the peak months for malaria--that is, the post-monsoon months of September-October. Ideal ecological conditions are created for the mosquitoes to breed post rainfall and IRS can make the breeding sites inhospitable. But these timelines are now old, and “need to be revisited based on the extension of the malaria transmission window and must be planned at a localised level”, observed Ramesh Dhiman, former scientist at the National Institute of Malaria Research, who is currently the national coordinator for the Global Fund for Malaria, an international financing and partnership organisation to end the epidemics of HIV/AIDS, tuberculosis and malaria.

In two decades to 2019, Sonbhadra has seen declining rainfall. The following four years saw instances of erratic rainfall: 2020 and 2021 saw large amounts of rainfall pre-monsoon, while the monsoon was normal or near-normal; 2022 and 2023 saw deficit monsoons. Farmers have been put to distress by the erratic rainfall and intermittent periods of drought. In recent years, a prolonged transmission window for malaria has also emerged in Sonbhadra. The monthly data obtained from the District Malaria Unit showed that in 2019, malaria caseloads peaked in September. In 2020, the peak season extended to October and then to December in 2021 and 2022.

This year, Sonbhadra received excess rainfall in February. The average mean temperatures hovered between 20-22°C. In March too, the district received excess precipitation, with a mean temperature between 24-26°C. Most Anopheles mosquitoes develop in the optimal temperature range within 20-30°C, making both months favourable for breeding.

“The caseload is high even in months which weren’t considered as malaria transmission window earlier. Rising heat and changing rainfall patterns directly impacts the malaria transmission trends,” said Rajib Chattopadhyay, scientist at the India Meteorological Department, Pune who is also heading the Climate Application and User Interface team to look at the correlation of climate and health. The behaviour of the malaria vector is changing with a changing climate.

“Some places in high altitude regions where malaria was unheard of are facing the disease now. These can be directly attributed to climate change. In such a scenario, Uttar Pradesh can easily transform from a low-risk area into a high-risk area,” he added. In Amroha district in north-west Uttar Pradesh, for instance, there was a malaria outbreak in January, observed Vikasendu Agarwal, state surveillance officer under the Integrated Disease Surveillance Programme.

Need for a holistic approach

According to the World Malaria Report 2023, there were an estimated 249 million malaria cases in 85 malaria-endemic countries and areas in 2022, an increase of 5 million cases compared with 2021. India accounted for 1.4% of the global caseload and for two in three cases in the WHO’s South-East Asia region. However, India also recorded the highest decline in cases (30%) during 2021-22 among 11 high-burden countries. Malaria deaths also fell 34%.

These gains may be short-lived: The report noted that climate change has the potential to trigger reintroduction of malaria in areas that have high receptivity and in which malaria has recently been eliminated.

The decline in India’s caseload has been evident since 2015, after the country launched a National Framework for Malaria Elimination Programme in 2016. The strategy is to eliminate the disease in a phased manner by 2030 and prevent its resurgence in areas where malaria transmission has been interrupted. However, a review of malaria elimination in 2022 warned that the effect of climate change on malaria is a crucial epidemiological aspect that cannot be ignored any longer.

The review makes a series of recommendations including two that can help tackle malaria holistically, deploying a One Health approach: carry out climate change studies to understand the resurgence of malaria in areas where it has been well-controlled or eliminated, and include multisectoral as well as cross-border collaboration as a standard agenda item in the monthly meetings of state, district and block-level task forces.

One Health is a collaborative, multisectoral, and transdisciplinary approach, working at the local, regional, national, and global levels. The goal is to achieve optimal health outcomes recognising the interconnection between people, animals, plants, and their shared environment. Although malaria is not specifically included in India’s national programmes for One Health, a One Health-informed multisectoral and cross-collaborative approach is discussed in the country’s malaria elimination programme.

The review acknowledged that the collaboration efforts between the health and non-health sectors, such as water resources, panchayati raj and rural development, and agriculture were “mostly episodic” and that this was a gap in malaria elimination efforts.

For example, Sonbhadra has the long-standing problem of poor groundwater reserves. A 2012 report by the Central Ground Water Board had recommended groundwater recharge structures like check dams to counter this problem, “which are now active breeding sites for Anopheles,” said the district malaria officer. The erratic rainfall throughout the year is making these breeding sites perennial--like the unused well outside Ramji’s house which has standing water year-round, and the creeks surrounding Gulabi Devi’s house, adjacent to Rihand dam, which are water-logged everytime it rains.

Intense entomological studies are also the need of the hour, according to Atul Kumar, India Program Head - Health in the NGO Prayatna. Kumar has 13 years of experience working on malaria, and noted that Anopheles mosquitoes have altered their biting patterns. “Unless we study the vector behaviour, how will we develop a message for the community?” he questioned.

But Sonbhadra has no appointed insect collector or district-level entomologist to conduct such studies. The state entomologist Vipin Kumar could not detail any specific studies conducted in this regard. Dhiman calls this a case of negligence.

More than a health crisis

The malaria patients in Sonbhadra’s villages are dependent on paracetamol and painkillers, procured from quacks. Gulabi Devi prefers the quack because “the hospital is too far and Rs 150 required to reach there is too much”. Brihaspatiya Devi took Suninder to a quack because she can pay him as and when she has money. Sonu Devi didn’t go to the nearest primary healthcare centre in Kunwari because the doctors may not be available.

The jholachaps or unlicensed medical practitioners here have the trust of the community. ‘Jhola’ refers to the bag of remedies which the healer carries, which villagers view as a sufficient stamp of authority ‘chaap’ to heal the sick.

Poor awareness about effective malaria treatment amongst locals challenges the healthcare system too. The health department finds it difficult to convince them for testing and complete the medication course. The district malaria officer Srivastava cites an example: “Once we came across a woman who needed immediate medical attention for malaria but her husband told us that he would rather get a new wife in the amount he needs to spend treating his current wife.”

Brihaspatiya Devi and her husband Ramji are marginal workers who make Rs 250 per day working on construction sites. Collectively they lost Rs 1,250 since their son fell ill with malaria. The family had spent Rs 3,000 for injections, tablets and transportation. It had taken Brihaspatiya Devi over a year to save that money.

Gulabi Devi in Sendur relates to these circumstances. Her family depends on a small general store for a hand-to-mouth income. The malaria expenses have put them in an economic spiral.

“But how do I weigh the value of Rs 1,100 with my life,” she questioned.

This is the first part of a two-part series focusing on malaria from One Health lens, produced with support from Internews’ Earth Journalism Network.

This report is republished with permission from IndiaSpend.org, a data-driven, public-interest journalism non-profit. It has been lightly edited for style and clarity.

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