Risk of Nipah virus transmission through date palm sap trade in Bangladesh: a qualitative ethnographic study

Abstract

Background

Nipah virus is an emerging zoonotic pathogen with pandemic potential, primarily transmitted through the consumption of raw date palm sap contaminated with bat excretions. Despite recurring outbreaks in Bangladesh since 2001, limited research has explored sap harvesting and trading practices. This study aimed to understand raw date palm sap collection, trade, and the risk of Nipah virus spillover at the community level in Bangladesh.

Methods

A qualitative ethnographic study was conducted in two districts of Bangladesh associated with recurrent outbreaks in February 2021 and March 2022. We recorded participant observations and conducted ethnographic interviews with raw date palm sap collectors to gather data on collection, trading practices, and protective measures they used. Data analysis followed a grounded theory approach, identifying themes related to raw date palm sap harvesting and trading.

Results

Sap collectors sold raw sap locally and also used social media to reach buyers in other districts, where they could earn higher profits. Our observations and participant reports revealed that large fruit bats, small frugivorous bats, and rodents visited the trees and drank and contaminated raw sap with their excreta. A few sap collectors were aware of Nipah virus and used protection to avoid infection from drinking raw sap. Sap collectors prefer to use non-conventional protective apparatuses like jute bags, plastic bags, and polythene sheets due to the time and resource constraints to protect bats’ and rodents’ access to date palm trees.

Conclusions

This study provides important insights into the knowledge of Nipah virus and understanding of its transmission in the sap collector communities where outbreaks have occurred. It underscores the need for educational outreach programs to raise awareness and promote protective measures among the stakeholders engaged in raw date palm sap harvesting. Future research should explore raw sap distribution and trading networks in large areas to better characterize the geographies, behavioral, and cultural practices that influence Nipah virus transmission. Culture-sensitive interventions with economic incentives, involving harvesters, local governments, and non-governmental organizations, along with testing the effectiveness of protective measures, are essential to prevent the spillover of Nipah and other bat-borne emerging viruses in Bangladesh.

Supplementary Information

The online version contains supplementary material available at 10.1186/s42522-025-00181-5.

Background

Nipah virus (NiV) is an emerging zoonotic virus causing encephalitis with or without respiratory syndromes in animals and humans [1, 2]. The World Health Organization (WHO) included NiV on its blueprint list of priority diseases for research and development (R&D) due to its pandemic potential, broad geographical range, and high case fatality [3]. Shortly after the initial identification of NiV in Malaysia and Singapore from 1998 to 1999 [4], it was recognized as a causative factor for severe acute meningoencephalitis in both Bangladesh and India in 2001 [5, 6]. Since then, Bangladesh has experienced nearly annual outbreaks with a significant fatality rate of >70% [1, 5, 7], for a total of 343 human cases through 2024 [7, 8]. Cases of NiV encephalitis have also been documented in the Philippines in 2014 [9]. Due to the recurring outbreaks in Bangladesh and India, NiV has become a major public health concern. Its high pathogenicity, widely distributed host range, and lack of available countermeasures have led the WHO to assign it the utmost priority as a regional threat in Southeast Asia [10].

Pteropus medius, a large frugivorous bat commonly found across South Asia, has been identified as a natural reservoir for NiV [2, 4, 11, 12]. Zoonotic transmission of NiV occurs most commonly through the drinking of raw date palm sap (RDPS) or fermented date palm sap (locally referred to as tari), which is contaminated with bat excreta [13–15]. RDPS can become contaminated with saliva, urine, or feces from infected P. medius bats, who frequently feed on the sap of tapped date palm trees or from the collection pots hanging from the trees [14, 16]. Researchers have demonstrated that NiV can survive for several days in RDPS and that other animals can contract NiV through exposure to contaminated sap [17]. Furthermore, various outbreak investigations have identified RDPS or tari consumption as the epidemiological link to NiV exposure in Bangladesh and West Bengal [1, 14, 15, 18]. Person-to-person transmission is a commonly observed feature of NiV outbreaks [18–23]. So far, NiV outbreaks have been limited to fewer than five chains of transmission [19]. However, the potential of a more transmissible strain of NiV circulating in bats, combined with the recurrent opportunities for spillover, highlights the need to focus on prevention and control of Nipah and related viruses to prevent a larger-scale outbreak [10, 24, 25].

RDPS is a traditional delicacy enjoyed by Bengali people during the winter months (December through February). The practice of collecting and consuming RDPS is a long-standing tradition, and it holds cultural significance in Bengali culture. It is often consumed fresh and is known for its unique taste and nutritional value [26, 27]. In addition to raw consumption, RDPS is boiled to produce molasses, locally known as “gur”. It is also used in preparing traditional Bengali delicacies such as pithas (similar to pancakes) and payesh (rice pudding). The various practical and artisanal applications of RDPS serve as an example of the rich cultural and culinary heritage of the Bengali people [27, 28].

Since the emergence of NiV outbreaks in humans in Bangladesh, cases have been concentrated in the Northwestern part of the country. More than half of the total NiV cases have been reported among four districts: Faridpur, Rajbari, Rajshahi, and Naogaon [8]. Furthermore, the production of date palm juice is concentrated in the Western and Northwestern regions of Bangladesh. RDPS production has increased annually [29]. However, there is still limited research on RDPS harvesting. In addition, no studies have reported on trading practices, including the distribution of RDPS from harvesting sites and sellers to consumers throughout Bangladesh. Hence, we conducted a study to gain a better understanding of RDPS collection, trade, and the risk of NiV spillover at the community level.

Methods

Study site and data collection

We conducted a qualitative ethnographic study in two districts with recurring NiV outbreaks: Rajbari and Naogaon [7, 8], located in the northwestern part of Bangladesh (Fig. 1). We conducted data collection in February of 2021 and March of 2022, which coincided with NiV outbreaks in humans [8]. We conducted ethnographic interviews with 31 RDPS collectors (locally referred to as gachis) following the guidelines (Additional file 1). The gachis were selected purposively, focusing on mixed-scaled RDPS harvesters with experience across the study locations [30], since they are responsible for harvesting and selling RDPS. Through the interviews, we collected data on RDPS collection, trading practices, and protective apparatuses to interrupt bats, rodents, and other animals’ access to the sap. All interviews were conducted in Bangla and recorded on a voice recorder.

Fig. 1.

Map of Bangladesh showing study sites

To supplement the interviews, we conducted participant observations (n = 14) on RDPS trees of fourteen different gachis, including materials used for sap collection, animals seen visiting the date palm trees, and protective measures used to prevent animals (mainly bats) from accessing the collection pots and RDPS trading (Additional File 2). We observed shaving, cleaning, sap collection, pot hanging, and setting protective materials of the RDPS trees in the afternoon. We also observed bat access to the RDPS trees for three to four hours in the evening. We also observed RDPS trading in the study areas in the morning. We continued interviews and observations until data saturation [31] when we received similar information repeatedly. We recorded observation data in field notebooks and documented noteworthy events through photos and video recordings.

Data analysis

The audio recordings were transcribed word for word, to the extent possible. We read the interview transcripts several times to identify emerging concepts and themes, and developed themes using the grounded theory approach [32]. Some of the themes that emerged included ‘RDPS harvesting season’, ‘tools used for tree shaving and sap collection’, ‘bat visits and the use of protection preventing bat access to trees’, ‘gachis’ perceptions of using protective equipment on date palm trees’, and ‘diverse utilization and trade of RDPS’ (Table 1). Selective quotes were used to support specific themes and to highlight various commonalities and differences. The observation data were triangulated with interview data.

Table 1.

Emerging themes from grounded theory analysis of RDPS collection and trade practices in Bangladesh

Theme	Description	Supporting Evidence
RDPS harvesting season	Seasonal patterns of RDPS collection, linked to climate and local practices.	Interview accounts describing peak harvesting months; observation of seasonal activities.
Tools for tree shaving and sap collection	Specific tools and techniques used for shaving date palm trees and setting collection pots.	Gachis’ descriptions of their tools (knives, bamboo spouts, earthen/metal pots); field observations of their use.
Bat visits and protection of trees	Frequent bat activity at RDPS trees, and various protective materials used to restrict access.	Observations of bats visiting trees; use of bamboo skirts, nets, or polythene sheets documented in interviews and field notes.
Gachis’ perceptions of protective equipment	Attitudes, beliefs, and barriers regarding the adoption of protective measures to prevent contamination.	Interviews highlighting reluctance, perceived inefficacy, or cultural beliefs about protections.
Utilization and trade of RDPS	Multiple uses of RDPS (raw consumption, fermentation, sweets), and trading practices from collectors to consumers.	Observations of RDPS distribution, market transactions, and interview descriptions of diverse sap utilization.

Results

Demographic and socio-economic characteristics of gachis

All gachis were male, with a median age of 40 years (range: 18–71). Almost half of them (n = 15) had completed the primary level of education, while 11 individuals had not received any formal education. Only four gachis had attained a secondary level of education, and one had education beyond the secondary level. RDPS harvesting was reported as a source of supplemental income during the winter, rather than a primary occupation. Agriculture and/or crop production served as the primary source of income for the majority, with 24 out of 31 individuals relying on these activities. Other occupations included grocers, school teachers, fruit businessmen, and van (rickshaw) pullers. The average monthly family expenditure for gachi households was BDT 11,193 (equivalent to US$ 102). On average, the gachis had 15 years of experience in RDPS harvesting, ranging from 1 to 55 years. A comprehensive summary of all gachis demographics captured through the interviews is presented in Table 2.

Table 2.

Demographic and socio-economic characteristics of gachis

Characteristics	Naogaon n = 19	Rajbari n = 12	Total n = 31
Median Age in years (range)	45	40	40 (18–71)
Education Level
No formal education	08	03	11
Primary	08	07	15
Secondary	02	02	04
Above secondary	01	-	01
Main Occupation
Agriculture/crop production	17	07	24
Grocery	01	01	02
School teacher	01	-	01
Fruit business	-	01	01
Van (rickshaw) puller	-	03	03
Average family expenditure/month (BDT)	10,421	12,416	11,193
Average time (in years) of RDPS harvesting (range)	20	13	15 (1–55)

n = number

Date palm sap harvesting season

Our interviews revealed that RDPS harvesting is a meticulously timed endeavor that commences in the Bengali month of late Agrahan (corresponding to early November) and ends in the Bengali month of early Falgun (which aligns with March). The gachi community follows a well-structured sequence of activities leading up to the sap collection. As winter approaches, around late October or early November, they begin preparations by grooming and cleansing the date palm trees. According to the gachis, the actual sap collection phase typically starts in early December and continues until early March. Some gachis in the Naogaon field site reported exclusively working in the paddy field during the sap harvesting period, while others engaged in both activities simultaneously. Tree maintenance and pot hanging duties usually take place in the afternoon, allowing them to collect sap during the early morning hours before tending to their paddy fields.

Tools used for tree shaving and sap collection

Many gachis use a local tool known as the da or hysha, a sharply curved knife designed for shaving trees during sap collection (Fig. 2). At the Rajbari study site, a few gachis deviated from this common practice and use a ‘batal’- a knife characterized by its sharp front section, for tree shaving. In the late afternoon, it is a common practice for the gachis to use their thumbs to remove the foam that accumulates on the freshly shaved portions of the trees.

Fig. 2.

Tools used for tree shaving (a) bag for carrying tools (b) da/haysha for shaving tree (c) batal

Traditionally, the gachis prefer to collect fresh RDPS in earthen pots (Fig. 3). However, in recent times, the unavailability of traditional vessels has led to the adoption of plastic containers instead.

Nowadays earthen pots are costly and not available, besides, most of the potters shifted their occupations due to increased usage of plastic utensils. Now, we use discarded plastic containers of soyabean oil that are free of cost to collect sap. [ Gachi, Naogaon]

Fig. 3.

Sap collection pot (a) clay pot (b) plastic pot

Animal observation and use of protection to prevent contamination

The gachis commonly reported observing large fruit bats (Pteropus medius), locally known as ‘boro folkhaoya badur’, small frugivorus bats (e.g. Rousettus or Cynopterus spp.), locally known as ‘choto badur’, and rodents (e.g. Rattus spp.) visiting the date palm trees. They also noted that these animals drink free-flowing sap or drink directly from the collection pots. Our observations further confirmed the presence of small bats and rodents feeding on RDPS. As they feed on the sap and/or spend time above the collection pots, bats come into close contact with the sap. The sap can then become contaminated with their saliva, urine, and feces (Fig. 4).

Fig. 4.

Fruit bat (Pteropus medius) licking RDPS on tree

In response to this, gachis implement various measures to protect the sap from animal access and contamination. RDPS is locally referred to as “kacha khejuer rosh”, “kacha rosh’’ or simply “rosh”. To achieve this, gachis use several protective mechanisms such as bamboo skirts and non-conventional protective apparatuses like jute bags, plastic bags, polythene sheets, and nylon nets (Fig. 5). Most of the gachis used plastic bags rather than other protection materials (Table 3). According to the gachis, bamboo skirts are the most effective solution. However, they usually choose jute bags, plastic bags, and nylon nets, because these options are more convenient and time-efficient, requiring less preparation and fewer resources than bamboo skirts. The following quotes were selected from the interviews to highlight some of the gachis’ opinions regarding different protective mechanisms used to prevent contamination:

We collect it free of cost from the grocery or from a house under construction; they threw these out after finishing the goods… [Gachi, Plastic /Jute bag user]

It (net) can protect from bats but sometimes it may get stuck on the shaved part of the tree due to contact with bat’s fingers. Then, the rosh will leak. [Gachi, Nylon net user]

…I can use my own bamboo, besides bamboo is less expensive…, skirt is hardy, if bats sit on it, cannot go into the pot, but if it is used net, it might get attached to the shaved part and bat can drink rosh. [Gachi, Bamboo skirt user]

Fig. 5.

Use of different protective apparatuses on RDPS Tree (a) nylon net (b) plastic bag (c) polythene sheet (d) bamboo skirt

Table 3.

Types of protection materials used by gachis

Type of Material Used	Numbers (N = 31)
Nylon net	02
Plastic bag	08
Polythene sheet	03
Bamboo skirt	02
Jute bag	02
No use of any protections	14

Gachis’ perceptions of using protective equipment on date palm trees

More than half of the gachis (n = 17) reported using measures to prevent bats and other animals from accessing their date palm trees (Table 4) during the sap collection season (December to March). Only a few gachis (n = 5) were aware of the NiV; among them, 80% (n = 4) used protective measures to reduce their risk of exposure. Other motivations for protection include harvesting clean sap, preventing animals (particularly bats) from drinking the sap, and avoiding enteritis in humans who consume it. The remaining 14 gachis did not take any preventative measures.

Table 4.

Gachis’s knowledge on NiV and practice of protective measures

	Presence of NiV Knowledge (n = 5)		No Knowledge of NiV (n = 26)
Practice	Preventive measure	No preventive measure	Preventive measure	No preventive measure
No. of gachis	04	01	13	13
Reason behind preventive measure	To prevent NiV	-	-To get clean sap - To protect sap from bat consumption - To prevent enteritis in humans upon consuming the sap	-

The gachis further reported that, in recent years, bats have begun scratching bamboo skirts and trunks to access and consume the sap. According to the gachis, this behavior may be due to the scarcity of food for bats during the winter season.

Previously bats come only on the taller trees, recently, bats also come to small trees due to scarcity of bat food, so, we use protections on the trees. [Gachi, Naogaon]

Diverse utilization and trade of RDPS

The gachis collected RDPS from several trees and mainly sold it in two forms: raw sap and molasses. Raw sap is consumed without any additional preparation, usually within a few hours of collection. It can also be boiled at a high temperature to produce molasses. While raw sap has been identified as the primary route of NiV transmission in Bangladesh, molasses has not been linked to NiV exposure. According to one of gachis:

In winter, rosh is a fruit, it is sweet. We get rosh only in winter, many people drink it with their family and relatives. [Gachi, Rajbari]

In addition, our study explored how the gachi community engages in the production of tari, through the fermentation of RDPS by exposing it to sunlight for a period of one to three days. Sometimes, they store the tari in plastic containers or bottles for future use, with a shelf-life of up to six months. However, only a small portion of gachis participate in the sale of tari within their local vicinity. It is worth noting that the preference for marketing RDPS over gur is attributable to various factors, including the time required for gur preparation, the associated fuel costs, and the heightened consumer demand for RDPS.

Benefit of rosh - no fuel, no time spent, it is sold within a short time, I can do another work. [Gachi, Naogaon]

According to the gachis, the community people want to drink RDPS at least once in winter if it is available, although some people do not purchase it due to the high price. The gachis mainly sell RDPS within their local communities, including the village in which they reside and neighboring villages. Some locals buy RDPS directly from the date garden when the gachis collect it, and some buy it from the gachi’s house. In very few cases, the gachis send RDPS to the consumers’ houses. However, people place pre-orders with the gachis for RDPS because of high demand.

Many people come to buy rosh early in the morning under my trees, but I cannot provide to all. I get 3–4 pots of rosh, but demand is more. [Gachi, Rajbari]

Villagers or neighboring village people ask for the availability of rosh on the previous day of rosh collection, if, in the meantime, there is no other demand from someone, I will say that I will give him rosh, and after collection, I bring rosh by myself to his house. [Gachi, Naogaon]

Some gachis (16/31) reported that the distribution of RDPS extends beyond their immediate local community. They send RDPS to non-harvesting regions through intermediaries or middlemen, as well as through social media platforms, in response to consumer demand. The gachis also reported that individuals procure RDPS through their relatives residing in harvesting villages and send them to non-harvesting areas. They acquire RDPS from gachis and transport it in used plastic containers to their relatives’ homes during visits. Sometimes, they arrange for its shipment through inter-district bus services for a fee.

According to the gachis, within these non-harvesting areas, consumers seeking RDPS often rely on social media, particularly Facebook, to access information about its availability. Numerous Facebook pages feature advertisements for the selling of RDPS. The businessmen collect RDPS from the gachis and sell them to their customers who order rosh. Businesspeople in these areas typically source their RDPS from gachis via phone. Gachis fill the RDPS into plastic containers, which are then transported to the businesspeople through parcel services or by booking parcels in inter-district buses. Sometimes, a few Bangladeshi expats, while visiting Bangladesh, found online platforms of RDPS selling on Facebook and were encouraged to buy and drink RDPS. They took RDPS when returning with them for their relatives or friends. A diagram is illustrated in Fig. 6 for the detailed process of RDPS collection and trading or distribution to the consumers.

Fig. 6.

Collection and trade of RDPS. Gachis collected RDPS from the DPT and distributed it to the consumers through trading. RDPS: raw date palm sap, Gachi: RDPS collectors, and DPT: date palm tree. The figure was created with BioRender.com, accessed on 9 September 2025

Lastly, the gachis reported that several groups of young individuals from non-harvesting regions contact them by phone to purchase RDPS. They either travel to the gachi’s residence or a location near date palm trees to collect RDPS. The gachis also stated that these groups are particularly active during various national and international commemorative events, such as Bangladesh’s Victory Day on December 16th, Valentine’s Day on February 14st, International Mother Language Day on February 21st, and Bangladesh’s Independence Day on March 26st. On these occasions, the youth gather for social gatherings and feasts featuring RDPS and parched rice (locally referred to as muri).

Discussion

This qualitative ethnographic study incorporates multiple data sources, including participant observation and in-depth interviews, to mitigate potential research biases and ensure a balanced and accurate portrayal of RDPS collection and trade. This study provides an in-depth examination of the cultural and behavioral determinants influencing the risk of NiV transmission in Bangladesh, focusing on the practices surrounding the harvesting and trading of RDPS. Through an anthropological and epidemiological lens, we have uncovered key insights into how these practices intersect with public health concerns, particularly within the context of NiV and other emerging bat-borne infections. The triangulation of observation and interview data strengthens the research findings’ rigor, depth, and validity [33, 34]. Employing a grounded theory approach, this study enables a comprehensive understanding of RDPS harvesting and trading practices, capturing nuanced complexities and providing in-depth insights [32, 35].

By focusing on aspects such as animal behavior and protective measures against tree access, the research bolsters the validity and reliability of the conclusions drawn. It offers a robust framework for identifying wild animal species that visit date palm trees and potentially contaminate the sap, as well as for understanding the interactions between humans and wildlife. Additionally, it considers environmental factors—such as seasonality, RDPS tree ecology, and land use—that affect sap contamination and the risk of NiV transmission within the One Health approach [36, 37].

Furthermore, mathematical modeling studies on NiV spillover have mainly focused on estimating transmission dynamics and the probability of bat-to-human infection through the consumption of contaminated RDPS, often by simulating outbreak scenarios under different behavioral or environmental assumptions [38]. Such models are important for identifying high-risk behaviors and predicting the potential impact of control measures. However, ethnographic research offers a different but equally valuable perspective by providing a deeper understanding of the human behaviors, social meanings, and contextual factors that shape those very practices driving spillover. Ethnography reveals how local perceptions, motivations, and socio-economic pressures influence decision-making and risk negotiation. These dimensions are often difficult to quantify in mathematical or computational frameworks. While modeling can estimate the likelihood of transmission or forecast potential outbreaks, it may not fully capture the cultural logics, trust relationships, and lived experiences underlying risk behaviors. Rather than one approach providing a better understanding, both represent complementary epistemological lenses, such as ethnography helps explain ‘why people act in particular ways’, whereas modeling explores ‘how those actions translate into transmission outcomes’. Future research could benefit from integrating these two approaches, using qualitative insights to inform key behavioral parameters, validate model assumptions, and interpret model outputs within their socio-cultural contexts. Such integration would strengthen One Health efforts to understand and mitigate NiV spillover by linking human experience with disease dynamics.

Gachis harvest sap from date palm trees in the winter and sell products in the form of RDPS, molasses, and tari. Gachis prefer to market RDPS over other products due to the high consumer demand, as well as the reduced time and lower cost of preparation. RDPS is consumed as a traditional drink by the community people. However, RDPS is not always safe to drink due to contamination with the excreta of bats and rodents. People may be infected with bat-borne and other emerging zoonotic pathogens through the drinking of RDPS. Similarly, a study found that raw milk is traditionally consumed in some parts of the United States of America, because of its taste, availability, and comparatively less expensive than pasteurized milk for farm families [39]. Besides, some food-focused studies suggest that people consume more unhealthy food when it is readily available [40–42].

Some gachis knew about NiV transmission, so they used protective measures to prevent RDPS from contaminating the bats’ and rodents’ excreta. However, they do not take proper protective measures during the RDPS harvesting season, which aligns with the rice paddy season [43] while they find the opportunity to engage in paddy field work. Most of the NiV outbreaks occur in winter, when natural fruits are scarce, resulting in bats turning to easily available RDPS as an alternative food.

This study highlights the widespread distribution of RDPS products throughout the country, providing key insights into the methods of marketing and trading RDPS. Our findings show that social media platforms, particularly Facebook, play a growing role in RDPS distribution to non-harvesting regions, expanding potential Nipah exposure zones. This also has the possibility to distribute internationally among Bangladeshi expats, such as in the Middle East and the United States of America, where the number of Bangladeshi immigrants is higher. The young gather for social gatherings and feasts featuring RDPS and parched rice, which makes the young (6–30 years) more vulnerable to getting NiV infections frequently in Bangladesh [8]. Throughout the COVID-19 pandemic, electronic commerce experienced a surge in activity facilitated by social media engagement [44]. Notably, in Bangladesh, the COVID-19 crisis has led to a heightened reliance on e-commerce channels via social media platforms [45]. Social media plays a crucial role in the distribution and consumption of RDPS in communities where it might not otherwise be available. Therefore, the risk of NiV exposure is not limited to the vicinity in which RDPS is collected. It is important to consider the movement of RDPS products when planning NiV surveillance and to engage these social media platforms for tracking distribution and disseminating risk communication.

Limitations of the study

In qualitative research, samples are typically small and purposively selected, so findings reflect depth but not breadth. The voices and narratives that we collected may not capture the full diversity of perspectives on RDPS collection and trading across the broader population, which was also indicated in another study, particularly in RDPS harvesting and protection use [46]. In addition, during interviews, participants may have downplayed practices considered ‘use of protection’ and emphasized behaviors they thought the researchers would approve of. We have also collected data through observations as well as interviews that could minimize this bias.

We identify a minimal number of gachis individuals engaged in the production and sale of tari (2 out of 31) to their local communities. Besides RDPS, there exists a need for a more comprehensive investigation into the intricacies of tari production, sales, and distribution. In our study, we only reveal the knowledge and practices of gachis on NiV and other emerging zoonotic diseases in the Nipah belt, however, we did not include non-Nipah districts. The people who buy RDPS from gachis, we do not know how frequently they buy it. Interviewing them would give us an idea about the demand, the volume of RDPS they buy, and their perception of NiV transmission. Thus, the shifting or trading networks from harvesting to non-harvesting areas can be future research areas.

Conclusions

The study reveals that RDPS harvesting is relied upon as a seasonal source of income for gachis. Gachis predominantly sells RDPS to local communities. They also distribute it to non-harvesting areas through middlemen or social media. This pattern highlights the strong economic incentives driving RDPS trade beyond simply a local cottage industry. This study also reveals a discernible association between NiV knowledge and the use of protective measures to impede bats’ access to RDPS trees. Implementing educational outreach programs throughout the RDPS harvesting districts could help augment awareness of the connection between sap contamination and NiV transmission, which may increase the adoption of protective measures among the gachis and other stakeholders engaged in RDPS harvesting. We suggest future research focused on RDPS distribution and trading networks beyond harvesting areas to better understand the geographical, behavioral, and cultural factors associated with the risk of NiV transmission. This research should adopt a One Health approach that engages key stakeholders, including harvesters, local governments, digital platforms (both mass and social media), and non-governmental organizations (NGOs). Future studies should include Bangladeshi expats to better understand whether demand for RDPS is increasing and expanding internationally. In addition, we recommend adopting a culturally sensitive intervention, including testing bat access against various protection apparatuses alongside economic outcomes in RDPS harvesting practices to help prevent spillover of NiV and other emerging bat-borne viruses in Bangladesh. Furthermore, awareness messages on NiV transmission should be circulated on the electronic and print media, as well as social media, in collaboration with local leaders, including religious leaders, social influencers, and local government officials.

Supplementary Information

Below is the link to the electronic supplementary material.

Abbreviations

IEDCR

Institute of Epidemiology Disease Control and Research

NGOs

Non-governmental Organizations

NIH

National Institutes of Health

NiV

Nipah Virus

RDPS

Raw Date Palm Sap

DPT

Date Palm Tree

WHO

World Health Organization

Author contributions

AKMDK, AI, JHE, conceived and designed the sampling methods of the study. AKMDK, AI developed the IDI guidelines. AKMDK, MAK, MI, NNC, SDC managed the data collection. AKMDK, AI transcribed and developed thematic codes. AKMDK drafted the manuscript. AI, SM, PD, MAK, MI, NNC, SS, SDC, MK, TS, JHE reviewed and edited the manuscript. AI, TS, JHE supervised the study. TS, JHE, made the fund accusation. All authors were involved in the development and revision of the manuscript, and all authors read and approved the final manuscript.

Funding

This work was supported by the National Institutes of Health (NIH), National Institute of Allergy and Infectious Diseases (NIAID), Grant number: U01AI153420 and 5R24AI165424.

Data availability

All data supporting the findings of this study are available within the paper and its Supplementary files.

Declarations

Ethical approval and consent to participate

The study protocol was reviewed and approved by Health Media Lab, a United States-based IRB, (IRB: 758EHA20) as well as locally by IEDCR (protocol: IEDCR/IRB/12). Informed written consent was obtained from the study participants before the interview started. Participants’ anonymity and confidentiality were strictly maintained throughout the research process. Furthermore, participants were informed in advance that the researchers would not offer them any financial or other benefits for participating in this research.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.