The State Health & Family Welfare (H&FW) department has reported a dramatic decline in dengue cases in Nagaland this year, with only 16 cases recorded so far compared to 4,943 cases in the previous year.
This update was shared during a meeting of the National Vector Borne Diseases Control Programme (NVBDCP) convened by H&FW Commissioner and Secretary Anoop Khinchi.
Emphasising taking all precautionary measures by the public for prevention of dengue, Khinchi noted that the state had few dengue cases this year. However, for the prevention of any vector borne diseases, he urged the public to maintain clean surroundings by eliminating stagnant water to reduce mosquito breeding sites, wear long sleeves, and use long lasting insecticidal nets (LLINs) and repellents to prevent mosquito bites.
Referring to stagnant water in cups being used during rubber plantations in Wokha and Dimapur, he directed officials to notify the districts to take precautionary measures.
He stressed the need to reiterate precautionary steps and educate the public about the peak times of mosquito activity for their safety.
He also inquired about the status of the dengue helpline, hospital preparedness, and distribution of LLINs. While informing that the state had reported only 16 dengue cases as compared to 4,943 cases last year, NVBDCP state programme officer and joint director Dr Neisakho Kere attributed the decrease to effective advocacy and awareness campaigns focused on source reduction.
He informed the meeting that NVBDCP teams in the districts were actively conducting awareness programmes and checking domestic breeding sites to remove mosquito larvae. He said serotypes 1 and 2 were detected during last year’s outbreak.
Stating that since many people were affected by these serotypes, some immunity had developed, which could explain the few cases this year, he however cautioned that arrival of serotypes 3 and 4 could lead to a spike in cases.
In Dimapur, where the house index was notably high last year, it decreased this year due to mass awareness and intervention efforts. He mentioned that district hospitals had been directed to set up separate dengue wards.
Referring to Japanese encephalitis (JE), Kere expressed concern over the neurological deficits caused by the disease. He said four cases were recorded in Mon, five in Dimapur, and one in Peren this year, with no deaths recorded so far.
He mentioned that four districts — Mon, Peren, Phek, and Kiphire — were not covered by JE routine immunisation programme. Given the high JE fatality rate, he stressed introducing routine immunisation in these districts.
Kere explained that JE was transmitted by culex mosquitoes, which could amplify the virus in pigs, allowing it to survive for up to a year. While human-to-human transmission did not occur, he cautioned that mosquitoes that bit infected pigs could transmit the virus to humans.
He claimed that fogging for adult mosquitoes was being conducted in areas where cases had been detected. However, he admitted that fogging in jungle and paddy field areas, where JE virus was prevalent, was challenging. Despite this, he assured that NVBDCP teams were doing their best and the districts were on high alert, which had helped control the situation so far.
He predicted that dengue cases would decrease by October-end, as mosquitoes typically did not survive in winter. However, he underscored that dengue-infected mosquito eggs could survive for up to a year, and mosquitoes laid eggs in any discarded container where water accumulated.
Kere claimed that Mpox was not currently a threat in the state, but Zika virus transmitted by the same aedes mosquitoes responsible for dengue and chikungunya remained a concern.
Regarding malaria, Kere recounted that Nagaland recorded its highest number of malaria cases — 8,489 positive cases with 35 deaths– in 2009. Since then, he revealed that the number of cases had consistently decreased.
Last year, he mentioned that there were four indigenous cases and five imported cases, with “indigenous” meaning the infection originating in the state and “imported” indicating infection from outside the state. So far this year, he said only two malaria cases had been reported. He attributed the decline to changes in weather, noting that malaria vectors did not survive in higher temperatures and tended to move to cooler regions, according to an entomological report.
He stated that Aedes mosquitoes, which caused dengue and chikungunya, were more resilient than malaria vectors. Dimapur, once a malaria hotspot, had seen a reduction in cases due to interventions such as the distribution of larvivorous fish and LLINs. He said malaria vectors were now mainly found in the outskirts, particularly in jungle areas.
He highlighted that Aedes mosquitoes, which transmitted dengue, chikungunya, and Zika, bit during dawn and dusk, while Anopheles mosquitoes causing malaria bit at midnight.
Kere informed the participants that 8.45 lakh LLINs had been distributed across the state to families, jhum cultivators, migrant labourers, schools, colleges, and hospitals, with usage monitored fortnightly.
NVBDCP deputy director Dr Tinurenla Anicahri and state consultants also attended the meeting. This was stated in a press release.