Demographic profile of District
Table 1 showed the demography and capacity building for malaria control programme of Udalguri district of Assam. With 955 villages, 171462 households, the district has a population of 910261 as per the population census 2018 (Source NVBDCP Udalguri). The tribal population of the district constitutes about 44% of the total population. The population density of the district currently stands at 497 per sq km. The district has also a satisfactory sex ratio. The health-care system of Udalguri District comprises of 3 Block Primary Health Centers (Orang, Khairabari, and Udalguri, 1 District Hospital, 10 Primary Health Centers, 4 Community Health Centers, 9 Dispensaries, and 153 Sub Centers that have facility for diagnosis and treatment of Malaria.
Table 1. Demography and capacity building of Udalguri district of Assam, India
Udalguri District Profile
|
Capacity Building
|
Population
|
909442
|
District Malaria Officer
|
1
|
Tribal Population
|
401802
|
District VBD Consultant (GFATM)
|
1
|
Population Density
|
497 per sq km
|
Asst. Malaria Officer
|
1
|
Sex Ration (Male : Female)
|
1000:996
|
SA Cum DEO (GFATM)
|
1
|
Literacy Rate
|
80%
|
Malaria Technical Supervisor (GFATM)
|
3
|
District Hospital
|
1
|
Malaria Inspector
|
3
|
Block PHC
|
3
|
MPW (M)
|
46
|
CHC
|
4
|
SW/BHW/SI/BHI
|
72
|
PHC
|
10
|
Lab Technician
|
25
|
Dispensary
|
9
|
ASHA
|
1052
|
Sub-Centers
|
153
|
|
|
Tea Estates
|
23
|
|
|
No. of villages
|
955
|
|
|
The public health delivery system was also observed in the district. One District Malaria Officer, One District Vector Borne Disease Consultant, One Assistant Malaria Officer and one Secretarial Assistant cum Data Entry operator to monitor and supervise the programme activity in the district. The district has three block PHCs (2 to 5 lakh population) and each block PHC have one Malaria Inspector, one Malaria Technical Supervisor and one Laboratory Technician. There are 10 Primary Health Centers and 9 State Dispensaries (0.5 to 1.5 lakh population) and each have one Health Inspector and one Laboratory Technician in each lab of the PHC. Under this PHCs/SDs there are 153 Sub Centers and each SC having a population of 5 to 10 thousand populations and one Health Worker (M) designated as SW/BHW/MPW (M) and two health worker (Female) designated as ANM are appointed for active surveillance. And each Sub center have 3 to 5 village in average, each village have one or more than one Accredited Social Health Activist (ASHA) covering about 1000 population in average for passive surveillance. The ASHA workers were provided with RDKs, Slides and anti-malarial tablets like CQ & ACT for diagnosis and treatment of the Malaria patient at village level through passive surveillance. It was also observed that in 2018, under Intensify Malaria Control Project, phase I, the post of Malaria Technical Supervisor was created under the GFATM budget suppot and during 2012, Intensified Malaria Control Project, the post of District VBD Consultant was created as a technical support to the Programme along with a SA cum DEO for data management in district level under the GFATM budget head. There are 25 laboratories in the district and one Sentinel site Laboratory at District Hospital. It was observed that the reports are generate from the villages and first compilation was done at Sub Center level for both active and passive blood slide collection and forwarded to higher authority. It was observed that during 2017, a total no of 83414 numbers of blood slides were collected and 1102 of collected slides were found to be positive for malaria.
Malaria Prevalence in Udalguri District
Udalguri district is highly endemic in malaria, and several cases reported throughout the year. It was noticed that two major Plasmodium species (P. falciparum and P. vivax) are reported from the district. Figure 2 showed the population sizes of Udalguri district, blood sample examined as well as the positive cases of malaria reported during the year 2005 to 2017 in Udalguri district of Assam. It has been observed that there was a big increase in the population size of the district during the year 2005-2006. However, since 2006 onwards till 2017 there was a very little increase in the total population of the district. The blood smear collected and examined was about 6.22% of the total population in 2005 which increased up to 21.40% in 2012. The study also observed that there is no positive correlation (P≤0.05 level) to the number of BSC /BSE and ABER with the population size. The rate of annual blood examination rate decreased from 21.40% in 2012 to 9.21% in 2017. During the period since 2005 to 2017, the average value of ABER is 12.91%. We also observed that there is lesser blood examination since 2015 to 2017 averaging 9.44% per year. The study also observed that there is a significant decline in the trend of positive cases of malaria from 2005 to 2017. The percentage of positive cases out of blood smear collected and examined were found to be about 24% in 2005 and the rate decreased up to 1.35% in 2017.
Table 3: Comparative Epidemiological Reports 2005 to 2017- Udalguri District.
Year
|
Population
|
BSC /BSE
|
ABER
(%)
|
Total Positive
|
Pf
|
API
|
SPR
|
SFR
|
Death
|
2005
|
524400
|
32633
|
6.22
|
7832
|
1025
|
14.94
|
24.00
|
3.14
|
4
|
2006
|
813423
|
86328
|
10.61
|
16780
|
3909
|
20.63
|
19.44
|
4.53
|
4
|
2007
|
816208
|
66488
|
8.15
|
12075
|
2999
|
14.79
|
18.16
|
4.51
|
1
|
2008
|
929213
|
113039
|
12.17
|
13510
|
3219
|
14.54
|
11.95
|
2.85
|
5
|
2009
|
872888
|
126660
|
14.51
|
14376
|
4140
|
16.47
|
11.35
|
3.27
|
0
|
2010
|
867842
|
163446
|
18.83
|
13767
|
3188
|
15.86
|
8.42
|
1.95
|
2
|
2011
|
873262
|
156108
|
17.88
|
9584
|
3189
|
10.97
|
6.14
|
2.04
|
0
|
2012
|
876862
|
187688
|
21.4
|
8050
|
2163
|
9.18
|
4.29
|
1.15
|
0
|
2013
|
895171
|
145632
|
16.27
|
3874
|
1231
|
4.33
|
2.66
|
0.85
|
0
|
2014
|
875725
|
118114
|
13.49
|
2887
|
1739
|
3.3
|
2.44
|
1.47
|
0
|
2015
|
901396
|
92735
|
10.29
|
2386
|
1598
|
2.65
|
2.57
|
1.72
|
0
|
2016
|
901511
|
79724
|
8.84
|
1770
|
1139
|
1.96
|
2.22
|
1.43
|
0
|
2017
|
905688
|
83414
|
9.21
|
1129
|
874
|
1.22
|
1.35
|
1.05
|
0
|
BSC/BSE- Blood Smear Collected/ Examined; ABER- Annual Blood Examination Rate; Pf- Plasmodium falciparum, API – Annual Parasite Index, SPR – Slide Positivity Rate, SFR – Slide Falciparum Rate
Figure 3 showed the prevalence of P. falciparum burden among the population of Udalguri district of Assam. It is observed that among the positive cases only two plasmodium species i.e., P. falciparum and P. vivax were reported to be most active in the district followed by some mixed infections. Although there is sharp decline in the number of positive cases but the percentage of P. falciparum infection increased significantly over the period of 2005 to 2017. The burden of P. falciparum in 2005 was only 13.09% out of 7832 positive cases. In 2017, the total numbers of positive cases were 1129 with Pf value of 874 which represents about 77.41% of the total positive cases. On the contrary, the infection due to P. vivax was gradually declining.
The Annual Parasitic index (API) is an important parameter of malaria surveillance which provides important information about the malaria morbidity in a given year per 1000 population. Figure 3 showed the API and slide positivity rate of malaria cases per year in Udalguri district of Assam during the period since 2005 to 2017. The API was found to be 14.94 in 2005 and then declined to 1.12 by 2017. Similarly, the slide positivity rate per 100 individual screened for malaria burden was at very high 24% in 2005 and the SPR declined to 1.35% by 2017 indicating the significant decrease in the malaria cases in Udalguri district. However, while analysis the annual slide positivity rate (SPR), it was observed that highest no of cases reported (19%) in 2006, which decreased to 1.32% in 2017. Similarly the population of the District increased from 8.1 lakh in 2006 to 9.1 lakh in 2017. Similarly, the API decreased significantly from 20.63 per 1000 population in 2006 to 1.22 per 1000 population in 2017.
The disease prevalence by P. falciparum cases significantly decreased from 3.94 in 2008 to 0.96 cases per 1000 population in 2017. SFR was calculated to know the disease burden due to P. falciparum. It was noticed that the SFR is higher in comparison to Slide positivity rate (SPR). The SRF and SPR was found to be 2.85 and 11.35 in the year 2008 and 1.05 and 1.05 in the year 2017, respectively. It indicates that, the API and SPR were gradually declining but the PF% was increasing. In 2008, the Pf% was estimated as 23.82% and in 2017, it increased to 77.41%. Similarly, the prevalence of P. vivax cases was significantly decreasing from 12.06 cases per 1000 population in 2008 to 0.28 cases per 1000 population in 2017. The Pv% was 76% in 2008, and decreased by 22% in 2017.
Seasonal Prevalence of Malaria in Udalguri District (2011 – 2017)
Figure 4 showed the seasonal occurrence of malaria cases in Udalguri district during the period 2011 to 2017. It is observed from the study that there is a significant month-wise variation of malaria cases. The peaks of the cases were observed between the months of May to September every year. Highest spike of more than 1800 cases were observed in the year 2011 during the month of July. It is apparent from our study that the number of positive case declined significantly every year till 2017. The total and annual average positive cases in the year 2011 was found to be 9661 and 805.08, respectively. While in the same year the cases almost double 1375.75 during the months of April to August. We have found a steady decline in the malaria cases over the study period. In 2017, the number of positive cases stood at 1262 with an annual average 105.17. Similarly, the number of cases in the peak months (April to August) also declined significant to 154.5 cases.
Spatial Distribution of Malaria Endemicity
Spatial distribution of API of malaria has been done from 2010 to 2017. Because the malaria prevalence varied largely between different health centers of the district (ranging from 0 to 10 and above), stratification of API were also calculated (Fig. 6a,b). During 2010 out of 147 health centers, 95 health centers reported >1 API which covered 71% of total district population. But in 2017, it is observed that there was significant decline of malaria cases and only 8 Health centers out of 153 had 1 or more than 1 API covering only 8% of total district population (Fig. 5).
A spatial map of malaria endemicity was prepared to classify the endemic areas of the district and compared with different colors in Figure 6. Red marked indicates the highest endemicity, API above 10 and the dark green indicates API less than 1. Dark yellow indicates API ranges from 5-10, while light yellow indicated 2 to 5 API. It is observed that during 2013 there were so many health centers which API more than 10. But in 2017, only one health centers that reported API >10.