3
Bolivia
Overview of the situation Figures 1-5
In Bolivia, malaria is endemic in two main areas - in the north and in the south of the country. Malaria transmission is most intense in the Amazon Departments of Beni and Pando, which border Brazil and Peru. Plasmodium falciparumborne malaria is highly focal in this region of the country, where transmission peaks are associated with the harvesting activities in which a large part of the population is engaged. The perpetuation of malaria transmission can be traced to the difficulties in timely access to health services and poor living conditions of the population groups that move around to harvest Brazil nuts in those regions. In 2008, 9,748 cases of malaria were reported in Bolivia, of which 836 were P. falciparum -borne, making it the country with the smallest percentage of transmission by P. falciparum in the Amazon region. The Department of Beni reported 5,826 cases (59%), most of them in people involved in carrying out harvesting activities in the adjacent Department of Pando. As in the rest of the Amazon region of the neighboring countries, Anopheles darlingi is the principal species of malaria vector. As part of the vector control activities, entomological studies were recently conducted in areas of high malaria transmission in the Departments of Beni and Pando; mosqui70
to biting rates were found between 1.2 and 242 bites per night inside dwellings. The Municipality of Guayaramerin, adjacent to the border with the Brazilian State of Rondonia, has the second highest number of cases and is an important urban malaria transmission area. In southern Bolivia, on the border with Argentina and Paraguay, malaria is concentrated in a few pockets in the Department of Tarija, where Plasmodium vivax-borne malaria predominates. In this region, Yacuiba reported 858 cases in 2008, making it the country’s third-highest municipality in malaria incidence. In localities of this region with less intensive malaria transmission, Anopheles pseudopunctipenis is the responsible vector species.
Morbidity and mortality trends Figures 4 – 9
Malaria transmission in Bolivia has dropped considerably over the past 10 years. P. vivaxborne malaria was 30.6% lower in 2008 than the previous year, while the drop in P. falciparum transmission is almost 50% in the same period. The 9,748 cases reported in 2008 constitute the lowest figure since the 1998 epidemic, when 74,350 cases were reported. There have been no reported deaths from malaria in the country since 2003.
R e por t o n t h e S i t uat i o n o f M a l ar i a i n t h e A m e r i c as , 2 0 0 8
R e por t o n t h e S i t uat i o n o f M a l ar i a i n t h e A m e r i c as , 2 0 0 8
Geographical distribution Figures 1, 12 – 19
The Municipality of Riberalta, in the Department of Beni, with 3,620 cases reported in 2008, accounts for 38.4% of the country’s total malaria cases. This municipality along with the municipality of Guayaramerin accounted for 60% of Bolivia’s malaria morbidity. This shows a high concentration of malaria cases in this region, which could offer a good opportunity for control efforts. While malaria transmission was found to exist in 66 municipalities in 2008, 19 of these reported less than 5 cases each, while 17 had more than 50. Only 13 municipalities reported 1 or more cases of P.falciparum-borne malaria and only 3 reported more than 10 cases transmitted by this parasite species during the period. Bolivia’s malaria situation is better than that of its neighbors. Given its highly focal transmission, high impact operations can be expected to be successful in the short term. In 2006, the malaria program, which had previously used the total populations of malariaendemic municipalities, adjusted the population at risk. Even so, Annual Parasite Incidence (API) dropped, particularly in the high-risk municipalities. Furthermore, the number of malaria-endemic municipalities gradually decreased, from 150 in 2005 to 66 in 2008.
Malaria in priority groups Figures 25 – 28
In 2008, 9.4% of the malaria cases reported in Bolivia were among children under the age of 5. Malaria transmission in urban areas, namely the municipality of Guayaramerin, in the Department of Pando, accounted for 11% of the total cases.
B O LI V I A
Although the malaria information system does not record the ethnic origin of the cases, because of Bolivia’s demographic characteristics, most of these are considered indigenous. This is especially obvious among the Brazil nut harvesters in the Departments of Beni and Pando, where over 60% of the cases are reported. The individual reporting-based information system under implementation since 2007 made it possible to determine that in 2008, 6.3% of the cases of malaria among women of childbearing age in the Departments of Beni and Pando were in pregnant women. Inasmuch as the general fertility rate in Bolivia is close to 110 per 1,000 (11%), the reported percentage of pregnant women with malaria could mean that a sizeable number of such women with malaria are not being reported as being pregnant and are possibly not receiving the special care they need.
Diagnosis and treatment Figures 20 – 24, 29 – 30
In 2008, the malaria program conducted 159,826 slides were examined in suspected cases with access to the health system. The SPR was 6.1%, lowest since 2000. Although the SPR in the Department of Beni, where most of the malaria cases are concentrated, was higher than that of other departments, it was lower than that reported in areas with higher levels of malaria transmission in other countries of the region, like Brazil and Colombia. In 2008, 48% of the malaria cases were diagnosed within the first 72 hours after the onset of symptoms. Late initiation of treatment in a large number of cases is apparently a determining factor in continued malaria transmission in the most endemic areas.
71
72
B O LI V I A
R e por t o n t h e S i t uat i o n o f M a l ar i a i n t h e A m e r i c as , 2 0 0 8
In 2005, Bolivia started to use RDTs for malaria diagnosis and in 2008, 5,000 tests were used, amounting to 3% of all suspected cases examined. Timely access to parasitological diagnostic test for malaria is impossible in difficult-to-reach scattered areas. Although no objective information exists about cases of fever among people who have no contact with the health system, their existence can be assumed in several malaria endemic areas, particularly in the Amazon region. Bolivia was the second country in the region to introduce the use of ACTs for malaria treatment. The country has been using the ASU+MQ combination since 2001 as a first-line therapy for uncomplicated P. falciparum malaria. The introduction of ACT treatment in 2001 coincided with a marked decline in the number and percentage of P. falciparum malaria cases. However, despite the continued use of ACTs, the proportion of P. falciparum malaria rose between 2005 and 2007, dropping once again in 2008.
Prevention and vector control Figures 31-33
While IRS continues to be one of the vector control strategies in Bolivia, its use declined simultaneously with the drop in the number of malaria cases between 2005 and 2008. The number of people protected by IRS in 2008 was almost 6 times smaller than in 2005; it should be noted, however, that over the past three years, a total of approximately 60,000 persons have been protected by LLINs, close in number to the total people protected by IRS in 2005, when malaria episodes in the country surpassed 20,000.
The widest coverage through the use of LLINs introduced in Bolivia in 2005, was reached in 2006, during the implementation of the project financed by the Global Fund. In 2007, with support from the USAID-funded AMI Initiative, the LLIN implementation strategy was launched in selected localities, with the adoption of a package of operating requirements focused on achieving good usage coverage in the localities benefited and appropriate handling to safeguard duration. In 2008, 5,000 LLINs were distributed.
Financing of malaria control Figure 34
Between 2004 and 2006, Bolivia benefited from a malaria control project financed by the Global Fund. The financing was suspended in 2007 and a second project submitted during the 8th convocation of the GFATM was approved in 2008.
B O LI V I A
R e por t o n t h e S i t uat i o n o f M a l ar i a i n t h e A m e r i c as , 2 0 0 8
Figure 1. Number of cases by ADM 2 level (municipality, district), 2008
Legend P. falciparum
1 Dot = 10 cases P. vivax
Brazil
1 - 73 74 - 216 217 - 315 316 - 1170 1171 - 4890 Peru
No cases
Bolivia
Chile Paraguay
Argentina
Figure 2. Proportion of cases by species, 2008
9%
91%
Plasmodium species P. vivax P. falciparum and mixed
3
73
B O LI V I A
R e por t o n t h e S i t uat i o n o f M a l ar i a i n t h e A m e r i c as , 2 0 0 8
Figure 3. Number of malaria cases by species by ADM1 level in 2008 P. falciparum + mixed
P. vivax
Total cases
Beni
726
5,100
5,826
Beni
Tarija
0
1,424
1,424
Tarija
Santa Cruz
24
889
913
Santa Cruz
Pando
70
730
800
Pando
Cochabamba
3
247
250
Cochabamba
La paz
13
234
247
La paz
Potosi
0
156
156
Potosi
Chuquisaca
0
132
132
Chuquisaca
ADM1
ADM1
0
Plasmodium species
2,000 4,000 6,000 0% 50% 100% Total number of cases Percentage of total cases
P. vivax
Figure 5. Number of malaria cases, 2000 - 2008
Figure 4. Number of cases by species, 2000 - 2008 40,000
30,000 28,932
31,469
P. falciparum and mixed
2,446 808
0
727
793
695
1,080
1,785
1,610
18,995
20,142
10,000
8,912 836
0
9,748
12,988
14,610
13,549
10,000
20,000
14,910
14,215
20,343
17,210 14,957
14,276
19,062
17,319
15,765
20,000
Number of cases
30,000
2000 2001 2002 2003 2004 2005 2006 2007 2008
2000 2001 2002 2003 2004 2005 2006 2007 2008
Year
Year
Plasmodium species P. falciparum and mixed
P. vivax
Figure 6. Number of malaria deaths, 2000-2008 4
4
4
Figure 7. Number of hospitalized malaria cases, 2000 - 2008
4
300
3 2
Number of cases
Number of deaths
74
2
1 0
0
0
0
0
200 100
82 44
0
2000 2001 2002 2003 2004 2005 2006 2007 2008 Year
285
0
NA
NA
0
6
0
0
2000 2001 2002 2003 2004 2005 2006 2007 2008 Year NA - No Data Available
B O LI V I A
R e por t o n t h e S i t uat i o n o f M a l ar i a i n t h e A m e r i c as , 2 0 0 8
Figure 8. Annual variations in number of cases 4,847
3,770
-1,638
-175
-98
-1,408
-1,852
-3,104
-5,000
0%
705
385
66
-81
0
0%
-774
-4,222 -4,076
-10,000
Percentage difference
Difference in number of cases
500
Figure 9. Percentage difference in number of cases compared to 2000
-20% -27% -34%
-40%
-48%
-40% -53%
-60%
-56% -70%
2000 2001 2002 2003 2004 2005 2006 2007 2008
-51%
-67%
-13,975
-68%
-80%
-34% -41% -55%
-72%
Year
Plasmodium species P. falciparum and mixed
P. vivax
Plasmodium species P. falciparum and mixed
Figure 11. Percentage of hospitalized cases, 2008
Figure 10. Number of cases and RBM / MDG targets for 2010 and 2015
0%
30,000
20,000
10,000 2015
2014
2013
2012
2011
2010
2009
2008
2007
2006
2005
2004
2003
2002
2001
100% 2000
Number of cases
-69%
2000 2001 2002 2003 2004 2005 2006 2007 2008
Year
Percentage of cases
Year Reported cases
-66%
RBM / MDG Targets
Oupatients Hospitalized
P. vivax
75
B O LI V I A
R e por t o n t h e S i t uat i o n o f M a l ar i a i n t h e A m e r i c as , 2 0 0 8
Figure 12. Districts (ADM2) with highest malaria burden and cummulative proportion of total cases in the country, 2008 Riberalta
3,620
Guayaramerin
38%
1,994
Yacuiba
60%
858
San Ignacio de Velasco
327
Bermejo
312
El Torno
306
69% 72% 75% 79%
Villa Tunari
215
Buena Vista
186
San Lorenzo (Exaltación)
156
85%
Bolivar (Sena)
139
86%
Baures
116
87%
Carapari
106
88%
Nueva Esperanza (Nuevo M.)
102
90%
Toro Toro
85
90%
Villamontes
79
91%
Victoria (Puerto Rico)
70
92%
Ayata
53 0
81% 83%
93% 1,000
2,000
3,000
4,000 0%
Number of cases
20%
40%
60%
80%
100%
Cummulative proportion (%) of total cases
* See Annex A for a complete list.
Figure 13. Districts (ADM2) by number of malaria cases, 2008
501-1,000
Figure 14. Districts (ADM2) by number of P. falciparum cases, 2008 Number of
Number of cases >1,001
P. falciparum cases
2 1
251-500
3
101-250
251-500
1
101-250
1
11-50
1
7
51-100
6-10
4
11-50
7
Grand Total
7
1-5
3
1-5
23
6-10
13 0
19
2
4
Grand Total
6
8
10
12
14
Number of districts 0
10
20
30
40
50
60
70
Number of districts
Figure 15. Districts (ADM2) by number of cases, API and percentage of P. falciparum cases, 2008 API
250
25 Percentage of P. falciparum cases
76
25
0.05 20
20
40
Santos Mercado (Eureka)
60 80
15
105.15
Ixiamas Riberalta Guayaramerin
Bella Flor (Costa Rica) 10 Villa Nueva (Loma Alta) 5
Bolivar (Sena)
Santa Rosa del Abuna (Nacebe) 0
ZudanezAcasio 2
5
Ayata 10
20
50
Yacuiba
Baures 100
200
Number of cases (logarithmic scale)
500
1,000
2,000
5,000
B O LI V I A
R e por t o n t h e S i t uat i o n o f M a l ar i a i n t h e A m e r i c as , 2 0 0 8
Figure 16. Annual Parasite Index (API) by districts (ADM2), 2008
Legend Municipal API
0.01 - 1.00 1.01 - 5.00
Brazil
5.01 - 10.00 10.01 - 50.00 50.01 - 100.00 100.01 - 500.00
Peru
Bolivia
Chile Paraguay
Argentina
Figure 17. Population by malaria transmission risk, 2008
2% 5% 7%
86%
Population High risk (API > 10/1000) Medium risk (1/1000 < API < 10/1000) Low risk (API < 1/1000 ) Malaria free areas (No indigenous transmission)
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78
B O LI V I A
R e por t o n t h e S i t uat i o n o f M a l ar i a i n t h e A m e r i c as , 2 0 0 8
Figure 19. Population by malaria transmission risk, 2000-08
Figure 18. Annual Parasite Index (API) and number of cases by district*, 2008
Year
Nueva Esperanza (Nuevo)
102
Bolivar (Sena)
139
105.15
3,620 156
Malaria free areas (No indigenous transmission)
44.33
2000
742,000
2,828,000
0
4,857,790
42.67
2001
337,000
1,434,000
100,000
6,753,268
41.01
2002
294,000
666,000
2,377,000
5,486,743
38.83
2003
1,429,000
339,000
1,544,000
5,712,922
36.32
2004
427,000
461,000
2,482,000
5,856,511
1,994 53
Riberalta San Lorenzo (Exaltacion)
Low risk (API < 1/1000)
55.87
Guayaramerin Ayata
Medium risk (1/1000 < API < 10/1000)
High risk (API > 10/1000)
Santos Mercado (Eureka)
28
Villa Nueva (Loma Alta)
35
29.89
2005
368,000
423,000
2,887,000
5,749,219
Ravelo (Moro Moro)
36
28.57
2006
271,000
438,000
720,000
8,198,269
Gral. Juan Jose Perez
23
27.06
2007
271,388
438,495
849,532
8,268,107
Baures
116
2008
188,804
516,248
678,535
8,644,057
Victoria (Puerto Rico)
70
22.02 15.35
Toro Toro
85
14.04
Ingavi (Humaita)
12
13.19
Buena Vista Villa Serrano
186
12.82
16
10.7
Carapari
106
10.61
Bella Flor (Costa Rica)
23
10
Acasio
7
9.03
Santa Rosa del Abuna
23
8.97
Bermejo
312
8.03
San Ignacio de Velasco
327
6.99
Yacuiba Azurduy
858
6.82
37
El Torno
6.69
306
6.36
Teoponte
26
6.19
Agua Dulce (Pto. G. More)
29
6.15
Zudanez
4
6.02
Ixiamas
45
5.81
Porvenir (Campo Ana)
23
5.36
Villa Tunari
215
Year
Number of slides examined
Number of slides positive
Slide Positivity Rate (%)
2000
143,990
31,469
21.85
2001
122,933
15,765
12.82
2002
137,509
14,276
10.38
2003
158,299
20,343
12.85
2004
163,307
14,910
9.13
2005
202,021
20,142
9.97
2006
208,616
18,995
9.11
2007
180,316
14,610
8.05
2008
159,826
9,748
6.1
4.38
Padcaya
24
3.69
Padilla
21
3.35
0
Figure 20. Slides examined and Slide Positivity Rate (SPR), 2000-2008
2,000
4,000
Number of cases
0
50
100
150
API
Figure 21. Cases diagnosed by microscopy and RDTs, 2000-08
API (cases/ 1000 people at risk) 0
105.15
Diagnostic Method * See Annex A for a complete list
Year 2000 2001 2002 2003 2004 2005 2006 2007 2008
Microscopy
RDTs
143,990 122,933 137,509 158,299 163,307 202,021 6,000 208,616 6,000 180,316 159,826 5,000 0
100,000
200,000
Number of cases
0
100,000
200,000
Number of cases
B O LI V I A
R e por t o n t h e S i t uat i o n o f M a l ar i a i n t h e A m e r i c as , 2 0 0 8
Figure 23. Slide Positivity Rate (SPR) by ADM1, 2008
Figure 22. Number of cases diagnosed and cases treated, 2000-2008 ADM1
Year 2000
Diagnosed cases Cases treated Diagnosed cases Cases treated
2001
Diagnosed cases Cases treated
2002
Diagnosed cases
2003
Cases treated Diagnosed cases Diagnosed cases Cases treated
2005
Diagnosed cases Cases treated
2006
Diagnosed cases
2007
Cases treated Diagnosed cases
2008
Cases treated Diagnosed cases
Total cases
65,694 36,375 25,914 18,393 1,729 4,121
5,826 1,424 913 800 250 247
8.87 3.91 3.52 4.35 14.46 5.99
1,998 5,602 ---
156 132 0
7.81 2.36 0
Potosi Chuquisaca Oruro
Cases treated
2004
Examined
Beni Tarija Santa Cruz Pando Cochabamba La paz
SPR (%)
--- Data not available
Figure 25. Number and percentage of cases by age group, 2008
Cases treated
0
10,000
20,000
30,000
Number of cases diagnosed/treated
50
9.4% 26.4% 54.9% 9.3% 0
2,000
4,000
Number of cases
Figure 24. Time span between onset of symptoms and diagnosis, 2008
Figure 26. Number and percentage of cases by locality type, 2008 52%
Urban Rural
11.0% 89.0% 0
2,000
4,000
6,000
8,000
Number of cases
Figure 27. Number and percentage of cases in pregnant women among women of child bearing age, 2008
48%
Time span between onset of symptoms and diagnosis
Pregnant Not pregnant
6.3% 93.7% 0
>72 hours
500
1000
1500
Number of cases