JOURNAL OF THE LOUISIANA STATE MEDICAL SOCIETY
Annual Malaria Cases
2004
2009 2010 2011 2012
2013
Mean ± SD
1,640 ± 191 6 ± 2 1,607 ± 240 1.2 ± 0.75 0.5 ± 0.76 1.7 ± 1.25 0.2 ± 0.37 0.5 ± 0.5 0.12 ± 0.37
1,727
1,687
1,925
1,691
Total cases (n)
1,324
1,484
10
6
5
9
4
4
Case fatalities (n)
1,720
1,683
1,920
1,688
1,154
1,478
Imported cases (n)
4
0
2
1
2
0
Autochthonous cases (n)
2
0
0
0
0
1
Transfusion cases (n)
3
3
0
2
0
2
Congenital cases (n)
0
0
0
0
0
1
Transplant cases (n)
0
1
1
0
1
0
Lab accident cases (n)
0
0
0
0
0
1
Nosocomical cases (n)
Causative Plasmodium Species
53.6 ± 5.6 17.8 ± 4.4 2.8 ± 0.69 2.7 ± 0.75
58
49
58
61
50
46
P. falciparum (%)
19
22
14
24
11
17
P. vivax (%) P. malariae (%)
3
4
3
2
2
3
4
2
2
3
3
2
P. ovale (%)
21 ± 9
40
21
20
17
13
13
Mixed infections (%)
Table 1: Annual Trends in Malaria Cases by Acquisition, Transmission, and Infecting Plasmodium Species over the Reporting Period, 2004-2013 5-10 Source: United States Centers for Disease Control and Prevention, National Malaria Surveillance System (NMSS). SD: standard deviation of the mean.
stages of the parasite’s life cycle and require shorter durations of therapy post-travel with improved patient compliance, such atovaquone-proguanil and primaquine. Since only the blood stages of the parasite are responsible for the symptoms of malaria, drugs that are effective against the blood stages, such as the sporozoite and merozoite stages, will reduce the potential for infection caused by sporozoites and the febrile paroxysms caused by the massive release of merozoites from hepatocytes and erythrocytes. On the other hand, drugs that are effective against the asymptomatic liver stages of the parasite, such as the exoerythrocytic schizogony and hypnozoite stages, will not need to be administered as long post-travel. Primaquine is the only antimalarial drug that is effective against the hypnozoite stages of P. vivax and P. ovale . It is also the only antimalarial drug that is gametocidal. Therefore, primaquine can prevent relapsing malaria caused by P. vivax and P. ovale and reduce the vector-borne transmission of malaria by
killing gametocytes. Primaquine may be used for the primary chemoprophylaxis of P. vivax, P. ovale, P. malariae, and P. knowlesi, but is not recommended for the primary chemoprophylaxis of P. falciparum. Recommendations for Malaria Chemoprophylaxis for Short-term Travelers All of the current strategies for malaria chemoprophylaxis share several important characteristics including: (1) initial designs for the prevention of death due to severe P. falciparum malaria; (2) inability to prevent initial malaria infections at the sporozoite stage; (3) inability to prevent malaria with 100% efficacy (overall efficacy ≥ 90%); and (4) antimalarial actions confined to human, not mosquito stages, and primarily blood (erythrocytic), not liver stages. Since chloroquine resistance is almost universal, mefloquine, atovaquone-proguanil, or doxycycline are recommended for chemoprophylaxis in P. falciparum endemic
J La State Med Soc VOL 169 SEPTEMBER/OCTOBER 2017 133
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