Epidemiology of Plasmodium falciparum Malaria and Risk Factors for Severe Disease in Hubei Province, China

Abstract

This study aimed to describe the epidemiology of Plasmodium falciparum malaria and identify risk factors for severe disease in Hubei Province, China, using a case-based survey of retrospective data from 2013 to 2018. From 2013 to 2018, a total of 763 imported malaria cases were reported in Hubei Province; 69.2% (528/763) cases were caused by P. falciparum species. The proportion of malaria caused by P. falciparum increased from 66.7% in 2013 to 74.0% in 2018 (χ 2 = 21.378, P < 0.05). Plasmodium falciparum malaria was reported in 77 counties of Hubei Province. The majority of imported P. falciparum cases originated from Africa (98.9%, 522/528); 9.7% (51/528) of patients infected with P. falciparum developed severe malaria. Three deaths (case fatality rate: 0.6%) were related to imported P. falciparum malaria. Risk factors for severe malaria were being female (odds ratio [OR] = 3.593, 95% CI: 1.003-12.874), age ³ 50 years (OR = 2.674, 95% CI: 1.269-5.634), > 3 days between symptom onset and diagnosis (OR = 2.383, 95% CI: 1.210-4.693), and the first-visit medical institution at the township level or lower (OR = 2.568, 95% CI: 1.344-4.908). Malaria prevention should be undertaken among high-risk groups, infection with P. falciparum should be detected early to prevent severe disease and death, and healthcare providers in health facilities at the township level should be trained on early recognition of malaria.

Profiling the imported human malaria in Sarawak, Malaysia in 2011–2019

“…A similar study conducted in Sweden revealed that the percentages of severe imported malaria cases by species were 9.4% due to P. falciparum, 7.7% P. vivax, 5.3% P. ovale, 3.3% P. malariae, and 21.1% mixed infection with P. falciparum [56]. Additionally, the percentages of severe imported falciparum malaria reported in China and Japan were 9.7% and 13.3% respectively [57,58]. In contrast, we reported a higher percentage of severe falciparum malaria patients (36.9%), which was similar to those previously documented in East London, United Kingdom, where 36.3% of falciparum malaria cases were severe [59].…”

Malaria among the elderly in five communities of Osun East district, Southwest Nigeria: Prevalence and association with non-communicable diseases

“…It is however also possible that there may be a reduction in the capacity of the ageing immune system to mount a robust defence against the infection. 11 , 34 Elderly patients are more susceptible to having complications from various infectious diseases. This tends to be a result of multimorbidity and a diminished capacity to establish sufficient immune response.…”

“… 35 , 36 This state of diminishing age-specific immunity to malaria has however not been conclusively proven in older individuals in highly endemic areas, who are regularly exposed to plasmodia. 11 , 34 , 37 This is indeed an area for further research, considering that the primary mechanisms of the host response and immunity to plasmodial infection are not fully understood.…”

The spectrum of clinical biomarkers in severe malaria and new avenues for exploration

“…Few studies that addressed the risk factors of SM listed some frequently identified factors as distance to the nearest health facility, concurrent comorbidities, nonuse of preventive methods, immune status, pregnancy, duration of illness before receiving antimalarial drug, delayed care, seeking self-medication, and patients' age [ 21–28 ]. For instance, Xia and colleagues have recently found that the risk of SM was higher in females and patients' aged ≥50 years old in the Hubei Province, a low malaria endemic area in China [ 28 ]. Few unusually addressed risk factors such as ethnicity have also been identified among Pf -infected adults [ 29 ].…”