Non-bacterial etiologies of diarrheal diseases in Afghanistan

Systematic review of the rotavirus infection burden in the WHO-EMRO region

Rotavirus gastroenteritis imposes a heavy burden on low- and middle-income countries. The World Health Organization defines the Eastern Mediterranean region (WHO-EMRO) as a diverse area in terms of socioeconomic status and health indicators. Rotavirus vaccination has been introduced, at least partially, in 19 out of the 22 EM countries; however, vaccine coverage remains low, and data on rotavirus disease burden is scarce.Available data on rotavirus prevalence, seasonality, vaccination status, and genotype evolution was systematically compiled following a literature review that identified 165 relevant WHO-EMRO epidemiology studies published between 1990 and 2017.Although the infectious agents responsible for acute gastroenteritis vary over time, rotavirus remained the leading cause of acute gastroenteritis in children, as seen in 76.3% of reviewed publications. Younger children (<2 years old) were at higher risk and thus increased vaccination coverage and surveillance systems are required to reduce the rotavirus gastroenteritis burden in WHO-EMRO countries.

Rotavirus is the leading cause of hospitalizations for severe acute gastroenteritis among Afghan children <5 years old

BACKGROUND

Rotavirus gastroenteritis is estimated to cause approximately five thousand deaths annually among Afghan children under 5 years old. Because laboratory confirmation of rotavirus is not routinely performed in clinical settings, assessing the precise burden of disease attributable to severe rotavirus gastroenteritis typically requires active surveillance efforts. This study describes the current burden of pediatric hospitalizations attributable to rotavirus gastroenteritis among Afghan children using surveillance data collected from 2013 to 2015.

METHODS

Rotavirus surveillance was conducted from January 2013 through December 2015 at two of the largest hospitals in the country, Indira Gandhi Children Hospital in Kabul and Herat Regional Hospital. Children between 1 and 60 months of age who were admitted to these hospitals for diarrhea were consented and enrolled. Information on age, gender, and seasonality were collected. Stool specimens were collected and tested by enzyme immunoassay for the presence of rotavirus at the central public health laboratory in Afghanistan.

RESULTS

Overall, 1,413 of 2,737 (52%) of hospitalized children under five years old with diarrhea were rotavirus cases. The overwhelming majority of rotavirus hospitalizations occurred in children younger than two years of age (93%) while 42% of all rotavirus hospitalizations occurred in children between 6 and 11 months of age. Rotavirus transmission occurred year-round.

CONCLUSIONS

Rotavirus is a major cause of severe acute gastroenteritis hospitalizations in young Afghan children, responsible for over half of diarrheal hospitalizations in this population. The Afghanistan Ministry of Public Health has prioritized reducing child mortality by 2020 and is actively working towards the introduction of rotavirus vaccination in Afghan children. These data will be instrumental in understanding the potential impact upon child health that may be achieved through the introduction of rotavirus vaccines in Afghanistan.

Cryptosporidium spp. infection in Iranian children and immunosuppressive patients: A systematic review and meta-analysis

BACKGROUND

Cryptosporidiosis is an important cause of diarrhea in children and immunosuppressive patients. The current study was intended to evaluate the prevalence rate of Cryptosporidium infection and clarify the epidemiological characteristics of the infection in both children and immunosuppressive patients in Iran.

METHODS

Five English electronic databases including PubMed, Google Scholar, Science Direct, Scopus and Cochrane, and two Persian language databases Magiran and Scientific Information Database were searched. Additionally, reports from the Iranian congresses of parasitology and graduate student thesis dissertations were assessed manually.

RESULTS

Out of 1856 studies from the literature search, our search resulted in a total of 27 articles published from 1991 to 2016. These include 14 reports on cryptosporidiosis in children and 13 papers regarding immunosuppressive patients. 8520 children and 2015 immunosuppressed cases were evaluated. Oocysts of Cryptosporidium were found in 3.8% and 8% children cases and immunosuppressed patients, respectively. There was a relatively high variation in the prevalence estimates among different studies, and the Q statistics was high among articles regarding children (p<0.0001) and also between records regarding immunosuppressed patients (p<0.0001). Findings showed that the prevalence rates of Cryptosporidium infection are significantly higher in children under 5 years (P=0.00).

CONCLUSIONS

In summary, the present study provides a comprehensive view of the epidemiology of Cryptosporidium in children and immunosuppressive patients in Iran. Furthermore, a multidisciplinary and multicenter study to evaluate the real prevalence of Cryptosporidium infection and to determine its risk factors using an adequate sample size and standardized methods is highly recommended.

Cryptosporidium infection in children with cancer undergoing chemotherapy: how important is the prevention of opportunistic parasitic infections in patients with malignancies?

Cryptosporidiosis is a relatively uncommon disease in healthy individuals but could be potentially worrisome in immunocompromised patients. This study aimed to evaluate Cryptosporidium infection in children with cancer undergoing chemotherapy. A case-control study was conducted in 132 children with cancer undergoing chemotherapy and 132 non-cancer controls. The modified Ziehl-Neelsen (MZN) staining and polymerase chain reaction methods were used for the detection of Cryptosporidium parasite. All positive isolates were sequenced for phylogenetic analysis. Statistical analysis was performed using the SPSS version 16 and Fisher exact test. The rate of cryptosporidiosis in children with cancer undergoing chemotherapy was 3.8%, which was higher than that of the control group. Other intestinal parasites detected in patients with cancer included Giardia lamblia (3%), Entamoeba coli (1.5%), and Chilomastix mesnili (0.8%). In the control group, only two (1.5%) cases were positive for G. lamblia. No significant difference was observed between the gender, age, residency, contact with domestic animals, stool appearance, neutropenia, chemotherapy period, and type of malignancy with regard to cryptosporidiosis. Phylogenetic analysis revealed that Cryptosporidium parvum isolates in this study relied on a branch that represents similar sequences from Iran and other countries. Although the rate of Cryptosporidium infection was relatively higher in children with cancer undergoing chemotherapy compared to the control group, any statistically significant difference has not been found between them. These findings should not be contrary to the need for healthcare to prevent opportunistic parasitic infections in malignant and immunocompromised patients.

Trends of vaccine-preventable diseases in Afghanistan from the Disease Early Warning System, 2009-2015

BACKGROUND

Afghanistan's public health system was neglected during decades of military and civil conflict, and trends in infectious disease occurrence remain poorly characterized. This study examines cyclical and long-term trends of six vaccine-preventable diseases: pneumonia, diarrhea, meningitis, typhoid, measles, and acute viral hepatitis.

METHODS

Using weekly data collected between 2009 and 2015 through Afghanistan's Disease Early Warning System, we calculated monthly case counts, and fit a Poisson regression with a Fourier transformation for seasonal cycles and dummy variables for year.

RESULTS

We found the greatest incidence of diarrhea and typhoid in the summer, pneumonia in the winter, and measles in the late spring. Meningitis and acute viral hepatitis did not demonstrate substantial seasonality. Rates of pneumonia and diarrhea were constant across years whereas rates of meningitis, typhoid, and acute viral hepatitis decreased. Measles incidence increased in 2015.

CONCLUSIONS

Communicable disease reporting systems can guide public health operations-such as the implementation of new vaccines, and permit evaluation of health interventions. For example, measles supplementary immunization activities in Afghanistan have not slowed long-term transmission of the disease, but decreases in typhoid fever and acute viral hepatitis are probably tied to improvements in sanitation in the country.